Study of Arachidonic Acid Pathway in Human Bladder Tumor

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Masahide Matsuyama

2009-01-01

Full Text Available Recent epidemiological studies and animal experiments have demonstrated that nonsteroidal anti-inflammatory drugs (NSAIDs reduce the incidence of colorectal carcinoma. Cyclooxygenase (COX is the principal target of NSAIDs. COX is the first oxidase in the process of prostaglandin production from arachidonic acid. COX enzyme may be involved in the initiation and/or the promotion of tumorigenesis due to NSAIDs inhibition of COX. Lipoxygenase (LOX is also an initial enzyme in the pathway for producing leukotrienes from arachidonic acid. Similar to COX, LOX enzyme may also be involved in the initiation and/or promotion of tumorigenesis. Peroxisome proliferator activator-receptor (PPAR-γ is a ligand-activated transcriptional factor belonging to the steroid receptor superfamily. PPAR-γ plays a role in both adipocyte differentiation and tumorigenesis. PPAR-γ is one target for cell growth modulation of NSAIDs. In this review, we report the expression of COX-2, LOX and PPAR-γ in human bladder tumor tissues as well as the effects of COX-2 and LOX inhibitors and PPAR-γ ligand.

Pregnancy duration and the ratio of long-chain n-3 fatty acids to arachidonic acid in erythrocytes from Faroese women

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Olsen, S.F.; Hansen, Harald S.; Jensen, B.

1989-01-01

of long-chain n-3 FA to arachidonic acid (the (3/6) ratio) was used as the most relevant single measure of exposure. In 18 women with certain gestational age and with spontaneous onset of delivery, gestational age was significantly associated with the (3/6) ratio quantified in PC (correlation coefficient......Dietary long-chain n-3 fatty acids (FA) may prolong gestation by inhibiting formation of prostaglandins from arachidonic acid. FA were quantified in phosphatidylcholine (PC), phosphatidylethanolamine (PE), and total lipids (TL) of red cells sampled during pregnancy from 29 Faroese women. The ratio...

Nitric oxide production from macrophages is regulated by arachidonic acid metabolites.

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Imai, Y; Kolb, H; Burkart, V

1993-11-30

In activated macrophages the inducible form of the enzyme nitric oxide (NO) synthase generates high amounts of the toxic mediator NO. After 20 h of treatment with LPS rat peritoneal macrophages release 12-16 nmol NO2-/10(5) cells which is detectable in the culture supernatant by the Griess reaction as a measure of NO formation. The addition of aminoguanidine (1 mM), a preferential inhibitor of the inducible NO-synthase, completely abolished NO2-accumulation. Incubation with indomethacin or acetyl-salicylic acid, preferential inhibitors of the cyclooxygenase pathway of the arachidonic acid metabolism, did not influence NO2- levels. Nordihydro-guaiaretic acid (50 microM), a preferential inhibitor of the lipoxygenase pathway, caused strong reduction of NO2- accumulation to 1.9 +/- 0.3 nmol/200 microliter. Simultaneous inhibition of cyclo- and lipoxygenase by BW755c resulted in an intermediate effect (7.3 +/- 1.1 nmol/200 microliter NO2-). These results show that the induction of NO production in activated macrophages is regulated by products of the lipoxygenase-pathway of the arachidonic acid metabolism.

Carbon monoxide is not responsible for the cigarette smokeinduced changes in the pulmonary metabolism of arachidonic acid and prostaglandin E2

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Maennistoe, J.; Puustinen, T.; Uotila, P.

1985-01-01

Cigarette smoke is known to interfere with the pulmonary metabolism of arachidomic acid and prostaglandin E 2 (PGE 2 ). We investigated the possible role of carbon monoxide in these cigarette smoke-infuced alterations. 4 C-Arachidonic acid (50 nmol) was indused into the pulmonary circulation of isolated perfused hamster lungs and the radioactive metabolites in the perfusion effluent, as well as the distribution of incorporated radioactive arachidonic acid within the lung lipids, were analysed. Carbon monoxide, added into the ventilatory air, had no effect on the oxidative metabolism of arachidonic acid or on the distribution of radioactive arachidonic acid within the lung. In addition, carbon monoxide had no effect on the metabolism of PGE 2 following infusion of 100 nmol of 14 C-PGE 2 into the rat pulmonary circulation. The present study suggests that carbon monoxide is not responsible for the cigarette smoke-induced changes in the pulmonary metabolism of arachidonic acid and PGE 2 . (author)

Effect of supplementation of arachidonic acid (AA) or a combination of AA plus docosahexaenoic acid on breastmilk fatty acid composition

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Smit, EN; Koopmann, M; Boersma, ER; Muskiet, FAJ

We investigated whether supplementation with arachidonic acid (20:4 omega 6; AA), ora combination of AA and docosahexaenoic acid (22:6 omega 3; DHA) would affect human milk polyunsaturated fatty acid (PUFA) composition. Ten women were daily supplemented with 300 mg AA, eight with 300 mg AA, 110 mg

Arachidonic acid reduces the stress response of gilthead seabream Sparus aurata L.

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Anholt, R.D. van; Spanings, F.A.T.; Koven, WM; Nixon, O.; Wendelaar Bonga, S.E.

2004-01-01

In this study the influence of the dietary level of the fatty acid arachidonic acid (ArA, 20:4n-6) was determined on the acute stress response and osmoregulation of adult gilthead seabream Sparus aurata L. Seabream were fed a diet containing either 0.9% or 2.4% of total fatty acids as ArA for 18

Differential stimulation of luminol-enhanced chemiluminescence (CL) and arachidonic acid metabolism in rat peritoneal neutrophils

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Sturm, R.J.; Adams, L.M.; Cullinan, C.A.; Berkenkopf, J.W.; Weichman, B.M.

1986-03-05

Phorbol 12-myristate, 13-acetate (PMA) induced the production of radical oxygen species (ROS) from rat peritoneal neutrophils as assessed by CL. ROS generation occurred in a time- (maximum at 13.5 min) and dose- (concentration range of 1.7-498 nM) related fashion. However, 166 nM PMA did not induce either cyclooxygenase (CO) or lipoxygenase (LPO) product formation by 20 min post-stimulation. Conversely, A23187, at concentrations between 0.1 and 10 ..mu..M, stimulated both pathways of arachidonic acid metabolism, but had little or no effect upon ROS production. When suboptimal concentrations of PMA (5.5 nM) and A23187 (0.1-1 ..mu..M) were coincubated with the neutrophils, a synergistic ROS response was elicited. However, arachidonic acid metabolism in the presence of PMA was unchanged relative to A12187 alone. Nordihydroguaiaretic acid (NDGA) inhibited both PMA-induced CL (IC/sub 50/ = 0.9 ..mu..M) and A23187-induced arachidonic acid metabolism (IC/sub 50/ = 1.7 ..mu..M and 6.0 ..mu..M for LPO and CO, respectively). The mixed LPO-CO inhibitor, BW755C, behaved in a qualitatively similar manner to NDGA, whereas the CO inhibitors, indomethacin, piroxicam and naproxen had no inhibitory effect on ROS generation at concentrations as high as 100 ..mu..M. These results suggest that NDGA and BW755C may inhibit CL and arachidonic acid metabolism by distinct mechanisms in rat neutrophils.

Relative turnover of [3H]arachidonic acid and [14C]eicosapentaenoic acid in stimulated human platelets

International Nuclear Information System (INIS)

Weaver, B.J.; Holub, B.J.

1986-01-01

The relative release of arachidonic acid (AA) versus eicosapentaenoic acid (EPA) from platelet phospholipids may be important in accounting for the potential of dietary fish oil containing EPA to alter platelet reactivity. Human platelets enriched in EPA and prelabelled with [ 3 H]AA and [ 14 C]EPA were used to examine the relative losses of these fatty acids from platelet phospholipids upon stimulation. Washed dual-labelled platelets were incubated with and without thrombin in the presence of BW755C and in the presence and absence of trifluoperazine. The platelet lipids were extracted and the individual phospholipids as well as diacylglycerol (DG), phosphatidic acid (PA), etc. were separated by thin-layer chromatography and the radioactivity in each fraction determined. The [ 3 H]AA/[ 14 C]EPA dpm ratio for the loss in radioactivity from PC upon thrombin stimulation was similar to that for the PC in resting platelets. This suggests no marked selectivity in the degradation of AA versus EPA species of PC during platelet activation. The [ 3 H]/[ 14 C] ratios for the increased radioactivity in DG and PA upon thrombin stimulation were slightly higher than the ratio in PI from resting platelets suggesting only a minor preference for 1-acyl 2-arachidonoyl PI over 1-acyl 2-eicosapentaenoyl PI in the pathway from PI to DG to PA

Monoglyceride lipase as a drug target: At the crossroads of arachidonic acid metabolism and endocannabinoid signaling.

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Grabner, Gernot F; Zimmermann, Robert; Schicho, Rudolf; Taschler, Ulrike

2017-07-01

Monoglyerides (MGs) are short-lived, intermediary lipids deriving from the degradation of phospho- and neutral lipids, and monoglyceride lipase (MGL), also designated as monoacylglycerol lipase (MAGL), is the major enzyme catalyzing the hydrolysis of MGs into glycerol and fatty acids. This distinct function enables MGL to regulate a number of physiological and pathophysiological processes since both MGs and fatty acids can act as signaling lipids or precursors thereof. The most prominent MG species acting as signaling lipid is 2-arachidonoyl glycerol (2-AG) which is the most abundant endogenous agonist of cannabinoid receptors in the body. Importantly, recent observations demonstrate that 2-AG represents a quantitatively important source for arachidonic acid, the precursor of prostaglandins and other inflammatory mediators. Accordingly, MGL-mediated 2-AG degradation affects lipid signaling by cannabinoid receptor-dependent and independent mechanisms. Recent genetic and pharmacological studies gave important insights into MGL's role in (patho-)physiological processes, and the enzyme is now considered as a promising drug target for a number of disorders including cancer, neurodegenerative and inflammatory diseases. This review summarizes the basics of MG (2-AG) metabolism and provides an overview on the therapeutic potential of MGL. Copyright © 2017 Elsevier Inc. All rights reserved.

Raloxifene and hormone replacement therapy increase arachidonic acid and docosahexaenoic levels in postmenopausal women

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Giltay, E.J.; Duschek, E.J.J.; Katan, M.B.; Neele, S.J.; Netelenbos, J.C.; Zock, P.L.

2004-01-01

Estrogens may affect the essential n-6 and n-3 fatty acids arachidonic acid (AA; C20:4n-6) and docosahexaenoic acid (DHA; C22:6n-3). Therefore, we investigated the long-term effects of hormone replacement therapy and raloxifene, a selective estrogen-receptor modulator, in two randomized,

Arachidonic and oleic acid exert distinct effects on the DNA methylome

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Silva-Martínez, Guillermo A.; Rodríguez-Ríos, Dalia; Alvarado-Caudillo, Yolanda

2016-01-01

ABSTRACT: Abnormal fatty acid metabolism and availability are landmarks of metabolic diseases, which in turn are associated with aberrant DNA methylation profiles. To understand the role of fatty acids in disease epigenetics, we sought DNA methylation profiles specifically induced by arachidonic....... The divergent response to AA and OA was prominent within the gene body of target genes, where it correlated positively with transcription. AA-induced DNA methylation profiles were similar to the corresponding profiles described for palmitic acid, atherosclerosis, diabetes, obesity, and autism, but relatively...

Lipoxygenase-mediated pro-radical effect of melatonin via stimulation of arachidonic acid metabolism

International Nuclear Information System (INIS)

Radogna, F.; Sestili, P.; Martinelli, C.; Paolillo, M.; Paternoster, L.; Albertini, M.C.; Accorsi, A.; Gualandi, G.; Ghibelli, L.

2009-01-01

We have shown that melatonin immediately and transiently stimulates intracellular free radical production on a set of leukocytes, possibly as a consequence of calmodulin binding. We show here that melatonin-induced ROS are produced by lipoxygenase (LOX), since they are prevented by a set of LOX inhibitors, and are accompanied by increase of the 5-LOX product 5-HETE. LOX activation is accompanied by strong liberation of AA; inhibition of Ca 2+ -independent, but not Ca 2+ -dependent, phospholipase A2 (PLA2), prevents both melatonin-induced arachidonic acid and ROS production, whereas LOX inhibition only prevents ROS, indicating that PLA2 is upstream with respect to LOX, as occurs in many signaling pathways. Chlorpromazine, an inhibitor of melatonin-calmodulin interaction, inhibits both ROS and arachidonic acid production, thus possibly placing calmodulin at the origin of a melatonin-induced pro-radical pathway. Interestingly, it is known that Ca 2+ -independent PLA2 binds to calmodulin: our results are compatible with PLA2 being liberated by melatonin from a steady-state calmodulin sequestration, thus initiating an arachidonate signal transduction. These results delineate a novel molecular pathway through which melatonin may participate to the inflammatory response.

A novel dioxygenation product of arachidonic acid possesses potent chemotactic activity for human polymorphonuclear leukocytes.

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Shak, S; Perez, H D; Goldstein, I M

1983-12-25

We have found that a novel dioxygenation product of arachidonic acid, 8(S),15(S)-dihydroxy-5,11-cis-9,13-trans-eicosatetraenoic acid (8,15-diHETE), possesses chemotactic activity for human polymorphonuclear leukocytes comparable to that of leukotriene B4. Authentic 8,15-diHETE, identified by gas chromatography-mass spectrometry, was prepared by treating arachidonic acid with soybean lipoxygenase and was purified by reverse-phase high performance liquid chromatography. Using a "leading front" assay, 8,15-diHETE exhibited significant chemotactic activity at a concentration of 5.0 ng/ml. Maximum chemotactic activity was observed at a concentration of 30 ng/ml. The 8,15-diHETE generated by mixed human leukocytes after stimulation with arachidonic acid and the calcium ionophore, A23187, exhibited quantitatively similar chemotactic activity. Two synthetic all-trans conjugated isomers of 8,15-diHETE, however, were not chemotactic at concentrations up to 500 ng/ml. In contrast to its potent chemotactic activity, 8,15-diHETE (at concentrations up to 10 micrograms/ml) was relatively inactive with respect to its ability to provoke either degranulation or generation of superoxide anion radicals by cytochalasin B-treated leukocytes. Both leukotriene B4 and 8,15-diHETE may be important mediators of inflammation.

Effect of selenium and vitamin E deficiencies on the fate of arachidonic acid in rat isolated lungs

International Nuclear Information System (INIS)

Uotila, P.; Puustinen, T.

1985-01-01

The fate of exogenous 14 C-arachidonic acid ( 14 C-AA) was investigated in the isolated lungs of rats fed selenium and vitamin E deficient diet or diets supplemented with selenium and/or vitamin E. When 80 nmol of 14 C-AA was infused into the pulmonary circulation most of the infused 14 C-AA was found in different phospholipid and neutral lipid fractions of the perfused lungs. Only less than ten percent of the infused radioactivity was recovered in the perfusion effluent. The amount of arachidonate metabolites in the perfusion effluent was negligible, and most of the radioactivity in the perfusion effluent consisted of unmetabolized arachidonate. Selenium deficiency had no significant effect on the distribution of 14 C-AA in different lung lipid fractions. However, in the lungs of vitamin E deficient rats the amount of radioactivity was slightly increased in the neutral lipid fraction, which was due to the increased amount of 14 C-AA in the diacylglycerols. The amount of radioactivity was increased especially in the 1,3-diacylglycerols. The amount of radioactivity was increased especially in the 1,3-diacylglycerols. The amount of 14 C-AA in the triacylglycerols and in different phospholipids was not significantly changed. The present study might indicate that selenium deficiency has no significant effect on the fate of exogenous arachidonic acid in isolated rat lungs, and that vitamin E deficiency would slightly increase the amount of arachidonic acid in the diacylglycerols

Ultraviolet B irradiation induces changes in the distribution and release of arachidonic acid, dihomo-gamma-linolenic acid, and eicosapentaenoic acid in human keratinocytes in culture

International Nuclear Information System (INIS)

Punnonen, K.; Puustinen, T.; Jansen, C.T.

1987-01-01

There is increasing evidence that derivatives of 20-carbon polyunsaturated fatty acids, the eicosanoids, play an important role in the inflammatory responses of the human skin. To better understand the metabolic fate of fatty acids in the skin, the effect of ultraviolet B (UVB) irradiation (280-320 nm) on the distribution and release of 14 C-labeled arachidonic acid, dihomo-gamma-linolenic acid, and eicosapentaenoic acid in human keratinocytes in culture was investigated. Ultraviolet B irradiation induced the release of all three 14 C-labeled fatty acids from the phospholipids, especially from phosphatidylethanolamine, and this was accompanied by increased labeling of the nonphosphorus lipids. This finding suggests that UVB induces a significant liberation of eicosanoid precursor fatty acids from cellular phospholipids, but the liberated fatty acids are largely reincorporated into the nonphosphorus lipids. In conclusion, the present study suggests that not only arachidonic acid but also dihomo-gamma-linolenic acid, and eicosapentaenoic acid might be involved in the UVB irradiation-induced inflammatory reactions of human skin

Arachidonic acid metabolites in normal and autoimmune mice do not influence lymphocyte-high endothelial venule interactions.

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Manolios, N; Bakiera, B; Geczy, C L; Schrieber, L

1991-02-01

In peripheral lymphoid organs the number of lymphocytes and the proportion of functional lymphocyte subsets are regulated by multiple factors including the control of lymphocyte migration by selective lymphocyte-high endothelial venule (HEV) interactions. In this study, prostaglandin E2 (PGE2) levels from normal and autoimmune mouse lymph node cells were measured. The contribution of eicosanoids to lymphocyte-HEV interactions in normal (CBA/T6) and autoimmune (MRL/n) mice was examined. There was no association between PGE2 production in normal or autoimmune mice and the age of onset of disease activity in the latter strains. Arachidonic acid metabolites, in particular PGE2 and leukotriene B4 (LTB4), did not have any effects on lymphocyte-HEV binding. Likewise, lymphocytes treated in vivo and/or in vitro with arachidonic acid metabolite inhibitors (acetyl salicylic acid, indomethacin, BW755C) did not alter lymphocyte-HEV binding interactions in both normal and autoimmune mice. No clinical significance could be attributed to lymph node PGE2 production and the age of onset of autoimmune disease. In summary, these findings cast doubt on the role of arachidonic acid metabolites in lymphocyte-HEV binding interactions.

Docosahexaenoic acid affects arachidonic acid uptake in megakaryocytes

International Nuclear Information System (INIS)

Schick, P.K.; Webster, P.

1987-01-01

Dietary omega 3 fatty acids are thought to prevent atherosclerosis, possibly by modifying platelet (PT) function and arachidonic acid (20:4) metabolism. The study was designed to determine whether omega 3 fatty acids primarily affect 20:4 metabolism in megakaryocytes (MK), bone marrow precursors of PT, rather than in circulating PT. MK and PT were isolated from guinea pigs and incubated with [ 14 C]-20:4 (0.13uM). Docosahexaenoic acid (22:6) is a major omega 3 fatty acid in marine oils. The incubation of MK with 22:6 (0.1, 1.0 uM) resulted in the decrease of incorporation of [ 14 C]-20:4 into total MK phospholipids, 16% and 41% respectively. Alpha-linolenic acid (18:3), a major omega 3 fatty acid present in American diets, had no effect on 20:4 uptake in MK. 22:6 primarily affected the uptake of [ 14 C]-20:4 into phosphatidylethanolamine (PE) and phosphatidylserine (PS) in MK. In MK, 22:6 (0.1, 1.0 uM) caused a decrease of incorporation of [ 14 C]-20:4 into PE, 21% and 55% respectively; a decrease into PS, 16% and 48% respectively; but only a decrease of 4% and 18%, respectively, into phosphatidylcholine; and a decrease of 3% and 21% into phosphatidylinositol 22:6 (3.0 uM) had no effect on the uptake of AA into PT phospholipids. The study shows that 22:6 has a selective effect on AA uptake in MK and that the acylation or transacylation of PE and PS are primarily affected. 22:6 and other marine omega 3 fatty acids appear to primarily affect megakaryocytes which may result in the production of platelets with abnormal content and compartmentalization of AA

Chronic cigarette smoke exposure adversely alters 14C-arachidonic acid metabolism in rat lungs, aortas and platelets

International Nuclear Information System (INIS)

Lubawy, W.C.; Valentovic, M.A.; Atkinson, J.E.; Gairola, G.C.

1983-01-01

Male rats were exposed to freshly generated cigarette smoke once daily, 5 times a week for 10 weeks. Inhalation of smoke was verified by elevated carboxyhemoglobin in blood sampled immediately after smoke exposure and by increased lung aryl hydrocarbon hydroxylase activity 24 hours after the last smoke exposure. Aortic rings isolated from smoke-exposed rats synthesized less prostacyclin (PGI2) from 14 C-arachidonic acid than rings from sham rats. Platelets from smoke-exposed rats synthesized more thromboxane (TXA2) from 14 C-arachidonic acid than platelets from room controls but not those from sham rats. Lung microsomes from smoke-exposed rats synthesized more TXA2 and had a lower PGI2/TXA2 ratio than lung microsomes from room controls and shams. It is concluded that chronic cigarette smoke exposure alters arachidonic acid metabolism in aortas, platelets and lungs in a manner resulting in decreased PGI2 and increased TXA2, thereby creating a condition favoring platelet aggregation and a variety of cardiovascular diseases

Synergy by secretory phospholipase A2 and glutamate on inducing cell death and sustained arachidonic acid metabolic changes in primary cortical neuronal cultures

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Kolko, M; DeCoster, M A; de Turco, E B

1996-01-01

glutamate and sPLA2 from bee venom. sPLA2, at concentrations eliciting low neurotoxicity (acid into triacylglycerols. Free [3H]arachidonic acid accumulated at higher enzyme concentrations......, from Taipan snake venom. The NMDA receptor antagonist MK-801 blocked glutamate effects and partially inhibited sPLA2 OS2 but not sPLA2 from bee venom-induced arachidonic acid release. Thus, the synergy with glutamate and very low concentrations of exogenously added sPLA2 suggests a potential role......Secretory and cytosolic phospholipases A2 (sPLA2 and cPLA2) may contribute to the release of arachidonic acid and other bioactive lipids, which are modulators of synaptic function. In primary cortical neuron cultures, neurotoxic cell death and [3H]arachidonate metabolism was studied after adding...

Role of arachidonic acid metabolism in transcriptional induction of tumor necrosis factor gene expression by phorbol ester

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Horiguchi, J.; Spriggs, D.; Imamura, K.; Stone, R.; Luebbers, R.; Kufe, D.

1989-01-01

The treatment of human HL-60 promyelocytic leukemia cells with 12-0 tetradecanoylphorbol-13-acetate (TPA) is associated with induction of tumor necrosis factor (TNF) transcripts. The study reported here has examined TPA-induced signaling mechanisms responsible for the regulation of TNF gene expression in these cells. Run-on assays demonstrated that TPA increases TNS mRNA levels by transcriptional activation of this gene. The induction of TNF transcripts by TPA was inhibited by the isoquinolinesulfonamide derivative H7 but not by HA1004, suggesting that this effect of TPA is mediated by activation of protein kinase C. TPA treatment also resulted in increased arachidonic acid release. Moreover, inhibitors of phospholipase, A/sub 2/ blocked both the increase in arachidonic acid release and the induction of TNF transcripts. These findings suggest that TPA induces TNF gene expression through the formation of arachidonic acid metabolites. Although indomethacin had no detectable effect on this induction of TNF transcripts, ketoconazole, an inhibitor of 5-lipoxygenase, blocked TPA-induced increases in TNF mRNA levels. Moreover, TNF mRNA levels were increased by the 5-lipoxygenase metabolite leukotriene B/sub 4/. In contrast, the cyclooxygenase metabolite prostaglandin E/sub 2/ inhibited the induction of TNF transcripts by TPA. Taken together, these results suggest that TPA induces TNF gene expression through the arachidonic acid cascade and that the level of TNF transcripts is regulated by metabolites of the pathway, leukotriene B/sub 4/ and prostaglandin E/sub 2/.

Effects of thyroid hormone status on metabolic pathways of arachidonic acid in mice and humans: A targeted metabolomic approach.

Science.gov (United States)

Yao, Xuan; Sa, Rina; Ye, Cheng; Zhang, Duo; Zhang, Shengjie; Xia, Hongfeng; Wang, Yu-cheng; Jiang, Jingjing; Yin, Huiyong; Ying, Hao

2015-01-01

Symptoms of cardiovascular diseases are frequently found in patients with hypothyroidism and hyperthyroidism. However, it is unknown whether arachidonic acid metabolites, the potent mediators in cardiovascular system, are involved in cardiovascular disorders caused by hyperthyroidism and hypothyroidism. To answer this question, serum levels of arachidonic acid metabolites in human subjects with hypothyroidism, hyperthyroidism and mice with hypothyroidism or thyroid hormone treatment were determined by a mass spectrometry-based method. Over ten arachidonic acid metabolites belonging to three catalytic pathways: cyclooxygenases, lipoxygenases, and cytochrome P450, were quantified simultaneously and displayed characteristic profiles under different thyroid hormone status. The level of 20-hydroxyeicosatetraenoic acid, a cytochrome P450 metabolite, was positively correlated with thyroid hormone level and possibly contributed to the elevated blood pressured in hyperthyroidism. The increased prostanoid (PG) I2 and decreased PGE2 levels in hypothyroid patients might serve to alleviate atherosclerosis associated with dyslipidemia. The elevated level of thromboxane (TX) A2, as indicated by TXB2, in hyperthyroid patients and mice treated with thyroid hormone might bring about pulmonary hypertension frequently found in hyperthyroid patients. In conclusion, our prospective study revealed that arachidonic acid metabolites were differentially affected by thyroid hormone status. Certain metabolites may be involved in cardiovascular disorders associated with thyroid diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

Arachidonic acid production by the oleaginous fungus Mortierella alpina 1S-4: A review

Directory of Open Access Journals (Sweden)

Hiroshi Kikukawa

2018-05-01

Full Text Available The filamentous fungus Mortierella alpina 1S-4 is capable of accumulating a large amount of triacylglycerol containing C20 polyunsaturated fatty acids (PUFAs. Indeed, triacylglycerol production by M. alpina 1S-4 can reach 20 g/L of culture broth, and the critical cellular signaling and structural PUFA arachidonic acid (ARA comprises 30%–70% of the total fatty acid. The demonstrated health benefits of functional PUFAs have in turn encouraged the search for rich sources of these compounds, including fungal strains showing enhanced production of specific PUFAs. Screening for mutants and targeted gene manipulation of M. alpina 1S-4 have elucidated the functions of various enzymes involved in PUFA biosynthesis and established lines with improved PUFA productivity. In some cases, these strains have been used for indistrial-scale production of PUFAs, including ARA. In this review, we described practical ARA production through mutant breeding, functional analyses of genes encoding enzymes involved in PUFA biosynthesis, and recent advances in the production of specific PUFAs through molecular breeding of M. alpina 1S-4. Keywords: Arachidonic acid, Mortierella alpina, Molecular breeding, Fatty acid desaturase

Novel metabolic pathways for linoleic and arachidonic acid metabolism.

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Moghaddam, M; Motoba, K; Borhan, B; Pinot, F; Hammock, B D

1996-08-13

Mouse liver microsomes oxidized linoleic acid to form 9,10- or 12,13-epoxyoctadecenoate. These monoepoxides were subsequently hydrolyzed to their corresponding diols in the absence of the microsomal epoxide hydrolase inhibitor, 1,2-epoxy-3,3,3-trichloropropane. Furthermore, both 9,10- and 12,13-epoxyoctadecenoates were oxidized to diepoxyoctadecanoate at apparently identical rates by mouse liver microsomal P-450 epoxidation. Both epoxyoctadecanoates and diepoxyoctadecanoates were converted to tetrahydrofuran-diols by microsomes. Tetrahydroxides of linoleate were produced as minor metabolites. Arachidonic acid was metabolized to epoxyeicosatrienoates, dihydroxyeicosatrienoates, and monohydroxyeicosatetraenoates by the microsomes. Microsomes prepared from clofibrate (but not phenobarbital) -treated mice exhibited much higher production rates for epoxyeicosatrienoates and vic-dihydroxyeicosatrienoates. This indicated an induction of P-450 epoxygenase(s) and microsomal epoxide hydrolase in mice by clofibrate and not by phenobarbital. Incubation of synthetic epoxyeicosatrienoates with microsomes led to the production of diepoxyeicosadienoates. Among chemically generated diepoxyeicosadienoate isomers, three of them possessing adjacent diepoxides were hydrolyzed to their diol epoxides which cyclized to the corresponding tetrahydrofuran-diols by microsomes as well as soluble epoxide hydrolase at a much higher rate. Larger cyclic products from non-adjacent diepoxides were not observed. The results of our in vitro experiments suggest that linoleic and arachidonic acid can be metabolized to their tetrahydrofuran-diols by two consecutive microsomal cytochrome P-450 epoxidations followed by microsomal or soluble epoxide hydrolase catalyzed hydrolysis of the epoxides. Incubation experiments with the S-9 fractions indicate that the soluble epoxide hydrolase is more important in this conversion. This manuscript is the first report of techniques for the separation and

Production of arachidonic and linoleic acid metabolites by guinea pig tracheal epithelial cells

International Nuclear Information System (INIS)

Oosthuizen, M.J.; Engels, F.; Van Esch, B.; Henricks, P.A.; Nijkamp, F.P.

1990-01-01

Pulmonary epithelial cells may be responsible for regulating airway smooth muscle function, in part by release of fatty acid-derived mediators. Incubation of isolated guinea pig tracheal epithelial cells with radiolabeled arachidonic acid (AA) leads to the production of 5- and 15-hydroxyeicosatetraenoic acid (5- and 15-HETE) and smaller amounts of leukotriene (LT) B4 and C4 and 12-hydroxyheptadecatrienoic acid (HHT). Epithelial cells also are able to release linoleic acid (LA) metabolites. Incubation with radiolabeled linoleic acid leads to the formation of 9- and 13-hydroxyoctadecadienoic acid (9- and 13-HODE). The biological significance of these mediators produced by epithelial cells is discussed

The effect of cigarette smoke on the metabolism of arachidonic acid in isolated hamster lungs

International Nuclear Information System (INIS)

Maennistoe, J.; Toivonen, H.; Hartiala, J.; Bakhle, Y.S.; Uotila, P.

1981-01-01

The effects of cigarette smoke on the metabolism of exogenous arachidonic acid (AA) were investigated in isolated hamster lungs. Arachidonate was injected into the pulmonary circulation and the metabolites were analysed from the nonrecirculating perfusion effluent by thin layer chromatography. After the pulmonary injection of 66 nmol of 14C-AA about 20% of the injected radioactivity appeared in the perfusion effluent mostly as metabolites in six minutes. When isolated lungs were ventilated with cigarette smoke during the perfusion, the amounts of PGF2 alpha, PGE2 and two unidentified metabolite groups increased in the lung effluent. In two other experimental series hamsters were exposed to cigarette smoke before the lung perfusion either once for 30 min or during one hour daily for ten consecutive days. Neither pre-exposures caused any changes in the amounts of arachidonate metabolites in the lung effluent

Maternal and fetal brain contents of docosahexaenoic acid (DHA) and arachidonic acid (AA) at various essential fatty acid (EFA), DHA and AA dietary intakes during pregnancy in mice

NARCIS (Netherlands)

van Goor, Saskia A; Dijck-Brouwer, D A Janneke; Fokkema, M Rebecca; van der Iest, Theo Hans; Muskiet, Frits A J

We investigated essential fatty acids (EFA) and long-chain polyunsaturated fatty acids (LCP) in maternal and fetal brain as a function of EFA/LCP availability to the feto-maternal unit in mice. Diets varying in parent EFA, arachidonic acid (AA), and docosahexaenoic acid (DHA) were administered from

The influence of supplemental docosahexaenoic and arachidonic acids during pregnancy and lactation on neurodevelopment at eighteen months

NARCIS (Netherlands)

van Goor, Saskia A.; Dijck-Brouwer, D. A. Janneke; Erwich, Jan Jaap H. M.; Schaafsma, Anne; Hadders-Algra, Mijna

2011-01-01

Docosahexaenoic acid (DHA) and arachidonic acid (AA) are important for neurodevelopment. The effects of DHA (220 mg/day, n=41), DHA+AA (220 mg/day, n=39) or placebo (n=34) during pregnancy and lactation on neurodevelopment at 18 months, and the relations between umbilical cord DHA, AA and Mead acid

Effects of arachidonic acid and 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine on prolactin secretion from anterior pituitary cells

International Nuclear Information System (INIS)

Camoratto, A.M.

1988-01-01

The role of two lipids, arachidonic acid and 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine, as modulators or prolactin secretion has been examined. Stimulators of phospholipase A 2 activity, melittin and mastoparan, were found to increase prolactin release. Melittin also caused release of previously incorporated 3 H-arachidonic acid and this effect was associated with loss of radiolabel from the phospholipid fraction. Exogenous arachidonic acid also stimulated prolactin secretion. Conversely, inhibitors of phospholipase A 2 activity, dibromoacetophenone and U10029A, decreased basal and stimulated prolactin release. Prolactin release could also be lowered by ETYA, BW755C and NDGA, inhibitors of arachidonic acid metabolism. In the second series of experiments the effects of the biologically active phospholipid 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine (platelet activating factor, PAF) on prolactin release were examined. PAF is an ether-linked phospholipid known to stimulate granule release in a variety of cell types including both inflammatory and noninflammatory cells. PAF increased release of prolactin from dispersed rat anterior pituitary cells; stimulation was not due to cell lysis. PAF-induced prolactin release could be blocked by the dopaminergic agonists apomorphine and bromocriptine as well as by two PAF receptor antagonists, SRI 63-072 and L-652-731

mRNA levels of enzymes and receptors implicated in arachidonic acid metabolism in gliomas.

Science.gov (United States)

De Armas, Rafael; Durand, Karine; Guillaudeau, Angélique; Weinbreck, Nicolas; Robert, Sandrine; Moreau, Jean-Jacques; Caire, François; Acosta, Gisela; Pebet, Matias; Chaunavel, Alain; Marin, Benoît; Labrousse, François; Denizot, Yves

2010-07-01

Gliomas are tumors of the central nervous system derived from glial cells. They show cellular heterogeneity and lack specific diagnostic markers. Although a possible role for the eicosanoid cascade has been suggested in glioma tumorigenesis, the relationship between enzymes and receptors implicated in arachidonic acid metabolism, with histological tumor type has not yet been determined. Quantitative real-time reverse transcription-polymerase chain reaction was performed to measure and compare transcript levels of enzymes and receptors implicated in both lipoxygenase and cyclooxygenase pathways between oligodendrogliomas, astrocytomas, glioblastomas and mixed oligoastrocytomas. Arachidonic acid metabolism-related enzymes and receptor transcripts (i) were underexpressed in classical oligodendrogliomas compared to astrocytomas and/or glioblastomas, (ii) differed between astrocytomas and glioblastomas and (iii) had an intermediate expression in mixed oligoastrocytomas. mRNA levels of enzymes and receptors implicated both in lipoxygenase and cyclooxygenase pathways differed significantly in gliomas according to the histological type. Copyright 2010 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Hydrocortisone selectively inhibits IgE-dependent arachidonic acid release from rat peritoneal mast cells

International Nuclear Information System (INIS)

Heiman, A.S.; Crews, F.T.

1984-01-01

Purified rat mst cells were used to study the effects of antiinflammatory steroids on the release of [1-14C]-arachidonic acid ([1-14C]AA) and metabolites. Mast cell were incubated overnight with glucocorticoids, [1-14C]AA incorporated into cellular phospholipids and the release of [1-14C]AA, and metabolites determined using a variety of secretagogues. Release of [1-14C]AA and metabolites by concanavalin A, the antigen ovalbumin and anti-immunoglobulin E antibody was markedly reduced by glucocorticoid treatment. Neither the total incorporation of [1-14C]AA nor the distribution into phospholipids was altered by hydrocortisone pretreatment. Glucocorticoid pretreatment did not alter [1-14C]AA release stimulated by somatostatin, compound 48/80, or the calcium ionophore, A23187. These data indicate that antiinflammatory steroids selectively inhibit immunoglobulin dependent release of arachidonic acid from rat mast cells. These findings question the role of lipomodulin and macrocortin as general phospholipase inhibitors and suggest that they may be restricted to immunoglobulin stimuli

Decreased arachidonic acid content and metabolism in tissues of NZB/W F1 females fed a diet containing 0.45% dehydroisoandrosterone (DHA)

International Nuclear Information System (INIS)

Matsunaga, A.; Cottam, G.L.

1987-01-01

A diet containing 0.45% DHA fed to NZB/W mice, a model of systemic lupus erythematosus, delays the time of onset, improves survival and decreases the formation of antibodies to ds-DNA. Essential fatty acid-deficient diets or inclusion of eicosapentaenoic acid have similar beneficial effects and led them to investigate arachidonic acid metabolism in response to feeding DHA. The arachidonic acid content of plasma cholesteryl ester decreased from 37.4 +/- 2.2 to 28.2 +/- 1.3 mg%. In total liver phospholipid the value decreased from 18.1 +/- 0.52 to 13.7 +/- 1.3 mg%, in total kidney phospholipid the value decreased from 24.10 +/- 0.87 to 20.7 +/- 0.32 mg% and in resident peritoneal macrophages the value decreased from 15.4 +/- 4.6 to 3.6 +/- 1.4 mg%. The metabolism of exogenous [1- 14 C]arachidonic acid by resident peritoneal macrophages in response to Zymosan stimulation for 2 hr was examined by extraction of metabolites and separation by HPLC. Cells isolated from DHA-fed animals produced less PGE2 than controls, yet similar amounts of 6-keto PGF1α were produced. Arachidonic acid metabolites have significant effects on the immune system and may be a mechanism involved in the benefits obtained by inclusion of DHA in the diet

Role of lipoxygenase metabolites of arachidonic acid in enhanced pulmonary artery contractions of female rabbits.

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Pfister, Sandra L

2011-04-01

Pulmonary arterial hypertension is characterized by elevated pulmonary artery pressure and vascular resistance. In women the incidence is 4-fold greater than that in men. Studies suggest that sustained vasoconstriction is a factor in increased vascular resistance. Possible vasoconstrictor mediators include arachidonic acid-derived lipoxygenase (LO) metabolites. Our studies in rabbits showed enhanced endothelium-dependent contractions to arachidonic acid in pulmonary arteries from females compared with males. Because treatment with a nonspecific LO inhibitor reduced contractions in females but not males, the present study identified which LO isoform contributes to sex-specific pulmonary artery vasoconstriction. The 15- and 5- but not 12-LO protein expressions were greater in females. Basal and A23187-stimulated release of 15-, 5-, and 12-hydroxyeicosatetraenoic acids (HETEs) from females and males were measured by liquid chromatography/mass spectrometry. Only 15-HETE synthesis was greater in females compared with males under both basal and stimulated conditions. Vascular contractions to 15-HETE were enhanced in females compared with males (maximal contraction: 44±6%versus 25±3%). The specific 15-LO inhibitor PD146176 (12 μmol/L) decreased arachidonic acid-induced contractions in females (maximal contraction: 93±4% versus 57±10%). If male pulmonary arteries were incubated with estrogen (1 μmol/L, 18 hours), protein expression of 15-LO and 15-HETE production increased. Mechanisms to explain the increased incidence of pulmonary hypertension in women are not known. Results suggest that the 15-LO pathway is different between females and males and is regulated by estrogen. Understanding this novel sex-specific mechanism may provide insight into the increased incidence of pulmonary hypertension in females.

Lipoxin A4 and lipoxin B4 stimulate the release but not the oxygenation of arachidonic acid in human neutrophils: Dissociation between lipid remodeling and adhesion

Energy Technology Data Exchange (ETDEWEB)

Nigam, S.; Fiore, S.; Luscinskas, F.W.; Serhan, C.N. (Brigham and Women' s Hospital, Boston, MA (USA))

1990-06-01

The profiles of actions of lipoxin A4 (LXA4) and lipoxin B4 (LXB4), two lipoxygenase-derived eicosanoids, were examined with human neutrophils. At nanomolar concentrations, LXA4 and LXB4 each stimulated the release of (1-14C)arachidonic acid from esterified sources in neutrophils. Lipoxin-induced release of (1-14C)arachidonic acid was both dose- and time-dependent and was comparable to that induced by the chemotactic peptide f-met-leu-phe. Time-course studies revealed that lipoxin A4 and lipoxin B4 each induced a biphasic release of (1-14C)arachidonic acid, which was evident within seconds (5-15 sec) in its initial phase and minutes (greater than 30 sec) in the second phase. In contrast, the all-trans isomers of LXA4 and LXB4 did not provoke (1-14C)AA release. Lipoxin-induced release of arachidonic acid was inhibited by prior treatment of the cells with pertussis toxin but not by its beta-oligomers, suggesting the involvement of guaninine nucleotide-binding regulatory proteins in this event. Dual radiolabeling of neutrophil phospholipid classes with (1-14C)arachidonic acid and (3H)palmitic acid showed that phosphatidylcholine was a major source of lipoxin-induced release of (1-14C)arachidonic acid. They also demonstrated that lipoxins rapidly stimulate both formation of phosphatidic acid as well as phospholipid remodeling. Although both LXA4 and LXB4 (10(-8)-10(-6) M) stimulated the release of (1-14C)arachidonic acid, neither compound evoked its oxygenation by either the 5- or 15-lipoxygenase pathways (including the formation of LTB4, 20-COOH-LTB4, 5-HETE, or 15-HETE). LXA4 and LXB4 (10(-7) M) each stimulated the elevation of cytosolic Ca2+ as monitored with Fura 2-loaded cells, albeit to a lesser extent than equimolar concentrations of FMLP. Neither lipoxin altered the binding of (3H)LTB4 to its receptor on neutrophils.

Glutamate signalling and secretory phospholipase A2 modulate the release of arachidonic acid from neuronal membranes

DEFF Research Database (Denmark)

Rodriguez De Turco, Elena B; Jackson, Fannie R; DeCoster, Mark A

2002-01-01

The lipid mediators generated by phospholipases A(2) (PLA(2)), free arachidonic acid (AA), eicosanoids, and platelet-activating factor, modulate neuronal activity; when overproduced, some of them become potent neurotoxins. We have shown, using primary cortical neuron cultures, that glutamate...... and secretory PLA(2) (sPLA(2)) from bee venom (bv sPLA(2)) and Taipan snake venom (OS2) elicit synergy in inducing neuronal cell death. Low concentrations of sPLA(2) are selective ligands of cell-surface sPLA(2) receptors. We investigated which neuronal arachidonoyl phospholipids are targeted by glutamate......) and in minor changes in other phospholipids. A similar profile, although of greater magnitude, was observed 20 hr posttreatment. Glutamate (80 microM) induced much less mobilization of (3)H-AA than did sPLA(2) and resulted in a threefold greater degradation of (3)H-AA PE than of (3)H-AA PC by 20 hr...

Food Polyphenol Apigenin Inhibits the Cytochrome P450 Monoxygenase Branch of the Arachidonic Acid Cascade.

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Steuck, Maryvonne; Hellhake, Stefan; Schebb, Nils Helge

2016-11-30

The product of cytochrome P450 monooxygenase (P450) ω-hydroxylation of arachidonic acid (AA), 20- hydroxyeicosatetraenoic acid (HETE), is a potent vasoconstrictor. Utilizing microsomes as well as individual CYP4 isoforms we demonstrate here that flavonoids can block 20-HETE formation. Apigenin inhibits CYP4F2 with an IC 50 value of 4.6 μM and 20-HETE formation in human liver and kidney microsomes at 2.4-9.8 μM. Interestingly, the structurally similar naringenin shows no relevant effect on the formation of 20-HETE. Based on these in vitro data, it is impossible to evaluate if a relevant blockade of 20-HETE formation can result in humans from intake of polyphenols with the diet. However, the potency of apigenin is comparable to those of P450 inhibitors such as ketoconazole. Moreover, an IC 50 value in the micromolar range is also described for the inhibition of CYP-mediated drug metabolism leading to food-drug interactions. The modulation of the arachidonic acid cascade by food polyphenols therefore warrants further investigation.

Mechanism for release of arachidonic acid during guinea pig platelet aggregation: a role for the diacylglycerol lipase inhibitor RHC 80267

International Nuclear Information System (INIS)

Amin, D.

1986-01-01

The mechanism of the release of arachidonic acid from phospholipids after the stimulation of guinea pig platelets with collagen, thrombin and platelet activating factor (PAF) was studied. RHC 80267, a diacylglycerol lipase inhibitor, and indomethacin, a cyclooxygenase inhibitor, were used. Various in vitro assays for enzymes involved in arachidonic acid release and metabolism were conducted. Platelet aggregation and simultaneous release of ADP from platelets were monitored using a Chrono-log Lumiaggregometer. Platelets were labeled with ( 14 C)arachidonic acid to facilitate sensitive determination of small changes in platelet phospholipids during platelet aggregation. In the present investigation it is shown that collagen, thrombin and PAF increased phospholipase C activity. It was also discovered that cyclooxygenase products were responsible for further stimulation (a positive feed-back) of phospholipase C activity, while diacylglycerol provided a negative feed-back control over receptor-stimulated phospholipase C activity and inhibited ADP release. The guinea pig platelet is an ideal model to study phospholipase C-diacylglycerol lipase pathway for the release of arachidonic acid from platelet phospholipids because it does not have any phospholipase A 2 activity. It was observed that cyclooxygenase products were responsible for collagen-induced guinea pig platelet aggregation. Indomethacin completely inhibited collagen-induced platelet aggregation, was less effective against thrombin, and had no effect on PAF-induced platelet aggregation. On the other hand, RHC 80267 was a powerful inhibitor of aggregation and ADP release induced by all three of these potent aggregating agents

Tamoxifen and the Rafoxifene analog LY117018: their effects on arachidonic acid release from cells in culture and on prostaglandin I2 production by rat liver cells

International Nuclear Information System (INIS)

Levine, Lawrence

2004-01-01

Tamoxifen is being used successfully to treat breast cancer. However, tamoxifen also increases the risk of developing endometrial cancer in postmenopausal women. Raloxifene also decreases breast cancer in women at high risk and may have a lower risk at developing cancer of the uterus. Tamoxifen has been shown to stimulate arachidonic acid release from rat liver cells. I have postulated that arachidonic acid release from cells may be associated with cancer chemoprevention. Rat liver, rat glial, human colon carcinoma and human breast carcinoma cells were labelled with [ 3 H] arachidonic acid. The release of the radiolabel from these cells during incubation with tamoxifen and the raloxifene analog LY117018 was measured. The prostaglandin I 2 produced during incubation of the rat liver cells with μM concentrations of tamoxifen and the raloxifene analog was quantitatively estimated. Tamoxifen is about 5 times more effective than LY117018 at releasing arachidonic acid from all the cells tested. In rat liver cells only tamoxifen stimulates basal prostaglandin I 2 production and that induced by lactacystin and 12-O-tetradecanoyl-phorbol-13-acetate. LY117018, however, blocks the tamoxifen stimulated prostaglandin production. The stimulated prostaglandin I 2 production is rapid and not affected either by preincubation of the cells with actinomycin or by incubation with the estrogen antagonist ICI-182,780. Tamoxifen and the raloxifene analog, LY117018, may prevent estrogen-independent as well as estrogen-dependent breast cancer by stimulating phospholipase activity and initiating arachidonic acid release. The release of arachidonic acid and/or molecular reactions that accompany that release may initiate pathways that prevent tumor growth. Oxygenation of the intracellularly released arachidonic acid and its metabolic products may mediate some of the pharmacological actions of tamoxifen and raloxifene

Effects of different arachidonic acid supplementation on psychomotor development in very preterm infants; a randomized controlled trial.

Science.gov (United States)

Alshweki, Ayham; Muñuzuri, Alejandro Pérez; Baña, Ana M; de Castro, Ma José; Andrade, Fernando; Aldamiz-Echevarría, Luís; de Pipaón, Miguel Sáenz; Fraga, José M; Couce, María L

2015-09-30

Nutritional supplementation with polyunsaturated fatty acids is important in preterm infants neurodevelopment, but it is not known if the omega-6/omega-3 ratio affects this process. This study was designed to determine the effects of a balanced contribution of arachidonic acid in very preterm newborns fed with formula milk. This was a randomized trial, in which newborns psychomotor development was assessed using the Brunet Lézine scale at 24 months corrected age. A control group, for comparison of Brunet Lézine score, was made up of 25 newborns from the SEN1500 project, who were fed exclusively with breast milk. At 12 months, arachidonic acid values were significantly higher in group A than in group B (6.95 ± 1.55% vs. 4.55 ± 0.78%), as were polyunsaturated fatty acids (41.02 ± 2.09% vs. 38.08 ± 2.32%) achieved a higher average. Group A achieved a higher average Brunet Lézine score at 24 months than group B (99.9 ± 9 vs. 90.8 ± 11, p =0.028). The Brunet Lézine results from group A were compared with the control group results, with very similar scores registered between the two groups (99.9 ± 9 vs. 100.5 ± 7). There were no significant differences in growth or evoked potentials between the two formula groups. Very preterm infants who received formula with an ω-6/ω-3 ratio of 2/1 had higher blood levels of essential fatty acids during the first year of life, and better psychomotor development, compared with very preterm newborns who consumed formula with an ω-6/ω-3 of 1/1. Therefore, formula milk with an arachidonic acid quantity double that of docosahexaenoic acid should be considered for feeding very preterm infants. ClinicalTrials.gov Identifier NCT02503020.

Arachidonic acid/docosahexaenoic acid-supplemented diet in early life reduces body weight gain, plasma lipids, and adiposity in later life in ApoE*3 Leiden mice

NARCIS (Netherlands)

Wielinga, P.Y.; Harthoorn, L.F.; Verschuren, L.; Schoemaker, M.H.; Jouni, Z.E.; Tol, E.A.F. van; Kleemann, R.; Kooistra, T.

2012-01-01

Scope: This study addresses whether early life arachidonic acid (ARA)/docosahexaenoic acid (DHA) supplementation or eicosapentaenoic acid (EPA)/DHA (Omacor) supplementation affects body weight gain, lipid metabolism, and adipose tissue quantity and quality in later life in ApoE*3Leiden-transgenic

Effect of ethanol amine plasmalogens on Fe-induced peroxidation of arachidonic acid in dipalmitoylphosphatidylcholine vesicles.

Science.gov (United States)

Omodeo Salè, M F; Rizzo, A M; Masserini, M

2000-12-01

We have investigated the influence of ethanolamine plasmalogens on iron-induced oxidation of arachidonic acid in dipalmitoylphosphatidylcholine (DPPC) vesicles. Lipoperoxidation was induced by the addition of 50 microM FeSO4 and studied above (50 degrees C) and below (15 degrees C) the gel-to liquid transition temperature of the vesicles, at two different pH values (7.4 or 6.4). The extent of peroxidation was measured as thiobarbituric reactive product formed and the influence exerted by ethanolamine plasmalogens (PEPL) in this process was compared to that of dipalmitoylphosphatidylethanolamine (DPPE) and diacylphosphatidylethanolamines (DAPE). The extent of peroxidation of arachidonic acid embedded in DPPC vesicles was similar at the two temperatures and greater at 50 degrees C under acidic conditions. However, the peroxidative process was significantly decreased at 50 degrees C in the presence of PEPL, but not of DPPE or DAPE and the inhibitory effect was enhanced at pH 6.4. The possibility that a different phase distribution of the phospholipids, namely a transition from a lamellar to a hexagonal phase, may play a role in the scavenger effect of ethanolamine plasmalogens is discussed.

Pulmonary arachidonic acid metabolism following acute exposures to ozone and nitrogen dioxide

International Nuclear Information System (INIS)

Schlesinger, R.B.; Driscoll, K.E.; Gunnison, A.F.; Zelikoff, J.T.

1990-01-01

Ozone (O 3 ) and nitrogen dioxide (NO 2 ) are common air pollutants, and exposure to these gases has been shown to affect pulmonary physiology, biochemistry, and structure. This study examined their ability to modulate arachidonic acid metabolites (eicosanoids) in the lungs. Rabbits were exposed for 2 h to O 3 at 0.1, 0.3, or 1 ppm; NO 2 at 1, 3, or 10 ppm; or to a mixture of 0.3 ppm O 3 and 3 ppm NO 2 . Groups of animals sacrificed either immediately or 24 h after each exposure underwent broncho-pulmonary lavage. Selected eicosanoids were assessed in lavage fluid by radioimmunoassay. Increases in prostaglandins E2 (PGE2) and F2 alpha (PGF2 alpha) were found immediately after exposure to 1 ppm O 3 . Exposure to 10 ppm NO 2 resulted in a depression of 6-keto-PGF1 alpha, while thromboxane B2 (TxB2) was elevated after exposure to 1 ppm NO 2 and depressed following 3 and 10 ppm. The O 3 /NO 2 mixture resulted in synergistic increases in PGE2 and PGF2 alpha, with the response appearing to be driven by O 3 . This study has demonstrated that acute exposure to either O 3 or NO 2 can alter pulmonary arachidonic acid metabolism and that the responses to these oxidants differ, both quantitatively and qualitatively

12(R)-hydroxyicosatetraenoic acid: a cytochrome P450-dependent arachidonate metabolite that inhibits Na+, K+-ATPase in the cornea

International Nuclear Information System (INIS)

Schwartzman, M.L.; Balazy, M.; Masferrer, J.; Abraham, N.G.; McGiff, J.C.; Murphy, R.C.

1987-01-01

When corneal microsomes were incubated with arachidonic acid in the presence of an NADPH-generating system, four polar metabolites (compounds A-D) were formed. Synthesis of these metabolites could be inhibited by carbon monoxide, SKF 525A, and anti-cytochrome c reductase antibodies. One of the metabolites, compound C, was found to inhibit partially purified Na + , K + -ATPase from the corneal epithelium in a dose-dependent manner. After compound C was purified by TLC and HPLC, it was found to have a UV absorption spectrum with a maximum absorbance at 236 nm suggesting the presence of a conjugated diene. Mass spectrometric analysis using positive- and negative-ionization modes was carried out on derivatized compound C. Abundant fragment ions were consistent with compound C being a monooxygenated derivative of arachidonic acid with a hydroxyl substituent at carbon-12 of the icosanoid backbone; all deuterium atoms from [ 2 H 8 ]arachidonate were retained in the structure. Compound C was characterized as a 12-hydroxyicosatetraenoic acid. However, only 12(R) isomer was found to be an inhibitor of the Na + , K + -ATPase from the corneal epithelium, suggesting that the biologically active compound C was 12(R)-hydroxyy-5,8,10,14-icosatetraenoic acid. Such an inhibitor of Na + , K + -ATPase synthesized in the cornea may have an important role in regulating ocular transparency and aqueous human secretion

Clinical implications of eicosapentaenoic acid/arachidonic acid ratio (EPA/AA) in adult patients with congenital heart disease.

Science.gov (United States)

Kanoh, Miki; Inai, Kei; Shinohara, Tokuko; Tomimatsu, Hirofumi; Nakanishi, Toshio

2017-12-01

Recent studies showed that a low ratio between the levels of eicosapentaenoic acid and those of arachidonic acid (EPA/AA) is associated with higher incidence of coronary artery disease and poor prognosis of heart failure, arrhythmia, and cardiac sudden death. However, the clinical implications of EPA/AA in adult patients with congenital heart disease remain unclear. We aimed to assess the prognostic value of EPA/AA regarding cardiac events in adult patients with congenital heart disease. We measured the serum levels of eicosapentaenoic acid and arachidonic acid in 130 adult patients (median age, 31 years) stratified into two groups according to their EPA/AA (low, ≤0.22; high, >0.22). We prospectively analyzed the association between EPA/AA and incidence of cardiac events during a mean observation period of 15 months, expressed in terms of hazard ratio (HR) with 95% confidence interval (95% CI). In the subgroup of patients with biventricular circulation (2VC) (n = 76), we analyzed the same clinical endpoints. In our study population, EPA/AA was not associated with the incidence of arrhythmic events (HR, 1.52; 95% CI, 0.82-2.85; p = 0.19), but low EPA/AA was a predictor of heart failure hospitalization (HR, 2.83; 95% CI, 1.35-6.30; p AA of ≤0.25 was associated with a significantly higher risk of arrhythmic events (HR, 2.55; 95% CI, 1.11-6.41; p = 0.03) and heart failure hospitalization (HR, 5.20; 95% CI, 1.78-18.1; p AA represents a useful predictor of cardiac events in adult patients with congenital heart disease.

Dietary arachidonic acid in perinatal nutrition: a commentary.

Science.gov (United States)

Lauritzen, Lotte; Fewtrell, Mary; Agostoni, Carlo

2015-01-01

Arachidonic acid (AA) is supplied together with docosahexaenoic acid (DHA) in infant formulas, but we have limited knowledge about the effects of supplementation with either of these long-chain polyunsaturated fatty acids (LCPUFA) on growth and developmental outcomes. AA is present in similar levels in breast milk throughout the world, whereas the level of DHA is highly diet dependent. Autopsy studies show similar diet-dependent variation in brain DHA, whereas AA is little affected by intake. Early intake of DHA has been shown to affect visual development, but the effect of LCPUFA on neurodevelopment remains to be established. Few studies have found any functional difference between infants supplemented with DHA alone compared to DHA+AA, but some studies show neurodevelopmental advantages in breast-fed infants of mothers supplemented with n-3 LCPUFA alone. It also remains to be established whether the AA/DHA balance could affect allergic and inflammatory outcomes later in life. Disentangling effects of genetic variability and dietary intake on AA and DHA-status and on functional outcomes may be an important step in the process of determining whether AA-intake is of any physiological or clinical importance. However, based on the current evidence we hypothesize that dietary AA plays a minor role on growth and development relative to the impact of dietary DHA.

Molecular characterization of an enzyme that degrades neuromodulatory fatty-acid amides.

Science.gov (United States)

Cravatt, B F; Giang, D K; Mayfield, S P; Boger, D L; Lerner, R A; Gilula, N B

1996-11-07

Endogenous neuromodulatory molecules are commonly coupled to specific metabolic enzymes to ensure rapid signal inactivation. Thus, acetylcholine is hydrolysed by acetylcholine esterase and tryptamine neurotransmitters like serotonin are degraded by monoamine oxidases. Previously, we reported the structure and sleep-inducing properties of cis-9-octadecenamide, a lipid isolated from the cerebrospinal fluid of sleep-deprived cats. cis-9-Octadecenamide, or oleamide, has since been shown to affect serotonergic systems and block gap-junction communication in glial cells (our unpublished results). We also identified a membrane-bound enzyme activity that hydrolyses oleamide to its inactive acid, oleic acid. We now report the mechanism-based isolation, cloning and expression of this enzyme activity, originally named oleamide hydrolase, from rat liver plasma membranes. We also show that oleamide hydrolase converts anandamide, a fatty-acid amide identified as the endogenous ligand for the cannabinoid receptor, to arachidonic acid, indicating that oleamide hydrolase may serve as the general inactivating enzyme for a growing family of bioactive signalling molecules, the fatty-acid amides. Therefore we will hereafter refer to oleamide hydrolase as fatty-acid amide hydrolase, in recognition of the plurality of fatty-acid amides that the enzyme can accept as substrates.

Effects of fluticasone propionate inhalation on levels of arachidonic acid metabolites in patients with chronic obstructive pulmonary disease

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Gert T. Verhoeven

2001-01-01

Full Text Available Background: In smoking COPD patients the bronchoalveolar lavage (BAL fluid contains high numbers of inflammatory cells. These cells might produce arachidonic acid (AA metabolites, which contribute to inflammation and an increased bronchomotor tone.

Identification of rabbit cytochromes P450 2C1 and 2C2 as arachidonic acid epoxygenases.

Science.gov (United States)

Laethem, R M; Koop, D R

1992-12-01

Microsomes prepared from COS-1 cells transiently expressing rabbit cytochromes P450 2C1 and 2C2 catalyzed the metabolism of arachidonic acid to predominantly 11,12- and 14,15-epoxyeicosatrienoic acids (EETs) when microsomal epoxide hydrolase activity was inhibited by 0.2 mM 1,2-epoxy-3,3,3-trichloropropane. P450 2C2 catalyzed the formation of 11,12-EET and 14,15-EET at a ratio of 3.0 and also produced 19-hydroxyeicosatetraenoic acid (19-HETE). The 11,12-EET, 14,15-EET, and 19-HETE represented 48.3, 15.9, and 12.8%, respectively, of the total metabolites formed. P450 2C1 produced a similar but distinct ratio of 11,12-EET to 14,15-EET (2.0) and did not produce any detectable 19-HETE. The 11,12-EET and 14,15-EET represented 63.0 and 31.1%, respectively, of the total metabolites formed. The 8,9- and 5,6-EETs were not detected with either enzyme. The ratio of the 11,12-EET to 14,15-EET was 1.5 with P450 2CAA, a P450 arachidonic acid epoxygenase (P450 2CAA) that had an amino-terminal sequence identical to that of P450 2C2 [J. Biol. Chem. 267:5552-5559 (1992)]. P450 2C1, 2C2, and 2CAA metabolized lauric acid. The ratio of omega-1- to omega-hydroxylated laurate was 3.6, 3.4, and 2.4 for P450 2CAA, P450 2C2, and P450 2C1, respectively. Purified P450 2CAA had a slightly greater apparent molecular weight than expressed P450 2C2 on sodium dodecyl sulfate-polyacrylamide gels. The results clearly establish that rabbit P450 2C1 and 2C2 are arachidonic acid epoxygenases, and they suggest that P450 2CAA and 2C2 are very similar but may not be identical isoforms.

The effects of the oral administration of fish oil concentrate on the release and the metabolism of [14C]arachidonic acid and [14C]eicosapentaenoic acid by human platelets

International Nuclear Information System (INIS)

Hirai, A.; Terano, T.; Hamazaki, T.

1982-01-01

It has been suggested by several investigators that eicosapentaenoic acid (C20:5 omega 3, EPA) might have anti-thrombotic effects. In this experiment, the effect of the oral administration of EPA rich fish oil concentrate on platelet aggregation and the release and the metabolism of [ 1 - 14 C]arachidonic acid and [(U)- 14 C]eicosapentaenoic acid by human platelets was studied. Eight healthy male subjects ingested 18 capsules of fish oil concentrate (EPA 1.4 g) per day for 4 weeks. Plasma and platelet concentrations of EPA markedly increased, while those of arachidonic acid (C20:4 omega 6, AA) and docosahexaenoic acid (C22:6 omega 3, DHA) did not change. Platelet aggregation induced by collagen and ADP was reduced. Collagen induced [ 14 C]thromboxane B2 (TXB2) formation from [ 14 C]AA prelabeled platelets decreased. There was no detectable formation of [ 14 C]TXB3 from [ 14 C]EPA prelabeled platelets, and the conversion of exogenous [ 14 C]EPA to [ 14 C]TXB3 was lower than that of [ 14 C]AA to [ 14 C]TXB2. The release of [ 14 C]AA from [ 14 C]AA prelabeled platelets by collagen was significantly decreased. These observations raise the possibility that the release of arachidonic acid from platelet lipids might be affected by the alteration of EPA content in platelets

Effect of amiloride on arachidonic acid and histamine release from rat mast cells

DEFF Research Database (Denmark)

Linnebjerg, H.; Hansen, Harald S.; Jensen, B.

1989-01-01

The effect of a putative Na/H exchange inhibition on histamine and [C]arachidonic acid ([C]AA) release has been examined in rat peritoneal mast cells, using either addition of amiloride or removal of extracellular Na. The cells were stimulated by non-immunological agents, i.e. calcium ionophore A......23187, nerve growth factor (NGF), thapsigargin and compound 48/80. On the basis of the results obtained, a possible role for Na/H exchange in rat mast cell secretion is discussed....

Involvement of arachidonate metabolism in neurotensin-induced prolactin release in vitro

International Nuclear Information System (INIS)

Canonico, P.L.; Speciale, C.; Sortino, M.A.; Scapagnini, U.

1985-01-01

Neurotensin increased in a concentration-dependent manner the level of hypophyseal [ 3 H]arachidonic acid in vitro as well as prolactin release from hemipituitary glands. The effect of 1 microM neurotensin on arachidonate release was already present at 2.5 min, maximal at 5, and disappeared after a 10-min incubation. Neurotensin analogues produced an enhancement of hypophyseal arachidonate similar to their relative potencies in other cellular systems, whereas other peptides (somatostatin and vasoactive intestinal peptide) were devoid of any effect on the concentration of the fatty acid in the pituitary. Seventy micromoles RHC 80267, a rather selective inhibitor of diacylglycerol lipase, completely prevented the neurotensin-stimulated prolactin release and decreased arachidonate release both in basal or in neurotensin-induced conditions. Similar results were obtained with 50 microM quinacrine, a phospholipase A2 inhibitor. To clarify whether arachidonate released by neurotensin requires a further metabolism through specific pathways to stimulate prolactin release, the authors used indomethacin and BW 755c, two blockers of cyclooxygenase and lipoxygenase pathways. Thirty micromoles indomethacin, a dose active to inhibit cyclooxygenase, did not affect unesterified arachidonate levels either in basal or in neurotensin-induced conditions; moreover, the drug did not modify basal prolactin release but slightly potentiated the stimulatory effect of neurotensin on the release of the hormone. On the other hand, 250 microM BW 755c, an inhibitor of both cyclooxygenase and lipoxygenase pathways, significantly inhibited both basal and neurotensin-stimulated prolactin release and further potentiated the increase of the fatty acid concentrations produced by 1 microM neurotensin

Effect of dietary arachidonic acid, eicosapentaenoic acid and docosahexaenoic acid on survival, growth and pigmentation in larvae of common sole ( Solea solea L.)

DEFF Research Database (Denmark)

Lund, Ivar; Steenfeldt, Svend Jørgen; Hansen, B.W.

2007-01-01

Evidence confirms that polyunsaturated fatty acids (PUFAs), arachidonic acid (ARA), eicosapentaenoic acid (EPA) and docosahexaenoic acid, DHA are involved in growth as well in pigmentation of marine fish larvae. In the present study we examined the performance of common sole larvae reared...... on Artemia enriched with 10 formulated emulsions, differing in inclusions of ARA, EPA, and DHA. The specific growth rate of the sole larvae until late metamorphosis, 21 days after hatching (dah) was 20 to 27% d(-1). Even though the relative tissue essential fatty acid (EFA) concentrations significantly...... reflected dietary composition, neither standard growth nor larval survival were significantly related to the absolute concentrations of ARA, EPA and DHA or their ratios. This suggests low requirements for essential polyunsaturated fatty acids (PUFAs) in common sole. Malpigmentation was significantly related...

Lung, aorta, and platelet metabolism of 14C-arachidonic acid in vitamin E deficient rats

International Nuclear Information System (INIS)

Valentovic, M.A.; Gairola, C.; Lubawy, W.C.

1982-01-01

14 C-arachidonic acid metabolism was determined in aortas, platelets, and perfused lungs from rats pair fed a basal diet supplemented with 0 or 100 ppm vitamin E for 11 weeks. Spontaneous erythrocyte hemolysis tests showed 92% and 8% hemolysis for the 0 and 100 ppm vitamin E groups, respectively. Elevated lung homogenate levels of malonaldehyde in the 0 ppm group confirmed its deficient vitamin E status. Aortas from the vitamin E deficient group synthesized 54% less prostacyclin than aortas from the supplemented group (p less than 0.05). Although thromboxane generation by platelets from the vitamin E deficient group exhibited a 37% increase, this difference was not statistically significant compared to the supplemented animals. Greater amounts of PGE2, PGF2 alpha, TXB2, and 6-keto-PGF1 alpha were obtained in albumin buffer perfusates from lungs of vitamin E deficient rats than in those from supplemented rats. Significant differences (p less than 0.05) were noticed, however, only for PGE2 and PGF2 alpha. These studies indicate that vitamin E quantitatively alters arachidonic acid metabolism in aortic and lung tissue but its effect on thromboxane synthesis by platelets is less marked

A new model to study the role of arachidonic acid in colon cancer pathophysiology

OpenAIRE

Fan, Yang-Yi; Callaway, Evelyn; Monk, Jennifer M.; Goldsby, Jennifer S.; Yang, Peiying; Vincent, Logan; Chapkin, Robert S.

2016-01-01

A significant increase in cyclooxygenase 2 (COX2) gene expression has been shown to promote cylcooxygenase-dependent colon cancer development. Controversy associated with the role of COX2 inhibitors indicates that additional work is needed to elucidate the effects of arachidonic acid (AA) derived (cyclooxygenase and lipoxygenase) eicosanoids in cancer initiation, progression and metastasis. We have recently developed a novel Fads1 knockout mouse model, which allows for the investigation of AA...

Arachidonic Acid-Induced Expression of the Organic Solute and Steroid Transporter-beta (Ost-beta) in a Cartilaginous Fish Cell Line

Science.gov (United States)

Hwang, Jae-Ho; Parton, Angela; Czechanski, Anne; Ballatori, Nazzareno; Barnes, David

2008-01-01

The organic solute and steroid transporter (OST/Ost) is a unique membrane transport protein heterodimer composed of subunits designated alpha and beta, that transports conjugated steroids and prostaglandin E2 across the plasma membrane. Ost was first identified in the liver of the cartilaginous fish Leucoraja erinacea, the little skate, and subsequently was found in many other species, including humans and rodents. The present study describes the isolation of a new cell line, LEE-1, derived from an early embryo of L. erinacea, and characterizes the expression of Ost in these cells. The mRNA size and amino acid sequence of Ost-beta in LEE-1 was identical to that previously reported for Ost-beta from skate liver, and the primary structure was identical to that of the spiny dogfish shark (Squalus acanthias) with the exception of a single amino acid. Ost-beta was found both on the plasma membrane and intracellularly in LEE-1 cells, consistent with its localization in other cell types. Interestingly, arachidonic acid, the precursor to eiconsanoids, strongly induced Ost-beta expression in LEE-1 cells and a lipid mixture containing arachidonic acid also induced Ost-alpha. Overall, the present study describes the isolation of a novel marine cell line, and shows that this cell line expresses relatively high levels of Ost when cultured in the presence of arachidonic acid. Although the function of this transport protein in embryo-derived cells is unknown, it may play a role in the disposition of eicosanoids or steroid-derived molecules. PMID:18407792

Roles of phospholipase A2 isoforms in swelling- and melittin-induced arachidonic acid release and taurine efflux in NIH3T3 fibroblasts

DEFF Research Database (Denmark)

Pedersen, Stine Helene Falsig; Poulsen, Kristian Arild; Lambert, Ian H.

2006-01-01

Osmotic swelling of NIH3T3 mouse fibroblasts activates a bromoenol lactone (BEL)-sensitive taurine efflux, pointing to the involvement of a Ca2+-independent phospholipase A2 (iPLA2) (Lambert IH. J Membr Biol 192: 19-32, 2003). We report that taurine efflux from NIH3T3 cells was not only increased...... by cell swelling but also decreased by cell shrinkage. Arachidonic acid release to the cell exterior was similarly decreased by shrinkage yet not detectably increased by swelling. NIH3T3 cells were found to express cytosolic calcium-dependent cPLA2-IVA, cPLA2-IVB, cPLA2-IVC, iPLA2-VIA, iPLA2-VIB......, and secretory sPLA2-V. Arachidonic acid release from swollen cells was partially inhibited by BEL and by the sPLA2-inhibitor manoalide. Cell swelling elicited BEL-sensitive arachidonic acid release from the nucleus, to which iPLA2-VIA localized. Exposure to the bee venom peptide melittin, to increase PLA2...

Arachidonic acid in health and disease with focus on hypertension and diabetes mellitus: A review

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Undurti N. Das

2018-05-01

Full Text Available Arachidonic acid (AA 20:4n-6 is an essential component of cell membranes and modulates cell membrane fluidity. AA is metabolized by cyclo-oxygenase (COX, lipoxygenase (LOX and cytochrome P450 enzymes to form several metabolites that have important biological actions. Of all the actions, role of AA in the regulation of blood pressure and its ability to prevent both type 1 and type 2 diabetes mellitus seems to be interesting. Studies showed that AA and its metabolites especially, lipoxin A4 (LXA4 and epoxyeicosatrienoic acids (EETs, potent anti-inflammatory metabolites, have a crucial role in the pathobiology of hypertension and diabetes mellitus. AA, LXA4 and EETs regulate smooth muscle function and proliferation, voltage gated ion channels, cell membrane fluidity, membrane receptors, G-coupled receptors, PPARs, free radical generation, nitric oxide formation, inflammation, and immune responses that, in turn, participate in the regulation blood pressure and pathogenesis of diabetes mellitus. In this review, role of AA and its metabolites LXA4 and EETs in the pathobiology of hypertension, pre-eclampsia and diabetes mellitus are discussed. Based on several lines of evidences, it is proposed that a combination of aspirin and AA could be of benefit in the prevention and management of hypertension, pre-eclampsia and diabetes mellitus. Keywords: Arachidonic acid, Lipoxin A4, Hypertension, Pre-eclampsia, Diabetes mellitus, Inflammation, Cytokines, Free radicals, Nitric oxide

Lowering dietary n-6 polyunsaturated fatty acids: interaction with brain arachidonic and docosahexaenoic acids.

Science.gov (United States)

Alashmali, Shoug M; Hopperton, Kathryn E; Bazinet, Richard P

2016-02-01

Arachidonic (ARA) and docosahexaenoic (DHA) acids are the most abundant polyunsaturated fatty acids (PUFA) in the brain, where they have many biological effects, including on inflammation, cell-signaling, appetite regulation, and blood flow. The Western diet contains a high ratio of n-6: n-3 PUFA. Although interest in lowering this ratio has largely focused on increasing intake of n-3 PUFA, few studies have examined lowering dietary n-6 PUFA. This review will evaluate the effect of lowering dietary n-6 PUFA on levels and metabolism of ARA and DHA in animal models and in humans, with a primary focus on the brain. In animal models, lowering dietary ARA or linoleic acid generally lowers levels of brain ARA and raises DHA. Lowering dietary n-6 PUFA can also modulate the levels of ARA and DHA metabolizing enzymes, as well as their associated bioactive mediators. Human studies examining changes in plasma fatty acid composition following n-6 PUFA lowering demonstrate no changes in levels of ARA and DHA, though there is evidence of alterations in their respective bioactive mediators. Lowering dietary n-6 PUFA, in animal models, can alter the levels and metabolism of ARA and DHA in the brain, but it remains to be determined whether these changes are clinically meaningful.

Metabolism and incorporation of orally administrated arachidonic acid in rats

International Nuclear Information System (INIS)

Magni, F.; Kikawa, Y.; Jedlinski, A.; Lands, W.E.M.

1986-01-01

50 mg 3 H 2 H-20: 4n-6 was administered by oral intubation to rats maintained on a normal diet. The distribution of radioactive arachidonate esterified in the various tissues was similar to that for EFA-deficient rats from their previous study. The amount incorporated in the tissues was 14% in normal rats and 16% in EFA-deficient rats. At 24 hrs, the relative radioactivity in PC was higher (and lower in PE) than after 20 days in the previous study. Urine had 3-4% of initial radioactivity in the first 12 hours and only 1% more by 24 hours. Urine components were analyzed as methyl ester-methoxime-t-butyldimethylsilyl ethers. Most of the arachidonate metabolites in urine reported in the literature have expected ECL values between 26 to 32, whereas they found 68% of radioactivity with ECL values below 26. This represents a substantial divergence from arachidonate metabolite patterns described for injected prostaglandins and indicates the need of examining the metabolites formed from endogenously formed eicosanoids

12(R)-hydroxyicosatetraenoic acid: a cytochrome P450-dependent arachidonate metabolite that inhibits Na/sup +/, K/sup +/-ATPase in the cornea

Energy Technology Data Exchange (ETDEWEB)

Schwartzman, M.L.; Balazy, M.; Masferrer, J.; Abraham, N.G.; McGiff, J.C.; Murphy, R.C.

1987-11-01

When corneal microsomes were incubated with arachidonic acid in the presence of an NADPH-generating system, four polar metabolites (compounds A-D) were formed. Synthesis of these metabolites could be inhibited by carbon monoxide, SKF 525A, and anti-cytochrome c reductase antibodies. One of the metabolites, compound C, was found to inhibit partially purified Na/sup +/, K/sup +/-ATPase from the corneal epithelium in a dose-dependent manner. After compound C was purified by TLC and HPLC, it was found to have a UV absorption spectrum with a maximum absorbance at 236 nm suggesting the presence of a conjugated diene. Mass spectrometric analysis using positive- and negative-ionization modes was carried out on derivatized compound C. Abundant fragment ions were consistent with compound C being a monooxygenated derivative of arachidonic acid with a hydroxyl substituent at carbon-12 of the icosanoid backbone; all deuterium atoms from (/sup 2/H/sub 8/)arachidonate were retained in the structure. Compound C was characterized as a 12-hydroxyicosatetraenoic acid. However, only 12(R) isomer was found to be an inhibitor of the Na/sup +/, K/sup +/-ATPase from the corneal epithelium, suggesting that the biologically active compound C was 12(R)-hydroxyy-5,8,10,14-icosatetraenoic acid. Such an inhibitor of Na/sup +/, K/sup +/-ATPase synthesized in the cornea may have an important role in regulating ocular transparency and aqueous human secretion.

Hypersensitivity to norepinephrine in vasa deferentia from diabetic rats. Possible participation of metabolic products of arachidonic acid

Energy Technology Data Exchange (ETDEWEB)

Peredo, H; Agostini, M D; Gimeno, M F; Borda, E S

1984-08-01

Contractile responses to norepinephrine of the vas deferens isolated from normal and diabetic rats as well as tissue radio-conversion of exogenous arachidonic acid, were studied. Vasa deferentia from rats with acute streptozotocin-induced diabetes showed hypersensitivity to exogenous norepinephrine (NE). This increased contractile response was associated with the interaction of the agonist with alpha adrenoceptors. Inhibitors of cyclooxygenase increased and inhibitors of lipoxygenase(s) abolished the enhanced response to NE of diabetic vas deferens. Vasa deferentia from both normal and diabetic rats, converted (1-/sup 14/C)-arachidonic acid (AA) into PGF, PGE, PGD and thromboxane (TX) B2, but the % of AA metabolites formed was significantly higher in the diabetic than in the normal condition. Moreover, the predominant prostanoid generated by tissue preparations from diabetic animals was PGD2. Taken together the present experimental findings indicate that preparations from rats with acute streptozotocin-induced diabetes have an augmented reactivity towards NE, which appeared associated with changes in metabolites of AA generated via cyclooxygenase and lipoxygenase catalized pathways.

Equine tracheal epithelial membrane strips - An alternate method for examining epithelial cell arachidonic acid metabolism

International Nuclear Information System (INIS)

Gray, P.R.; Derksen, F.J.; Robinson, N.E.; Peter-Golden, M.L.

1990-01-01

Arachidonic acid metabolism by tracheal epithelium can be studied using enzymatically dispersed cell suspensions or cell cultures. Both techniques require considerable tissue disruption and manipulation and may not accurately represent in vivo activity. The authors have developed an alternate method for obtaining strips of equine tracheal epithelium without enzymatic digestion. In the horse, a prominent elastic lamina supports the tracheal epithelium. By physical splitting this lamina, they obtained strips (≤12 x 1.5 cm) of pseudostratified columnar epithelium attached to a layer of elastic tissue 30-100 μm thick. Epithelial strips (1.2 x 0.5 cm) were attached to plexiglass rods and incubated with [ 3 H]arachidonic acid in M199 medium (0.5 μCi/ml) for 24 hours at 37C. The strips incorporated 36±4% (mean ± SEM) of the total radioactivity and released 8.0±1.2% of incorporated radioactivity when stimulated by 5.0 μM calcium ionophore A23187. The extracted supernatant was processed using HPLC, resulting in peaks of radioactivity that co-eluted with authentic PGE 2 , PGF 2 α, and 12-HETE standards. The greatest activity corresponded to the PGE 2 and PGF 2 α standards, which is a similar pattern to that reported for cultured human tracheal epithelium

Phospholipid sources for adrenic acid mobilization in RAW 264.7 macrophages. Comparison with arachidonic acid.

Science.gov (United States)

Guijas, Carlos; Astudillo, Alma M; Gil-de-Gómez, Luis; Rubio, Julio M; Balboa, María A; Balsinde, Jesús

2012-11-01

Cells metabolize arachidonic acid (AA) to adrenic acid (AdA) via 2-carbon elongation reactions. Like AA, AdA can be converted into multiple oxygenated metabolites, with important roles in various physiological and pathophysiological processes. However, in contrast to AA, there is virtually no information on how the cells regulate the availability of free AdA for conversion into bioactive products. We have used a comparative lipidomic approach with both gas chromatography and liquid chromatography coupled to mass spectrometry to characterize changes in the levels of AA- and AdA-containing phospholipid species in RAW 264.7 macrophage-like cells. Incubation of the cells with AA results in an extensive conversion to AdA but both fatty acids do not compete with each other for esterification into phospholipids. AdA but not AA, shows preference for incorporation into phospholipids containing stearic acid at the sn-1 position. After stimulation of the cells with zymosan, both AA and AdA are released in large quantities, albeit AA is released to a greater extent. Finally, a variety of phosphatidylcholine and phosphatidylinositol molecular species contribute to AA; however, AdA is liberated exclusively from phosphatidylcholine species. Collectively, these results identify significant differences in the cellular utilization of AA and AdA by the macrophages, suggesting non-redundant biological actions for these two fatty acids. Copyright © 2012 Elsevier B.V. All rights reserved.

Group I mGlu receptors potentiate synaptosomal [3H]glutamate release independently of exogenously applied arachidonic acid

International Nuclear Information System (INIS)

Reid, M.E.; Toms, N.J.; Bedingfield, J.S.; Roberts, P.J.

1999-01-01

In the current study, we have characterized group I metabotropic glutamate (mGlu) receptor enhancement of 4-aminopyridine (4AP)-evoked [ 3 H]glutamate release from rat cerebrocortical synaptosomes. The broad spectrum mGlu receptor agonist (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid ((1S,3R)-ACPD, 10 μM) increased 4AP-evoked [ 3 H]glutamate release (143.32±2.73% control) only in the presence of exogenously applied arachidonic acid; an effect reversed by the inclusion of bovine serum albumin (BSA, fatty acid free). In contrast, the selective group I mGlu receptor agonist (S)-3,5-dihydroxyphenylglycine (DHPG) potentiated (EC 50 =1.60±0.25 μM; E max =147.61±10.96% control) 4AP-evoked [ 3 H]glutamate release, in the absence of arachidonic acid. This potentiation could be abolished by either the selective mGlu 1 receptor antagonist (R,S)-1-aminoindan-1,5-dicarboxylic acid (AIDA, 1 mM) or the selective PKC inhibitor (Ro 31-8220, 10 μM) and was BSA-insensitive. The selective mGlu 5 receptor agonist (R,S)-2-chloro-5-hydroxyphenylglycine (CHPG, 300μM) was without effect. DHPG (100 μM) also potentiated both 30 mM and 50 mM K + -evoked [ 3 H]glutamate release (121.60±12.77% and 121.50±4.45% control, respectively). DHPG (100 μM) failed to influence both 4AP-stimulated 45 Ca 2+ influx and 50 mM K + -induced changes in synaptosomal membrane potential. Possible group I mGlu receptor suppression of tonic adenosine A 1 receptor, group II/III mGlu receptors or GABA B receptor activity is unlikely since 4AP-evoked [ 3 H]glutamate release was insensitive to the selective inhibitory receptor antagonists 8-cyclopentyl-1,3-dimethylxanthine, (R,S)-α-cyclopropyl-4-phosphonophenylglycine or CGP55845A, respectively. These data suggest an 'mGlu 1 receptor-like' receptor potentiates [ 3 H]glutamate release from cerebrocortical synaptosomes in the absence of exogenously applied arachidonic acid. This PKC dependent effect is unlikely to be via modulation of synaptosomal membrane

cPLA2a-evoked formation of arachidonic acid and lysophospholipids is required for exocytosis in mouse pancreatic ß-cells

DEFF Research Database (Denmark)

Juhl, Kirstine; Høy, Marianne; Olsen, Hervør L.

2003-01-01

Using capacitance measurements, we investigated the effects of intracellularly applied recombinant human cytosolic phospholipase A2 (cPLA2 ) and its lipolytic products arachidonic acid and lysophosphatidylcholine on Ca2+-dependent exocytosis in single mouse pancreatic -cells. cPLA2 dose dependently......–80 to 280–300. cPLA2 -stimulated exocytosis was antagonized by the specific cPLA2 inhibitor AACOCF3. Ca2+-evoked exocytosis was reduced by 40% in cells treated with AACOCF3 or an antisense oligonucleotide against cPLA2 . The action of cPLA2 was mimicked by a combination of arachidonic acid...... and lysophosphatidylcholine (470% stimulation) in which each compound alone doubled the exocytotic response. Priming of insulin-containing secretory granules has been reported to involve Cl- uptake through ClC-3 Cl- channels. Accordingly, the stimulatory action of cPLA2 was inhibited by the Cl- channel inhibitor DIDS...

cPLA2alpha-evoked formation of arachidonic acid and lysophospholipids is required for exocytosis in mouse pancreatic beta-cells

DEFF Research Database (Denmark)

Juhl, Kirstine; Høy, Marianne; Olsen, Hervør L

2003-01-01

Using capacitance measurements, we investigated the effects of intracellularly applied recombinant human cytosolic phospholipase A2 (cPLA2alpha) and its lipolytic products arachidonic acid and lysophosphatidylcholine on Ca2+-dependent exocytosis in single mouse pancreatic beta-cells. cPLA2alpha...... from 70-80 to 280-300. cPLA2alpha-stimulated exocytosis was antagonized by the specific cPLA2 inhibitor AACOCF3. Ca2+-evoked exocytosis was reduced by 40% in cells treated with AACOCF3 or an antisense oligonucleotide against cPLA2alpha. The action of cPLA2alpha was mimicked by a combination...... of arachidonic acid and lysophosphatidylcholine (470% stimulation) in which each compound alone doubled the exocytotic response. Priming of insulin-containing secretory granules has been reported to involve Cl- uptake through ClC-3 Cl- channels. Accordingly, the stimulatory action of cPLA2alpha was inhibited...

2-hydroxy arachidonic acid: a new non-steroidal anti-inflammatory drug.

Directory of Open Access Journals (Sweden)

Daniel H Lopez

Full Text Available BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs are a family of COX1 and COX2 inhibitors used to reduce the synthesis of pro-inflammatory mediators. In addition, inflammation often leads to a harmful generation of nitric oxide. Efforts are being done in discovering safer NSAIDs molecules capable of inhibiting the synthesis of pro-inflammatory lipid mediators and nitric oxide to reduce the side effects associated with long term therapies. METHODOLOGY/PRINCIPAL FINDINGS: The analogue of arachidonic acid (AA, 2-hydroxy-arachidonic acid (2OAA, was designed to inhibit the activities of COX1 and COX2 and it was predicted to have similar binding energies as AA for the catalytic sites of COX1 and COX2. The interaction of AA and 2OAA with COX1 and COX2 was investigated calculating the free energy of binding and the Fukui function. Toxicity was determined in mouse microglial BV-2 cells. COX1 and COX2 (PGH2 production activities were measured in vitro. COX1 and COX2 expression in human macrophage-like U937 cells were carried out by Western blot, immunocytochemistry and RT-PCR analysis. NO production (Griess method and iNOS (Western blot were determined in mouse microglial BV-2 cells. The comparative efficacy of 2OAA, ibuprofen and cortisone in lowering TNF-α serum levels was determined in C57BL6/J mice challenged with LPS. We show that the presence of the -OH group reduces the likelihood of 2OAA being subjected to H* abstraction in COX, without altering significantly the free energy of binding. The 2OAA inhibited COX1 and COX2 activities and the expression of COX2 in human U937 derived macrophages challenged with LPS. In addition, 2OAA inhibited iNOS expression and the production of NO in BV-2 microglial cells. Finally, oral administration of 2OAA decreased the plasma TNF-α levels in vivo. CONCLUSION/SIGNIFICANCE: These findings demonstrate the potential of 2OAA as a NSAID.

Application of a ω-3 Desaturase with an Arachidonic Acid Preference to Eicosapentaenoic Acid Production in Mortierella alpina

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Chengfeng Ge

2018-01-01

Full Text Available In the industrial oleaginous fungus Mortierella alpina, the arachidonic acid (AA; C20:4; ω-6 fraction can reach 50% of the total fatty acids (TFAs in vivo. However, the eicosapentaenoic acid (EPA; C20:5; ω-3 fraction is less than 3% when this fungus is cultivated at a low temperature (12°C. Omega-3 fatty acid desaturase is a key enzyme in ω-3 long-chain polyunsaturated fatty acids biosynthesis pathways. To enhance EPA production, we transformed the ω-3 fatty acid desaturase (PaD17, which exhibits strong Δ-17 desaturase activity, into M. alpina, thus increasing the AA to EPA conversion rate to 49.8%. This PaD17-harboring M. alpina reconstruction strain produced 617 mg L−1 of EPA at room temperature in broth medium, this yield was increased to 1.73 g L−1 after culture medium optimization (i.e., about threefold higher than that under original culture conditions, with concomitant respective increases in dry cell weight and TFA content to 16.55 and 6.46 g L−1. These findings suggest a new platform for the future industrial production of EPA.

Use of reversed-phase gel partition chromatography for the purification of chemically synthesized (5,6,8,9,11,12,14,15(n)) octadeuterium- and octatritium-labelled arachidonic acid

Energy Technology Data Exchange (ETDEWEB)

Wollard, P M; Lascelles, P T [Department of Chemical Pathology, Institute of Neurology, London, Great Britain; Hensby, C N [Hammersmith Hospital, London (UK). Postgraduate Medical School

1978-12-11

The development of a method is described for the preparation and purification of (5,6,8,9,11,12,14,15(n)-/sup 2/H)arachidonic acid (/sup 2/H/sub 8/-AA). The /sup 2/H/sub 8/-AA was chemically synthesised by the selective reduction of 5,8,11,14-eiconsatetraynoic acid (ETYA) with deuterium gas. Using reversed-phase partition chromatography on a Lipidex 5000 column support, it was shown that: (1) The reaction products could readily be separated from each other to yield /sup 2/H/sub 8/-AA of greater than 98% mass purity by gas chromatography. (2) Closely related C20 cis-ethylenic fatty acids differing only in the degree of unsaturation are efficiently separated. The resolution increases exponentially on saturation of double bonds. (3) Commercially available (5,6,8,9,11,12,14,15(n))octatritium-labelled arachidonic acid (/sup 3/H/sub 8/-AA) was readily purified. Both (/sup 3/H/sub 8/)- and (1-/sup 14/C)arachidonic acid (/sup 14/C-AA) co-chromatographed with /sup 2/H/sub 8/-AA. (4) The mass spectra of the methyl ester and trimethylsilyl ester of the purified /sup 2/H/sub 8/-AA showed molecular ions at m/e 326 and 384, respectively.

Ethanolic extract of Piper betle Linn. leaves reduces nociception via modulation of arachidonic acid pathway.

Science.gov (United States)

De, Soumita; Maroo, Niteeka; Saha, Piu; Hazra, Samik; Chatterjee, Mitali

2013-01-01

The objective of this study was to evaluate the peripheral analgesic effect of Piper betle leaf extract (PBE) along with establishing its putative mechanism of action. Male Swiss albino mice after pre-treatment (1 h) with different doses of PBE were injected 0.8% (v/v) acetic acid i.p.; the onset and number of writhes were noted up to 15 min. To evaluate the mechanism of action, the murine peritoneal exudate was incubated with PBE for 1 h, followed by exposure to arachidonic acid (AA) and generation of reactive oxygen species (ROS) was measured by flow cytometry using 2',7'-dichlorodihydrofluorescein diacetate. PBE in a dose dependent manner significantly reduced acetic acid induced writhing response in mice (P < 0.001). In peritoneal exudates, PBE significantly inhibited AA induced generation of ROS, P < 0.01. The present study indicates that PBE has promising analgesic activity, worthy of future pharmacological consideration.

Supplementation of DHA but not DHA with arachidonic acid during pregnancy and lactation influences general movement quality in 12-week-old term infants

NARCIS (Netherlands)

van Goor, Saskia A.; Dijck-Brouwer, D. A. Janneke; Doornbos, Bennard; Erwich, Jan Jaap H. M.; Schaafsma, Anne; Muskiet, Frits A. J.; Hadders-Algra, Mijna

2010-01-01

DHA and arachidonic acid (AA) are important for neurodevelopment. A traditional neonatal neurological examination and the evaluation of general movement quality are sensitive techniques for assessing neurodevelopment in young infants. Mildly abnormal general movement,,; at 3 months have been

Group I mGlu receptors potentiate synaptosomal [{sup 3}H]glutamate release independently of exogenously applied arachidonic acid

Energy Technology Data Exchange (ETDEWEB)

Reid, M.E.; Toms, N.J.; Bedingfield, J.S.; Roberts, P.J. [Department of Pharmacology, School of Medical Sciences, University of Bristol, University Walk, Bristol, BS8 1TD (United Kingdom)

1999-04-01

In the current study, we have characterized group I metabotropic glutamate (mGlu) receptor enhancement of 4-aminopyridine (4AP)-evoked [{sup 3}H]glutamate release from rat cerebrocortical synaptosomes. The broad spectrum mGlu receptor agonist (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid ((1S,3R)-ACPD, 10 {mu}M) increased 4AP-evoked [{sup 3}H]glutamate release (143.32{+-}2.73% control) only in the presence of exogenously applied arachidonic acid; an effect reversed by the inclusion of bovine serum albumin (BSA, fatty acid free). In contrast, the selective group I mGlu receptor agonist (S)-3,5-dihydroxyphenylglycine (DHPG) potentiated (EC{sub 50}=1.60{+-}0.25 {mu}M; E{sub max}=147.61{+-}10.96% control) 4AP-evoked [{sup 3}H]glutamate release, in the absence of arachidonic acid. This potentiation could be abolished by either the selective mGlu{sub 1} receptor antagonist (R,S)-1-aminoindan-1,5-dicarboxylic acid (AIDA, 1 mM) or the selective PKC inhibitor (Ro 31-8220, 10 {mu}M) and was BSA-insensitive. The selective mGlu{sub 5} receptor agonist (R,S)-2-chloro-5-hydroxyphenylglycine (CHPG, 300{mu}M) was without effect. DHPG (100 {mu}M) also potentiated both 30 mM and 50 mM K{sup +}-evoked [{sup 3}H]glutamate release (121.60{+-}12.77% and 121.50{+-}4.45% control, respectively). DHPG (100 {mu}M) failed to influence both 4AP-stimulated {sup 45}Ca{sup 2+} influx and 50 mM K{sup +}-induced changes in synaptosomal membrane potential. Possible group I mGlu receptor suppression of tonic adenosine A{sub 1} receptor, group II/III mGlu receptors or GABA{sub B} receptor activity is unlikely since 4AP-evoked [{sup 3}H]glutamate release was insensitive to the selective inhibitory receptor antagonists 8-cyclopentyl-1,3-dimethylxanthine, (R,S)-{alpha}-cyclopropyl-4-phosphonophenylglycine or CGP55845A, respectively. These data suggest an 'mGlu{sub 1} receptor-like' receptor potentiates [{sup 3}H]glutamate release from cerebrocortical synaptosomes in the absence of

Improved mitochondrial function with diet-induced increase in either docosahexaenoic acid or arachidonic acid in membrane phospholipids.

Directory of Open Access Journals (Sweden)

Ramzi J Khairallah

Full Text Available Mitochondria can depolarize and trigger cell death through the opening of the mitochondrial permeability transition pore (MPTP. We recently showed that an increase in the long chain n3 polyunsaturated fatty acids (PUFA docosahexaenoic acid (DHA; 22:6n3 and depletion of the n6 PUFA arachidonic acid (ARA; 20:4n6 in mitochondrial membranes is associated with a greater Ca(2+ load required to induce MPTP opening. Here we manipulated mitochondrial phospholipid composition by supplementing the diet with DHA, ARA or combined DHA+ARA in rats for 10 weeks. There were no effects on cardiac function, or respiration of isolated mitochondria. Analysis of mitochondrial phospholipids showed DHA supplementation increased DHA and displaced ARA in mitochondrial membranes, while supplementation with ARA or DHA+ARA increased ARA and depleted linoleic acid (18:2n6. Phospholipid analysis revealed a similar pattern, particularly in cardiolipin. Tetralinoleoyl cardiolipin was depleted by 80% with ARA or DHA+ARA supplementation, with linoleic acid side chains replaced by ARA. Both the DHA and ARA groups had delayed Ca(2+-induced MPTP opening, but the DHA+ARA group was similar to the control diet. In conclusion, alterations in mitochondria membrane phospholipid fatty acid composition caused by dietary DHA or ARA was associated with a greater cumulative Ca(2+ load required to induced MPTP opening. Further, high levels of tetralinoleoyl cardiolipin were not essential for normal mitochondrial function if replaced with very-long chain n3 or n6 PUFAs.

Docosahexaenoic acid (DHA) and arachidonic acid (ARA) balance in developmental outcomes.

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Colombo, John; Jill Shaddy, D; Kerling, Elizabeth H; Gustafson, Kathleen M; Carlson, Susan E

2017-06-01

The DHA Intake and Measurement of Neural Development (DIAMOND) trial represents one of only a few studies of the long-term dose-response effects of LCPUFA-supplemented formula feeding during infancy. The trial contrasted the effects of four formulations: 0.00% docosahexaenoic acid (DHA)/0.00% arachidonic acid (ARA), 0.32% DHA/0.64% ARA, 0.64% DHA/0.64% ARA, and 0.96% DHA/0.64% ARA against a control condition (0.00% DHA/0.00% ARA). The results of this trial have been published elsewhere, and show improved cognitive outcomes for infants fed supplemented formulas, but a common finding among many of the outcomes show a reduction of benefit for the highest DHA dose (i.e., 0.96%DHA/0.64% ARA, that is, a DHA: ARA ratio 1.5:1.0). The current paper gathers and summarizes the evidence for the reduction of benefit at this dose, and in an attempt to account for this reduced benefit, presents for the first time data from infants' red blood cell (RBC) assays taken at 4 and 12 months of age. Those assays indicate that blood DHA levels generally rose with increased DHA supplementation, although those levels tended to plateau as the DHA-supplemented level exceeded 0.64%. Perhaps more importantly, ARA levels showed a strong inverted-U function in response to increased DHA supplementation; indeed, infants assigned to the formula with the highest dose of DHA (and highest DHA/ARA ratio) showed a reduction in blood ARA relative to more intermediate DHA doses. This finding raises the possibility that reduced ARA may be responsible for the reduction in benefit on cognitive outcomes seen at this dose. The findings implicate the DHA/ARA balance as an important variable in the contribution of LCPUFAs to cognitive and behavioral development in infancy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Modulation of hypericin photodynamic therapy by pretreatment with 12 various inhibitors of arachidonic acid metabolism in colon adenocarcinoma HT-29 cells

Czech Academy of Sciences Publication Activity Database

Kleban, J.; Mikeš, J.; Szilárdiová, B.; Koval, J.; Sačková, V.; Solár, P.; Horváth, Viktor; Hofmanová, Jiřina; Kozubík, Alois; Fedoročko, P.

2007-01-01

Roč. 83, č. 5 (2007), s. 1174-1185 ISSN 0031-8655 R&D Projects: GA AV ČR(CZ) 1QS500040507 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : hypericin * photodynamic therapy * arachidonic acid inhibitors Subject RIV: BO - Biophysics Impact factor: 2.172, year: 2007

Blood fatty acid composition of pregnant and nonpregnant Korean women: red cells may act as a reservoir of arachidonic acid and docosahexaenoic acid for utilization by the developing fetus.

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Ghebremeskel, K; Min, Y; Crawford, M A; Nam, J H; Kim, A; Koo, J N; Suzuki, H

2000-05-01

Relative fatty acid composition of plasma and red blood cell (RBC) choline phosphoglycerides (CPG), and RBC ethanolamine phosphoglycerides (EPG) of pregnant (n = 40) and nonpregnant, nonlactating (n = 40), healthy Korean women was compared. The two groups were of the same ethnic origin and comparable in age and parity. Levels of arachidonic (AA) and docosahexaenoic (DHA) acids were lower (P mothers were mobilizing membrane AA and DHA to meet the high fetal requirement for these nutrients. It may also suggest that RBC play a role as a potential store of AA and DHA and as a vehicle for the transport of these fatty acids from maternal circulation to the placenta to be utilized by the developing fetus.

The effect of the antipsoriatic drug metabolite etretin (Ro 10-1670) on UVB irradiation induced changes in the metabolism of arachidonic acid in human keratinocytes in culture

International Nuclear Information System (INIS)

Punnonen, Kari; Jansen, C.T.; Puustinen, Tapio

1986-01-01

[ 14 C]Arachidonic acid was avidly incorporated into human keratinocytes in culture and following exposure to UVB irradiation of 9 mJ/cm 2 (erythemally effective, EE) substantial amounts of 14 C-radiolabel were released from the cells. The release of radiolabel was accompanied by a decrease in the labelling of phosphatidylethanolamine whereas the labelling of triacylglycerols and cholesteryl esters was increased. Keratinocytes produced significant amounts of prostaglandin E 2 (PGE 2 ) and following UVB irradiation of 9 mJ/cm 2 (EE) the formation of prostaglandin E 2 was increased. Etretin (Ro 10-1670), the active metabolite of the antipsoriatic drug etretinate (Ro 10-9359), affected significantly neither the total release of radiolabel induced by UVB nor the formation of prostaglandin E 2 . However, in the presence of etretin the UVB irradiation induced transfer of [ 14 C]arachidonic acid into triacylglycerols and cholesteryl esters was not increased as much as in the corresponding experiments without etretin. On the basis of the present study it appears that etretin dose not interfere with the release of arachidonic acid in amounts which could be related to the therapeutic effects of the combination of retinoids with UVB irradiation (Re-UVB) in the treatment of psoriasis. (author)

Targeting arachidonic acid pathway by natural products for cancer prevention and therapy.

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Yarla, Nagendra Sastry; Bishayee, Anupam; Sethi, Gautam; Reddanna, Pallu; Kalle, Arunasree M; Dhananjaya, Bhadrapura Lakkappa; Dowluru, Kaladhar S V G K; Chintala, Ramakrishna; Duddukuri, Govinda Rao

2016-10-01

Arachidonic acid (AA) pathway, a metabolic process, plays a key role in carcinogenesis. Hence, AA pathway metabolic enzymes phospholipase A 2 s (PLA 2 s), cyclooxygenases (COXs) and lipoxygenases (LOXs) and their metabolic products, such as prostaglandins and leukotrienes, have been considered novel preventive and therapeutic targets in cancer. Bioactive natural products are a good source for development of novel cancer preventive and therapeutic drugs, which have been widely used in clinical practice due to their safety profiles. AA pathway inhibitory natural products have been developed as chemopreventive and therapeutic agents against several cancers. Curcumin, resveratrol, apigenin, anthocyans, berberine, ellagic acid, eugenol, fisetin, ursolic acid, [6]-gingerol, guggulsteone, lycopene and genistein are well known cancer chemopreventive agents which act by targeting multiple pathways, including COX-2. Nordihydroguaiaretic acid and baicalein can be chemopreventive molecules against various cancers by inhibiting LOXs. Several PLA 2 s inhibitory natural products have been identified with chemopreventive and therapeutic potentials against various cancers. In this review, we critically discuss the possible utility of natural products as preventive and therapeutic agents against various oncologic diseases, including prostate, pancreatic, lung, skin, gastric, oral, blood, head and neck, colorectal, liver, cervical and breast cancers, by targeting AA pathway. Further, the current status of clinical studies evaluating AA pathway inhibitory natural products in cancer is reviewed. In addition, various emerging issues, including bioavailability, toxicity and explorability of combination therapy, for the development of AA pathway inhibitory natural products as chemopreventive and therapeutic agents against human malignancy are also discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Arachidonic acid metabolites and endothelial dysfunction of portal hypertension.

Science.gov (United States)

Sacerdoti, David; Pesce, Paola; Di Pascoli, Marco; Brocco, Silvia; Cecchetto, Lara; Bolognesi, Massimo

2015-07-01

Increased resistance to portal flow and increased portal inflow due to mesenteric vasodilatation represent the main factors causing portal hypertension in cirrhosis. Endothelial cell dysfunction, defined as an imbalance between the synthesis, release, and effect of endothelial mediators of vascular tone, inflammation, thrombosis, and angiogenesis, plays a major role in the increase of resistance in portal circulation, in the decrease in the mesenteric one, in the development of collateral circulation. Reduced response to vasodilators in liver sinusoids and increased response in the mesenteric arterioles, and, viceversa, increased response to vasoconstrictors in the portal-sinusoidal circulation and decreased response in the mesenteric arterioles are also relevant to the pathophysiology of portal hypertension. Arachidonic acid (AA) metabolites through the three pathways, cyclooxygenase (COX), lipoxygenase, and cytochrome P450 monooxygenase and epoxygenase, are involved in endothelial dysfunction of portal hypertension. Increased thromboxane-A2 production by liver sinusoidal endothelial cells (LSECs) via increased COX-1 activity/expression, increased leukotriens, increased epoxyeicosatrienoic acids (EETs) (dilators of the peripheral arterial circulation, but vasoconstrictors of the portal-sinusoidal circulation), represent a major component in the increased portal resistance, in the decreased portal response to vasodilators and in the hyper-response to vasoconstrictors. Increased prostacyclin (PGI2) via COX-1 and COX-2 overexpression, and increased EETs/heme-oxygenase-1/K channels/gap junctions (endothelial derived hyperpolarizing factor system) play a major role in mesenteric vasodilatation, hyporeactivity to vasoconstrictors, and hyper-response to vasodilators. EETs, mediators of liver regeneration after hepatectomy and of angiogenesis, may play a role in the development of regenerative nodules and collateral circulation, through stimulation of vascular endothelial

Early docosahexaenoic and arachidonic acid supplementation in extremely-low-birth-weight infants.

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Robinson, Daniel T; Caplan, Michael; Carlson, Susan E; Yoder, Rachel; Murthy, Karna; Frost, Brandy

2016-10-01

Extremely-low-birth-weight (ELBW) infants accrue large deficits in docosahexaenoic acid (DHA) and arachidonic acid (ARA) and require improved supplementation strategies. We hypothesized that once daily DHA+ARA drops applied to buccal mucosa will increase blood levels. Thirty ELBW infants were randomized to receive DHA 20 mg/kg/d + ARA 40 or 60 mg/kg/d + ARA 120 mg/kg/d or placebo within 72 h of age for 8 wk duration. Red blood cell phospholipid levels of DHA (primary) and ARA (secondary) were measured at 2 and 8 wk of age. Twenty-eight survivors with a median birth weight of 806 g completed dosing and sampling. Red blood cell levels were similar between the three groups at 2 wk (DHA: 4.62 wt% (interquartile range (IQR) 4.1-5.5) for all, P = 0.29 between groups; ARA: 21.1 wt% (IQR 18.78-22.6) for all, P = 0.41 between groups) and 8 wk (DHA: 6.0 wt% (IQR 5.1-7.1) for all, P = 0.57 between groups; ARA: 20.1 wt% (IQR 18.3-23.1) for all, P = 0.63 between groups). DHA in all infants showed a median increase of 31% from 2 to 8 wk (P 0.6). Daily buccal DHA and ARA supplements did not affect fatty acid levels in ELBW infants.

IMAGING BRAIN SIGNAL TRANSDUCTION AND METABOLISM VIA ARACHIDONIC AND DOCOSAHEXAENOIC ACID IN ANIMALS AND HUMANS

Science.gov (United States)

Basselin, Mireille; Ramadan, Epolia; Rapoport, Stanley I.

2012-01-01

The polyunsaturated fatty acids (PUFAs), arachidonic acid (AA, 20:4n-6) and docosahexaenoic acid (DHA, 22:6n-3), important second messengers in brain, are released from membrane phospholipid following receptor-mediated activation of specific phospholipase A2 (PLA2) enzymes. We developed an in vivo method in rodents using quantitative autoradiography to image PUFA incorporation into brain from plasma, and showed that their incorporation rates equal their rates of metabolic consumption by brain. Thus, quantitative imaging of unesterified plasma AA or DHA incorporation into brain can be used as a biomarker of brain PUFA metabolism and neurotransmission. We have employed our method to image and quantify effects of mood stabilizers on brain AA/DHA incorporation during neurotransmission by muscarinic M1,3,5, serotonergic 5-HT2A/2C, dopaminergic D2-like (D2, D3, D4) or glutamatergic N-methyl-D-aspartic acid (NMDA) receptors, and effects of inhibition of acetylcholinesterase, of selective serotonin and dopamine reuptake transporter inhibitors, of neuroinflammation (HIV-1 and lipopolysaccharide) and excitotoxicity, and in genetically modified rodents. The method has been extended for the use with positron emission tomography (PET), and can be employed to determine how human brain AA/DHA signaling and consumption are influenced by diet, aging, disease and genetics. PMID:22178644

Vascular permeabilization by intravenous arachidonate in the rat peritoneal cavity: antagonism by ethamsylate.

Science.gov (United States)

Hannaert, Patrick; Alvarez-Guerra, Miriam; Hider, Hamida; Chiavaroli, Carlo; Garay, Ricardo P

2003-04-11

The hemostatic agent, ethamsylate, inhibits arachidonic acid metabolism by a mechanism independent of cyclooxygenase activity and blocks carrageenan-induced rat paw edema. Here, ethamsylate was investigated for (i) in vivo actions on the free radical-dependent, permeabilizing responses to arachidonic acid and (ii) its antioxidant potential in vitro. Vascular permeability was equated to the extravasation rate of Evans blue from plasma into the rat peritoneal cavity. Antioxidant potential was investigated by classical in vitro tests for superoxide radicals, hydroxyl radicals (OH(.)), and nitric oxide. Intravenous ethamsylate induced a very important and significant reduction of permeability responses to arachidonate, both when given preventively and cumulatively. Thus, (i) ethamsylate significantly reversed arachidonate-induced permeabilization, even at the lowest dose tested (44+/-5% at 10 mg/kg) and (ii) a maximal reversal (about 70%) was reached between 50 and 200 mg/kg ethamsylate. In contrast, ethamsylate (100 mg/kg) was unable to antagonize the vascular permeabilization induced by serotonin (5-HT). In antioxidant assays, ethamsylate showed scavenging properties against hydroxyl radicals generated by the Fenton reaction (H(2)O(2)/Fe(2+)) even at 0.1 microM (-20+/-3%). OH(.) scavenging by ethamsylate reached 42+/-8% at 10 microM and 57+/-7% at 1 mM and was comparable to that of reference compounds (vitamin E, troxerutin, and mannitol). Conversely, ethamsylate was a poor scavenger of superoxide and nitric oxide radicals. In conclusion, intravenous ethamsylate potently antagonized the peritoneal vascular permeabilization induced by arachidonate, an action likely due to its antioxidant properties, particularly against hydroxyl radical. Such a mechanism can explain previous observations that ethamsylate inhibits carrageenan-induced rat paw edema. Whether it also participates in the hemostatic action of ethamsylate deserves further investigation.

Hepatic arachidonic acid metabolism is disrupted after hexachlorobenzene treatment

International Nuclear Information System (INIS)

Billi de Catabbi, Silvia C.; Faletti, Alicia; Fuentes, Federico; San Martin de Viale, Leonor C.; Cochon, Adriana C.

2005-01-01

Hexaclorobenzene (HCB), one of the most persistent environmental pollutants, can cause a wide range of toxic effects including cancer in animals, and hepatotoxicity and porphyria both in humans and animals. In the present study, liver microsomal cytochrome P450 (CYP)-dependent arachidonic acid (AA) metabolism, hepatic PGE production, and cytosolic phospholipase A 2 (cPLA 2 ) activity were investigated in an experimental model of porphyria cutanea tarda induced by HCB. Female Wistar rats were treated with a single daily dose of HCB (100 mg kg -1 body weight) for 5 days and were sacrificed 3, 10, 17, and 52 days after the last dose. HCB treatment induced the accumulation of hepatic porhyrins from day 17 and increased the activities of liver ethoxyresorufin O-deethylase (EROD), methoxyresorufin O-demethylase (MROD), and aminopyrine N-demethylase (APND) from day 3 after the last dose. Liver microsomes from control and HCB-treated rats generated, in the presence of NADPH, hydroxyeicosatetraenoic acids (HETEs), epoxyeicosatrienoic acids (EETs), 11,12-Di HETE, and ω-OH/ω-1-OH AA. HCB treatment caused an increase in total NADPH CYP-dependent AA metabolism, with a higher response at 3 days after the last HCB dose than at the other time points studied. In addition, HCB treatment markedly enhanced PGE production and release in liver slices. This HCB effect was time dependent and reached its highest level after 10 days. At this time cPLA 2 activity was shown to be increased. Unexpectedly, HCB produced a significant decrease in cPLA 2 activity on the 17th and 52nd day. Our results demonstrated for the first time that HCB induces both the cyclooxygenase and CYP-dependent AA metabolism. The effects of HCB on AA metabolism were previous to the onset of a marked porphyria and might contribute to different aspects of HCB-induced liver toxicity such as alterations of membrane fluidity and membrane-bound protein function. Observations also suggested that a possible role of cPLA 2 in

Aryl hydrocarbon receptor–ligand axis mediates pulmonary fibroblast migration and differentiation through increased arachidonic acid metabolism

International Nuclear Information System (INIS)

Su, Hsiang-Han; Lin, Hsin-Ting; Suen, Jau-Ling; Sheu, Chau Chyun; Yokoyama, Kazunari K.; Huang, Shau-Ku; Cheng, Chih Mei

2016-01-01

Pulmonary fibroblast migration and differentiation are critical events in fibrogenesis; meanwhile, fibrosis characterizes the pathology of many respiratory diseases. The role of aryl hydrocarbon receptor (AhR), a unique cellular chemical sensor, has been suggested in tissue fibrosis, but the mechanisms through which the AhR-ligand axis influences the fibrotic process remain undefined. In this study, the potential impact of the AhR-ligand axis on pulmonary fibroblast migration and differentiation was analyzed using human primary lung fibroblasts HFL-1 and CCL-202 cells. Boyden chamber-based cell migration assay showed that activated AhR in HFL-1cells significantly enhanced cell migration in response to 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD), and a known AhR antagonist, CH223191, inhibited its migratory activity. Furthermore, the calcium mobilization and subsequent upregulated expression of arachidonic acid metabolizing enzymes, including cyclooxygenase2 (COX-2) and 5-lipoxygenase (5-LOX), were observed in TCDD-treated HFL-1 cells, concomitant with elevated levels of prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) secretion. Also, significantly increased expression of α-smooth muscle actin α-SMA), a fibroblast differentiation marker, was also noted in TCDD-treated HFL-1 cells (p < 0.05), resulting in a dynamic change in cytoskeleton protein levels and an increase in the nuclear translocation of the myocardin-related transcription factor. Moreover, the enhanced levels of α-SMA expression and fibroblast migration induced by TCDD, PGE2 and LTB4 were abrogated by selective inhibitors for COX-2 and 5-LOX. Knockdown of AhR by siRNA Completely diminished intracellular calcium uptake and reduced α-SMA protein verified by promoter-reporter assays and chromatin immunoprecipitation. Taken together, our results suggested the importance of the AhR-ligand axis in fibroblast migration and differentiation through its capacity in enhancing arachidonic acid metabolism.

Enhancement of arachidonic acid signaling pathway by nicotinic acid receptor HM74A

International Nuclear Information System (INIS)

Tang, Yuting; Zhou, Lubing; Gunnet, Joseph W.; Wines, Pamela G.; Cryan, Ellen V.; Demarest, Keith T.

2006-01-01

HM74A is a G protein-coupled receptor for nicotinic acid (niacin), which has been used clinically to treat dyslipidemia for decades. The molecular mechanisms whereby niacin exerts its pleiotropic effects on lipid metabolism remain largely unknown. In addition, the most common side effect in niacin therapy is skin flushing that is caused by prostaglandin release, suggesting that the phospholipase A 2 (PLA 2 )/arachidonic acid (AA) pathway is involved. Various eicosanoids have been shown to activate peroxisome-proliferator activated receptors (PPAR) that play a diverse array of roles in lipid metabolism. To further elucidate the potential roles of HM74A in mediating the therapeutic effects and/or side effects of niacin, we sought to explore the signaling events upon HM74A activation. Here we demonstrated that HM74A synergistically enhanced UTP- and bradykinin-mediated AA release in a pertussis toxin-sensitive manner in A431 cells. Activation of HM74A also led to Ca 2+ -mobilization and enhanced bradykinin-promoted Ca 2+ -mobilization through Gi protein. While HM74A increased ERK1/2 activation by the bradykinin receptor, it had no effects on UTP-promoted ERK1/2 activation.Furthermore, UTP- and bradykinin-mediated AA release was significantly decreased in the presence of both MAPK kinase inhibitor PD 098059 and PKC inhibitor GF 109203X. However, the synergistic effects of HM74A were not dramatically affected by co-treatment with both inhibitors, indicating the cross-talk occurred at the receptor level. Finally, stimulation of A431 cells transiently transfected with PPRE-luciferase with AA significantly induced luciferase activity, mimicking the effects of PPARγ agonist rosiglitazone, suggesting that alteration of AA signaling pathway can regulate gene expression via endogenous PPARs

Enhancement of arachidonic acid signaling pathway by nicotinic acid receptor HM74A

Energy Technology Data Exchange (ETDEWEB)

Tang, Yuting [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States); Zhou, Lubing [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States); Gunnet, Joseph W [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States); Wines, Pamela G [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States); Cryan, Ellen V [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States); Demarest, Keith T [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States)

2006-06-23

HM74A is a G protein-coupled receptor for nicotinic acid (niacin), which has been used clinically to treat dyslipidemia for decades. The molecular mechanisms whereby niacin exerts its pleiotropic effects on lipid metabolism remain largely unknown. In addition, the most common side effect in niacin therapy is skin flushing that is caused by prostaglandin release, suggesting that the phospholipase A{sub 2} (PLA{sub 2})/arachidonic acid (AA) pathway is involved. Various eicosanoids have been shown to activate peroxisome-proliferator activated receptors (PPAR) that play a diverse array of roles in lipid metabolism. To further elucidate the potential roles of HM74A in mediating the therapeutic effects and/or side effects of niacin, we sought to explore the signaling events upon HM74A activation. Here we demonstrated that HM74A synergistically enhanced UTP- and bradykinin-mediated AA release in a pertussis toxin-sensitive manner in A431 cells. Activation of HM74A also led to Ca{sup 2+}-mobilization and enhanced bradykinin-promoted Ca{sup 2+}-mobilization through Gi protein. While HM74A increased ERK1/2 activation by the bradykinin receptor, it had no effects on UTP-promoted ERK1/2 activation.Furthermore, UTP- and bradykinin-mediated AA release was significantly decreased in the presence of both MAPK kinase inhibitor PD 098059 and PKC inhibitor GF 109203X. However, the synergistic effects of HM74A were not dramatically affected by co-treatment with both inhibitors, indicating the cross-talk occurred at the receptor level. Finally, stimulation of A431 cells transiently transfected with PPRE-luciferase with AA significantly induced luciferase activity, mimicking the effects of PPAR{gamma} agonist rosiglitazone, suggesting that alteration of AA signaling pathway can regulate gene expression via endogenous PPARs.

Radiolytic degradation of sorbic acid in isolated systems

International Nuclear Information System (INIS)

Thakur, B.R.; Trehan, I.R.; Arya, S.S.

1990-01-01

Effect of Co(60) gamma-irradiation on stability of sorbic acid (SA) in solutions, dough and chapaties has been investigated. SA was highly susceptible to radiolytic degradation in aqueous systems. Rate of degradation decreased with rise in pH. Sugars, hydrocolloids except pectin, citric acid, lactic acid, malic acid, arginine and threonine, catalyzed degradation while oxalic acid, maleic acid, Cu2+, nitrite, nitrate and phthalate had protective effects. SA was more stable in alcohols and vegetable oils than in aqueous solutions. In wheat flour radiolytic degradation of SA was less at lower moisture. Relatively SA was more stable in chapaties than in dough. Gelatinization and addition of oil in dough reduced degradation of SA

Arachidonic acid triggers an oxidative burst in leukocytes

Directory of Open Access Journals (Sweden)

Pompeia C.

2003-01-01

Full Text Available The change in cellular reducing potential, most likely reflecting an oxidative burst, was investigated in arachidonic acid- (AA stimulated leukocytes. The cells studied included the human leukemia cell lines HL-60 (undifferentiated and differentiated into macrophage-like and polymorphonuclear-like cells, Jurkat and Raji, and thymocytes and macrophages from rat primary cultures. The oxidative burst was assessed by nitroblue tetrazolium reduction. AA increased the oxidative burst until an optimum AA concentration was reached and the burst decreased thereafter. In the leukemia cell lines, optimum concentration ranged from 200 to 400 µM (up to 16-fold, whereas in rat cells it varied from 10 to 20 µM. Initial rates of superoxide generation were high, decreasing steadily and ceasing about 2 h post-treatment. The continuous presence of AA was not needed to stimulate superoxide generation. It seems that the NADPH oxidase system participates in AA-stimulated superoxide production in these cells since the oxidative burst was stimulated by NADPH and inhibited by N-ethylmaleimide, diphenyleneiodonium and superoxide dismutase. Some of the effects of AA on the oxidative burst may be due to its detergent action. There apparently was no contribution of other superoxide-generating systems such as xanthine-xanthine oxidase, cytochromes P-450 and mitochondrial electron transport chain, as assessed by the use of inhibitors. Eicosanoids and nitric oxide also do not seem to interfere with the AA-stimulated oxidative burst since there was no systematic effect of cyclooxygenase, lipoxygenase or nitric oxide synthase inhibitors, but lipid peroxides may play a role, as indicated by the inhibition of nitroblue tetrazolium reduction promoted by tocopherol.

Peroxisome proliferation activation receptor alpha modulation of Ca2+-regulated exocytosis via arachidonic acid in guinea-pig antral mucous cells.

Science.gov (United States)

Sawabe, Yukinori; Shimamoto, Chikao; Sakai, Akiko; Kuwabara, Hiroko; Saad, Adel H; Nakano, Takashi; Takitani, Kimitaka; Tamai, Hiroshi; Mori, Hiroshi; Marunaka, Yoshinori; Nakahari, Takashi

2010-08-01

Indomethacin (IDM, 10 microm), not aspirin (ASA; 10 microm), enhanced the Ca(2+)-regulated exocytosis stimulated by 1 microm acetylcholine (ACh) in guinea-pig antral mucous cells. Indomethacin inhibits prostaglandin G/H (PGG/H) and 15R-hydroperoxy-eicosatetraenoic acid (15R-HPETE) production from arachidonic acid (AA), while ASA inhibits PGG/H production but accelerates 15R-HPETE production. This suggests that IDM accumulates AA. Arachidonic acid (2 microm) enhanced Ca(2+)-regulated exocytosis in antral mucous cells to a similar extent to IDM. Moreover, a stable analogue of AA, arachidonyltrifluoromethyl ketone (AACOCF(3)), also enhanced Ca(2+)-regulated exocytosis, indicating that AA, not products from AA, enhances Ca(2+)-regulated exocytosis. We hypothesized that AA activates peroxisome proliferation activation receptor alpha (PPARalpha), because AA is a natural ligand for PPARalpha. A PPARalpha agonist (WY14643; 1 microm) enhanced Ca(2+)-regulated exocytosis, and a PPARalpha blocker (MK886; 50 microm) abolished the enhancement of Ca(2+)-regulated exocytosis induced by AA, IDM, AACOCF(3) and WY14643. Western blotting and immunohistochemical examinations demonstrated that PPARalpha exists in antral mucous cells. Moreover, MK886 decreased the frequency of Ca(2+)-regulated exocytosis activated by 1 microm ACh or 2 microm thapsigargin alone by 25-30%. Thus, ACh stimulates AA accumulation via an [Ca(2+)](i) increase, which activates PPARalpha, leading to enhancement of Ca(2+)-regulated exocytosis in antral mucous cells. A novel autocrine mechanism mediated via PPARalpha enhances Ca(2+)-regulated exocytosis in guinea-pig antral mucous cells.

Influence of whole-body gamma irradiation upon arachidonic acid metabolism in rat platelets

International Nuclear Information System (INIS)

Lognonne, J.L.; Ducousso, R.; Rocquet, G.; Kergonou, J.F.

1985-01-01

The effects of whole-body gamma irradiation (8.4 Gy) were studied on arachidonic acid (AA) metabolism in rat's blood platelets, from day D + 1 to day D + 10 after irradiation. AA conversion into thromboxane B 2 (TxB 2 ) increased at D + 1 and then gradually decreased to very low values from D + 7 to D + 10. This decrease in the conversion of exogenous AA into TxB 2 was due to a lower AA incorporation into platelets and not to a decrease of cyclooxygenase and thromboxane-synthetase activities. AA incorporation into membrane phospholipids of blood platelets was much more decreased than AA incorporation into whole platelets; moreover, the lipid composition of the platelet membranes was markedly modified after irradiation, which must have resulted in structural and functional changes in these membranes; from these effects of whole-body gamma irradiation on platelets, the latter's membranes appeared as a major site of in vivo radiation damage in these cells

Effect of oxygen deprivation on metabolism of arachidonic acid by cultures of rat heart cells

International Nuclear Information System (INIS)

Freyss-Beguin, M.; Millanvoye-van Brussel, E.; Duval, D.

1989-01-01

To investigate the mechanisms responsible for the impairment of phospholipid metabolism observed in ischemic cells, we have studied the effect of conditions simulating ischemia on the metabolism of arachidonic acid (AA) by muscle (M-) and nonmuscle (F-) cells isolated from newborn rat hearts and cultured separately. In muscle cells, oxygen deprivation induces a significant stimulation of the release of [ 14 C]AA from prelabeled cells associated with a preferential redistribution of [ 14 C]AA into cell triglycerides but not formation of radioactive prostaglandins. Moreover, the fatty acid content of phospholipids, as measured by capillary gas chromatography, appears markedly reduced in ischemic myocardial cells. This fact may be related to phospholipase stimulation during ischemia as suggested by the antagonistic effect of mepacrine or p-bromophenacyl bromide. In contrast, oxygen deprivation failed to induce any significant alteration of AA metabolism in fibroblast-like heart cells. Our results indicate that these cultures of newborn rat heart cells, which exhibit many of the features observed in intact organ during ischemia, may represent a useful experimental model to investigate the pharmacological control of the membrane phospholipid turnover

Effect of extra virgin olive oil components on the arachidonic acid cascade, colorectal cancer and colon cancer cell proliferation

International Nuclear Information System (INIS)

Storniolo, C.E.; Moreno, J.J.

2016-01-01

The mediterranean diet (MD) reduced the risk of colorectal cancer (CRC), and olive oil, the primary source of fat in the MD, has also been found to have a protective effect. However, animals fed with oleic acid present a high number of intestinal tumours, suggesting that oleic acid and olive oil consumption can exert different effects on CRC. Considering that extra virgin olive oil (EVOO) is a complex mix of fatty acids and minor compounds such as polyphenols, hydrocarbons, phytosterols and triterpenes; and that these compounds have antioxidant activity and consequently they can modulate the arachidonic acid (AA) cascade and eicosanoid synthesis. This review analyzes the state of the art of olive oil components on the AA cascade and cellular mechanism involved in CRC such as intestinal epithelial cell growth/apoptosis, to understand the fact that the consumption of seed oils with high oleic content or EVOO will probably have different effects on CRC development. [es

Effect of extra virgin olive oil components on the arachidonic acid cascade, colorectal cancer and colon cancer cell proliferation

Directory of Open Access Journals (Sweden)

C. E. Storniolo

2016-12-01

Full Text Available The mediterranean diet (MD reduced the risk of colorectal cancer (CRC, and olive oil, the primary source of fat in the MD, has also been found to have a protective effect. However, animals fed with oleic acid present a high number of intestinal tumours, suggesting that oleic acid and olive oil consumption can exert different effects on CRC. Considering that extra virgin olive oil (EVOO is a complex mix of fatty acids and minor compounds such as polyphenols, hydrocarbons, phytosterols and triterpenes; and that these compounds have antioxidant activity and consequently they can modulate the arachidonic acid (AA cascade and eicosanoid synthesis. This review analyzes the state of the art of olive oil components on the AA cascade and cellular mechanism involved in CRC such as intestinal epithelial cell growth/apoptosis, to understand the fact that the consumption of seed oils with high oleic content or EVOO will probably have different effects on CRC development.

Gibberellic acid promoting phytic acid degradation in germinating soybean under calcium lactate treatment.

Science.gov (United States)

Hui, Qianru; Wang, Mian; Wang, Pei; Ma, Ya; Gu, Zhenxin; Yang, Runqiang

2018-01-01

Phytic acid as a phosphorus storage vault provides phosphorus for plant development. It is an anti-nutritional factor for humans and some animals. However, its degradation products lower inositol phosphates have positive effects on human health. In this study, the effect of gibberellic acid (GA) on phytic acid degradation under calcium lactate (Ca) existence was investigated. The results showed that Ca + GA treatment promoted the growth status, hormone metabolism and phytic acid degradation in germinating soybean. At the same time, the availability of phosphorus, the activity of phytic acid degradation-associated enzyme and phosphoinositide-specific phospholipase C (PI-PLC) increased. However, the relative genes expression of phytic acid degradation-associated enzymes did not vary in accordance with their enzymes activity. The results revealed that GA could mediate the transport and function of calcium and a series of physiological and biochemical changes to regulate phytic acid degradation of soybean sprouts. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Arachidonic acid metabolism in silica-stimulated bovine alveolar macrophages

International Nuclear Information System (INIS)

Englen, M.D.

1989-01-01

The in vitro production of arachidonic acid (AA) metabolites in adherent bovine alveolar macrophages (BAM) incubated with silica was investigated. BAM were pre-labelled with 3 H-AA, and lipid metabolites released into the culture medium were analyzed by high performance liquid chromatography (HPLC). Lactate dehydrogenase (LDH) release was simultaneously assayed to provide an indication of cell injury. Increasing doses of silica selectively stimulated the 5-lipoxygenase pathway of AA metabolism, while cyclooxygenase metabolite output was suppressed. LDH release increased in a linear, dose-dependent fashion over the range of silica doses used. Moreover, within 15 min following addition of a high silica dose, a shift to the production of 5-lipoxygenase metabolites occurred, accompanied by a reduction in cyclooxygenase products. This rapid alteration in AA metabolism preceded cell injury. To examine the relationship between cytotoxicity and AA metabolite release by BAM exposed to silicas with different cytotoxic and fibrogenic activities, BAM were exposed to different doses of DQ-12, Minusil-5, and Sigma silicas, and carbonyl iron beads. The median effective dose (ED 50 ) of each particulate to stimulate the release of AA metabolites and LDH was calculated. The ED 50 values for DQ-12, Minusil-5, and Sigma silica showed that the relative cytotoxicities of the different silicas for BAM corresponded to the relative potencies of the silicas to elicit 5-lipoxygenase metabolites from BAM. These results indicate that the cytotoxic, and presumed fibrogenic potential, of a silica is correlated with the potency to stimulate the release of leukotrienes from AM

High contents of both docosahexaenoic and arachidonic acids in milk of women consuming fish from lake Kitangiri (Tanzania) : targets for infant formulae close to our ancient diet?

NARCIS (Netherlands)

Kuipers, RS; Fokkema, MR; Smit, EN; van der Meulen, J; Boersma, ER; Muskiet, FAJ

Current recommendations for arachidonic (AA) and docosahexaenoic (DHA) acids in infant formulae are based on milk of Western mothers. Validity may be questioned in view of the profound dietary changes in the past 100 years, as opposed to our slowly adapting genome. Hominin evolution occurred in the

The relation between the omega-3 index and arachidonic acid is bell shaped : Synergistic at low EPA plus DHA status and antagonistic at high EPA plus DHA status

NARCIS (Netherlands)

Luxwolda, Martine F.; Kuipers, Remko S.; Smit, Ella N.; Velzing-Aarts, Francien V.; Dijck-Brouwer, D. A. Janneke; Muskiet, Frits A. J.

2011-01-01

Introduction: The relation between docosahexaenoic (DHA) and eicosapentaenoic (EPA) vs. arachidonic acid (AA) seems characterized by both synergism and antagonism. Materials and methods: Investigate the relation between EPA + DHA and AA in populations with a wide range of EPA + DHA status and across

Lamotrigine blocks NMDA receptor-initiated arachidonic acid signalling in rat brain: Implications for its efficacy in bipolar disorder

Science.gov (United States)

Ramadan, Epolia; Basselin, Mireille; Rao, Jagadeesh S.; Chang, Lisa; Chen, Mei; Ma, Kaizong; Rapoport, Stanley I.

2011-01-01

An upregulated brain arachidonic acid (AA) cascade and a hyperglutamatergic state characterize bipolar disorder (BD). Lamotrigine (LTG), a mood stabilizer approved for treating BD, is reported to interfere with glutamatergic neurotransmission involving N-methyl-D-aspartate receptors (NMDARs). NMDARs allow extracellular calcium into the cell, thereby stimulating calcium-dependent cytosolic phospholipase A2 (cPLA2) to release arachidonic acid (AA) from membrane phospholipid. We hypothesized that LTG, like other approved mood stabilizers, would reduce NMDAR-mediated AA signaling in rat brain. An acute subconvulsant dose of NMDA (25 mg/kg) or saline was administered intraperitoneally to unanesthetized rats that had been treated p.o. daily for 42 days with vehicle or a therapeutically relevant dose of LTG (10 mg/kg/.d). Regional brain AA incorporation coefficients k* and rates Jin, AA signals, were measured using quantitative autoradiography after intravenous [1-14C]AA infusion, as were other AA cascade markers. In chronic vehicle-treated rats, acute NMDA compared to saline increased k* and Jin in widespread regions of the brain, as well as prostaglandin (PG)E2 and thromboxane B2 concentrations. Chronic LTG treatment compared to vehicle reduced brain cyclooxygenase (COX) activity, PGE2 concentration, and DNA binding activity of the COX-2 transcription factor, NF-κB. Pretreatment with chronic LTG blocked the acute NMDA effects on AA cascade markers. In summary, chronic LTG like other mood stabilizers blocks NMDA-mediated signaling involving the AA metabolic cascade. Since markers of the AA cascade and of NMDAR signaling are up-regulated in the postmortem BD brain, mood stabilizers generally may be effective in BD by dampening NMDAR signalling and the AA cascade. PMID:21733229

Evaluation of a subchronic (13-week) oral toxicity study, preceded by an in utero exposure phase, with arachidonic acid oil derived from Mortierella alpina in rats

NARCIS (Netherlands)

Hempenius, R.A.; Lina, B.A.R.; Haggitt, R.C.

2000-01-01

Arachidonic acid oil (ARA-oil) derived from the fungus Mortierella alpina for use in infant nutrition was tested in a subchronic (13-week) oral toxicity study in rats, preceded by an in utero exposure phase. The ARA-oil was administered as admixture to the rodent diet at dose levels of 3000 ppm,

Mildly abnormal general movement quality in infants is associated with higher Mead acid and lower arachidonic acid and shows a U-shaped relation with the DHA/AA ratio.

Science.gov (United States)

van Goor, S A; Schaafsma, A; Erwich, J J H M; Dijck-Brouwer, D A J; Muskiet, F A J

2010-01-01

We showed that docosahexaenoic acid (DHA) supplementation during pregnancy and lactation was associated with more mildly abnormal (MA) general movements (GMs) in the infants. Since this finding was unexpected and inter-individual DHA intakes are highly variable, we explored the relationship between GM quality and erythrocyte DHA, arachidonic acid (AA), DHA/AA and Mead acid in 57 infants of this trial. MA GMs were inversely related to AA, associated with Mead acid, and associated with DHA/AA in a U-shaped manner. These relationships may indicate dependence of newborn AA status on synthesis from linoleic acid. This becomes restricted during the intrauterine period by abundant de novo synthesis of oleic and Mead acids from glucose, consistent with reduced insulin sensitivity during the third trimester. The descending part of the U-shaped relation between MA GMs and DHA/AA probably indicates DHA shortage next to AA shortage. The ascending part may reflect a different developmental trajectory that is not necessarily unfavorable. Copyright 2009 Elsevier Ltd. All rights reserved.

Diffusion of intracerebrally injected [1-14C]arachidonic acid and [2-3H]glycerol in the mouse brain. Effects of ischemia and electroconvulsive shock

International Nuclear Information System (INIS)

Pediconi, M.F.; Rodriguez de Turco, E.B.; Bazan, N.G.

1982-01-01

[2- 3 H]Glycerol and [1- 14 C]arachidonic acid were injected into the region of the frontal horn of the left ventricle of mice and were distributed rapidly throughout the brain. After 10 sec, most of the radioactive fatty acid was found in the hemisphere near the injection site; after 10 min, it was recovered in similar proportions in the cerebellum and brain stem. [2- 3 H]Glycerol showed a heterogeneous distribution, with most of the label remaining in the left hemisphere even after 10 min. On a fresh weight basis, cerebrum, cerebellum, and brain stem were found to contain similar amounts of labeled glycerol. However, the amount of [1- 14 C]arachidonate in cerebrum was only 50% of that recovered from cerebellum or brain stem. Brain ischemia or a single electroconvulsive shock reduced the spread of the label, producing an accumulation of radioactivity in the injected hemisphere, except for an increase in [2- 3 H]glycerol in the brain stem during ischemia. Despite the significant decrease in available precursor in the cerebellum and brain stem after electroshock, the amount of label incorporated into lipids was not altered in these areas and only slightly diminished in the cerebrum

Synthesis of (9Z, 12E-, (9E, 12Z-[1-¹⁴C]-linoleic acid, (9Z, 12Z, 15E-, (9E, 12Z, 15Z-[1-¹⁴C]-linolenic acid and (5Z, 8Z, 11Z, 14E-[1-¹⁴C]-arachidonic acid

Directory of Open Access Journals (Sweden)

Enard, Thierry

1996-04-01

Full Text Available Trans polyunsaturated fatty acids are produced in vegetable oils during heat treatment (240-250 °C.ln order to study the metabolic pathway of 9c, 12t and 9t, 12c linoleic acid and 9c, 12c, 15t and 9t, 12c, 15c linolenic acid, these products were prepared labelled with carbon 14 in the carboxylic position. 5c, 8c, 11c, 14t-Arachidonic acid was also labelled on the carboxylic position with carbon 14 in order to study its physiological effects. To introduce the labelling (E-bromo precursors with a 17 carbons chain or a 19 carbon chain were needed. The different syntheses were done by elongation steps and creation of cis double bonds via highly stereospecific Wittig reactions. The radioactive carbon atom was introduced from [¹⁴C]-potassium cyanide. The final radioactive fatty acids had a specific activity greater than 50 mCi/mmol and a radioactive purity better than 99 % for linoleic and linolenic and better than 98.6 % for arachidonic acid.

Food sources of arachidonic acid (PFA 20:4), listed in descending order by percentages of their contribution to intake, based on data from the National Health and Nutrition Examination Survey 2005-2006

Science.gov (United States)

Food sources of arachidonic acid (PFA 20:4), listed in descending order by percentages of their contribution to intake, based on data from the National Health and Nutrition Examination Survey 2005-2006

The influence of dietary concentrations of arachidonic acid and eicosapentaenoic acid at various stages of larval ontogeny on eye migration, pigmentation and prostaglandin content of common sole larvae ( Solea solea L.)

DEFF Research Database (Denmark)

Lund, Ivar; Steenfeldt, Svend Jørgen; Banta, G.

2008-01-01

Dietary manipulations of arachidonic acid, ARA and eicosapentaenoic acid, EPA may have an influence on pigmentation in common sole larvae (Solea solea L., Linnaeus 1758) which may be related to a "pigmentation window". This is a specific period in the larval ontogeny where nutritional factors...... metamorphosis. Initiation of metamorphosis (i.e. start of eye migration) was related to the size of larvae and not related to ARA or EPA content. Dietary EPA or DHA did not retard the advance of eye migration. More than 90 % of highly malpigmented juveniles, (i.e. "albinos") had a permanent aberrant eye...

In vitro Degradation of Butanediamine-Grafted Poly(DL-Lactic acids)

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

The degradation of butanediamine-grafted poly(DL-lactic acid) polymers (BDPLAs) in vitro together with PDLLA and maleic anhydride-grafted poly(DL-lactic acid) polymers (MPLAs) was investigated by observation of the changes of the pH value of incubation media, and weight loss ratio during degradation duration of 12 weeks. The results reveal that the acidity of PDLLA degradation products was weakened or neutralized by grafting butanediamine onto PDLLA. A uniform degradation of BDPLAs was observed in comparison with an acidity-induced auto-accelerating degradation featured by PDLLA and MPLAs. The biodegradation behaviors of BDPLAs can be adjusted by controlling the content of BDA. BDPLAs might be a new derivative of PDLLA-based biodegradable materials for medical applications without acidity-caused irritations and acidity-induced auto-accelerating degradation behavior as that of PDLLA.

Associations between dietary n-6 and n-3 fatty acids and arachidonic acid compositions in plasma and erythrocytes in young and elderly Japanese volunteers

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Kawabata Terue

2011-08-01

Full Text Available Abstract Background We reported that the compositions of arachidonic acid (ARA in erythrocytes and plasma phospholipids (PL in the elderly were lower than those in the young, though the ARA intake was nearly identical. Objective We further analyzed data in four study groups with different ages and sexes, and determined that the blood ARA levels were affected by the kinds of dietary fatty acids ingested. Methods One hundred and four healthy young and elderly volunteers were recruited. Dietary records together with photographic records from 28 consecutive days were reviewed and the fatty acid composition in plasma lipid fractions and erythrocyte PL was analyzed. Results No correlations for ARA between dietary fatty acids and blood lipid fractions were observed. A significant negative correlation between eicosapentaenoic acid (EPA + docosahexaenoic acid (DHA intake and ARA composition in erythrocyte PL was observed. ARA composition in erythrocyte PL was significantly lower in elderly subjects than in young subjects, because EPA and DHA intake in elderly subjects was higher than in young subjects. However, after removing the effect of dietary EPA+DHA intake, the ARA composition in erythrocyte PL in elderly subjects was significantly lower than that in young subjects. Conclusions Changes in physical conditions with aging influenced the low ARA composition of erythrocyte in elderly subjects in addition to the effects of dietary EPA and DHA.

Arachidonate 5-lipoxygenase (ALOX5) gene polymorphism is associated with Alzheimer's disease and body mass index

Czech Academy of Sciences Publication Activity Database

Šerý, Omar; Hlinecká, L.; Povová, J.; Bonczek, Ondřej; Zeman, T.; Janout, V.; Ambrož, P.; Khan, N. A.; Balcar, V. J.

2016-01-01

Roč. 362, č. 1 (2016), s. 27-32 ISSN 0022-510X Institutional support: RVO:67985904 Keywords : Arachidonic acid * genetics * inflammation * leukotrienes * curcumin Subject RIV: FH - Neurology Impact factor: 2.295, year: 2016

A New Model to Study the Role of Arachidonic Acid in Colon Cancer Pathophysiology.

Science.gov (United States)

Fan, Yang-Yi; Callaway, Evelyn; M Monk, Jennifer; S Goldsby, Jennifer; Yang, Peiying; Vincent, Logan; S Chapkin, Robert

2016-09-01

A significant increase in cyclooxygenase 2 (COX2) gene expression has been shown to promote cylcooxygenase-dependent colon cancer development. Controversy associated with the role of COX2 inhibitors indicates that additional work is needed to elucidate the effects of arachidonic acid (AA)-derived (cyclooxygenase and lipoxygenase) eicosanoids in cancer initiation, progression, and metastasis. We have recently developed a novel Fads1 knockout mouse model that allows for the investigation of AA-dependent eicosanoid deficiency without the complication of essential fatty acid deficiency. Interestingly, the survival rate of Fads1-null mice is severely compromised after 2 months on a semi-purified AA-free diet, which precludes long-term chemoprevention studies. Therefore, in this study, dietary AA levels were titrated to determine the minimal level required for survival, while maintaining a distinct AA-deficient phenotype. Null mice supplemented with AA (0.1%, 0.4%, 0.6%, 2.0%, w/w) in the diet exhibited a dose-dependent increase (P sibling littermate control mice. These data indicate that (i) basal/minimal dietary AA supplementation (0.6%) expands the utility of the Fads1-null mouse model for long-term cancer prevention studies and (ii) that AA content in the colonic epithelium modulates colon cancer risk. Cancer Prev Res; 9(9); 750-7. ©2016 AACR. ©2016 American Association for Cancer Research.

An updated review of worldwide levels of docosahexaenoic and arachidonic acid in human breast milk by region.

Science.gov (United States)

Fu, Yuanqing; Liu, Xin; Zhou, Bing; Jiang, Alice C; Chai, Lingying

2016-10-01

We aimed to evaluate the DHA and arachidonic acid (AA) levels in human breast milk worldwide by country, region and socio-economic status. Descriptive review conducted on English publications reporting breast-milk DHA and AA levels. We systematically searched and identified eligible literature in PubMed from January 1980 to July 2015. Data on breast-milk DHA and AA levels from women who had given birth to term infants were included. Seventy-eight studies from forty-one countries were included with 4163 breast-milk samples of 3746 individuals. Worldwide mean levels of DHA and AA in breast milk were 0·37 (sd 0·11) % and 0·55 (sd 0·14) % of total fatty acids, respectively. The breast-milk DHA levels from women with accessibility to marine foods were significantly higher than those from women without accessibility (0·35 (sd 0·20) % v. 0·25 (sd 0·14) %, Pworldwide variation in breast-milk DHA and AA levels and underlines the need for future population- or region-specific investigations.

Arachidonic Acid Metabolite as a Novel Therapeutic Target in Breast Cancer Metastasis

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Thaiz F. Borin

2017-12-01

Full Text Available Metastatic breast cancer (BC (also referred to as stage IV spreads beyond the breast to the bones, lungs, liver, or brain and is a major contributor to the deaths of cancer patients. Interestingly, metastasis is a result of stroma-coordinated hallmarks such as invasion and migration of the tumor cells from the primary niche, regrowth of the invading tumor cells in the distant organs, proliferation, vascularization, and immune suppression. Targeted therapies, when used as monotherapies or combination therapies, have shown limited success in decreasing the established metastatic growth and improving survival. Thus, novel therapeutic targets are warranted to improve the metastasis outcomes. We have been actively investigating the cytochrome P450 4 (CYP4 family of enzymes that can biosynthesize 20-hydroxyeicosatetraenoic acid (20-HETE, an important signaling eicosanoid involved in the regulation of vascular tone and angiogenesis. We have shown that 20-HETE can activate several intracellular protein kinases, pro-inflammatory mediators, and chemokines in cancer. This review article is focused on understanding the role of the arachidonic acid metabolic pathway in BC metastasis with an emphasis on 20-HETE as a novel therapeutic target to decrease BC metastasis. We have discussed all the significant investigational mechanisms and put forward studies showing how 20-HETE can promote angiogenesis and metastasis, and how its inhibition could affect the metastatic niches. Potential adjuvant therapies targeting the tumor microenvironment showing anti-tumor properties against BC and its lung metastasis are discussed at the end. This review will highlight the importance of exploring tumor-inherent and stromal-inherent metabolic pathways in the development of novel therapeutics for treating BC metastasis.

Differentiation of U937 cells induced by 5,8,11,14-eicosatetraynoic acid, a competitive inhibitor of arachidonic acid metabolism

International Nuclear Information System (INIS)

Ondrey, F.; Anderson, K.; Hoeltgen, D.; Harris, J.

1988-01-01

5,8,11,14-Eicosatetraynoic acid, a competitive inhibitor of arachidonic acid metabolism, rapidly and reversibly inhibited DNA synthesis in U937 cells. This inhibition was not due to cytotoxicity, as judged by studies with trypan blue, release of 51 Cr-labeled proteins, and its reversibility. When cells were cultured in the presence of ETYA for several days, morphologic, enzymatic, and functional changes consistent with differentiation occurred. The cells enlarged, the ratio of cytoplasm to nuclei increased, secretory granules and vacuoles developed, the apparent activity of nonspecific esterase rose, and ingestion of latex particles increased. A morphology consistent with that of an immature monocyte was evident by electron microscopy. When cells differentiated by ETYA were cultured in media free of the inhibitor, DNA synthesis reinitiated and the cell number increased; differentiation was phenotypic and not genotypic. To examine whether ETYA-induced differentiation was obligatorily related to its suppression of DNA synthesis, cells were incubated in 50 μM hydroxyurea and DNA synthesis was inhibited for 24 to 36 h without morphologic evidence of cellular differentiation. However, addition of ETYA to cells prevented from dividing by hydroxyurea and subsequent culture for 72 h induced morphologic evidence of differentiation. The effects of ETYA on cell division and cell differentiation are closely related but can be dissociated

Ultrastructural autoradiographic localization of exogenous arachidonic acid in cultured endothelial and smooth muscle cells

International Nuclear Information System (INIS)

Tasca, S.I.; Galis, Z.

1988-01-01

The uptake and intracellular localization of exogenous arachidonic acid (AA) were investigated in cultured endothelial (EC) and smooth muscle cells (SMC) isolated from bovine aorta. The [ 14 C]AA uptake was assessed biochemically and by light and electron microscopic autoradiography. The highest values of silver grain surface density were associated with the mitochondria, lysosomes, and the Golgi apparatus of the EC. The grain linear density was greater on the nuclear envelope than on plasmalemma. On SMC, the grain density was highest on lipid droplets whereas the linear densities of the nuclear envelope and plasmalemma were similar. The share of each subcellular compartment in the AA distribution was estimated as the percentage of the individual silver grain count out of the total cell-associated radioactivity. The results showed that cytoplasm (including endoplasmic reticulum, ribosomes, and small vesicles) made the main contribution followed by the nucleus and at lower values by other organelles. These subcompartments may represent the intracellular sites from which AA could be mobilized for prostanoid synthesis by EC and SMC. (author)

Oxidation of esterified arachidonate by rat liver microsomes

International Nuclear Information System (INIS)

Davis, H.W.; Suzuki, T.; Schenkman, J.B.

1986-01-01

The authors have previously demonstrated a relationship between phospholipid arachidonate in liver microsomes and malondialdehyde (MDA) formation during lipid peroxidation. In this study arachidonic acid (U- 14 C) was incorporated into rat liver microsomes and NADPH-supported peroxidation was carried out at 37 0 C for 15 minutes. The microsomes were pelleted by centrifugation and the labeled products in the supernatant were isolated by a solid phase method. Pellets were hydrolyzed with phospholipase A 2 and extracted with diethyl ether and the products from both fractions were separated by reverse phase HPLC. The results show that (1) oxidation occurs in all of the major phospholipids but that phosphatidylethanolamine is the most susceptible; (2) a linear correlation exists between MDA formation and supernatant radioactivity; (3) several different polar products are found in both the supernatant and the hydrolyzed pellet but that the ratios of product peaks in HPLC do not change during the peroxidation, indicating no secondary metabolism or propagation; and (4) cytochrome P-450 is not involved in the peroxidative reactions since no oxidation occurs in the absence of Fe 3+ and since product formation is unaffected in the presence of carbon monoxide

Arachidonic Acid and Eicosapentaenoic Acid Metabolism in Juvenile Atlantic Salmon as Affected by Water Temperature.

Science.gov (United States)

Norambuena, Fernando; Morais, Sofia; Emery, James A; Turchini, Giovanni M

2015-01-01

Salmons raised in aquaculture farms around the world are increasingly subjected to sub-optimal environmental conditions, such as high water temperatures during summer seasons. Aerobic scope increases and lipid metabolism changes are known plasticity responses of fish for a better acclimation to high water temperature. The present study aimed at investigating the effect of high water temperature on the regulation of fatty acid metabolism in juvenile Atlantic salmon fed different dietary ARA/EPA ratios (arachidonic acid, 20:4n-6/ eicosapentaenoic acid, 20:5n-3), with particular focus on apparent in vivo enzyme activities and gene expression of lipid metabolism pathways. Three experimental diets were formulated to be identical, except for the ratio EPA/ARA, and fed to triplicate groups of Atlantic salmon (Salmo salar) kept either at 10°C or 20°C. Results showed that fatty acid metabolic utilisation, and likely also their dietary requirements for optimal performance, can be affected by changes in their relative levels and by environmental temperature in Atlantic salmon. Thus, the increase in temperature, independently from dietary treatment, had a significant effect on the β-oxidation of a fatty acid including EPA, as observed by the apparent in vivo enzyme activity and mRNA expression of pparα -transcription factor in lipid metabolism, including β-oxidation genes- and cpt1 -key enzyme responsible for the movement of LC-PUFA from the cytosol into the mitochondria for β-oxidation-, were both increased at the higher water temperature. An interesting interaction was observed in the transcription and in vivo enzyme activity of Δ5fad-time-limiting enzyme in the biosynthesis pathway of EPA and ARA. Such, at lower temperature, the highest mRNA expression and enzyme activity was recorded in fish with limited supply of dietary EPA, whereas at higher temperature these were recorded in fish with limited ARA supply. In consideration that fish at higher water temperature

Thiyl radical-induced cis-trans-isomerization of arachidonic acid inhibits prostaglandin metabolism

International Nuclear Information System (INIS)

Kratzsch, S.; Droessler, K.; Sprinz, H.; Brede, O.

2002-01-01

Complete text of publication follows. Thiyl radicals radiolytically generated from thiophenol in methanolic solution are known to isomerise double bonds of poly-unsaturated fatty acids (PUFA). γ-irradiating of such a system containing all-cis 5,8,11,14 eicosatetraenoic acid (arachidonic acid, AA) with low doses (0.1-0.8 kGy) results in a mixture of 8 to 32% mono-trans-isomers. Here we report about the influence of mono-trans-AA on the primary steps of AA-metabolism and prostaglandin synthesis, catalysed by cyclooxygenase (COX). In the cell-free model system the reaction of COX-1 with AA was analysed by controlling the oxygen level during the enzymatic reaction. As an example, a mixture of a low quantity of mono-trans-isomerized AA (10%) and 90% all-cis-isomer exhibits a marked reduced oxygen consumption by 45%. As further proofs - the yield of reactive oxygen species (ROS) generated by the COX-coupled peroxidase reaction was detected, - and the COX-1 activity in presence of different amounts of trans-AA was characterized using a photometric assay based on the oxidation of TMPD. All these methods indicated semiquantitatively a reduced activity of COX-1, depending on the trans-isomer yield. Therefore, an inhibition of COX-1 activity by only one trans-double-bond in AA could be concluded. Furthermore, in vitro cell-line experiments were performed analysing the influence of mono-trans-isomerized AA on the activity of the cell-own COX-2. Hence, VD 3 -differentiated and LPS-stimulated monocyte-like cells were incubated with mono-trans-AA and ROS-production was detected by the chemiluminescence measurements mentioned above. Compared to the reaction with all-cis-AA we found a considerable lowered formation of ROS. Likewise, we obtained a reduced PGE 2 -expression between 15 and 40% for cells treated with 8 to 29% trans-AA. The model as well as in vivo experiments demonstrate an inhibition effect of mono-trans-AA and give rise for postulating an enzyme blocking mechanism

Arachidonic acid and other unsaturated fatty acids and some of their metabolites function as endogenous antimicrobial molecules: A review

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Undurti N. Das

2018-05-01

Full Text Available Our body is endowed with several endogenous anti-microbial compounds such as interferon, cytokines, free radicals, etc. However, little attention has been paid to the possibility that lipids could function as antimicrobial compounds. In this short review, the antimicrobial actions of various polyunsaturated fatty acids (PUFAs, mainly free acids and their putative mechanisms of action are described. In general, PUFAs kill microbes by their direct action on microbial cell membranes, enhancing generation of free radicals, augmenting the formation of lipid peroxides that are cytotoxic, and by increasing the formation of their bioactive metabolites, such as prostaglandins, lipoxins, resolvins, protectins and maresins that enhance the phagocytic action of leukocytes and macrophages. Higher intakes of α-linolenic and cis-linoleic acids (ALA and LA respectively and fish (a rich source of eicosapentaenoic acid and docosahexaenoic acid might reduce the risk pneumonia. Previously, it was suggested that polyunsaturated fatty acids (PUFAs: linoleic, α-linolenic, γ-linolenic (GLA, dihomo-GLA (DGLA, arachidonic (AA, eicosapentaenoic (EPA, and docosahexaenoic acids (DHA function as endogenous anti-bacterial, anti-fungal, anti-viral, anti-parasitic, and immunomodulating agents. A variety of bacteria are sensitive to the growth inhibitory actions of LA and ALA in vitro. Hydrolyzed linseed oil can kill methicillin-resistant Staphylococcus aureus. Both LA and AA have the ability to inactivate herpes, influenza, Sendai, and Sindbis virus within minutes of contact. AA, EPA, and DHA induce death of Plasmodium falciparum both in vitro and in vivo. Prostaglandin E1 (PGE1 and prostaglandin A (PGA, derived from DGLA, AA, and EPA inhibit viral replication and show anti-viral activity. Oral mucosa, epidermal cells, lymphocytes and macrophages contain and release significant amounts of PUFAs on stimulation. PUFAs stimulate NADPH-dependent superoxide production by

A new model to study the role of arachidonic acid in colon cancer pathophysiology

Science.gov (United States)

Fan, Yang-Yi; Callaway, Evelyn; Monk, Jennifer M.; Goldsby, Jennifer S.; Yang, Peiying; Vincent, Logan; Chapkin, Robert S.

2016-01-01

A significant increase in cyclooxygenase 2 (COX2) gene expression has been shown to promote cylcooxygenase-dependent colon cancer development. Controversy associated with the role of COX2 inhibitors indicates that additional work is needed to elucidate the effects of arachidonic acid (AA) derived (cyclooxygenase and lipoxygenase) eicosanoids in cancer initiation, progression and metastasis. We have recently developed a novel Fads1 knockout mouse model, which allows for the investigation of AA-dependent eicosanoid deficiency without the complication of essential fatty acid deficiency. Interestingly, the survival rate of Fads1 null mice is severely compromised after 2 months on a semi-purified AA-free diet, which precludes long-term chemoprevention studies. Therefore, in this study, dietary AA levels were titrated to determine the minimal level required for survival, while maintaining a distinct AA-deficient phenotype. Null mice supplemented with AA (0.1, 0.4, 0.6, 2.0%, w/w) in the diet exhibited a dose-dependent increase (P diet were injected with a colon-specific carcinogen (azoxymethane) in order to assess cancer susceptibility. Null mice exhibited significantly (P < 0.05) reduced levels/multiplicity of aberrant crypt foci (ACF) as compared to wild type sibling littermate control mice. These data indicate that (i) basal/minimal dietary AA supplementation (0.6%) expands the utility of the Fads1 Null mouse model for long-term cancer prevention studies, and (ii) that AA content in the colonic epithelium modulates colon cancer risk. PMID:27339171

Docosahexaenoic acid (DHA) supplementation in pregnancy differentially modulates arachidonic acid and DHA status across FADS genotypes in pregnancy.

Science.gov (United States)

Scholtz, S A; Kerling, E H; Shaddy, D J; Li, S; Thodosoff, J M; Colombo, J; Carlson, S E

2015-03-01

Some FADS alleles are associated with lower DHA and ARA status assessed by the relative amount of arachidonic acid (ARA) and docosahexaenoic acid (DHA) in plasma and red blood cell (RBC) phospholipids (PL). We determined two FADS single nucleotide polymorphisms (SNPs) in a cohort of pregnant women and examined the relationship of FADS1rs174533 and FADS2rs174575 to DHA and ARA status before and after supplementation with 600mg per day of DHA. The 205 pregnant women studied were randomly assigned to placebo (mixed soy and corn oil) (n=96) or 600mg algal DHA (n=109) in 3 capsules per day for the last two trimesters of pregnancy. Women homozygous for the minor allele of FADS1rs174533 (but not FADS2rs174575) had lower DHA and ARA status at baseline. At delivery, minor allele homozygotes of FADS1rs174533 in the placebo group had lower RBC-DHA compared to major-allele carriers (P=0.031), while in the DHA-supplemented group, all genotypes had higher DHA status compared to baseline (P=0.001) and status did not differ by genotype (P=0.941). Surprisingly, DHA but not the placebo decreased ARA status of minor allele homozygotes of both FADS SNPs but not major allele homozygotes at delivery. Any physiological effects of changing the DHA to ARA ratio by increasing DHA intake appears to be greater in minor allele homozygotes of some FADS SNPs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Combination Therapy of PPAR Ligands and Inhibitors of Arachidonic Acid in Lung Cancer

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Jordi Tauler

2008-01-01

Full Text Available Lung cancer is the leading cause of cancer death in the United States and five-year survival remains low. Numerous studies have shown that chronic inflammation may lead to progression of carcinogenesis. As a result of inflammatory stimulation, arachidonic acid (AA metabolism produces proliferation mediators through complex and dynamic interactions of the products of the LOX/COX enzymes. One important mediator in the activation of the AA pathways is the nuclear protein PPAR. Targeting LOX/COX enzymes and inducing activation of PPAR have resulted in significant reduction of cell growth in lung cancer cell lines. However, specific COX-inhibitors have been correlated with an increased cardiovascular risk. Clinical applications are still being explored with a novel generation of dual LOX/COX inhibitors. PPAR activation through synthetic ligands (TZDs has revealed a great mechanistic complexity since effects are produced through PPAR-dependent and -independent mechanisms. Furthermore, PPAR could also be involved in regulation of COX-2. Overexpression of PPAR has reported to play a role in control of invasion and differentiation. Exploring the function of PPAR, in this new context, may provide a better mechanistic model of its role in cancer and give an opportunity to design a more efficient therapeutic approach in combination with LOX/COX inhibitors.

The TIP30 protein complex, arachidonic acid and coenzyme A are required for vesicle membrane fusion.

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Chengliang Zhang

Full Text Available Efficient membrane fusion has been successfully mimicked in vitro using artificial membranes and a number of cellular proteins that are currently known to participate in membrane fusion. However, these proteins are not sufficient to promote efficient fusion between biological membranes, indicating that critical fusogenic factors remain unidentified. We have recently identified a TIP30 protein complex containing TIP30, acyl-CoA synthetase long-chain family member 4 (ACSL4 and Endophilin B1 (Endo B1 that promotes the fusion of endocytic vesicles with Rab5a vesicles, which transport endosomal acidification enzymes vacuolar (H⁺-ATPases (V-ATPases to the early endosomes in vivo. Here, we demonstrate that the TIP30 protein complex facilitates the fusion of endocytic vesicles with Rab5a vesicles in vitro. Fusion of the two vesicles also depends on arachidonic acid, coenzyme A and the synthesis of arachidonyl-CoA by ACSL4. Moreover, the TIP30 complex is able to transfer arachidonyl groups onto phosphatidic acid (PA, producing a new lipid species that is capable of inducing close contact between membranes. Together, our data suggest that the TIP30 complex facilitates biological membrane fusion through modification of PA on membranes.

Subchronic (13-week) oral toxicity study, preceded by an in utero exposure phase, with arachidonate-enriched triglyceride oil (SUNTGA40S) in rats

NARCIS (Netherlands)

Lina, B.A.R.; Wolterbeek, A.P.M.; Suwa, Y.; Fujikawa, S.; Ishikura, Y.; Tsuda, S.; Dohnalek, M.

2006-01-01

Polyunsaturated fatty acids (PUFAs), such as arachidonic acid (ARA) and docosahexaenoic acid (DHA) are natural constituents found in human milk, fish oil or egg yolk. Until recently, infant formulas, though providing the essential fatty acid precursors for these PUFAs, did not contain preformed ARA

Anti-inflammatory effects of chronic aspirin on brain arachidonic acid metabolites

Science.gov (United States)

Basselin, Mireille; Ramadan, Epolia; Chen, Mei; Rapoport, Stanley I.

2010-01-01

Pro-inflammatory and anti-inflammatory mediators derived from arachidonic acid (AA) modulate peripheral inflammation and its resolution. Aspirin (ASA) is a unique non-steroidal anti-inflammatory drug, which switches AA metabolism from prostaglandin E2 (PGE2) and thromboxane B2 (TXB2) to lipoxin A4 (LXA4) and 15-epi-LXA4. However it is unknown whether chronic therapeutic doses of ASA are anti-inflammatory in the brain. We hypothesized that ASA would dampen increases in brain concentrations of AA metabolites in a rat model of neuroinflammation, produced by a 6-day intracerebroventricular infusion of bacterial lipopolysaccharide (LPS). In rats infused with LPS (0.5 ng/h) and given ASA-free water to drink, concentrations in high-energy microwaved brain of PGE2, TXB2 and leukotriene B4 (LTB4) were elevated. In rats infused with artificial cerebrospinal fluid, 6 weeks of treatment with a low (10 mg/kg/day) or high (100 mg/kg/day) ASA dose in drinking water decreased brain PGE2, but increased LTB4, LXA4 and 15-epi-LXA4 concentrations. Both doses attenuated the LPS effects on PGE2, and TXB2. The increments in LXA4 and 15-epi-LXA4 caused by high-dose ASA were significantly greater in LPS-infused rats. The ability of ASA to increase anti-inflammatory LXA4 and 15-epi-LXA4 and reduce pro-inflammatory PGE2 and TXB2 suggests considering aspirin further for treating clinical neuroinflammation. PMID:20981485

Arachidonic Acid and Eicosapentaenoic Acid Metabolism in Juvenile Atlantic Salmon as Affected by Water Temperature.

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Fernando Norambuena

Full Text Available Salmons raised in aquaculture farms around the world are increasingly subjected to sub-optimal environmental conditions, such as high water temperatures during summer seasons. Aerobic scope increases and lipid metabolism changes are known plasticity responses of fish for a better acclimation to high water temperature. The present study aimed at investigating the effect of high water temperature on the regulation of fatty acid metabolism in juvenile Atlantic salmon fed different dietary ARA/EPA ratios (arachidonic acid, 20:4n-6/ eicosapentaenoic acid, 20:5n-3, with particular focus on apparent in vivo enzyme activities and gene expression of lipid metabolism pathways. Three experimental diets were formulated to be identical, except for the ratio EPA/ARA, and fed to triplicate groups of Atlantic salmon (Salmo salar kept either at 10°C or 20°C. Results showed that fatty acid metabolic utilisation, and likely also their dietary requirements for optimal performance, can be affected by changes in their relative levels and by environmental temperature in Atlantic salmon. Thus, the increase in temperature, independently from dietary treatment, had a significant effect on the β-oxidation of a fatty acid including EPA, as observed by the apparent in vivo enzyme activity and mRNA expression of pparα -transcription factor in lipid metabolism, including β-oxidation genes- and cpt1 -key enzyme responsible for the movement of LC-PUFA from the cytosol into the mitochondria for β-oxidation-, were both increased at the higher water temperature. An interesting interaction was observed in the transcription and in vivo enzyme activity of Δ5fad-time-limiting enzyme in the biosynthesis pathway of EPA and ARA. Such, at lower temperature, the highest mRNA expression and enzyme activity was recorded in fish with limited supply of dietary EPA, whereas at higher temperature these were recorded in fish with limited ARA supply. In consideration that fish at higher

Maternal dietary n-6 polyunsaturated fatty acid deprivation does not exacerbate post-weaning reductions in arachidonic acid and its mediators in the mouse hippocampus.

Science.gov (United States)

Alashmali, Shoug M; Kitson, Alex P; Lin, Lin; Lacombe, R J Scott; Bazinet, Richard P

2017-09-13

The present study examines how lowering maternal dietary n-6 polyunsaturated fatty acids (PUFA) (starting from pregnancy) compared to offspring (starting from post-weaning) affect the levels of n-6 and n-3 fatty acids in phospholipids (PL) and lipid mediators in the hippocampus of mice. Pregnant mice were randomly assigned to consume either a deprived or an adequate n-6 PUFA diet during pregnancy and lactation (maternal exposure). On postnatal day (PND) 21, half of the male pups were weaned onto the same diet as their dams, and the other half were switched to the other diet for 9 weeks (offspring exposure). At PND 84, upon head-focused high-energy microwave irradiation, hippocampi were collected for PL fatty acid and lipid mediator analyses. Arachidonic acid (ARA) concentrations were significantly decreased in both total PL and PL fractions, while eicosapentaenoic acid (EPA) concentrations were increased only in PL fractions upon n-6 PUFA deprivation of offspring, regardless of maternal exposure. Several ARA-derived eicosanoids were reduced, while some of the EPA-derived eicosanoids were elevated by n-6 PUFA deprivation in offspring. There was no effect of diet on docosahexaenoic acid (DHA) or DHA-derived docosanoids concentrations under either maternal or offspring exposure. These results indicate that the maternal exposure to dietary n-6 PUFA may not be as important as the offspring exposure in regulating hippocampal ARA and some lipid mediators. Results from this study will be helpful in the design of experiments aimed at testing the significance of altering brain ARA levels over different stages of life.

Effects of sexually dimorphic growth hormone secretory patterns on arachidonic acid metabolizing enzymes in rodent heart

Energy Technology Data Exchange (ETDEWEB)

Zhang, Furong; Yu, Xuming [Department of Pharmacology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); He, Chunyan [Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Ouyang, Xiufang; Wu, Jinhua; Li, Jie; Zhang, Junjie; Duan, Xuejiao [Department of Pharmacology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Wan, Yu [Department of Physiology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Yue, Jiang, E-mail: yuejiang@whu.edu.cn [Department of Pharmacology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China)

2015-12-15

The arachidonic acid (AA) metabolizing enzymes are the potential therapeutic targets of cardiovascular diseases (CVDs). As sex differences have been shown in the risk and outcome of CVDs, we investigated the regulation of heart AA metabolizing enzymes (COXs, LOXs, and CYPs) by sex-dependent growth hormone (GH) secretory patterns. The pulsatile (masculine) GH secretion at a physiological concentration decreased CYP1A1 and CYP2J3 mRNA levels more efficiently in the H9c2 cells compared with the constant (feminine) GH secretion; however, CYP1B1 mRNA levels were higher following the pulsatile GH secretion. Sex differences in CYP1A1, CYP1B1, and CYP2J11 mRNA levels were observed in both the wild-type and GHR deficient mice. No sex differences in the mRNA levels of COXs, LOXs, or CYP2E1 were observed in the wild-type mice. The constant GH infusion induced heart CYP1A1 and CYP2J11, and decreased CYP1B1 in the male C57/B6 mice constantly infused with GH (0.4 μg/h, 7 days). The activity of rat Cyp2j3 promoter was inhibited by the STAT5B protein, but was activated by C/EBPα (CEBPA). Compared with the constant GH administration, the levels of the nuclear phosphorylated STAT5B protein and its binding to the rat Cyp2j3 promoter were higher following the pulsatile GH administration. The constant GH infusion decreased the binding of the nuclear phosphorylated STAT5B protein to the mouse Cyp2j11 promoter. The data suggest the sexually dimorphic transcription of heart AA metabolizing enzymes, which might alter the risk and outcome of CVDs. GHR-STAT5B signal transduction pathway may be involved in the sex difference in heart CYP2J levels. - Highlights: • The transcription of heart Cyp1a1, Cyp1b1 and Cyp2j genes is sexually dimorphic. • There are no sex differences in the mRNA levels of heart COXs, LOXs, or CYP2E1. • GHR-STAT5B pathway is involved in sexually dimorphic transcription of heart Cpy2j genes. • Heart CYPs-mediated metabolism pathway of arachidonic acid may be sex

Effects of sexually dimorphic growth hormone secretory patterns on arachidonic acid metabolizing enzymes in rodent heart

International Nuclear Information System (INIS)

Zhang, Furong; Yu, Xuming; He, Chunyan; Ouyang, Xiufang; Wu, Jinhua; Li, Jie; Zhang, Junjie; Duan, Xuejiao; Wan, Yu; Yue, Jiang

2015-01-01

The arachidonic acid (AA) metabolizing enzymes are the potential therapeutic targets of cardiovascular diseases (CVDs). As sex differences have been shown in the risk and outcome of CVDs, we investigated the regulation of heart AA metabolizing enzymes (COXs, LOXs, and CYPs) by sex-dependent growth hormone (GH) secretory patterns. The pulsatile (masculine) GH secretion at a physiological concentration decreased CYP1A1 and CYP2J3 mRNA levels more efficiently in the H9c2 cells compared with the constant (feminine) GH secretion; however, CYP1B1 mRNA levels were higher following the pulsatile GH secretion. Sex differences in CYP1A1, CYP1B1, and CYP2J11 mRNA levels were observed in both the wild-type and GHR deficient mice. No sex differences in the mRNA levels of COXs, LOXs, or CYP2E1 were observed in the wild-type mice. The constant GH infusion induced heart CYP1A1 and CYP2J11, and decreased CYP1B1 in the male C57/B6 mice constantly infused with GH (0.4 μg/h, 7 days). The activity of rat Cyp2j3 promoter was inhibited by the STAT5B protein, but was activated by C/EBPα (CEBPA). Compared with the constant GH administration, the levels of the nuclear phosphorylated STAT5B protein and its binding to the rat Cyp2j3 promoter were higher following the pulsatile GH administration. The constant GH infusion decreased the binding of the nuclear phosphorylated STAT5B protein to the mouse Cyp2j11 promoter. The data suggest the sexually dimorphic transcription of heart AA metabolizing enzymes, which might alter the risk and outcome of CVDs. GHR-STAT5B signal transduction pathway may be involved in the sex difference in heart CYP2J levels. - Highlights: • The transcription of heart Cyp1a1, Cyp1b1 and Cyp2j genes is sexually dimorphic. • There are no sex differences in the mRNA levels of heart COXs, LOXs, or CYP2E1. • GHR-STAT5B pathway is involved in sexually dimorphic transcription of heart Cpy2j genes. • Heart CYPs-mediated metabolism pathway of arachidonic acid may be sex

D-2 dopamine receptor activation reduces free [3H]arachidonate release induced by hypophysiotropic peptides in anterior pituitary cells

International Nuclear Information System (INIS)

Canonico, P.L.

1989-01-01

Dopamine reduces the stimulation of intracellular [ 3 H]arachidonate release produced by the two PRL-stimulating peptides angiotensin-II and TRH. This effect is concentration dependent and is mediated by stimulation of D-2 dopamine receptors. D-2 receptor agonists (bromocriptine, dihydroergocryptine, and dihydroergocristine) inhibit the release of fatty acid induced by angiotensin-II with a potency that parallels their ability to inhibit PRL release in vitro. Conversely, the selective D-2 receptor antagonist L-sulpiride completely prevents dopamine's effect, whereas SCH 23390 (a D-1 receptor antagonist) is ineffective. The inhibitory action of dopamine does not seem to be consequent to an action on the adenylate cyclase-cAMP system, as 8-bromo-cAMP (1 mM) does not affect either basal or dopamine-inhibited [ 3 H]arachidonate release. However, a 24-h pertussis toxin pretreatment significantly reduces the action of dopamine on fatty acid release. Collectively, these results suggest that D-2 dopamine receptor-mediated inhibition of intracellular [ 3 H]arachidonate release requires the action of a GTP-binding protein, but is not a consequence of an inhibitory action on cAMP levels

Effect of Polylactic Acid-Degradable Film Mulch on Soil Temperature and Cotton Yield

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ZHANG Ni

2016-03-01

Full Text Available Concern on biodegradable plastic film is increasing because of pollution problems caused by the plastic films currently used. The objective of this field experiment is to evaluate the effect of two thicknesses of polyactic acid-degradable film on soil temperature and cotton yield. The results showed that small holes appeared in the polyactic acid-degradable film at 17~22 d after it was installed. Burst period appeared about 60 d after installation. Splits were observed in the polyactic acid-degradable film at 130 d after installation. Soil temperatures rose slowly under polyactic acid-degradable film during the cotton seedling stage. Daytime soil temperatures were 0.8℃ and 6.2℃ lower under 18μm and 15μm thick polyactic acid-degradable film than non-degradable plastic film(CK, respectively. Nighttime soil temperatures under the polyactic acid-degradable film were about 1℃ warmer than CK. There was no significant difference in cotton yields between the 18μm polyactic acid degradable film treatment and CK. In contrast, yields in the 15μm degradable plastic film treatment were 8.9% less than that in CK. This study indicated that 18μm polyactic acid degradable plastic film had good degradability and no negative effect on cotton growth. The 18μm polyactic acid degradable plastic film can replace ordinary plastic film in agricultural production.

Arachidonic acid metabolism by bovine placental tissue during the last month of pregnancy

International Nuclear Information System (INIS)

Hoedemaker, M.; Weston, P.G.; Wagner, W.C.

1991-01-01

Conversion of tritiated arachidonic acid (AA) into metabolites of the cyclo- and lipoxygenase pathways by bovine fetal placental tissue (200 mg) and fetal plus maternal placental tissue (400 mg) of Days 255, 265, 275 of gestation and at parturition (n = 5) during a 30 min incubation was measured using reverse-phase high pressure liquid chromatography. Fetal placental tissue produced 13,14-dihydro-15-keto-prostaglandin E2 (PGEM) as the major metabolite, the synthesis of which increased from Day 265 to Day 275 and parturition by 150% and 475%, respectively. In tissues collected at parturition, PGE2 synthesis was also detected. On Day 275 and at parturition fetal placental tissue synthesized the metabolite 12-hydroxyheptadecatrienoic acid (HHT), and throughout the experimental period the lipoxygenase product 15-HETE was detected with synthesis rates increasing over time of gestation. In addition, an unidentified metabolite was regularly found in the radiochromatograms which eluted at 1 h and 1 min (U101), between HHT and 15-HETE. The synthesis of this metabolite decreased as pregnancy progressed. Furthermore, various other polar and nonpolar metabolites pooled under the heading UNID were eluted, the production of which increased over time of gestation. The presence of maternal placental tissue did not influence the synthesis of PGEM, 15-HETE and U101, but the production of HHT was decreased when maternal tissue was present. Also, as pregnancy progressed, maternal placental tissue seemed to contribute to the pool of unidentified metabolites. In conclusion, fetal placental tissue seems to be the major source of the AA metabolites when compared with maternal placental tissue, and AA metabolism by bovine placental tissue is markedly increased throughout the last month of pregnancy, suggesting a role for AA metabolites in mechanisms controlling parturition

Effect of Eu(III) on the degradation of malic acid by Pseudomonas fluorescens

International Nuclear Information System (INIS)

Nankawa, T.; Ozaki, T.; Ohnuki, T.; Suzuki, Y.; Francis, A.J.

2005-01-01

Full text of publication follows: The transuranic elements, such as Am(III) and Cm(III), are highly toxic because they emit high-energy α particles and have long half-lives. To estimate their long-term environmental behavior, we need to elucidate degradation of actinide-organic complexes by microorganisms. We studied the biodegradation of Eu(III)-malic acid complexes by Pseudomonas fluorescens. Malic acid is ubiquitous in the environment and is one of the microbial metabolites that is part of the tri-carboxylic acid (TCA) cycle. Europium(III) is a good analogue for Am(III) and Cm(III). To investigate the effect of Eu(III) on the degradation of malic acid by P. fluorescens, we compared the degradation behavior of Eu(III)-malic acid complexes to that of Fe(III) and Al(III)-malic acid complexes. In the medium containing 1 mM malic acid and 0-0.5 mM Fe(III), malic acid was degraded completely. In the medium containing 1 mM malic acid and 0.05-0.5 mM Al(III), malic acid was degraded until the concentration of malic acid became equal to that of Al(III), indicating that Al(III)-malic acid complex with 1: 1 molar ratio was recalcitrant to biodegradation. In the medium containing 1 mM malic acid and 0.05-0.5 mM Eu(III), degradation of malic acid was not observed. The effect of metals on degradation of malic acid was in the order of Fe(III) < Al(III) < Eu(III). The stability constants of 1:1 Fe(III)-, Al(III)-, and Eu(III)-malic acid complexes are 7.1, 4.6, and 4.9, respectively. These results indicate that degradability of malic acid does not depend on the stability constants of metal-malic acid complexes. We found that 10 mM malic acid was degraded in the presence of 0.05 and 0.1 mM Eu(III) but 1 mM malic acid was not degraded in the presence of 0.05 and 0.1 mM Eu(III). The degradation rate of malic acid increased with a decreasing ratio of Eu(III) to malic acid. (authors)

Poly(Aspartic Acid) Degradation by a Sphingomonas sp. Isolated from Freshwater

OpenAIRE

Tabata, Kenji; Kasuya, Ken-Ichi; Abe, Hideki; Masuda, Kozue; Doi, Yoshiharu

1999-01-01

A poly(aspartic acid) degrading bacterium (strain KT-1 [JCM10459]) was isolated from river water and identified as a member of the genus Sphingomonas. The isolate degraded only poly(aspartic acid)s of low molecular masses (

Main chain acid-degradable polymers for the delivery of bioactive materials

Science.gov (United States)

Frechet, Jean M. J. [Oakland, CA; Standley, Stephany M [Evanston, IL; Jain, Rachna [Milpitas, CA; Lee, Cameron C [Cambridge, MA

2012-03-20

Novel main chain acid degradable polymer backbones and drug delivery systems comprised of materials capable of delivering bioactive materials to cells for use as vaccines or other therapeutic agents are described. The polymers are synthesized using monomers that contain acid-degradable linkages cleavable under mild acidic conditions. The main chain of the resulting polymers readily degrade into many small molecules at low pH, but remain relatively stable and intact at physiological pH. The new materials have the common characteristic of being able to degrade by acid hydrolysis under conditions commonly found within the endosomal or lysosomal compartments of cells thereby releasing their payload within the cell. The materials can also be used for the delivery of therapeutics to the acidic regions of tumors and other sites of inflammation.

Essential function of linoleic acid esterified in acylglucosylceramide and acylceramide in maintaining the epidermal water permeability barrier. Evidence from feeding studies with oleate, linoleate, arachidonate, columbinate and a-linolenate

DEFF Research Database (Denmark)

Hansen, Harald S.; Jensen, B.

1985-01-01

sphingolipids. These rats showed increased evaporation which was comparable to that of essential fatty acid-deficient rats. We interpret these results as strong evidence for a very specific and essential function of linoleic acid in maintaining the integrity of the epidermal water permeability barrier......Essential fatty acid-deficient rats were supplemented with 300 mg per day of pure fatty acid esters: oleate (O), linoleate (L), arachidonate (A), and columbinate (C) for 10 days. During this period, the rats in groups L, A, and C all showed a decrease in their initially high trans-epidermal water...... loss, a classical essential fatty acid-deficiency symptom, to a level seen in non-deficient rats (group N). The trans-epidermal water loss in rats of group O was unaffected by the supplementation. Fatty acid composition of two epidermal sphingolipids, acylglucosylceramide and acylceramide, from...

Water and UV degradable lactic acid polymers

Science.gov (United States)

Bonsignore, P.V.; Coleman, R.D.

1996-10-08

A water and UV light degradable copolymer is described made from monomers of lactic acid and a modifying monomer selected from the class consisting of ethylene glycol, propylene glycol, P-dioxanone, 1,5 dioxepan-2-one, 1,4-oxathialan-2-one, 1,4-dioxide and mixtures thereof. These copolymers are useful for waste disposal and agricultural purposes. Also disclosed is a water degradable blend of polylactic acid or modified polylactic acid and high molecular weight polyethylene oxide wherein the high molecular weight polyethylene oxide is present in the range of from about 2 by weight to about 50% by weight, suitable for films. A method of applying an active material selected from the class of seeds, seedlings, pesticides, herbicides, fertilizers and mixtures thereof to an agricultural site is also disclosed.

Influence of humic acid on the trichloroethene degradation by Dehalococcoides-containing consortium

International Nuclear Information System (INIS)

Hu Miao; Zhang Ying; Wang Zhigang; Jiang Zhao; Li Juan

2011-01-01

By taking an anaerobic Dehalococcoides-containing consortium (designated UC-1) as the research object, the influence of humic acid on the degradation of TCE by UC-1 was examined. The results indicated that (i) TCE was more rapidly degraded in the presence of humic acid compared with the control and the TCE removal efficiencies increased with the increase of concentrations of humic acid; and (ii) at the end of experiments, in the presence of humic acid, much more ethene was produced compared with the control, whereas less VC was accumulated in the medium. Presumably, humic acid improves the activity of organisms in dechlorinating populations resulting in more ethene accumulated in the medium, and (iii) the degradation of TCE stimulated by humic acid by UC-1 might be a biotic process or an abiotic process. Thus, humic acid could influence the degradation of TCE by UC-1 directly via enhancing electron transfer between UC-1 and TCE. This work is a preliminary step for accelerating the degradation of TCE in the groundwater environment using a kind of natural organic matter - humic acid.

Influence of humic acid on the trichloroethene degradation by Dehalococcoides-containing consortium

Energy Technology Data Exchange (ETDEWEB)

Hu Miao [School of Resources Environment, Northeast Agricultural University, Harbin 150030 (China); Zhang Ying, E-mail: zhangyinghr@hotmail.com [School of Resources Environment, Northeast Agricultural University, Harbin 150030 (China); Wang Zhigang; Jiang Zhao; Li Juan [School of Resources Environment, Northeast Agricultural University, Harbin 150030 (China)

2011-06-15

By taking an anaerobic Dehalococcoides-containing consortium (designated UC-1) as the research object, the influence of humic acid on the degradation of TCE by UC-1 was examined. The results indicated that (i) TCE was more rapidly degraded in the presence of humic acid compared with the control and the TCE removal efficiencies increased with the increase of concentrations of humic acid; and (ii) at the end of experiments, in the presence of humic acid, much more ethene was produced compared with the control, whereas less VC was accumulated in the medium. Presumably, humic acid improves the activity of organisms in dechlorinating populations resulting in more ethene accumulated in the medium, and (iii) the degradation of TCE stimulated by humic acid by UC-1 might be a biotic process or an abiotic process. Thus, humic acid could influence the degradation of TCE by UC-1 directly via enhancing electron transfer between UC-1 and TCE. This work is a preliminary step for accelerating the degradation of TCE in the groundwater environment using a kind of natural organic matter - humic acid.

Arachidonic acid-and docosahexaenoic acid-enriched formulas modulate antigen-specific T cell responses to influenza virus in neonatal piglets.

Science.gov (United States)

Bassaganya-Riera, Josep; Guri, Amir J; Noble, Alexis M; Reynolds, Kathryn A; King, Jennifer; Wood, Cynthia M; Ashby, Michael; Rai, Deshanie; Hontecillas, Raquel

2007-03-01

Whereas the immunomodulatory effects of feeding either arachidonic acid (AA) or docosahexaenoic acid (DHA) separately have been previously investigated, little is known about the immunomodulatory efficacy of AA or DHA when they are fed in combination as infant formula ingredients. The objective of this study was to investigate the ability of AA- and DHA(AA/DHA)-enriched infant formula to modulate immune responses in the neonate in response to an inactivated influenza virus vaccine. Neonatal piglets (n = 48) were weaned on day 2 of age and distributed into 16 blocks of 3 littermate piglets each. Within each block, piglets were randomly assigned to a control formula, AA/DHA-enriched formula (0.63% AA and 0.34% DHA), or sow milk for 30 d. On day 9, 8 blocks of piglets were immunized with an inactivated influenza virus vaccine. On days 0, 9, 16, 23, and 30 after weaning, we measured influenza virus-specific T cell proliferation and phenotype of T subsets in peripheral blood. A delayed-type hypersensitivity reaction test was administered on day 28. Cytokine messenger RNA expression was determined by quantitative real time reverse transcriptase-polymerase chain reaction on day 30. The influenza virus-specific CD4(+) and CD8(+) T cell ex vivo lymphoproliferative responses were significantly lower on day 23 after immunization in piglets receiving dietary AA/DHA supplementation and sow milk than in those receiving the unsupplemented control formula. The immunomodulatory effects of AA/DHA-enriched formulas were consistent with up-regulation of interleukin 10 in peripheral blood mononuclear cells. Overall, it appears that the AA/DHA-enriched formula modulated antigen-specific T cell responses in part through an interleukin 10-dependent mechanism.

Humic Acid Degradation by ZnO Photocatalyst

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Sekartaji Putri A.

2016-01-01

Full Text Available Humic acid (HA is universally present in soils and natural water resources in a yellow-brown form. HA can react with chlorine during drinking water treatment and produce disinfection byproducts (DBPs, such as trihalomethanes (THMs and haloacetic acids (HAAs, which are harmful for health. Therefore, HA has to be eliminated from water environment. The photocatalysis is an effective alternative solution for the degradation of HA in a water environment. This research aims to degrade HA from water environment. The rapid degradation of HA, using zinc oxide nanoparticles, irradiated by ultraviolet light (ZnO/UV, is investigated. The optimum conditions of pertinent factors, which include the light wavelength (UV-A and UV-C, and light intensity, HA concentration, ZnO dose, and contact time are investigated at neutral pH conditions, considered for drinking water treatment. HA degradation efficiency reached more than 80% after 60 min for both types of irradiation in optimum conditions of 0.3 g/L ZnO dose in 180 min of contact time. Comparisons for degradation efficiency under UV-A and UV-C irradiation indicate that UV-C has higher efficiency, up to 150 min of contact time. The reusability of catalyst is performed for three reuses and still revealed effective for beneficial commercial applications.

Enhancement of carboxylic acid degradation with sulfate radical generated by persulfate activation.

Science.gov (United States)

Criquet, J; Nebout, P; Karpel Vel Leitner, N

2010-01-01

The aim of this work was to investigate the generation of sulfate radical for the removal of two carboxylic acids in aqueous solution: acetic and citric acids. From photochemical and radiolytic processes, kinetics of the degradation of these two carboxylic acids was studied as a function of the pH of the solution. It was shown that the maximum of acetic acid degradation occurred at pH 5. Above this pH, competitive reactions with the carbon mineralized inhibit the reaction of with the solute. In the case of citric acid, pH has only a little effect on the kinetic of citric acid degradation. The determination of mineralization yields shows several differences depending on carboxylic acids and pH. The degradation of both carboxylic acids was also studied in the radiolysis process whether with or without persulfate addition. A comparison of the processes of sulfate radical production is presented.

The effect of non-steroidal anti-inflammatory drugs on the metabolism of 14C-arachidonic acid by human gingival tissue in vitro

International Nuclear Information System (INIS)

Elattar, T.M.; Lin, H.S.; Tira, D.E.

1983-01-01

We investigated the effect of non-steroidal anti-inflammatory drugs on prostaglandins (PGs) and 12-hydroxyeicosatetraenoic acid (12-HETE) formation by inflamed human gingival tissues. Gingival tissue homogenates were incubated with 14 C-arachidonic acid in the presence of indomethacin, piroxicam, or ibuprofen, and the organic solvent extracts were chromatographed on silica gel plates with standards for radiometric assay. There was a significant negative trend between the doses (10(-7)-10(-3) M) of each of indomethacin, piroxicam, and ibuprofen, and the amounts of PGF2 alpha, PGE2, PGD2, and 15-keto-PGE2 produced. All three drugs have a significant inhibitory effect on PGs and 12-HETE production at 10(-3) M when compared with the control. The rank order effectiveness of the drugs, at 10(-3) M, on PG inhibition was indomethacin greater than piroxicam greater than ibuprofen, and on 12-HETE inhibition was indomethacin greater than ibuprofen greater than piroxicam

Arachidonic acid metabolism in fibroblasts derived from canine myocardium

International Nuclear Information System (INIS)

Weber, D.R.; Prescott, S.M.

1986-01-01

Canine fibroblasts from normal or healing infarcted myocardium were grown in culture. The cells were morphologically indistinguishable, but the doubling time of cells from healing myocardium was 39.6 +/- 3.5 hr whereas that of normals was 24 +/- 3.7 (n=5, p 3 H]arachidonate (AA) into phospholipids. Calcium ionophore A23187 (10 μM) caused release and metabolism of [ 3 H] AA. A23187 or AA (10μM) induced production of 6-keto PGF1α, PGE2, and a hydroxy metabolite of AA. RIA of 6-keto PGF1α showed that subconfluent cells from healing myocardium produced 1202 +/- 354 pg/mg protein whereas that of normals was 551 +/- 222 (n=7, p 3 H]AA released but did not metabolize [ 3 H]AA. In coincubations, fibroblasts incorporated myocyte-derived AA. Subsequent stimulation of the fibroblasts with A23187 induced the synthesis of 6-keto PGF1α, PGE2 and a hydroxy metabolite. The fibroblast content of healing myocardium was 35-1000 times that of normal tissue (n=7). Thus even a moderate change in AA metabolism, amplified by the AA released from deteriorating myocytes, may be a significant physiologic or pathologic event

Developmental Outcomes at 24 Months of Age in Toddlers Supplemented with Arachidonic Acid and Docosahexaenoic Acid: Results of a Double Blind Randomized, Controlled Trial

Science.gov (United States)

Devlin, Angela M.; Chau, Cecil M. Y.; Matheson, Julie; McCarthy, Deanna; Yurko-Mauro, Karin; Innis, Sheila M.; Grunau, Ruth E.

2017-01-01

Little is known about arachidonic acid (ARA) and docosahexaenoic acid (DHA) requirements in toddlers. A longitudinal, double blind, controlled trial in toddlers (n = 133) age 13.4 ± 0.9 months (mean ± standard deviation), randomized to receive a DHA (200 mg/day) and ARA (200 mg/day) supplement (supplement) or a corn oil supplement (control) until age 24 months determined effects on neurodevelopment. We found no effect of the supplement on the Bayley Scales of Infant and Toddler Development 3rd Edition (Bayley-III) cognitive and language composites and Beery–Buktenica Developmental Test of Visual–Motor Integration (Beery VMI) at age 24 months. Supplemented toddlers had higher RBC phosphatidylcholine (PC), phosphatidylethanolamine (PE), and plasma DHA and ARA compared to placebo toddlers at age 24 months. A positive relationship between RBC PE ARA and Bayley III Cognitive composite (4.55 (0.21–9.00), B (95% CI), p = 0.045) in supplemented boys, but not in control boys, was observed in models adjusted for baseline fatty acid, maternal non-verbal intelligence, and BMI z-score at age 24 months. A similar positive relationship between RBC PE ARA and Bayley III Language composite was observed for supplemented boys (11.52 (5.10–17.94), p < 0.001) and girls (11.19 (4.69–17.68), p = 0.001). These findings suggest that increasing the ARA status in toddlers is associated with better neurodevelopment at age 24 months. PMID:28878181

Developmental Outcomes at 24 Months of Age in Toddlers Supplemented with Arachidonic Acid and Docosahexaenoic Acid: Results of a Double Blind Randomized, Controlled Trial

Directory of Open Access Journals (Sweden)

Angela M. Devlin

2017-09-01

Full Text Available Little is known about arachidonic acid (ARA and docosahexaenoic acid (DHA requirements in toddlers. A longitudinal, double blind, controlled trial in toddlers (n = 133 age 13.4 ± 0.9 months (mean ± standard deviation, randomized to receive a DHA (200 mg/day and ARA (200 mg/day supplement (supplement or a corn oil supplement (control until age 24 months determined effects on neurodevelopment. We found no effect of the supplement on the Bayley Scales of Infant and Toddler Development 3rd Edition (Bayley-III cognitive and language composites and Beery–Buktenica Developmental Test of Visual–Motor Integration (Beery VMI at age 24 months. Supplemented toddlers had higher RBC phosphatidylcholine (PC, phosphatidylethanolamine (PE, and plasma DHA and ARA compared to placebo toddlers at age 24 months. A positive relationship between RBC PE ARA and Bayley III Cognitive composite (4.55 (0.21–9.00, B (95% CI, p = 0.045 in supplemented boys, but not in control boys, was observed in models adjusted for baseline fatty acid, maternal non-verbal intelligence, and BMI z-score at age 24 months. A similar positive relationship between RBC PE ARA and Bayley III Language composite was observed for supplemented boys (11.52 (5.10–17.94, p < 0.001 and girls (11.19 (4.69–17.68, p = 0.001. These findings suggest that increasing the ARA status in toddlers is associated with better neurodevelopment at age 24 months.

Arachidonic acid-mediated inhibition of a potassium current in the giant neurons of Aplysia

International Nuclear Information System (INIS)

Carlson, R.O.

1990-01-01

Biochemical and electrophysiological approaches were used to investigate the role of arachidonic acid (AA) in the modulation of an inwardly rectifying potassium current (I R ) in the giant neurons of the marine snail, Aplysia californica. Using [ 3 H]AA as tracer, the intracellular free AA pool in Aplysia ganglia was found to be in a state of constant and rapid turnover through deacylation and reacylation of phospholipid, primarily phosphatidyl-inositol. This constant turnover was accompanied by a constant release of free AA and eicosanoids into the extracellular medium. The effects of three pharmacological agents were characterized with regard to AA metabolism in Aplysia ganglia. 4-O-tetra-decanoylphorbol 13-acetate (TPA), an activator of protein kinase C, stimulated liberation of AA from phospholipid, and 4-bromophenacylbromide (BPB), an inhibitor of phospholipate A 2 , inhibited this liberation. Indomethacin at 250 μM was found to inhibit uptake of AA, likely through inhibition of acyl-CoA synthetase. These agents were also found to modulate I R in ways which were consistent with their biological effects: TPA inhibited I R , and both BPB and indomethacin stimulated I R . Modulation of I R by these substances was found not to involve cAMP metabolism. Acute application of exogenous AA did not affect I R ; however, I R in giant neurons was found to be inhibited after dialysis with AA or other unsaturated fatty acids. Also, after perfusion with BSA overnight, a treatment which strips the giant neurons of AA in lipid storage, I R was found to have increased over 2-fold. This perfusion-induced increase was inhibited by the presence of AA or by pretreatment of the giant neurons with BPB. These results suggest AA, provided through constant turnover from phospholipid, mediates constitutive inhibition of I R

A role for AMPK in the inhibition of glucose-6-phosphate dehydrogenase by polyunsaturated fatty acids

Energy Technology Data Exchange (ETDEWEB)

Kohan, Alison B.; Talukdar, Indrani; Walsh, Callee M. [Department of Biochemistry, West Virginia University, Morgantown, WV (United States); Salati, Lisa M., E-mail: lsalati@hsc.wvu.edu [Department of Biochemistry, West Virginia University, Morgantown, WV (United States)

2009-10-09

Both polyunsaturated fatty acids and AMPK promote energy partitioning away from energy consuming processes, such as fatty acid synthesis, towards energy generating processes, such as {beta}-oxidation. In this report, we demonstrate that arachidonic acid activates AMPK in primary rat hepatocytes, and that this effect is p38 MAPK-dependent. Activation of AMPK mimics the inhibition by arachidonic acid of the insulin-mediated induction of G6PD. Similar to intracellular signaling by arachidonic acid, AMPK decreases insulin signal transduction, increasing Ser{sup 307} phosphorylation of IRS-1 and a subsequent decrease in AKT phosphorylation. Overexpression of dominant-negative AMPK abolishes the effect of arachidonic acid on G6PD expression. These data suggest a role for AMPK in the inhibition of G6PD by polyunsaturated fatty acids.

Effects of organic acids, amino acids and ethanol on the radio-degradation of patulin in an aqueous model system

International Nuclear Information System (INIS)

Yun, Hyejeong; Lim, Sangyong; Jo, Cheorun; Chung, Jinwoo; Kim, Soohyun; Kwon, Joong-Ho; Kim, Dongho

2008-01-01

The effects of organic acids, amino acids, and ethanol on the radio-degradation of patulin by gamma irradiation in an aqueous model system were investigated. The patulin, dissolved in distilled water at a concentration of 50 ppm, was practically degraded by the gamma irradiation at the dose of 1.0 kGy, while 33% of the patulin remained in apple juice. In the aqueous model system, the radio-degradation of patulin was partially inhibited by the addition of organic acids, amino acids, and ethanol. The proportions of remaining patulin after irradiation with the dose of 1.0 kGy in the 1% solution of malic acid, citric acid, lactic acid, acetic acid, ascorbic acid, and ethanol were 31.4%, 2.3%, 31.2%, 6.1%, 50.8%, and 12.5%, respectively. During 30 days of storage, the remaining patulin was reduced gradually in the solution of ascorbic acid and malic acid compared to being stable in other samples. The amino acids, serine, threonine, and histidine, inhibited the radio-degradation of patulin. In conclusion, it was suggested that 1 kGy of gamma irradiation (recommended radiation doses for radicidation and/or quarantine in fruits) is effective for the reduction of patulin, but the nutritional elements should be considered because the radio-degradation effects are environment dependent

Biologically Safe Poly(l-lactic acid) Blends with Tunable Degradation Rate: Microstructure, Degradation Mechanism, and Mechanical Properties.

Science.gov (United States)

Oyama, Hideko T; Tanishima, Daisuke; Ogawa, Ryohei

2017-04-10

Although poly(l-lactic acid) (PLLA) is reputed to be biodegradable in the human body, its hydrophobic nature lets it persist for ca. 5.5 years. This study demonstrates that biologically safe lactide copolymers, poly(aspartic acid-co-l-lactide) (PAL) and poly(malic acid-co-l-lactide) (PML), dispersed in the PLLA function as detonators (triggers) for its hydrolytic degradation under physiological conditions. The copolymers significantly enhance hydrolysis, and consequently, the degradation rate of PLLA becomes easily tunable by controlling the amounts of PAL and PML. The present study elucidates the effects of uniaxial drawing on the structural development, mechanical properties, and hydrolytic degradation under physiological conditions of PLLA blend films. At initial degradation stages, the mass loss was not affected by uniaxial drawing; however, at late degradation stages, less developed crystals as well as amorphous chains were degradable at low draw ratio (DR), whereas not only highly developed crystals but also the oriented amorphous chains became insensitive to hydrolysis at high DR. Our work provides important molecular level results that demonstrate that biodegradable materials can have superb mechanical properties and also disappear in a required time under physiological conditions.

Varying Conditions for Hexanoic Acid Degradation with BioTiger™

Energy Technology Data Exchange (ETDEWEB)

Foreman, Koji [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Milliken, Charles [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Brigmon, Robin [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2016-07-27

BioTiger™ (BT) is a consortium of 12 bacteria designed for petroleum waste biodegradation. BT is currently being studied and could be considered for bioremediation of the Athabasca oil sands refineries in Canada and elsewhere. The run-off ponds from the petroleum extraction processes, called tailings ponds, are a mixture of polycyclic aromatic hydrocarbons, naphthenic acids, hydrocarbons, toxic chemicals like heavy metals, water, and sand. Due to environmental regulations the oil industry would like to separate and degrade the hazardous chemical species from the tailings ponds while recycling the water. It has been shown that BT at 30 C° is able to completely degrade 10 mM hexanoic acid (HA) co-metabolically with 0.2% yeast extract (w/v) in 48 hours when starting at 0.4 OD 600nm. After establishing this stable degradation capability, variations were tested to explore the wider parameters of BT activity in temperature, pH, intermediate degradation, co-metabolic dependence, and transfer stability. Due to the vast differences in temperature at various points in the refineries, a wide range of temperatures were assessed. The results indicate that BT retains the ability to degrade HA, a model surrogate for tailings pond contaminants, at temperatures ranging from 15°C to 35°C. Hexanamide (HAM) was shown to be an intermediate generated during the degradation of HA in an earlier work and HAM is completely degraded after 48 hours, indicating that HAM is not the final product of HA degradation. Various replacements for yeast extract were attempted. Glucose, a carbon source; casein amino acids, a protein source; additional ammonia, mimicking known media; and additional phosphate with Wolffe’s vitamins and minerals all showed no significant degradation of HA compared to control. Decreasing the yeast extract concentration (0.05%) demonstrated limited but significant degradation. Finally, serial inoculations of BT were performed to determine the stability of degradation

Anaerobic degradation of linoleic oleic acids

Energy Technology Data Exchange (ETDEWEB)

Lalman, J.A.; Bagley, D.M.

1999-07-01

The anaerobic degradation of linoleic (C18:2) and oleic (C18:1) acids was examined in batch experiments. By-product distribution depended on both the type of long chain fatty acid added and initial substrate concentration. Major by-products were palmitic (C16), myristic (C14) and acetic acids. Trace quantities of palmitoleic (C16:1) and lauric (C12) acids were observed together with larger amounts of palmitic (C16), myristic (C14) and hexanoic (C6) acids in cultures incubated with 100 mg/L linoleic (C18:2) acid. Bio-hydrogenation of C18 fatty acids was not necessary for the {beta}-oxidation mechanism to proceed. Aceticlastic methanogenic inhibition was observed in cultures inoculated with greater than 50 mg/L linoleic (C18:2) acid. In cultures incubated with greater than 50 mg/L oleic (C18:1) acid, aceticlastic methanogenic inhibition was observed for a short time period.

Platelet Arachidonic Acid Deficiency May Contribute to Abnormal Platelet Function During Parenteral Fish Oil Monotherapy in a Piglet Model.

Science.gov (United States)

Turner, Justine M; Field, Catherine J; Goruk, Sue; Wizzard, Pamela; Dicken, Bryan J; Bruce, Aisha; Wales, Paul W

2016-05-01

Fish oil monotherapy has been an advance for treating intestinal failure-associated liver disease (IFALD). However, such patients are at risk of bleeding complications from liver disease and because fish oil can inhibit thrombosis. We have previously reported abnormal platelet function in neonatal piglets given fish oil monotherapy during parenteral nutrition (PN). The purpose of this study was to determine if abnormal fatty acid composition of the platelets could explain the prior observed antiplatelet effect. Neonatal piglets were assigned to 2 treatments: PN with fish oil monotherapy (FO; n = 4) or PN with soy oil (SO; n = 5). On day 14, plasma was collected and platelets isolated by centrifuging. The fatty acid content in plasma and platelet plug were measured using gas liquid chromatography and compared with controls (CON; n = 5). The arachidonic acid (AA) content in the FO group was on average half that of the SO group, in both the platelets (FO, 3.5% vs SO, 7.6%; P = .021; CON, 4.5%-11%) and the plasma (FO, 3.8% vs SO, 9.2%; P = .002; CON, 6.1%-9.5%). No bleeding complications were observed for any piglets during PN treatment. Using platelet mapping, we have previously shown that neonatal piglets given fish oil monotherapy have abnormal platelet function in the AA pathway. This report demonstrates that such an abnormality can be explained by platelet AA deficiency. Platelet mapping and platelet fatty acid analysis should be undertaken in human infants treated with fish oil monotherapy during PN. © 2015 American Society for Parenteral and Enteral Nutrition.

Experimental and modeling study of Portland cement paste degradation in boric acid

International Nuclear Information System (INIS)

Benakli, A.; Chomat, L.; Le Bescop, P.; Wall, J.

2015-01-01

In the framework of Spent Fuel Pools (SFP) lifetime studies, an investigation of the Portland cement degradation in boric acid has been requested by the Electric Power Research Institute. The main goal of this study is to identify the physico-chemical degradation mechanisms involved in boric acid media. Both experimental and modeling approaches are considered. Concerning degradation experiments, sample of cement paste are immersed during three and nine months in a boric acid solution at 2400 ppm that is periodically renewed. Boric acid concentration has been chosen to be representative of SFP solution. Results will be confronted with reactive transport numerical calculations performed by the reactive transport code HYTEC associated with a dedicated extended database called Thermoddem. The analysis of degradation solution revealed a main ions release mechanism driven by diffusion especially for calcium, nitrate, sodium and sulfate. Leaching behavior of magnesium seems to be more complex. Decalcification is the major degradation process involved, even if a non-negligible contribution of further cations (Mg 2+ , Na + ) and anions (SO 4 2- ) has been noticed. Analysis of degradation soution also revealed that kinetic of Portland cement paste degradation in boric acid is higher than in pure water, regarding the degraded depths measured and calcium leaching rate. This observation has been confirmed by solid characterization. Microstructure analysis of degraded Portland cement paste showed a global porosity increase in the degraded zone that might be mainly attributed to Portlandite dissolution. An Ettringite reprecipitation in the degraded zone has been suspected but could also be Ettringite-like phases containing boron. The analysis techniques used did not allow us to differentiate it, and no others specific mineral phases containing boron has been identified. Profile pattern by XRD analysis allowed us to identify four zones composing the degraded Portland cement paste

Prostacyclin production in rabbit arteries in situ: inhibition by arachidonic acid-induced endothelial cell damage or by low-dose aspirin.

Science.gov (United States)

Ingerman-Wojenski, C; Silver, M J; Smith, J B; Nissenbaum, M; Sedar, A W

1981-04-01

The central artery of the rabbit ear was perfused in situ and effluent fractions from the artery were assayed for 6-keto-prostaglandin F1 alpha (6-K-PGF1 alpha) and thromboxane B2 (TxB2), the stable metabolites of prostacyclin (PGI2) and TxA2, using specific radioimmunoassays. These metabolites of arachidonic acid (AA) were not detected in the effluent during infusion of Tyrode's solution but both metabolites were detected when small amounts of AA were infused into the artery. Examination of the arteries by scanning electron microscopy revealed that high concentrations of AA which caused a short burst of 6-K-PGF1 alpha and TxB2 production damaged the endothelial cells while lower concentrations which stimulated continuous production did not cause damage. When a non-damaging concentration of AA was infused into an artery that had previously received a damaging concentration, PG production was greatly reduced. Pretreatment of the rabbits with 4 mg/kg acetyl-salicylic acid (ASA) inhibited 6-K-PGF1 alpha production by the rabbit ear artery in response to AA and 70% inhibition was still evident 18 hours after ASA.

Hydroxyurea Therapy Mobilises Arachidonic Acid from Inner Cell Membrane Aminophospholipids in Patients with Homozygous Sickle Cell Disease

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A. A. Daak

2011-01-01

Full Text Available The cytotoxic compound hydroxyurea (HU is effective therapy for sickle cell disease. However, its effect on unsaturated membrane lipids is unknown. Red cell fatty acids were investigated in HU-treated (n=19 and HU-untreated (n=17 sickle cell patients and controls (n=20. The HU-treated compared with the HU-untreated patients had lower arachidonic (AA acid level in ethanolamine, physphoglycerids (EPG (22.9±1.2   versus   24.0±1.1%,  P<0.05 serine SPG (22.13±2.2   versus   24.9±2.3%,  P<0.01 phosphoglycerides. The treated patients and controls had comparable levels of docosahexaenoic (DHA and total n-3 fatty acids in EPG and choline phosphoglycerides (CPG. In contrast, the untreated group had significantly (P<0.05 lower DHA and total n-3 compared with the controls in EPG (2.7±0.4   versus   3.2±0.6% and 4.6±0.5   versus   5.2±0.7% and CPG (0.7±0.2   versus   1.0±0.2% and 1.2±0.2   versus   1.4±0.3. HU is known to activate cytosolic phospholipase A2 and cyclooxygenase 2, and from this study, it appears to induce mobilisation of AA from the inner cell membrane EPG and SPG. Hence, eicosanoids generated from the released AA may play a role in clinical improvements which occur in HU-treated patients.

The effect of non-steroidal anti-inflammatory drugs on the metabolism of /sup 14/C-arachidonic acid by human gingival tissue in vitro

Energy Technology Data Exchange (ETDEWEB)

Elattar, T.M.; Lin, H.S.; Tira, D.E.

1983-09-01

We investigated the effect of non-steroidal anti-inflammatory drugs on prostaglandins (PGs) and 12-hydroxyeicosatetraenoic acid (12-HETE) formation by inflamed human gingival tissues. Gingival tissue homogenates were incubated with /sup 14/C-arachidonic acid in the presence of indomethacin, piroxicam, or ibuprofen, and the organic solvent extracts were chromatographed on silica gel plates with standards for radiometric assay. There was a significant negative trend between the doses (10(-7)-10(-3) M) of each of indomethacin, piroxicam, and ibuprofen, and the amounts of PGF2 alpha, PGE2, PGD2, and 15-keto-PGE2 produced. All three drugs have a significant inhibitory effect on PGs and 12-HETE production at 10(-3) M when compared with the control. The rank order effectiveness of the drugs, at 10(-3) M, on PG inhibition was indomethacin greater than piroxicam greater than ibuprofen, and on 12-HETE inhibition was indomethacin greater than ibuprofen greater than piroxicam.

Valnoctamide, which reduces rat brain arachidonic acid turnover, is a potential non-teratogenic valproate substitute to treat bipolar disorder.

Science.gov (United States)

Modi, Hiren R; Ma, Kaizong; Chang, Lisa; Chen, Mei; Rapoport, Stanley I

2017-08-01

Valproic acid (VPA), used for treating bipolar disorder (BD), is teratogenic by inhibiting histone deacetylase. In unanaesthetized rats, chronic VPA, like other mood stabilizers, reduces arachidonic acid (AA) turnover in brain phospholipids, and inhibits AA activation to AA-CoA by recombinant acyl-CoA synthetase-4 (Acsl-4) in vitro. Valnoctamide (VCD), a non-teratogenic constitutional isomer of VPA amide, reported effective in BD, also inhibits recombinant Acsl-4 in vitro. VCD like VPA will reduce brain AA turnover in unanaesthetized rats. A therapeutically relevant (50mg/kg i.p.) dose of VCD or vehicle was administered daily for 30 days to male rats. AA turnover and related parameters were determined using our kinetic model, following intravenous [1- 14 C]AA in unanaesthetized rats for 10min, and measuring labeled and unlabeled lipids in plasma and high-energy microwaved brain. VCD, compared with vehicle, increased λ, the ratio of brain AA-CoA to unesterified plasma AA specific activities; and decreased turnover of AA in individual and total brain phospholipids. VCD's ability like VPA to reduce rat brain AA turnover and inhibit recombinant Acsl-4, and its efficacy in BD, suggest that VCD be further considered as a non-teratogenic VPA substitute for treating BD. Published by Elsevier B.V.

Influence of water solubility, side chain degradability and side chain configuration on the degradation of phthalic acid esters under methanogenic conditions

Energy Technology Data Exchange (ETDEWEB)

Alnervik, M.

1996-12-31

Water solubility and degradability of side chains estrifying phthalic acid are factors possible to influence the degradation of phthalic acid esters (PAEs). To investigate the importance of these factors degradation of butyl 2-ethylhexyl phthalate (BEHP), bis(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), dihexyl phthalate (DHP), dioctyl phthalate (DOP) and didecyl phthalate (DDP) were examined under methanogenic conditions as well as was the degradability of the alcohols estrifying these PAEs. We also investigated if the degradation of resistant PAEs could be stimulated by the addition of a degradable PAE. Synthesis of degradation intermediates and two methods for PAE analyses are presented. The investigation showed that all alcohols were degraded to methane and carbon dioxide and that the degradation of PAE occurred in incubations amended with BBP, BEHP, DHP and DBP, whilst DEHP, DOP and DDP were unaffected throughout the experimental period. BBP added to incubations with DEHP, could not stimulate DEHP degradation. In conclusion, the degradability of alcohols estrifying phthalic acid in this study does not affect the anaerobic degradability of PAEs. Water solubility of a PAE can not be rejected as a factor limiting phthalate degradation under methanogenic conditions. Anaerobic degradation of persistent PAEs can not be stimulated by mixing it with a degradable phthalate. 23 refs, 11 figs, 2 tabs

Arachidonic acid-induced Ca2+ entry and migration in a neuroendocrine cancer cell line.

Science.gov (United States)

Goswamee, Priyodarshan; Pounardjian, Tamar; Giovannucci, David R

2018-01-01

Store-operated Ca 2+ entry (SOCE) has been implicated in the migration of some cancer cell lines. The canonical SOCE is defined as the Ca 2+ entry that occurs in response to near-maximal depletion of Ca 2+ within the endoplasmic reticulum. Alternatively, arachidonic acid (AA) has been shown to induce Ca 2+ entry in a store-independent manner through Orai1/Orai3 hetero-multimeric channels. However, the role of this AA-induced Ca 2+ entry pathway in cancer cell migration has not been adequately assessed. The present study investigated the involvement of AA-induced Ca 2+ entry in migration in BON cells, a model gastro-enteropancreatic neuroendocrine tumor (GEPNET) cell line using pharmacological and gene knockdown methods in combination with live cell fluorescence imaging and standard migration assays. We showed that both the store-dependent and AA-induced Ca 2+ entry modes could be selectively activated and that exogenous administration of AA resulted in Ca 2+ entry that was pharmacologically distinct from SOCE. Also, whereas homomeric Orai1-containing channels appeared to largely underlie SOCE, the AA-induced Ca 2+ entry channel required the expression of Orai3 as well as Orai1. Moreover, we showed that AA treatment enhanced the migration of BON cells and that this migration could be abrogated by selective inhibition of the AA-induced Ca 2+ entry. Taken together, these data revealed that an alternative Orai3-dependent Ca 2+ entry pathway is an important signal for GEPNET cell migration.

Effect of extracellular fatty acids on lipid metabolism in cultured rabbit articular chondrocytes

International Nuclear Information System (INIS)

Nagao, M.; Ishii, S.; Murata, Y.; Akino, T.

1991-01-01

Rabbit articular chondrocytes were cultured for 8 h in the presence of various concentrations (5-500 microM) of 14 C oleic, 14 C linoleic, and 3H arachidonic acids. The radioactive unsaturated fatty acids were incorporated into triacylglycerol (TG) and phosphatidylcholine (PC) in a concentration-dependent manner; more fatty acids were incorporated into TG than into PC, at higher concentrations of extracellular fatty acids. Among these fatty acids, arachidonic acid was incorporated into TG much more than into PC, in spite of a very low concentration of arachidonic acid in TG. After transfer of the labeled cells to maintenance medium, the radioactivity in TG declined rapidly and 3 H arachidonic acid radioactivity in PC increased continuously during the chase time periods. Palmitoyl-unsaturated species were mainly formed in PC when cultured at a concentration of 5 microM of each fatty acid. However, when cultured at 500 microM, unsaturated-unsaturated species, specific for each unsaturated fatty acid were actively formed. These findings indicate that (1) fatty acid composition of TG and PC in articular chondrocytes is influenced by the degree of fatty acid supply, (2) formation and turnover of TG plays a role in fatty acid metabolism of cells, and (3) fatty acid pairing in PC is modulated by extracellular fatty acid concentrations

Chemical composition and ruminal degradation kinetics of crude protein and amino acids, and intestinal digestibility of amino acids from tropical forages

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Lidia Ferreira Miranda

2012-03-01

Full Text Available The objective of this research was to determine the chemical composition and ruminal degradation of the crude protein (CP, total and individual amino acids of leaves from tropical forages: perennial soybean (Neonotonia wightii, cassava (Manihot esculenta, leucaena (Leucaena leucocephala and ramie (Boehmeria nivea, and to estimate the intestinal digestibility of the rumen undegradable protein (RUDP and individual amino acids of leaves from the tropical forages above cited, but including pigeon pea (Cajanus cajan. Three nonlactating Holstein cows were used to determine the in situ ruminal degradability of protein and amino acids from leaves (6, 18 and 48 hours of ruminal incubation. For determination of the intestinal digestibility of RUDP, the residue from ruminal incubation of the materials was used for 18 hours. A larger concentration of total amino acids for ramie and smaller for perennial soybean were observed; however, they were very similar in leucaena and cassava. Leucine was the essential amino acid of greater concentration, with the exception of cassava, which exhibited a leucine concentration 40.45% smaller. Ramie showed 14.35 and 22.31% more lysine and methionine, respectively. The intestinal digestibility of RUDP varied from 23.56; 47.87; 23.48; 25.69 and 10.86% for leucaena, perennial soybean, cassava, ramie and pigeon pea, respectively. The individual amino acids of tropical forage disappeared in different extensions in the rumen. For the correct evaluation of those forages, one should consider their composition of amino acids, degradations and intestinal digestibility, once the amino acid composition of the forage does not reflect the amino acid profiles that arrived in the small intestine. Differences between the degradation curves of CP and amino acids indicate that degradation of amino acids cannot be estimated through the degradation curve of CP, and that amino acids are not degraded in a similar degradation profile.

Kinetic study on the photocatalytic degradation of salicylic acid using ZnO catalyst

International Nuclear Information System (INIS)

Nageswara Rao, A.; Sivasankar, B.; Sadasivam, V.

2009-01-01

The photocatalytic degradation of salicylic acid was studied by a batch process using ZnO as the catalyst on irradiation with UV light. The effect of process parameters such as pH, catalyst loading and initial concentration of salicylic acid on the extent of degradation was investigated. The degradation of salicylic acid was found to be effective in the neutral pH range. The optimum catalyst loading was observed at 2.0 g/L. The process followed first order kinetics and the apparent rate constant decreased with increase in the initial concentration of salicylic acid. The mechanism for the degradation of salicylic acid could be explained on the basis of Langmuir-Hinshelwood mechanism. The complete mineralization of salicylic acid was observed in the presence of ZnO photocatalyst. The ZnO was found to be quite stable and undergoes photocorrosion only to a negligible extent.

Identification of an itaconic acid degrading pathway in itaconic acid producing Aspergillus terreus.

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Chen, Mei; Huang, Xuenian; Zhong, Chengwei; Li, Jianjun; Lu, Xuefeng

2016-09-01

Itaconic acid, one of the most promising and flexible bio-based chemicals, is mainly produced by Aspergillus terreus. Previous studies to improve itaconic acid production in A. terreus through metabolic engineering were mainly focused on its biosynthesis pathway, while the itaconic acid-degrading pathway has largely been ignored. In this study, we used transcriptomic, proteomic, bioinformatic, and in vitro enzymatic analyses to identify three key enzymes, itaconyl-CoA transferase (IctA), itaconyl-CoA hydratase (IchA), and citramalyl-CoA lyase (CclA), that are involved in the catabolic pathway of itaconic acid in A. terreus. In the itaconic acid catabolic pathway in A. terreus, itaconic acid is first converted by IctA into itaconyl-CoA with succinyl-CoA as the CoA donor, and then itaconyl-CoA is hydrated into citramalyl-CoA by IchA. Finally, citramalyl-CoA is cleaved into acetyl-CoA and pyruvate by CclA. Moreover, IctA can also catalyze the reaction between citramalyl-CoA and succinate to generate succinyl-CoA and citramalate. These results, for the first time, identify the three key enzymes, IctA, IchA, and CclA, involved in the itaconic acid degrading pathway in itaconic acid producing A. terreus. The results will facilitate the improvement of itaconic acid production by metabolically engineering the catabolic pathway of itaconic acid in A. terreus.

Changes in cholesterol content and fatty acid composition of serum lipid in irradiated rat

International Nuclear Information System (INIS)

Ohashi, Shigeru

1979-01-01

The effect of a single dose of whole body irradiation on the serum cholesterol content and fatty acid composition of serum lipids in rats was investigated. A change in the fatty acid composition of liver lipids was also observed. After 600 rad of irradiation, the cholesterol content increased, reached a maximum 3 days after irradiation, and then decreased. After irradiation, an increase in cholesterol content and a marked decrease in triglyceride content were observed, bringing about a change in the amount of total serum lipids. The fatty acid compositions of normal and irradiated rat sera were compared. The relative percentages of palmitic and oleic acids in total lipids decreased while those of stearic and arachidonic acids increased. Serum triglyceride had trace amounts of arachidonic acid and the unsaturated fatty acid component decreased after irradiation. On the other hand, unsaturated fatty acid in cholesterol ester increased after irradiation, while linoleic and arachidonic acids made up 29% and 22% in the controls and 17% and 61% after irradiation, respectively. The fatty acid composition of total liver lipids after irradiation showed a decrease in palmitic and oleic acids and an increase in stearic and arachidonic acids, the same trend as observed in serum lipid fatty acid. Liver cholesterol ester showed trace amounts of linoleic and arachidonic acids and an increase in short-chain fatty acid after irradiation. The major component of serum phospholipids was phosphatidylcholine while palmitostearyl lecithine and unsaturated fatty acid were minor components. Moreover, phosphatidylcholine and phosphatidylethanolamine were the major components of liver phospholipids, having highly unsaturated fatty acids. The changes in fatty acid composition were similar to the changes in total phospholipids. (J.P.N.)

Bifidobacterium breve with α-linolenic acid and linoleic acid alters fatty acid metabolism in the maternal separation model of irritable bowel syndrome.

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Barrett, Eoin; Fitzgerald, Patrick; Dinan, Timothy G; Cryan, John F; Ross, R Paul; Quigley, Eamonn M; Shanahan, Fergus; Kiely, Barry; Fitzgerald, Gerald F; O'Toole, Paul W; Stanton, Catherine

2012-01-01

The aim of this study was to compare the impact of dietary supplementation with a Bifidobacterium breve strain together with linoleic acid & α-linolenic acid, for 7 weeks, on colonic sensitivity and fatty acid metabolism in rats. Maternally separated and non-maternally separated Sprague Dawley rats (n = 15) were orally gavaged with either B. breve DPC6330 (10(9) microorganisms/day) alone or in combination with 0.5% (w/w) linoleic acid & 0.5% (w/w) α-linolenic acid, daily for 7 weeks and compared with trehalose and bovine serum albumin. Tissue fatty acid composition was assessed by gas-liquid chromatography and visceral hypersensitivity was assessed by colorectal distension. Significant differences in the fatty acid profiles of the non-separated controls and maternally separated controls were observed for α-linolenic acid and arachidonic acid in the liver, oleic acid and eicosenoic acid (c11) in adipose tissue, and for palmitoleic acid and docosahexaenoic acid in serum (pbreve DPC6330 to MS rats significantly increased palmitoleic acid, arachidonic acid and docosahexaenoic acid in the liver, eicosenoic acid (c11) in adipose tissue and palmitoleic acid in the prefrontal cortex (pbreve DPC6330 to non separated rats significantly increased eicosapentaenoic acid and docosapentaenoic acid in serum (pbreve DPC6330 in combination with linoleic acid and α-linolenic acid to maternally separated rats significantly increased docosapentaenoic acid in the serum (pbreve DPC6330 with fatty acid supplementation to non-separated rats significantly increased liver and serum docosapentaenoic acid (pbreve DPC6330 influenced host fatty acid metabolism. Administration of B. breve DPC6330 to maternally separated rats significantly modified the palmitoleic acid, arachidonic acid and docosahexaenoic acid contents in tissues. The effect was not observed in non-separated animals.

Varying Conditions for Hexanoic Acid Degradation with BioTigerTM

International Nuclear Information System (INIS)

Foreman, Koji; Milliken, Charles; Brigmon, Robin

2016-01-01

BioTiger TM (BT) is a consortium of 12 bacteria designed for petroleum waste biodegradation. BT is currently being studied and could be considered for bioremediation of the Athabasca oil sands refineries in Canada and elsewhere. The run-off ponds from the petroleum extraction processes, called tailings ponds, are a mixture of polycyclic aromatic hydrocarbons, naphthenic acids, hydrocarbons, toxic chemicals like heavy metals, water, and sand. Due to environmental regulations the oil industry would like to separate and degrade the hazardous chemical species from the tailings ponds while recycling the water. It has been shown that BT at 30 C° is able to completely degrade 10 mM hexanoic acid (HA) co-metabolically with 0.2% yeast extract (w/v) in 48 hours when starting at 0.4 OD 600nm. After establishing this stable degradation capability, variations were tested to explore the wider parameters of BT activity in temperature, pH, intermediate degradation, co-metabolic dependence, and transfer stability. Due to the vast differences in temperature at various points in the refineries, a wide range of temperatures were assessed. The results indicate that BT retains the ability to degrade HA, a model surrogate for tailings pond contaminants, at temperatures ranging from 15°C to 35°C. Hexanamide (HAM) was shown to be an intermediate generated during the degradation of HA in an earlier work and HAM is completely degraded after 48 hours, indicating that HAM is not the final product of HA degradation. Various replacements for yeast extract were attempted. Glucose, a carbon source; casein amino acids, a protein source; additional ammonia, mimicking known media; and additional phosphate with Wolffe's vitamins and minerals all showed no significant degradation of HA compared to control. Decreasing the yeast extract concentration (0.05%) demonstrated limited but significant degradation. Finally, serial inoculations of BT were performed to determine the stability of

Abscisic acid-regulated protein degradation causes osmotic stress-induced accumulation of branched-chain amino acids in Arabidopsis thaliana.

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Huang, Tengfang; Jander, Georg

2017-10-01

Whereas proline accumulates through de novo biosynthesis in plants subjected to osmotic stress, leucine, isoleucine, and valine accumulation in drought-stressed Arabidopsis thaliana is caused by abscisic acid-regulated protein degradation. In response to several kinds of abiotic stress, plants greatly increase their accumulation of free amino acids. Although stress-induced proline increases have been studied the most extensively, the fold-increase of other amino acids, in particular branched-chain amino acids (BCAAs; leucine, isoleucine, and valine), is often higher than that of proline. In Arabidopsis thaliana (Arabidopsis), BCAAs accumulate in response to drought, salt, mannitol, polyethylene glycol, herbicide treatment, and nitrogen starvation. Plants that are deficient in abscisic acid signaling accumulate lower amounts of BCAAs, but not proline and most other amino acids. Previous bioinformatic studies had suggested that amino acid synthesis, rather than protein degradation, is responsible for the observed BCAA increase in osmotically stressed Arabidopsis. However, whereas treatment with the protease inhibitor MG132 decreased drought-induced BCAA accumulation, inhibition of BCAA biosynthesis with the acetolactate synthase inhibitors chlorsulfuron and imazapyr did not. Additionally, overexpression of BRANCHED-CHAIN AMINO ACID TRANSFERASE2 (BCAT2), which is upregulated in response to osmotic stress and functions in BCAA degradation, decreased drought-induced BCAA accumulation. Together, these results demonstrate that BCAA accumulation in osmotically stressed Arabidopsis is primarily the result of protein degradation. After relief of the osmotic stress, BCAA homeostasis is restored over time by amino acid degradation involving BCAT2. Thus, drought-induced BCAA accumulation is different from that of proline, which is accumulated due to de novo synthesis in an abscisic acid-independent manner and remains elevated for a more prolonged period of time after removal of

Neutron scattering and HPLC study on L-ascorbic acid and its degradation

International Nuclear Information System (INIS)

Bellocco, E.; Barreca, D.; Lagana, G.; Leuzzi, U.; Migliardo, F.; Torre, R. La; Galli, G.; Galtieri, A.; Minutoli, L.; Squadrito, F.

2008-01-01

The present paper shows a systematic dynamic and kinetic study on L-ascorbic acid and its degradation at high temperature. The neutron scattering study allows, through the behavior of quasi-elastic neutron scattering (QENS) spectra, to characterize the diffusive dynamics of L-ascorbic acid in water mixtures. Ascorbic acid undergoes degradation process at high temperature, but the presence of trehalose in solution markedly avoids ascorbic acid loss enhancing its t 1/2 (half life time), as determined by high performance liquid chromatography (HPLC)

Isoliquiritigenin induces growth inhibition and apoptosis through downregulating arachidonic acid metabolic network and the deactivation of PI3K/Akt in human breast cancer

International Nuclear Information System (INIS)

Li, Ying; Zhao, Haixia; Wang, Yuzhong; Zheng, Hao; Yu, Wei; Chai, Hongyan; Zhang, Jing; Falck, John R.; Guo, Austin M.; Yue, Jiang; Peng, Renxiu; Yang, Jing

2013-01-01

Arachidonic acid (AA)-derived eicosanoids and its downstream pathways have been demonstrated to play crucial roles in growth control of breast cancer. Here, we demonstrate that isoliquiritigenin, a flavonoid phytoestrogen from licorice, induces growth inhibition and apoptosis through downregulating multiple key enzymes in AA metabolic network and the deactivation of PI3K/Akt in human breast cancer. Isoliquiritigenin diminished cell viability, 5-bromo-2′-deoxyuridine (BrdU) incorporation, and clonogenic ability in both MCF-7 and MDA-MB-231cells, and induced apoptosis as evidenced by an analysis of cytoplasmic histone-associated DNA fragmentation, flow cytometry and hoechst staining. Furthermore, isoliquiritigenin inhibited mRNA expression of multiple forms of AA-metabolizing enzymes, including phospholipase A2 (PLA2), cyclooxygenases (COX)-2 and cytochrome P450 (CYP) 4A, and decreased secretion of their products, including prostaglandin E 2 (PGE 2 ) and 20-hydroxyeicosatetraenoic acid (20-HETE), without affecting COX-1, 5-lipoxygenase (5-LOX), 5-lipoxygenase activating protein (FLAP), and leukotriene B 4 (LTB 4 ). In addition, it downregulated the levels of phospho-PI3K, phospho-PDK (Ser 241 ), phospho-Akt (Thr 308 ), phospho-Bad (Ser 136 ), and Bcl-x L expression, thereby activating caspase cascades and eventually cleaving poly(ADP-ribose) polymerase (PARP). Conversely, the addition of exogenous eicosanoids, including PGE 2 , LTB 4 and a 20-HETE analog (WIT003), and caspase inhibitors, or overexpression of constitutively active Akt reversed isoliquiritigenin-induced apoptosis. Notably, isoliquiritigenin induced growth inhibition and apoptosis of MDA-MB-231 human breast cancer xenografts in nude mice, together with decreased intratumoral levels of eicosanoids and phospho-Akt (Thr 308 ). Collectively, these data suggest that isoliquiritigenin induces growth inhibition and apoptosis through downregulating AA metabolic network and the deactivation of PI3K/Akt in

The role of arachidonic acid metabolites in signal transduction in an identified neural network mediating presynaptic inhibition in Aplysia

International Nuclear Information System (INIS)

Shapiro, E.; Piomelli, D.; Feinmark, S.; Vogel, S.; Chin, G.; Schwartz, J.H.

1988-01-01

Neuromodulation is a form of signal transduction that results in the biochemical control of neuronal excitability. Many neurotransmitters act through second messengers, and the examination of biochemical cascades initiated by neurotransmitter-receptor interaction has advanced the understanding of how information is acquired and stored in the nervous system. For example, 5-HT and other facilitory transmitters increase cAMP in sensory neurons of Aplysia, which enhances excitability and facilitates transmitter output. The authors have examined the role of arachidonic acid metabolites in a neuronal circuit mediating presynaptic inhibition. L32 cells are a cluster of putative histaminergic neurons that each make dual-action synaptic potentials onto two follower neurons, L10 and L14. The synaptic connections, biophysical properties, and roles in behavior of the L10 and L14 follower cells have been well studied. The types of ion channels causing each component of the L32-L10 and L32-L14 dual actions have been characterized and application of histamine mimics the effects of stimulating L32 in both L10 and L14

Quantitative analysis of Loperamide hydrochloride in the presence its acid degradation products

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Savić Ivana M.

2009-01-01

Full Text Available The aim of this work was to develop a new RP-HPLC method for the determination of loperamide hydrochloride in the presence of its acid degradation products. Separation of loperamide from degradation products was performed using ZORBAX Eclipse XDB C-18, column with a mobile phase consisting of 0.1% sodium-octansulphonate, 0.05% triethylamine, 0.1% ammonium hydroxide in water:acetonitrile (45:55 v/v. The mobile phase was adjusted to pH 3.2 with phosphoric acid. The method showed high sensitivity with good linearity over the concentration range of 10 to 100 μg cm-3. The method was successfully applied to the analysis of a pharmaceutical formulation (Loperamide, Zdravlje-Actavis, Serbia containing loperamide hydrochloride with excellent recovery. The loperamide hydrochloride degradation during acid hydrolysis and kinetics investigation was carried out in hydrochloric acid solutions of 0.1, 1.0 and 1.5 mol dm-3, at different temperatures (25 and 40°C, by monitoring the parent compound itself. The first order reaction of loperamide degradation in acid solution was determined. The activation energy was estimated from the Arrhenius plot and it was found to be 38.81 kJ mol-1 at 40°C. The developed procedure was successfully applied for the rapid determination of loperamide hydrochloride in pharmaceutical formulation (Loperamide, Zdravlje-Actavis, Serbia and in the presence of its acid degradation products.

Degradation of gas-liquid gliding arc discharge on Acid Orange II

International Nuclear Information System (INIS)

Yan, J.H.; Liu, Y.N.; Bo, Zh.; Li, X.D.; Cen, K.F.

2008-01-01

The effects of pH value, initial concentration of dye solution and temperature on the degradation efficiency of Acid Orange II (AO7) using gas-liquid gliding arc discharge were investigated. The influences of pH value and temperature on degradation efficiency were not apparent. Increasing initial solution concentration caused the decrease of degradation rate and the increase of absolute degradation quantity. Considering energy efficiency and absolute degradation quantity, the gas-liquid gliding arc discharge is fit for treating high concentration organic wastewater. A possible mineralization pathway was proposed through the analysis of intermediate products detected by gas chromatograph coupled with mass spectrophotometer (GC-MS) and ion chromatograph (IC). Hydroxyl radicals reacted with the azo linkage-bearing carbon of a hydroxy-substituted ring, leading to the cleavage of -C-N- and degradation of AO7. The solution biodegradability was significantly improved (BOD 5 /COD from 0.02 to 0.43). The toxicity of intermediate products was lower than that of the initial Acid Orange II

[Degradation of urea and ethyl carbamate in Chinese Rice wine by recombinant acid urease].

Science.gov (United States)

Zhou, Jianli; Kang, Zhen; Liu, Qingtao; Du, Guocheng; Chen, Jian

2016-01-01

Ethyl carbamate (EC) as a potential carcinogen commonly exists in traditional fermented foods. It is important eliminate urea that is the precursors of EC in many fermented foods, including Chinese Rice wine. On the basis of achieving high-level overexpression of food-grade ethanol-resistant acid urease, we studied the hydrolysis of urea and EC with the recombinant acid urease. Recombinant acid urease showed degraded urea in both the simulated system with ethanol and Chinese Rice wine (60 mg/L of urea was completely degraded within 25 h), indicating that the recombinant enzyme is suitable for the elimination of urea in Chinese Rice wine. Although recombinant acid urease also has degradation catalytic activity on EC, no obvious degradation of EC was observed. Further investigation results showed that the Km value for urea and EC of the recombinant acid urease was 0.7147 mmol/L and 41.32 mmol/L, respectively. The results provided theoretical foundation for realizing simultaneous degradation of urea and EC.

Neutron scattering and HPLC study on L-ascorbic acid and its degradation

Energy Technology Data Exchange (ETDEWEB)

Bellocco, E. [Department of Organic and Biological Chemistry, University of Messina, Messina (Italy)], E-mail: bellocco@isengard.unime.it; Barreca, D.; Lagana, G.; Leuzzi, U. [Department of Organic and Biological Chemistry, University of Messina, Messina (Italy); Migliardo, F.; Torre, R. La; Galli, G. [Department of Physics, University of Messina, Messina (Italy); Galtieri, A. [Department of Organic and Biological Chemistry, University of Messina, Messina (Italy); Minutoli, L.; Squadrito, F. [Department of Clinical and Experimental Medicine and Pharmacology, University of Messina, Messina (Italy)

2008-04-18

The present paper shows a systematic dynamic and kinetic study on L-ascorbic acid and its degradation at high temperature. The neutron scattering study allows, through the behavior of quasi-elastic neutron scattering (QENS) spectra, to characterize the diffusive dynamics of L-ascorbic acid in water mixtures. Ascorbic acid undergoes degradation process at high temperature, but the presence of trehalose in solution markedly avoids ascorbic acid loss enhancing its t{sub 1/2} (half life time), as determined by high performance liquid chromatography (HPLC)

Dietary effects of arachidonate-rich fungal oil and fish oil on murine hepatic and hippocampal gene expression

Directory of Open Access Journals (Sweden)

Mutch David M

2002-10-01

Full Text Available Abstract Background The functions, actions, and regulation of tissue metabolism affected by the consumption of long chain polyunsaturated fatty acids (LC-PUFA from fish oil and other sources remain poorly understood; particularly how LC-PUFAs affect transcription of genes involved in regulating metabolism. In the present work, mice were fed diets containing fish oil rich in eicosapentaenoic acid and docosahexaenoic acid, fungal oil rich in arachidonic acid, or the combination of both. Liver and hippocampus tissue were then analyzed through a combined gene expression- and lipid- profiling strategy in order to annotate the molecular functions and targets of dietary LC-PUFA. Results Using microarray technology, 329 and 356 dietary regulated transcripts were identified in the liver and hippocampus, respectively. All genes selected as differentially expressed were grouped by expression patterns through a combined k-means/hierarchical clustering approach, and annotated using gene ontology classifications. In the liver, groups of genes were linked to the transcription factors PPARα, HNFα, and SREBP-1; transcription factors known to control lipid metabolism. The pattern of differentially regulated genes, further supported with quantitative lipid profiling, suggested that the experimental diets increased hepatic β-oxidation and gluconeogenesis while decreasing fatty acid synthesis. Lastly, novel hippocampal gene changes were identified. Conclusions Examining the broad transcriptional effects of LC-PUFAs confirmed previously identified PUFA-mediated gene expression changes and identified novel gene targets. Gene expression profiling displayed a complex and diverse gene pattern underlying the biological response to dietary LC-PUFAs. The results of the studied dietary changes highlighted broad-spectrum effects on the major eukaryotic lipid metabolism transcription factors. Further focused studies, stemming from such transcriptomic data, will need to

Enzymatic oxalic acid regulation correlated with wood degradation in four brown-rot fungi

Science.gov (United States)

Anne Christine Steenkjær Hastrup; Frederick Green III; Patricia K. Lebow; Bo Jensen

2012-01-01

Oxalic acid is a key component in the initiation of brown-rot decay and it has been suggested that it plays multiple roles during the degradation process. Oxalic acid is accumulated to varying degrees among brown-rot fungi; however, details on active regulation are scarce. The accumulation of oxalic acid was measured in this study from wood degraded by the four brown-...

Degradation of chitosan hydrogel dispersed in dilute carboxylic acids by solution plasma and evaluation of anticancer activity of degraded products

Science.gov (United States)

Chokradjaroen, Chayanaphat; Rujiravanit, Ratana; Theeramunkong, Sewan; Saito, Nagahiro

2018-01-01

Chitosan is a polysaccharide that has been extensively studied in the field of biomedicine, especially its water-soluble degraded products called chitooligosaccharides (COS). In this study, COS were produced by the degradation of chitosan hydrogel dispersed in a dilute solution (i.e., 1.55 mM) of various kinds of carboxylic acids using a non-thermal plasma technology called solution plasma (SP). The degradation rates of chitosan were influenced by the type of carboxylic acids, depending on the interaction between chitosan and each carboxylic acid. After SP treatment, the water-soluble degraded products containing COS could be easily separated from the water-insoluble residue of chitosan hydrogel by centrifugation. The production yields of the COS were mostly higher than 55%. Furthermore, the obtained COS products were evaluated for their inhibitory effect as well as their selectivity against human lung cancer cells (H460) and human lung normal cells (MRC-5).

Ameliorative effects of polyunsaturated fatty acids against palmitic acid-induced insulin resistance in L6 skeletal muscle cells

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Sawada Keisuke

2012-03-01

Full Text Available Abstract Background Fatty acid-induced insulin resistance and impaired glucose uptake activity in muscle cells are fundamental events in the development of type 2 diabetes and hyperglycemia. There is an increasing demand for compounds including drugs and functional foods that can prevent myocellular insulin resistance. Methods In this study, we established a high-throughput assay to screen for compounds that can improve myocellular insulin resistance, which was based on a previously reported non-radioisotope 2-deoxyglucose (2DG uptake assay. Insulin-resistant muscle cells were prepared by treating rat L6 skeletal muscle cells with 750 μM palmitic acid for 14 h. Using the established assay, the impacts of several fatty acids on myocellular insulin resistance were determined. Results In normal L6 cells, treatment with saturated palmitic or stearic acid alone decreased 2DG uptake, whereas unsaturated fatty acids did not. Moreover, co-treatment with oleic acid canceled the palmitic acid-induced decrease in 2DG uptake activity. Using the developed assay with palmitic acid-induced insulin-resistant L6 cells, we determined the effects of other unsaturated fatty acids. We found that arachidonic, eicosapentaenoic and docosahexaenoic acids improved palmitic acid-decreased 2DG uptake at lower concentrations than the other unsaturated fatty acids, including oleic acid, as 10 μM arachidonic acid showed similar effects to 750 μM oleic acid. Conclusions We have found that polyunsaturated fatty acids, in particular arachidonic and eicosapentaenoic acids prevent palmitic acid-induced myocellular insulin resistance.

Bifidobacterium breve with α-linolenic acid and linoleic acid alters fatty acid metabolism in the maternal separation model of irritable bowel syndrome.

Directory of Open Access Journals (Sweden)

Eoin Barrett

Full Text Available The aim of this study was to compare the impact of dietary supplementation with a Bifidobacterium breve strain together with linoleic acid & α-linolenic acid, for 7 weeks, on colonic sensitivity and fatty acid metabolism in rats. Maternally separated and non-maternally separated Sprague Dawley rats (n = 15 were orally gavaged with either B. breve DPC6330 (10(9 microorganisms/day alone or in combination with 0.5% (w/w linoleic acid & 0.5% (w/w α-linolenic acid, daily for 7 weeks and compared with trehalose and bovine serum albumin. Tissue fatty acid composition was assessed by gas-liquid chromatography and visceral hypersensitivity was assessed by colorectal distension. Significant differences in the fatty acid profiles of the non-separated controls and maternally separated controls were observed for α-linolenic acid and arachidonic acid in the liver, oleic acid and eicosenoic acid (c11 in adipose tissue, and for palmitoleic acid and docosahexaenoic acid in serum (p<0.05. Administration of B. breve DPC6330 to MS rats significantly increased palmitoleic acid, arachidonic acid and docosahexaenoic acid in the liver, eicosenoic acid (c11 in adipose tissue and palmitoleic acid in the prefrontal cortex (p<0.05, whereas feeding B. breve DPC6330 to non separated rats significantly increased eicosapentaenoic acid and docosapentaenoic acid in serum (p<0.05 compared with the NS un-supplemented controls. Administration of B. breve DPC6330 in combination with linoleic acid and α-linolenic acid to maternally separated rats significantly increased docosapentaenoic acid in the serum (p<0.01 and α-linolenic acid in adipose tissue (p<0.001, whereas feeding B. breve DPC6330 with fatty acid supplementation to non-separated rats significantly increased liver and serum docosapentaenoic acid (p<0.05, and α-linolenic acid in adipose tissue (p<0.001. B. breve DPC6330 influenced host fatty acid metabolism. Administration of B. breve DPC6330 to maternally separated

Recovery of acid-degraded tributyl phosphate by solvent extraction

International Nuclear Information System (INIS)

Young, G.C.; Holladay, D.W.

1981-01-01

During nuclear fuel reprocessing the organic solvent becomes loaded with various acidic degradation products, which can be effectively removed through solvent extraction. Studies have been made with a small bench-scale solvent extraction system to optimize such parameters as pH of aqueous phase, phase ratio, residence time, flow rates, and temperature. The necessary decontamination factors have been obtained for various degradation products during continuous solvent extraction in one stage, with the aqueous phase being recycled. The aqueous phase contains compounds that can be degraded to gases to minimize waste disposal problems

Nanobiocatalytic Degradation of Acid Orange 7

Science.gov (United States)

Hastings, Jason

The catalytic properties of various metal nanoparticles have led to their use in environmental remediation applications. However, these remediation strategies are limited by their ability to deliver catalytic nanoparticles and a suitable electron donor to large treatment zones. Clostridium pasteurianum BC1 cells, loaded with bio-Pd nanoparticles, were used to effectively catalyze the reductive degradation and removal of Acid Orange 7 (AO7), a model azo compound. Hydrogen produced fermentatively by the C. pasteurianum BC1 acted as the electron donor for the process. Pd-free bacterial cultures or control experiments conducted with heat-killed cells showed limited reduction of AO7. Experiments also showed that the in situ biological production of H2 by C. pasteurianum BC1 was essential for the degradation of AO7, which suggests a novel process where the in situ microbial production of hydrogen is directly coupled to the catalytic bio-Pd mediated reduction of AO7. The differences in initial degradation rate for experiments conducted using catalyst concentrations of 1ppm Pd and 5ppm Pd and an azo dye concentration of 100ppm AO7 was 0.39 /hr and 1.94 /hr respectively, demonstrating the importance of higher concentrations of active Pd(0). The degradation of AO7 was quick as demonstrated by complete reductive degradation of 50ppm AO7 in 2 hours in experiments conducted using a catalyst concentration of 5ppm Pd. Dye degradation products were analyzed via Gas Chromatograph-Mass Spectrometer (GCMS), High Performance Liquid Chromatography (HPLC), UltraViolet-Visible spectrophotometer (UV-Vis) and Matrix-Assisted Laser Desorption/Ionization (MALDI) spectrometry. The presence of 1-amino 2-naphthol, one of the hypothesized degradation products, was confirmed using mass spectrometry.

Participation of Arachidonic Acid Metabolism in the Aortic Aneurysm Formation in Patients with Marfan Syndrome

Directory of Open Access Journals (Sweden)

María E. Soto

2018-02-01

Full Text Available Marfan syndrome (MFS is a pleiotropic genetic disease involving the cardiovascular system where a fibrillin-1 mutation is present. This mutation is associated with accelerated activation of transforming growth factor β (TGFβ1 which contributes to the formation of aneurysms in the root of the aorta. There is an imbalance in the synthesis of thromboxane A2 (TXA2 and prostacyclin, that is a consequence of a differential protein expression of the isoforms of cyclooxygenases (COXs, suggesting an alteration of arachidonic acid (AA metabolism. The aim of this study was to analyze the participation of AA metabolism associated with inflammatory factors in the dilation and dissection of the aortic aneurysm in patients with MFS. A decrease in AA (p = 0.02, an increase in oleic acid (OA, TGFβ1, tumor necrosis factor alpha (TNFα, prostaglandin E2 (PGE2 (p < 0.05, and COXs activity (p = 0.002 was found. The expressions of phospholipase A2 (PLA2, cytochrome P450 (CYP450 4A, 5-lipoxygenase (5-LOX, COX2 and TXA2R (p < 0.05 showed a significant increase in the aortic aneurysm of patients with MFS compared to control subjects. COX1, 6-keto-prostaglandin 1 alpha (6-keto-PG1α and 8-isoprostane did not show significant changes. Histological examination of the aortas showed an increase of cystic necrosis, elastic fibers and collagen in MFS. The results suggest that there are inflammatory factors coupled to genetic factors that predispose to aortic endothelial dysfunction in the aortic tissue of patients with MFS. There is a decrease in the percentage of AA, associated with an increase of PLA2, COX2/TXA2R, CYP450 4A, and 5-LOX which leads to a greater synthesis of PGE2 than of 6-keto-PGF1α, thus contributing to the formation of the aortic aneurysm. The evident loss of the homeostasis in these mechanisms confirms that there is a participation of the AA pathway in the aneurysm progression in MFS.

Mechanistic Perspectives of Maslinic Acid in Targeting Inflammation

Directory of Open Access Journals (Sweden)

Wei Hsum Yap

2015-01-01

Full Text Available Chronic inflammation drives the development of various pathological diseases such as rheumatoid arthritis, atherosclerosis, multiple sclerosis, and cancer. The arachidonic acid pathway represents one of the major mechanisms for inflammation. Prostaglandins (PGs are lipid products generated from arachidonic acid by the action of cyclooxygenase (COX enzymes and their activity is blocked by nonsteroidal anti-inflammatory drugs (NSAIDS. The use of natural compounds in regulation of COX activity/prostaglandins production is receiving increasing attention. In Mediterranean diet, olive oil and table olives contain significant dietary sources of maslinic acid. Maslinic acid is arising as a safe and novel natural pentacyclic triterpene which has protective effects against chronic inflammatory diseases in various in vivo and in vitro experimental models. Understanding the anti-inflammatory mechanism of maslinic acid is crucial for its development as a potential dietary nutraceutical. This review focuses on the mechanistic action of maslinic acid in regulating the inflammation pathways through modulation of the arachidonic acid metabolism including the nuclear factor-kappa B (NF-κB/COX-2 expression, upstream protein kinase signaling, and phospholipase A2 enzyme activity. Further investigations may provide insight into the mechanism of maslinic acid in regulating the molecular targets and their associated pathways in response to specific inflammatory stimuli.

Photo-degradation of clofibric acid by ultraviolet light irradiation at 185 nm.

Science.gov (United States)

Li, Wenzhen; Lu, Shuguang; Chen, Nuo; Gu, Xiaogang; Qiu, Zhaofu; Fan, Ji; Lin, Kuangfei

2009-01-01

As a metabolite of lipid regulators, clofibric acid (CA) was investigated in this study for its ultraviolet (UV) degradation at monochromatic wavelength of 185 nm using Milli-Q water and sewage treatment plant (STP) effluent. The effects of CA initial concentration, solution pH, humic acid (HA), nitrate and bicarbonate anions on CA degradation performances were evaluated. All CA degradation patterns well fitted the pseudo-first-order kinetic model. The results showed that OH generated from water photolysis by UV185 irradiation was involved, resulting in indirect CA photolysis but contributed less to the whole CA removal when compared to the main direct photolysis process. Acid condition favored slightly to CA degradation and other constituents in solution, such as HA (5.0-100.0 mg L(-1)), nitrate and bicarbonate anions (1.0x10(-3) mol L(-1) and 0.1 mol L(-1)), had negative effects on CA degradation. When using real STP effluent CA degradation could reach 97.4% (without filtration) and 99.3% (with filtration) after 1 hr irradiation, showing its potential mean in pharmaceuticals removal in UV disinfection unit. Mineralization tests showed that rapid chloride ion release happened, resulting in no chlorinated intermediates accumulation, and those non-chlorinated intermediate products could further be nearly completely degraded to CO2 and H2O after 6 hrs.

Transient postnatal fluoxetine decreases brain concentrations of 20-HETE and 15-epi-LXA4, arachidonic acid metabolites in adult mice.

Science.gov (United States)

Yuan, Zhi-Xin; Rapoport, Stanley I

2015-10-01

Transient postnatal exposure of rodents to the selective serotonin (5-HT) reuptake inhibitor (SSRI) fluoxetine alters behavior and brain 5-HT neurotransmission during adulthood, and also reduces brain arachidonic (ARA) metabolic consumption and protein level of the ARA metabolizing enzyme, cytochrome P4504A (CYP4A). Brain 20-hydroxyeicosatetraenoic acid (20-HETE), converted by CYP4A from ARA, will be reduced in adult mice treated transiently and postnatally with fluoxetine. Male mice pups were injected i.p. daily with fluoxetine (10mg/kg) or saline during P4-P21. At P90 their brain was high-energy microwaved and analyzed for 20-HETE and six other ARA metabolites by enzyme immunoassay. Postnatal fluoxetine vs. saline significantly decreased brain concentrations of 20-HETE (-70.3%) and 15-epi-lipoxin A4 (-60%) in adult mice, but did not change other eicosanoid concentrations. Behavioral changes in adult mice treated postnatally with fluoxetine may be related to reduced brain ARA metabolism involving CYP4A and 20-HETE formation. Published by Elsevier Ltd.

Electrochemical degradation of clofibric acid in water by anodic oxidation

Energy Technology Data Exchange (ETDEWEB)

Sires, Ignasi [Laboratori de Ciencia i Tecnologia Electroquimica de Materials, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Cabot, Pere Lluis [Laboratori de Ciencia i Tecnologia Electroquimica de Materials, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Centellas, Francesc [Laboratori de Ciencia i Tecnologia Electroquimica de Materials, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Garrido, Jose Antonio [Laboratori de Ciencia i Tecnologia Electroquimica de Materials, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Rodriguez, Rosa Maria [Laboratori de Ciencia i Tecnologia Electroquimica de Materials, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Arias, Conchita [Laboratori de Ciencia i Tecnologia Electroquimica de Materials, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Brillas, Enric [Laboratori de Ciencia i Tecnologia Electroquimica de Materials, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain)]. E-mail: brillas@ub.edu

2006-10-05

Aqueous solutions containing the metabolite clofibric acid (2-(4-chlorophenoxy)-2-methylpropionic acid) up to close to saturation in the pH range 2.0-12.0 have been degraded by anodic oxidation with Pt and boron-doped diamond (BDD) as anodes. The use of BDD leads to total mineralization in all media due to the efficient production of oxidant hydroxyl radical ({center_dot}OH). This procedure is then viable for the treatment of wastewaters containing this compound. The effect of pH, apparent current density, temperature and metabolite concentration on the degradation rate, consumed specific charge and mineralization current efficiency has been investigated. Comparative treatment with Pt yields poor decontamination with complete release of stable chloride ion. When BDD is used, this ion is oxidized to Cl{sub 2}. Clofibric acid is more rapidly destroyed on Pt than on BDD, indicating that it is more strongly adsorbed on the Pt surface enhancing its reaction with {center_dot}OH. Its decay kinetics always follows a pseudo-first-order reaction and the rate constant for each anode increases with increasing apparent current density, being practically independent of pH and metabolite concentration. Aromatic products such as 4-chlorophenol, 4-chlorocatechol, 4-chlororesorcinol, hydroquinone, p-benzoquinone and 1,2,4-benzenetriol are detected by gas chromatography-mass spectrometry (GC-MS) and reversed-phase chromatography. Tartronic, maleic, fumaric, formic, 2-hydroxyisobutyric, pyruvic and oxalic acids are identified as generated carboxylic acids by ion-exclusion chromatography. These acids remain stable in solution using Pt, but they are completely converted into CO{sub 2} with BDD. A reaction pathway for clofibric acid degradation involving all these intermediates is proposed.

Electrochemical degradation of clofibric acid in water by anodic oxidation

International Nuclear Information System (INIS)

Sires, Ignasi; Cabot, Pere Lluis; Centellas, Francesc; Garrido, Jose Antonio; Rodriguez, Rosa Maria; Arias, Conchita; Brillas, Enric

2006-01-01

Aqueous solutions containing the metabolite clofibric acid (2-(4-chlorophenoxy)-2-methylpropionic acid) up to close to saturation in the pH range 2.0-12.0 have been degraded by anodic oxidation with Pt and boron-doped diamond (BDD) as anodes. The use of BDD leads to total mineralization in all media due to the efficient production of oxidant hydroxyl radical (·OH). This procedure is then viable for the treatment of wastewaters containing this compound. The effect of pH, apparent current density, temperature and metabolite concentration on the degradation rate, consumed specific charge and mineralization current efficiency has been investigated. Comparative treatment with Pt yields poor decontamination with complete release of stable chloride ion. When BDD is used, this ion is oxidized to Cl 2 . Clofibric acid is more rapidly destroyed on Pt than on BDD, indicating that it is more strongly adsorbed on the Pt surface enhancing its reaction with ·OH. Its decay kinetics always follows a pseudo-first-order reaction and the rate constant for each anode increases with increasing apparent current density, being practically independent of pH and metabolite concentration. Aromatic products such as 4-chlorophenol, 4-chlorocatechol, 4-chlororesorcinol, hydroquinone, p-benzoquinone and 1,2,4-benzenetriol are detected by gas chromatography-mass spectrometry (GC-MS) and reversed-phase chromatography. Tartronic, maleic, fumaric, formic, 2-hydroxyisobutyric, pyruvic and oxalic acids are identified as generated carboxylic acids by ion-exclusion chromatography. These acids remain stable in solution using Pt, but they are completely converted into CO 2 with BDD. A reaction pathway for clofibric acid degradation involving all these intermediates is proposed

Arachidonic acid and DHA status in pregnant women is not associated with cognitive performance of their children at 4 or 6-7 years.

Science.gov (United States)

Crozier, Sarah R; Sibbons, Charlene M; Fisk, Helena L; Godfrey, Keith M; Calder, Philip C; Gale, Catharine R; Robinson, Sian M; Inskip, Hazel M; Baird, Janis; Harvey, Nicholas C; Cooper, Cyrus; Burdge, Graham C

2018-06-01

Arachidonic acid (ARA) and DHA, supplied primarily from the mother, are required for early development of the central nervous system. Thus, variations in maternal ARA or DHA status may modify neurocognitive development. We investigated the relationship between maternal ARA and DHA status in early (11·7 weeks) or late (34·5 weeks) pregnancy on neurocognitive function at the age of 4 years or 6-7 years in 724 mother-child pairs from the Southampton Women's Survey cohort. Plasma phosphatidylcholine fatty acid composition was measured in early and late pregnancy. ARA concentration in early pregnancy predicted 13 % of the variation in ARA concentration in late pregnancy (β=0·36, PDHA concentration in early pregnancy predicted 21 % of the variation in DHA concentration in late pregnancy (β=0·46, PDHA nor ARA concentrations in early or late pregnancy were associated significantly with neurocognitive function in children at the age of 4 years or the age of 6-7 years. These findings suggest that ARA and DHA status during pregnancy in the range found in this cohort are unlikely to have major influences on neurocognitive function in healthy children.

Convergent synthesis of degradable dendrons based on L-malic acid

DEFF Research Database (Denmark)

Meyhoff, Ulrich; Riber, Ulla; Boas, Ulrik

2015-01-01

New degradable polyester dendrons based on the cellular tricarboxylic acid cycle component L-malic acid were synthesized up to the third generation by convergent synthesis. The dendron wedges could be introduced in a stepwise, highly regioselective fashion. HMBC-NMR revealed that the C1-carbonyl...

Degradation of L-Ascorbic Acid in the Amorphous Solid State.

Science.gov (United States)

Sanchez, Juan O; Ismail, Yahya; Christina, Belinda; Mauer, Lisa J

2018-03-01

Ascorbic acid degradation in amorphous solid dispersions was compared to its degradation in the crystalline state. Physical blends and lyophiles of ascorbic acid and polymers (pectins and polyvinylpyrrolidone [PVP]) were prepared initially at 50:50 (w/w), with further studies using the polymer that best inhibited ascorbic acid crystallization in the lyophiles in 14 vitamin : PVP ratios. Samples were stored in controlled environments (25 to 60 °C, 0% to 23% RH) for 1 mo and analyzed periodically to track the physical appearance, change in moisture content, physical state (powder x-ray diffraction and polarized light microscopy), and vitamin loss (high performance liquid chromatography) over time. The glass transition temperatures of select samples were determined using differential scanning calorimetry, and moisture sorption profiles were generated. Ascorbic acid in the amorphous form, even in the glassy amorphous state, was more labile than in the crystalline form in some formulations at the highest storage temperature. Lyophiles stored at 25 and 40 °C and those in which ascorbic acid had crystallized at 60 °C (≥70% ascorbic acid : PVP) had no significant difference in vitamin loss (P > 0.05) relative to physical blend controls, and the length of storage had little effect. At 60 °C, amorphous ascorbic acid lyophiles (≤60% ascorbic acid : PVP) lost significantly more vitamin (P vitamin loss significantly increased over time. In these lyophiles, vitamin degradation also significantly increased (P vitamins are naturally present or added at low concentrations and production practices may promote amorphization of the vitamin. Vitamin C is one of the most unstable vitamins in foods. This study documents that amorphous ascorbic acid is less stable than crystalline ascorbic acid in some environments (for example, higher temperatures within 1 wk), especially when the vitamin is present at low concentrations in a product. These findings increase the understanding of

THERMAL DEGRADATION OF THERMOTROPIC LIQUID CRYSTALLINE TERPOLYESTERS BASED ON VANILLIC ACID, p-HYDROXYBENZOIC ACID AND POLY(ETHYLENE TEREPHTHALATE)

Institute of Scientific and Technical Information of China (English)

LI Xingui; HUANG Meirong; GUAN Guihe; SUN Tong

1993-01-01

Nine thermotropic liquid crystalline terpolyesters based on vanillic acid(V), p-hydroxybenzoic acid(H) and poly(ethylene terephthalate)(E) were investigated by thermogravimetry to ascertain their thermostability and the kinetic parameters for thermal degradation. Overall activation energy data of the degradation had been calculated over the range 5～70% weight loss. The temperatures and the activation energy of the degradation lie in the ranges of 384～394 ℃ at a heating rate of 1 ℃/min and 176～205 KJ/mol at the weight loss of 5%, respectively, which suggests that the terpolyesters have good thermostability.

Anti-Inflammatory Effects of Benfotiamine are Mediated Through the Regulation of Arachidonic Acid Pathway in Macrophages

Science.gov (United States)

Shoeb, Mohammad; Ramana, Kota V

2011-01-01

Benfotiamine, a lipid-soluble analogue of vitamin B1, is a potent anti-oxidant that is used as a food supplement for the treatment of diabetic complications. Our recent study indicates a novel role of benfotiamine in the prevention of bacterial endotoxin, lipopolysaccharide (LPS)-induced cytotoxicity and inflammatory response in murine macrophages. Nevertheless, it remains unclear how benfotiamine mediates anti-inflammatory effects. In this study, we investigated the anti-inflammatory role of benfotiamine in regulating the arachidonic acid (AA) pathway generated inflammatory lipid mediators in RAW 264.7 macrophages. Benfotiamine prevented the LPS-induced activation of cPLA2 and release of AA metabolites such as leukotrienes (LTB4), prostaglandin E2 (PGE2), thromboxanes 2 (TXB2) and prostacyclin (PGI2) in macrophages. Further, LPS-induced expressions of AA metabolizing enzymes such as COX-2, LOX-5, TXB synthase and PGI2 synthase were significantly blocked by benfotiamine. Furthermore, benfotiamine prevented the LPS-induced phosphorylation of ERK1/2 and expression of transcription factors NF-kB, and Egr-1. Benfotiamine also prevented the LPS-induced oxidative stress and protein-HNE adducts formation. Most importantly, as compared to specific COX-2 and LOX-5 inhibitors, benfotiamine significantly prevented the LPS-induced macrophage death and monocytes adhesion to endothelial cells. Thus, our studies indicate that the dual regulation of COX and LOX pathways in AA metabolism could be a novel mechanism by which benfotiamine exhibits its potential anti-inflammatory response. PMID:22067901

Modeling the degradation of Portland cement pastes by biogenic organic acids

International Nuclear Information System (INIS)

De Windt, Laurent; Devillers, Philippe

2010-01-01

Reactive transport models can be used to assess the long-term performance of cement-based materials subjected to biodegradation. A bioleaching test (with Aspergillus niger fungi) applied to ordinary Portland cement pastes during 15 months is modeled with HYTEC. Modeling indicates that the biogenic organic acids (acetic, butyric, lactic and oxalic) strongly accelerate hydrate dissolution by acidic hydrolysis whilst their complexation of aluminum has an effect on the secondary gel stability only. The deepest degradation front corresponds to portlandite dissolution and decalcification of calcium silicate hydrates. A complex pattern of sulfate phases dissolution and precipitation takes place in an intermediate zone. The outermost degraded zone consists of alumina and silica gels. The modeling accurateness of calcium leaching, pH evolution and degradation thickness is consistently enhanced whilst considering increase of diffusivity in the degraded zones. Precipitation of calcium oxalate is predicted by modeling but was hindered in the bioleaching reactor.

Physical fertility of degraded acid sands in South-eastern Nigeria ...

African Journals Online (AJOL)

We evaluated the physical fertility of degraded and undegraded acid sands in Akwa Ibom State, South-eastern Nigeria. The soils were similar in texture, being predominantly sandy, averaging 90.1% in degraded and 89.9% in undegraded soil. Bulk density averaged 1.50g/cm3 and 1.45g/cm3, while macropores averaged ...

Thermal degradation kinetics of polylactic acid/acid fabricated cellulose nanocrystal based bionanocomposites.

Science.gov (United States)

Monika; Dhar, Prodyut; Katiyar, Vimal

2017-11-01

Cellulose nanocrystals (CNC) are fabricated from filter paper (as cellulosic source) by acid hydrolysis using different acids such as sulphuric (H 2 SO 4 ), phosphoric (H 3 PO 4 ), hydrochloric (HCl) and nitric (HNO 3 ) acid. The resulting acid derived CNC are melt mixed with Polylactic acid (PLA) using extruder at 180°C. Thermogravimetric (TGA) result shows that increase in 10% and 50% weight loss (T 10 , T 50 ) temperature for PLA-CNC film fabricated with HNO 3 , H 3 PO 4 and HCl derived CNC have improved thermal stability in comparison to H 2 SO 4 -CNC. Nonisothermal kinetic studies are carried out with modified-Coats-Redfern (C-R), Ozawa-Flynn-Wall (OFW) and Kissinger method to predict the kinetic and thermodynamic parameters. Subsequently prediction of these parameter leads to the proposal of thermal induced degradation mechanism of nanocomposites using Criado method. The distribution of E a calculated from OFW model are (PLA-H 3 PO 4 -CNC: 125-139 kJmol -1 ), (PLA-HNO 3 -CNC: 126-145 kJmol -1 ), (PLA-H 2 SO 4 -CNC: 102-123 kJmol -1 ) and (PLA-HCl-CNC: 140-182 kJmol -1 ). This difference among E a for the decomposition of PLA-CNC bionanocomposite is probably due to various acids used in this study. The E a calculated by these two methods are found in consonance with that observed from Kissinger method. Further, hyphenated TG-Fourier transform infrared spectroscopy (FTIR) result shows that gaseous products such as CO 2 , CO, lactide, aldehydes and other compounds are given off during the thermal degradation of PLA-CNC nanocomposite. Copyright © 2017 Elsevier B.V. All rights reserved.

"Click" synthesis of fatty acid derivatives as fast-degrading polyanhydride precursors.

Science.gov (United States)

Lluch, Cristina; Lligadas, Gerard; Ronda, Joan C; Galià, Marina; Cadiz, Virginia

2011-09-01

Fast-degrading linear and branched polyanhydrides are obtained by melt-condensation of novel di- and tri-carboxylic acid monomers based on oleic and undecylenic acid synthesized using photoinitiated thiol-ene click chemistry. (1)H NMR spectroscopy, size exclusion chromatography, differential scanning calorimetry, thermogravimetric analysis, and FT-IR spectroscopy have been used to fully characterize these polymers. The hydrolytic degradation of these polymers was studied by means of weight loss, anhydride bond loss, and changes in molecular weight, showing fast degrading properties. Drug release studies from the synthesized polyanhydrides have also been conducted, using rhodamine B as a hydrophobic model drug, to evaluate the potential of these polymers in biomedical applications. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Decreased Polyunsaturated Fatty Acid Content Contributes to Increased Survival in Human Colon Cancer

Directory of Open Access Journals (Sweden)

Manuela Oraldi

2009-01-01

Full Text Available Among diet components, some fatty acids are known to affect several stages of colon carcinogenesis, whereas others are probably helpful in preventing tumors. In light of this, our aim was to determine the composition of fatty acids and the possible correlation with apoptosis in human colon carcinoma specimens at different Duke's stages and to evaluate the effect of enriching human colon cancer cell line with the possible reduced fatty acid(s. Specimens of carcinoma were compared with the corresponding non-neoplastic mucosa: a significant decrease of arachidonic acid, PPARα, Bad, and Bax and a significant increase of COX-2, Bcl-2, and pBad were found. The importance of arachidonic acid in apoptosis was demonstrated by enriching a Caco-2 cell line with this fatty acid. It induced apoptosis in a dose- and time-dependent manner via induction of PPARα that, in turn, decreased COX-2. In conclusion, the reduced content of arachidonic acid is likely related to carcinogenic process decreasing the susceptibility of cancer cells to apoptosis.

Cathepsin B-sensitive polymers for compartment-specific degradation and nucleic acid release.

Science.gov (United States)

Chu, David S H; Johnson, Russell N; Pun, Suzie H

2012-02-10

Degradable cationic polymers are desirable for in vivo nucleic acid delivery because they offer significantly decreased toxicity over non-degradable counterparts. Peptide linkers provide chemical stability and high specificity for particular endopeptidases but have not been extensively studied for nucleic acid delivery applications. In this work, enzymatically degradable peptide-HPMA copolymers were synthesized by RAFT polymerization of HPMA with methacrylamido-terminated peptide macromonomers, resulting in polymers with low polydispersity and near quantitative incorporation of peptides. Three peptide-HPMA copolymers were evaluated: (i) pHCathK(10), containing peptides composed of the linker phe-lys-phe-leu (FKFL), a substrate of the endosomal/lysosomal endopeptidase cathepsin B, connected to oligo-(L)-lysine for nucleic acid binding, (ii) pHCath(D)K(10), containing the FKFL linker with oligo-(D)-lysine, and (iii) pH(D)Cath(D)K(10), containing all (D) amino acids. Cathepsin B degraded copolymers pHCathK(10) and pHCath(D)K(10) within 1 h while no degradation of pH(D)Cath(D)K(10) was observed. Polyplexes formed with pHCathK(10) copolymers show DNA release by 4 h of treatment with cathepsin B; comparatively, polyplexes formed with pHCath(D)K(10) and pH(D)Cath(D)K(10) show no DNA release within 8 h. Transfection efficiency in HeLa and NIH/3T3 cells were comparable between the copolymers but pHCathK(10) was less toxic. This work demonstrates the successful application of peptide linkers for degradable cationic polymers and DNA release. Copyright © 2011 Elsevier B.V. All rights reserved.

Modeling the degradation kinetics of ascorbic acid.

Science.gov (United States)

Peleg, Micha; Normand, Mark D; Dixon, William R; Goulette, Timothy R

2018-06-13

Most published reports on ascorbic acid (AA) degradation during food storage and heat preservation suggest that it follows first-order kinetics. Deviations from this pattern include Weibullian decay, and exponential drop approaching finite nonzero retention. Almost invariably, the degradation rate constant's temperature-dependence followed the Arrhenius equation, and hence the simpler exponential model too. A formula and freely downloadable interactive Wolfram Demonstration to convert the Arrhenius model's energy of activation, E a , to the exponential model's c parameter, or vice versa, are provided. The AA's isothermal and non-isothermal degradation can be simulated with freely downloadable interactive Wolfram Demonstrations in which the model's parameters can be entered and modified by moving sliders on the screen. Where the degradation is known a priori to follow first or other fixed order kinetics, one can use the endpoints method, and in principle the successive points method too, to estimate the reaction's kinetic parameters from considerably fewer AA concentration determinations than in the traditional manner. Freeware to do the calculations by either method has been recently made available on the Internet. Once obtained in this way, the kinetic parameters can be used to reconstruct the entire degradation curves and predict those at different temperature profiles, isothermal or dynamic. Comparison of the predicted concentration ratios with experimental ones offers a way to validate or refute the kinetic model and the assumptions on which it is based.

Arachidonic acid metabolomic study of BPH in rats and the interventional effects of Zishen pill, a traditional Chinese medicine.

Science.gov (United States)

Bian, Qiaoxia; Wang, Weihui; Wang, Nannan; Peng, Yan; Ma, Wen; Dai, Ronghua

2016-09-05

Zishen pill (ZSP) is a traditional Chinese medicine (TCM) used to treat benign prostatic hyperplasia (BPH). The study used a metabolomic approach based on UHPLC-MS/MS to profile arachidonic acid (AA) metabolic changes and to investigate the interventional mechanisms of ZSP in testosterone- induced BPH rats. In order to explore the potential therapeutic effect of ZSP, rat models were constructed and orally administrated with ZSP. Plasma and urine samples were collected after four weeks and then eleven potential biomarkers (15-HETE, 12-HETE, TXA2, 5-HETE, AA, PGI2, PGF2α, 8-HETE, PGD2, PGE2 and LTB4) were identified and quantified by UHPLC-MS/MS. The chromatographic separation was carried out with gradient elution using a mobile phase comprised of 0.05% formic acid aqueous solution (pH=3.3) (A) and acetonitrile: methanol (80:20, V/V) (B), and each AA metabolites was measured using electrospray ionization source with negative mode and multiple reaction monitoring. The eleven biomarkers in BPH group rat plasma and urine were significant higher than those in sham group rats. Using the potential biomarkers as a screening index, the results suggest that ZSP can potentially reverse the process of BPH by partially regulating AA metabolism through refrain the expression of cyclooxygenase (COX) and lipoxygenase (LOX). This study demonstrates that a metabolomic strategy is useful for identifying potential BPH biomarkers and investigating the underlying mechanisms of a TCM in BPH treatment. Copyright © 2016 Elsevier B.V. All rights reserved.

[Simulated study of algal fatty acid degradation in hypoxia seawater-sediment interface along China coastal area].

Science.gov (United States)

Sui, Wei-Wei; Ding, Hai-Bing; Yang, Gui-Peng; Lu, Xiao-Lan; Li, Wen-Juan; Sun, Li-Qun

2013-11-01

Series of laboratory incubation experiments were conducted to simulate degradation of organic matter in sediment-seawater interface in hypoxia enviroments along China coastal area. Under four different redox conditions (oxygen saturation: 100%, 50%, 25% and 0%), degradations of seveal biomarkers originated from Skeletonema costatum, a typical red tide alage along China coastal area were tracked. By analyzing concentrations of four fatty acid biomarkers [14:0, 16:0, 16:1(7) and 20:5] obtained at various sampling time, results showed that their concentrations decreased significantly after 2-3 weeks' incubation. Then, their concentrations changed very slowly or very little. However, degradation of the four fatty acids varied dramatically in different incubation systems. Fatty acids 14:0, 16:1(7) and 20:5 were degraded completely in all incubation systems after two-month incubation, but 25% to 35% of 16:0 was reserved in the systems. Based on multi-G model, degradations of the four fatty acids were quantively described. The results indicated that all four fatty acids had fast-degraded and slow-degraded fractions. Their degradation rate constants (k(av)) ranged from 0.079 to 0.84 d(-1). The fastest degradation of 14:0 and 16:1 (7) occurred under 25% oxygen concentrations. For these two compounds, in the fastest degradation system, their k(av), values were 2.3 folds and 1.7 folds higher than those in the slowest degradation system [50% oxygen saturation for 14:0 and 100% oxygen saturation for 16:1(7)] respectively. The 16:0 was degraded fastest under the anoxic condition and slowest under the 50% oxygen saturation. The ratio of the two k(av)s was 2.1. The k(av)s of 20:5 had a positive relationship with oxygen saturations. Results of this study suggested that besides oxgen saturations, structure and features of organic compounds, roles of microbe in the envrioments and etc. might affect degradations of fatty acids in S. costatum in hypoxia sediment-seawater interface

Degradation Behaviour of Gamma Irradiated Poly(Acrylic Acid)-graft-Chitosan Superabsorbent Hydrogel

Science.gov (United States)

Ria Barleany, Dhena; Ilhami, Alpin; Yusuf Yudanto, Dea; Erizal

2018-03-01

A series of superabsorbent hydrogels were prepared from chitosan and partially neutralized acrylic acid at room temperature by gamma irradiation technique. The effect of irradiation and chitosan addition to the degradation behaviour of polymer were investigated. The gel content, swelling capacity, Equillibrium Degree of Swelling (EDS), Fourier Transform Infra Red (FTIR), and Scanning Electron Microscopy (SEM) study were also performed. Natural degradation in soil and thermal degradation by using of TGA analysis were observed. The variation of chitosan compositions were 0.5, 1, 1.5, and 2 g and the total irradiation doses were 5, 10, 15, and 20 kGy. The highest water capacity of 583.3 g water/g dry hydrogel was resulted from 5 kGy total irradiation dose and 0,5 g addition of chitosan. From the thermal degradation evaluation by using of TGA analysis showed that irradiation dose did not give a significant influence to the degradation rate. The rate of thermal degradation was ranged between 2.42 to 2.55 mg/min. In the natural test of degradation behaviour by using of soil medium, the hydrogel product with chitosan addition was found to have better degradability compared with the poly(acrylic acid) polymer without chitosan.

Degradation of 3-phenoxybenzoic acid by a Bacillus sp.

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Shaohua Chen

Full Text Available 3-Phenoxybenzoic acid (3-PBA is of great environmental concern with regards to endocrine disrupting activity and widespread occurrence in water and soil, yet little is known about microbial degradation in contaminated regions. We report here that a new bacterial strain isolated from soil, designated DG-02, was shown to degrade 95.6% of 50 mg·L(-1 3-PBA within 72 h in mineral salt medium (MSM. Strain DG-02 was identified as Bacillus sp. based on the morphology, physio-biochemical tests and 16S rRNA sequence. The optimum conditions for 3-PBA degradation were determined to be 30.9°C and pH 7.7 using response surface methodology (RSM. The isolate converted 3-PBA to produce 3-(2-methoxyphenoxy benzoic acid, protocatechuate, phenol, and 3,4-dihydroxy phenol, and subsequently transformed these compounds with a q(max, K(s and K(i of 0.8615 h(-1, 626.7842 mg·L(-1 and 6.7586 mg·L(-1, respectively. A novel microbial metabolic pathway for 3-PBA was proposed on the basis of these metabolites. Inoculation of strain DG-02 resulted in a higher degradation rate on 3-PBA than that observed in the non-inoculated soil. Moreover, the degradation process followed the first-order kinetics, and the half-life (t(1/2 for 3-PBA was greatly reduced as compared to the non-inoculated control. This study highlights an important potential application of strain DG-02 for the in situ bioremediation of 3-PBA contaminated environments.

Regulation of rat intrapulmonary arterial tone by arachidonic acid and prostaglandin E2 during hypoxia.

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Gaoliang Yan

Full Text Available Arachidonic acid (AA and its metabolites, prostaglandins (PG are known to be involved in regulation of vascular homeostasis including vascular tone and vessel wall tension, but their potential role in Hypoxic pulmonary vasoconstriction (HPV remains unclear. In this study, we examined the effects of AA and PGE2 on the hypoxic response in isolated rat intrapulmonary arteries (IPAs.We carried out the investigation on IPAs by vessel tension measurement. Isotetrandrine (20 µM significantly inhibited phase I, phase IIb and phase IIc of hypoxic vasoconstriction. Both indomethacin (100 µM and NS398 attenuated KPSS-induced vessel contraction and phase I, phase IIb and phase IIc of HPV, implying that COX-2 plays a primary role in the hypoxic response of rat IPAs. PGE2 alone caused a significant vasoconstriction in isolated rat IPAs. This constriction is mediated by EP4. Blockage of EP4 by L-161982 (1 µM significantly inhibited phase I, phase IIb and phase IIc of hypoxic vasoconstriction. However, AH6809 (3 µM, an antagonist of EP1, EP2, EP3 and DP1 receptors, exerted no effect on KPSS or hypoxia induced vessel contraction. Increase of cellular cAMP by forskolin could significantly reduce KPSS-induced vessel contraction and abolish phase I, phase II b and phase II c of HPV.Our results demonstrated a vasoconstrictive effect of PGE2 on rat IPAs and this effect is via activation of EP4. Furthermore, our results suggest that intracellular cAMP plays dual roles in regulation of vascular tone, depending on the spatial distribution of cAMP and its coupling with EP receptor and Ca(2+ channels.

Kinetics of Maleic Acid and Aluminum Chloride Catalyzed Dehydration and Degradation of Glucose

Energy Technology Data Exchange (ETDEWEB)

Zhang, Ximing; Hewetson, Barron B.; Mosier, Nathan S.

2015-04-16

We report the positive effect of maleic acid, a dicarboxylic acid, on the selectivity of hexose dehydration to 5-hydroxymethyfurfural (HMF) and subsequent hydrolysis to levulinic and formic acids. We also describe the kinetic analysis of a Lewis acid (AlCl3) alone and in combination with HCl or maleic acid to catalyze the isomerization of glucose to fructose, dehydration of fructose to HMF, hydration of HMF to levulinic and formic acids, and degradation of these compounds to humins. The results show that AlCl3 significantly enhances the rate of glucose conversion to HMF and levulinic acid in the presence of both maleic acid and HCl. In addition, the degradation of HMF to humins, rather than levulinic and formic acids, is reduced by 50% in the presence of maleic acid and AlCl3 compared to HCl combined with AlCl3. The results suggest different reaction mechanisms for the dehydration of glucose and rehydration of HMF between maleic acid and HCl.

Arachidonate metabolism increases as rat alveolar type II cells differentiate in vitro

International Nuclear Information System (INIS)

Lipchik, R.J.; Chauncey, J.B.; Paine, R.; Simon, R.H.; Peters-Golden, M.

1990-01-01

Rat type II alveolar epithelial cells are known to undergo morphological and functional changes when maintained in culture for several days. Having previously demonstrated that these cells can deacylate free arachidonic acid (AA) and metabolize it to products of the cyclooxygenase pathway, the present study was undertaken to determine whether in vitro differentiation was accompanied by alterations in the availability and metabolism of AA. We assessed the constitutive and ionophore A23187-induced deacylation and metabolism of endogenous AA, as well as the metabolism of exogenously supplied AA, in primary cultures of rat type II cells at days 2, 4, and 7 after isolation. Levels of free endogenous AA were increased at day 4, whereas eicosanoid synthesis, predominantly prostaglandin E2 and prostacyclin, increased markedly only at day 7. A similar time course of augmentation of prostanoid release was seen in response to exogenous AA. Type II cells cultured on fibronectin, intended to hasten cell flattening and spreading, demonstrated accelerated increases in available free AA in response to A23187; cells cultured on basement membrane derived from Engelbreth-Holm-Swarm mouse sarcoma, known to maintain the type II phenotype, exhibited diminished levels of available free AA. From these findings, we conclude that alterations in arachidonate metabolism are linked to alterations in cellular phenotype. The potentiation of eicosanoid synthesis accompanying in vitro differentiation suggests a possible role for the alveolar epithelium in the modulation of inflammation and fibrosis in the distal lung

Ionizing radiation induced degradation of salicylic acid in aqueous solution

Science.gov (United States)

Albarrán, Guadalupe; Mendoza, Edith

2018-06-01

The radiation-induced degradation of salicylic acid (SA-) in aqueous solutions (1.0 and 0.1 mmol dm-3) saturated with N2O or air or without oxygen were studied. Irradiation was carried out using a cobalt-60 source. With a 1 mmol dm-3 solution saturated with N2O a seemingly total degradation occurred at about 18 kGy, although small quantities of 2,3-dihydroxybenzoic acid, catechol and 2,5-dihydroxybenzoic acid were present at that dose at concentrations of 67, 22 and 6 μmol dm-3 respectively. Under air and when free oxygen, the three radiolytic products were present at 18.54 kGy while SA- was destroyed only to 90% and 62%, respectively. In the case of 0.1 mmol dm-3 SA- solutions, the acid was degraded at 3.5 kGy if the solution contained N2O, at 5.8 kGy in air and at 7 kGy without oxygen. The concentration of the radiolytic products increased with increasing dose and after a maximum they decreased. The oxidation was followed by measuring the chemical oxygen demand; the slopes were 0.48 and 0.11, 0.21 and 0.07, 0.15 and 0.03 mmol dm-3 kGy-1 for 1.0 and 0.10 mmol dm-3 solutions saturated with N2O or air or without oxygen, respectively.

Changes of fatty acid aerosol hygroscopicity induced by ozonolysis under humid conditions

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O. Vesna

2008-08-01

Full Text Available Unsaturated fatty acids are important constituents of the organic fraction of atmospheric aerosols originating from biogenic or combustion sources. Oxidative processing of these may change their interaction with water and thus affect their effect on climate. The ozonolysis of oleic and arachidonic acid aerosol particles was studied under humid conditions in a flow reactor at ozone exposures close to atmospheric levels, at concentrations between 0.5 and 2 ppm. While oleic acid is a widely used proxy for such studies, arachidonic acid represents polyunsaturated fatty acids, which may decompose into hygroscopic products. The hygroscopic (diameter growth factor at 93% relative humidity (RH of the oxidized arachidonic particles increased up to 1.09 with increasing RH during the ozonolysis. In contrast, the growth factor of oleic acid was very low (1.03 at 93% RH and was almost invariant to the ozonolysis conditions, so that oleic acid is not a good model to observe oxidation induced changes of hygroscopicity under atmospheric conditions. We show for arachidonic acid particles that the hygroscopic changes induced by humidity during ozonolysis are accompanied by about a doubling of the ratio of carboxylic acid protons to aliphatic protons. We suggest that, under humid conditions, the reaction of water with the Criegee intermediates might open a pathway for the formation of smaller acids that lead to more significant changes in hygroscopicity. Thus the effect of water to provide a competing pathway during ozonolysis observed in this study should be motivation to include water, which is ubiquitously present in and around atmospheric particles, in future studies related to aerosol particle aging.

Comparison of the effect of timegadine, levamisole, and D-penicillamine on human neutrophil metabolism of endogenous arachidonic acid and chemotaxis

Energy Technology Data Exchange (ETDEWEB)

Nielsen, O.H.; Ahnfelt-Roenne, I. Department of Pharmacology, Leo Pharmaceutical Products, Ballerup; Elmgreen, J.

1988-01-01

The effect of timegadine, a novel experimental antirheumatic drug, on human neutrophil (PMN) 5-lipoxygenase activity and leukotriene B/sub 4/ (LTB/sub 4/) chemotaxis was compared with that of two second-line antiinflammatory drugs, D-penicillamine and levamisole. 1-/sup 14/C-Arachidonic acid (AA) was incorporated into the purified cells until steady state conditions were obtained. After preincubation with serial dilutions of the three drugs, AA release and metabolism was stimulated with calcium ionophore A23187. The radioactive eicosanoids released were extracted and separated by thinlayer chromatography, followed by autoradiography and quantitative laser densitometry. Chemotaxi of PMNs towards LTB/sub 4/ was measured in a modified Boyden chamber. Timegardine showed dose-dependent inhibition of both the 5-lipoxygenase pathway (IC50 3.4 x 10/sup -5/ M), and of chemotaxis (IC50 3 x 10/sup -4/ M). Inhibition of the release of AA from phospholipids, however, occurred only at therapeutically irrelevant doses (millimolar concentrations). Levamisole and D-penicillamine did not inhibit any of the cell functions investigated. Inhibition of both neutrophil motility and cellular synthesis of pro-inflammatory eicosanoids, may thus contribute to the clinical effects of timegadine in rheumatoid arthritis.

Selective degradation of ibuprofen and clofibric acid in two model river biofilm systems.

Science.gov (United States)

Winkler, M; Lawrence, J R; Neu, T R

2001-09-01

A field survey indicated that the Elbe and Saale Rivers were contaminated with both clofibric acid and ibuprofen. In Elbe River water we could detect the metabolite hydroxy-ibuprofen. Analyses of the city of Saskatoon sewage effluent discharged to the South Saskatchewan river detected clofibric acid but neither ibuprofen nor any metabolite. Laboratory studies indicated that the pharmaceutical ibuprofen was readily degraded in a river biofilm reactor. Two metabolites were detected and identified as hydroxy- and carboxy-ibuprofen. Both metabolites were observed to degrade in the biofilm reactors. However, in human metabolism the metabolite carboxy-ibuprofen appears and degrades second whereas the opposite occurs in biofilm systems. In biofilms the pharmacologically inactive stereoisomere of ibuprofen is degraded predominantly. In contrast, clofibric acid was not biologically degraded during the experimental period of 21 days. Similar results were obtained using biofilms developed using waters from either the South Saskatchewan or Elbe River. In a sterile reactor no losses of ibuprofen were observed. These results suggested that abiotic losses and adsorption played only a minimal role in the fate of the pharmaceuticals in the river biofilm reactors.

Anaerobic degradation of veratrylglycerol-beta-guaiacyl ether and guaiacoxyacetic acid by mixed rumen bacteria.

OpenAIRE

Chen, W; Supanwong, K; Ohmiya, K; Shimizu, S; Kawakami, H

1985-01-01

Veratrylglycerol-beta-guaiacyl ether (0.2 g/liter), a lignin model compound, was found to be degraded by mixed rumen bacteria in a yeast extract medium under strictly anaerobic conditions to the extent of 19% within 24 h. Guaiacoxyacetic acid, 2-(o-methoxyphenoxy)ethanol, vanillic acid, and vanillin were detected as degradation products of veratrylglycerol-beta-guaiacyl ether by thin-layer chromatography, gas chromatography, and gas chromatography-mass spectrometry. Guaiacoxyacetic acid (0.25...

Degradation of 2,4-dichlorophenoxyacetic acid in water by ozone-hydrogen peroxide process

Institute of Scientific and Technical Information of China (English)

YU Ying-hui; MA Jun; HOU Yan-jun

2006-01-01

This study reports an investigation into the degradation of 2,4-dichlorophenoxyacetic acid in bubble contactor column by O3/H2O2 process, which is widely used as a principal advanced oxidation process. The degradation of 2,4-dichlorophenoxyacetic acid was studied under different H2O2/O3 molar ratio and pH value. Meanwhile, TOC removal was investigated both in distilled water and tap water. The influences of ozone transfer and consumed hydrogen peroxide were also discussed. The degradation products and oxidation intermediates were identified by GC-MS and LC-MS. A possible reaction mechanism was thus proposed.

Metabolism of arachidonic acid in 1 yr old New Zealand white (NZW) and watanabe heritable hyperlipidemic (WHHL) rabbit aortas

International Nuclear Information System (INIS)

Pfister, S.L.; Schmitz, J.M.; Willerson, J.T.; Campbell, W.B.

1986-01-01

This study was designed to characterize the metabolism of arachidonic acid (AA) in normal and atherosclerotic aortas. Segments of aortas were obtained from 1 yr old NZW rabbits, and WHHL rabbits, a genetic model of athero-sclerosis resembling familial hypercholesterolemia. Aortas were incubated at 37 0 C for 15 min with 14 C-AA (5 x 10 -5 M) during stimulation by A23187. The media was extracted using octadecylsilica columns and resolved into metabolites by reverse-phase HPLC. Prostaglandins (PGs) were identified by comigration of 14 C-metabolites with standards. The monoxygenated metabolites of AA (HETEs) were resolved by normal-phase HPLC, and their structures confirmed by GC-MS. In extracts from NZW and WHHL aortas, approximately 14% and 6% of the total radioactivity was converted to PGs and HETEs, respectively. The major PG produced by NZW and WHHL aortas was 6-keto PGF/sub 1α/ with lesser amounts of PGE 2 . Similarly, NZW and WHHL aortas produced primarily 12- and 15-HETE with lesser amounts of 11-, 9-, 8-, and 5-HETE. There were no qualitative differences between NZW and WHHL aortas in PG and HETE production. Therefore, despite extensive atherosclerosis in aortas of WHHL rabbits, the vessels maintain the ability to synthesize PGs and HETEs

Arachidonic acid containing phosphatidylcholine increases due to microglial activation in ipsilateral spinal dorsal horn following spared sciatic nerve injury.

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Tomohiro Banno

Full Text Available Peripheral nerve injury induces substantial molecular changes in the somatosensory system that leads to maladaptive plasticity and cause neuropathic pain. Understanding the molecular pathways responsible for the development of neuropathic pain is essential to the development of novel rationally designed therapeutics. Although lipids make up to half of the dry weight of the spinal cord, their relation with the development of neuropathic pain is poorly understood. We aimed to elucidate the regulation of spinal lipids in response to neuropathic peripheral nerve injury in mice by utilizing matrix-assisted laser desorption/ionization imaging mass spectrometry, which allows visualization of lipid distribution within the cord. We found that arachidonic acid (AA containing [PC(diacyl-16:0/20:4+K]+ was increased temporarily at superficial ipsilateral dorsal horn seven days after spared nerve injury (SNI. The spatiotemporal changes in lipid concentration resembled microglia activation as defined by ionized calcium binding adaptor molecule 1 (Iba1 immunohistochemistry. Suppression of microglial function through minocycline administration resulted in attenuation of hypersensitivity and reduces [PC(diacyl-16:0/20:4+K]+ elevation in the spinal dorsal horn. These data suggested that AA containing [PC(diacyl-16:0/20:4+K]+ is related to hypersensitivity evoked by SNI and implicate microglial cell activation in this lipid production.

A genomic view on syntrophic versus non-syntrophic lifestyle in anaerobic fatty acid degrading communities

NARCIS (Netherlands)

Worm, P.; Koehorst, J.J.; Visser, M.; Sedano Nunez, V.T.; Schaap, P.J.; Plugge, C.M.; Sousa, D.Z.; Stams, A.J.M.

2014-01-01

In sulfate-reducing and methanogenic environments complex biopolymers are hydrolyzed and degraded by fermentative micro-organisms that produce hydrogen, carbon dioxide and short chain fatty acids. Degradation of short chain fatty acids can be coupled to methanogenesis or to sulfate-reduction. Here

Coordination of gene expression of arachidonic and docosahexaenoic acid cascade enzymes during human brain development and aging.

Science.gov (United States)

Ryan, Veronica H; Primiani, Christopher T; Rao, Jagadeesh S; Ahn, Kwangmi; Rapoport, Stanley I; Blanchard, Helene

2014-01-01

The polyunsaturated arachidonic and docosahexaenoic acids (AA and DHA) participate in cell membrane synthesis during neurodevelopment, neuroplasticity, and neurotransmission throughout life. Each is metabolized via coupled enzymatic reactions within separate but interacting metabolic cascades. AA and DHA pathway genes are coordinately expressed and underlie cascade interactions during human brain development and aging. The BrainCloud database for human non-pathological prefrontal cortex gene expression was used to quantify postnatal age changes in mRNA expression of 34 genes involved in AA and DHA metabolism. Expression patterns were split into Development (0 to 20 years) and Aging (21 to 78 years) intervals. Expression of genes for cytosolic phospholipases A2 (cPLA2), cyclooxygenases (COX)-1 and -2, and other AA cascade enzymes, correlated closely with age during Development, less so during Aging. Expression of DHA cascade enzymes was less inter-correlated in each period, but often changed in the opposite direction to expression of AA cascade genes. Except for the PLA2G4A (cPLA2 IVA) and PTGS2 (COX-2) genes at 1q25, highly inter-correlated genes were at distant chromosomal loci. Coordinated age-related gene expression during the brain Development and Aging intervals likely underlies coupled changes in enzymes of the AA and DHA cascades and largely occur through distant transcriptional regulation. Healthy brain aging does not show upregulation of PLA2G4 or PTGS2 expression, which was found in Alzheimer's disease.

Coordination of gene expression of arachidonic and docosahexaenoic acid cascade enzymes during human brain development and aging.

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Veronica H Ryan

Full Text Available The polyunsaturated arachidonic and docosahexaenoic acids (AA and DHA participate in cell membrane synthesis during neurodevelopment, neuroplasticity, and neurotransmission throughout life. Each is metabolized via coupled enzymatic reactions within separate but interacting metabolic cascades.AA and DHA pathway genes are coordinately expressed and underlie cascade interactions during human brain development and aging.The BrainCloud database for human non-pathological prefrontal cortex gene expression was used to quantify postnatal age changes in mRNA expression of 34 genes involved in AA and DHA metabolism.Expression patterns were split into Development (0 to 20 years and Aging (21 to 78 years intervals. Expression of genes for cytosolic phospholipases A2 (cPLA2, cyclooxygenases (COX-1 and -2, and other AA cascade enzymes, correlated closely with age during Development, less so during Aging. Expression of DHA cascade enzymes was less inter-correlated in each period, but often changed in the opposite direction to expression of AA cascade genes. Except for the PLA2G4A (cPLA2 IVA and PTGS2 (COX-2 genes at 1q25, highly inter-correlated genes were at distant chromosomal loci.Coordinated age-related gene expression during the brain Development and Aging intervals likely underlies coupled changes in enzymes of the AA and DHA cascades and largely occur through distant transcriptional regulation. Healthy brain aging does not show upregulation of PLA2G4 or PTGS2 expression, which was found in Alzheimer's disease.

Targeted metabolomics analysis reveals the association between maternal folic acid supplementation and fatty acids and amino acids profiles in rat pups.

Science.gov (United States)

Liu, Zhipeng; Liu, Rui; Chou, Jing; Yu, Jiaying; Liu, Xiaowei; Sun, Changhao; Li, Ying; Liu, Liyan

2018-07-15

Maternal diet during pregnancy can influence offspring's health by affecting development and metabolism. This study aimed to analyze the influence of maternal folic acid (FA) supplementation on the metabolism of rat pups using targeted metabolomics. Twenty female rats were randomly assigned to a FA supplementation (FAS group, n = 10) or control group (n = 10), which were fed AIN93G diet with 2 or 10 mg/kg FA, respectively. We then measured amino acids and their derivatives, biogenic amines, and fatty acids in the female rats and their pups by ultra-high performance liquid chromatography-triple quadrupole mass spectrometry (UHPLC/MS-MS) and gas chromatography-mass spectrometry (GC/MS-MS). In maternal rats, the significant changes of three metabolites (proline, γ-aminobutyric acid and esterified octadecatetraenoic acid, P acids (leucine, isoleucine, serine, proline) were obtained in FAS pups. Furthermore, there were the decreased esterified fatty acids (arachidonic acid, eicosapentaenoic acid, and docosatetraenoic acid) and free fatty acids (oleic acid, linoleic acid, γ-linolenic acid, octadecatetraenoic acid, arachidonic acid, eicosapentaenoic acid and selacholeic acid) in FAS pups. Metabolic changes in the FAS pups were characterized by changes in fatty acids and amino acids. These results suggested that FA supplementation during pregnancy influenced amino acids and fatty acids metabolism in rat pups. This study provides new insights into the regulation of amino acids and fatty acids metabolism during early life. Copyright © 2018 Elsevier B.V. All rights reserved.

Developmentally dependent and different roles of fatty acids OMEGA-6 and OMEGA-3

DEFF Research Database (Denmark)

Mourek, J; Mourek, J

2011-01-01

The developmentally-dependent differences in the biological significances and effects of PUFA-OMEGA-6 (namely of arachidonic acid) and PUFA-OMEGA-3 (namely of docosahexaenoic acid) are discussed. The clinical results as well as developmental experiences are indicating a hypothesis of the evolution...... that created mutual relationship between those two substances (with immunological basis and following recuperation). The anti-inflammatory actions of PUFA-OMEGA-3 are the most visible (and significant) contrasts as compared with the large affects of namely arachidonic acid and its metabolites....

A human dietary arachidonic acid supplementation study conducted in a metabolic research unit: rationale and design.

Science.gov (United States)

Nelson, G J; Kelley, D S; Emken, E A; Phinney, S D; Kyle, D; Ferretti, A

1997-04-01

While there are many reports of studies that fed arachidonic acid (AA) to animals, there are very few reports of AA feeding to humans under controlled conditions. This 130-d study was conceived as a controlled, symmetrical crossover design with healthy, adult male volunteers. They lived in the metabolic research unit (MRU) of the Western Human Nutrition Research (WHNRC) for the entire study. All food was prepared by the WHNRC kitchen. The basal (low-AA) diet consisted of natural foods (30 en% fat, 15 en% protein, and 55 en% carbohydrate), containing 210 mg/d of AA, and met the recommended daily allowance for all nutrients. The high-AA (intervention) diet was similar except that 1.5 g/d of AA in the form of a triglyceride containing 50% AA replaced an equal amount of high-oleic safflower oil in the basal diet. The subjects (ages 20 to 39) were within -10 to +20% of ideal body weight, nonsmoking, and not allowed alcohol in the MRU. Their exercise level was constant, and their body weights were maintained within 2% of entry level. Subjects were initially fed the low-AA diet for 15 d. On day 16, half of the subjects (group A) wee placed on the high-AA diet, and the other group (B) remained on the low-AA diets. On day 65, the two groups switched diets. On day 115, group B returned to the low-AA diet. This design, assuming no carryover effect, allowed us to merge the data from the two groups, with the data comparison days being 65 (low-AA) and 115 (high-AA) for group B and 130 (low-AA) and 65 (high-AA) for group A. The main indices studied were the fatty acid composition of the plasma, red blood cells, platelets, and adipose tissue; in vitro platelet aggregation, bleeding times, clotting factors; immune response as measured by delayed hypersensitivity skin tests, cellular proliferation of peripheral blood mononuclear cells in response to various mitogens and antigens, natural killer cell activity, and response to measles/mumps/rubella and influenza vaccines; the

α-Amino acid containing degradable polymers as functional biomaterials: rational design, synthetic pathway, and biomedical applications.

Science.gov (United States)

Sun, Huanli; Meng, Fenghua; Dias, Aylvin A; Hendriks, Marc; Feijen, Jan; Zhong, Zhiyuan

2011-06-13

Currently, biomedical engineering is rapidly expanding, especially in the areas of drug delivery, gene transfer, tissue engineering, and regenerative medicine. A prerequisite for further development is the design and synthesis of novel multifunctional biomaterials that are biocompatible and biologically active, are biodegradable with a controlled degradation rate, and have tunable mechanical properties. In the past decades, different types of α-amino acid-containing degradable polymers have been actively developed with the aim to obtain biomimicking functional biomaterials. The use of α-amino acids as building units for degradable polymers may offer several advantages: (i) imparting chemical functionality, such as hydroxyl, amine, carboxyl, and thiol groups, which not only results in improved hydrophilicity and possible interactions with proteins and genes, but also facilitates further modification with bioactive molecules (e.g., drugs or biological cues); (ii) possibly improving materials biological properties, including cell-materials interactions (e.g., cell adhesion, migration) and degradability; (iii) enhancing thermal and mechanical properties; and (iv) providing metabolizable building units/blocks. In this paper, recent developments in the field of α-amino acid-containing degradable polymers are reviewed. First, synthetic approaches to prepare α-amino acid-containing degradable polymers will be discussed. Subsequently, the biomedical applications of these polymers in areas such as drug delivery, gene delivery and tissue engineering will be reviewed. Finally, the future perspectives of α-amino acid-containing degradable polymers will be evaluated.

Glycerol-plasticised silk membranes made using formic acid are ductile, transparent and degradation-resistant.

Science.gov (United States)

Allardyce, Benjamin J; Rajkhowa, Rangam; Dilley, Rodney J; Redmond, Sharon L; Atlas, Marcus D; Wang, Xungai

2017-11-01

Regenerated silk fibroin membranes tend to be brittle when dry. The use of plasticisers such as glycerol improve membrane ductility, but, when combined with aqueous processing, can lead to a higher degradation rate than solvent-annealed membranes. This study investigated the use of formic acid as the solvent with glycerol to make deformable yet degradation-resistant silk membranes. Here we show that membranes cast using formic acid had low light scattering, with a diffuse transmittance of less than 5% over the visible wavelengths, significantly lower than the 20% transmittance of aqueous derived silk/glycerol membranes. They had 64% β-sheet content and lost just 30% of the initial silk weight over 6h when tested with an accelerated enzymatic degradation assay, in comparison the aqueous membranes completely degraded within this timeframe. The addition of glycerol also improved the maximum elongation of formic acid derived membranes from under 3% to over 100%. They also showed good cytocompatibility and supported the adhesion and migration of human tympanic membrane keratinocytes. Formic acid based, silk/glycerol membranes may be of great use in medical applications such as repair of tympanic membrane perforation or ocular applications where transparency and resistance to enzymatic degradation are important. Copyright © 2017 Elsevier B.V. All rights reserved.

Enhanced degradation of Herbicide Isoproturon in wheat rhizosphere by salicylic acid.

Science.gov (United States)

Lu, Yi Chen; Zhang, Shuang; Miao, Shan Shan; Jiang, Chen; Huang, Meng Tian; Liu, Ying; Yang, Hong

2015-01-14

This study investigated the herbicide isoproturon (IPU) residues in soil, where wheat was cultivated and sprayed with salicylic acid (SA). Provision of SA led to a lower level of IPU residues in rhizosphere soil compared to IPU treatment alone. Root exudation of tartaric acid, malic acid, and oxalic acids was enhanced in rhizosphere soil with SA-treated wheat. We examined the microbial population (e.g., biomass and phospholipid fatty acid), microbial structure, and soil enzyme (catalase, phenol oxidase, and dehydrogenase) activities, all of which are associated with soil activity and were activated in rhizosphere soil of SA-treated wheat roots. We further assessed the correlation matrix and principal component to figure out the association between the IPU degradation and soil activity. Finally, six IPU degraded products (derivatives) in rhizosphere soil were characterized using ultraperformance liquid chromatography with a quadrupole-time-of-flight tandem mass spectrometer (UPLC/Q-TOF-MS/MS). A relatively higher level of IPU derivatives was identified in soil with SA-treated wheat than in soil without SA-treated wheat plants.

Mapping intermediate degradation products of poly(lactic-co-glycolic acid) in vitro.

Science.gov (United States)

Li, Jian; Nemes, Peter; Guo, Ji

2018-04-01

There is widespread interest in using absorbable polymers, such as poly(lactic-co-glycolic acid) (PLGA), as components in the design and manufacture of new-generation drug eluting stents (DES). PLGA undergoes hydrolysis to progressively degrade through intermediate chemical entities to simple organic acids that are ultimately absorbed by the human body. Understanding the composition and structure of these intermediate degradation products is critical not only to elucidate polymer degradation pathways accurately, but also to assess the safety and performance of absorbable cardiovascular implants. However, analytical approaches to determining the intermediate degradation products have yet to be established and evaluated in a standard or regulatory setting. Hence, we developed a methodology using electrospray ionization mass spectrometry to qualitatively and quantitatively describe intermediate degradation products generated in vitro from two PLGA formulations commonly used in DES. Furthermore, we assessed the temporal evolution of these degradation products using time-lapse experiments. Our data demonstrated that PLGA degradation products via heterogeneous cleavage of ester bonds are modulated by multiple intrinsic and environmental factors, including polymer chemical composition, degradants solubility in water, and polymer synthesis process. We anticipate the methodologies and outcomes presented in this work will elevate the mechanistic understanding of comprehensive degradation profiles of absorbable polymeric devices, and facilitate the design and regulation of cardiovascular implants by supporting the assessments of the associated biological response to degradation products. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1129-1137, 2018. © 2017 Wiley Periodicals, Inc.

Muscle protein degradation and amino acid metabolism during prolonged knee-extensor exercise in humans

DEFF Research Database (Denmark)

Van Hall, Gerrit; Saltin, B; Wagenmakers, A J

1999-01-01

to a substantial increase in net muscle protein degradation, and that a lowering of the starting muscle glycogen content leads to a further increase. The carbon atoms of the branched-chain amino acids (BCAA), glutamate, aspartate and asparagine, liberated by protein degradation, and the BCAA and glutamate......The aim of this study was to investigate whether prolonged one-leg knee-extensor exercise enhances net protein degradation in muscle with a normal or low glycogen content. Net amino acid production, as a measure of net protein degradation, was estimated from leg exchange and from changes...... in the concentrations of amino acids that are not metabolized in skeletal muscle. Experiments were performed at rest and during one-leg knee-extensor exercise in six subjects having one leg with a normal glycogen content and the other with a low glycogen content. Exercise was performed for 90 min at a workload of 60...

LC/MS/MS identification of some folic acid degradation products after E-beam irradiation

International Nuclear Information System (INIS)

Araújo, M.M.; Marchioni, E.; Zhao, M.; Kuntz, F.; Di Pascoli, T.; Villavicencio, A.L.C.H.; Bergaentzle, M.

2012-01-01

Folates belong to the B vitamin group based on the parental compound folic acid (FA). They are involved in important biochemical processes like DNA synthesis and repair. FA is composed of a pteridine ring, p-aminobenzoic acid and glutamate moieties. The human metabolism is not able to synthesize folates and therefore obtain them from diet. FA, a synthetic vitamin, is used as a food fortificant because of its low price, relative stability and increased bioavailability compared to natural folate forms. FA is known to be a sensitive compound easily degradable in aqueous solution by ultraviolet and visible light towards various by-products. Irradiation is a process for preservation of foods that uses accelerated electrons, gamma rays or X-rays. Irradiation is proposed for the treatment of various food products, eliminating or reducing pathogens and insects, increasing the storage time and replacing chemical fumigants. This study concerns the identification of degradation products of FA after E-beam irradiation. FA aqueous solutions were irradiated with a Van de Graaff electrons beam accelerator (2 MeV, 100 μA current, 20 cm scan width, dose rate about 2 kGy/s). Applied doses were between 0 (control) and 10.0 kGy. Absorbed doses were monitored with FWT 60.00 radiochromic dosimeters. - Highlights: ► We investigated the degradation of folic acid aqueous solution after electron beam treatment. ► Radiation doses over 5 kGy promote huge folic acid degradation and appearance of several degradation products. ► PCA, PABA and pABGA, already known folic acid degradation products, are formed due to E-beam treatment. ► Xanthopterin, a new radio-induced breakdown product, is formed after irradiation treatment.

The earthworm Aporrectodea caliginosa stimulates abundance and activity of phenoxyalkanoic acid herbicide degraders

Science.gov (United States)

Liu, Ya-Jun; Zaprasis, Adrienne; Liu, Shuang-Jiang; Drake, Harold L; Horn, Marcus A

2011-01-01

2-Methyl-4-chlorophenoxyacetic acid (MCPA) is a widely used phenoxyalkanoic acid (PAA) herbicide. Earthworms represent the dominant macrofauna and enhance microbial activities in many soils. Thus, the effect of the model earthworm Aporrectodea caliginosa (Oligochaeta, Lumbricidae) on microbial MCPA degradation was assessed in soil columns with agricultural soil. MCPA degradation was quicker in soil with earthworms than without earthworms. Quantitative PCR was inhibition-corrected per nucleic acid extract and indicated that copy numbers of tfdA-like and cadA genes (both encoding oxygenases initiating aerobic PAA degradation) in soil with earthworms were up to three and four times higher than without earthworms, respectively. tfdA-like and 16S rRNA gene transcript copy numbers in soil with earthworms were two and six times higher than without earthworms, respectively. Most probable numbers (MPNs) of MCPA degraders approximated 4 × 105 gdw−1 in soil before incubation and in soil treated without earthworms, whereas MPNs of earthworm-treated soils were approximately 150 × higher. The aerobic capacity of soil to degrade MCPA was higher in earthworm-treated soils than in earthworm-untreated soils. Burrow walls and 0–5 cm depth bulk soil displayed higher capacities to degrade MCPA than did soil from 5–10 cm depth bulk soil, expression of tfdA-like genes in burrow walls was five times higher than in bulk soil and MCPA degraders were abundant in burrow walls (MPNs of 5 × 107 gdw−1). The collective data indicate that earthworms stimulate abundance and activity of MCPA degraders endogenous to soil by their burrowing activities and might thus be advantageous for enhancing PAA degradation in soil. PMID:20740027

Consumption of Red Meat, but Not Cooking Oils High in Polyunsaturated Fat, Is Associated with Higher Arachidonic Acid Status in Singapore Chinese Adults

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Jowy Yi Hoong Seah

2017-01-01

Full Text Available High arachidonic acid (AA; 20:4 n − 6 status may have adverse effects on inflammation and risk of cardiovascular diseases. Concerns about high intake of n − 6 polyunsaturated fatty acids (PUFAs are based on the premise that endogenous conversion from linoleic acid (LA; 18:2 n − 6 is an important source of AA, but few population-based studies have investigated dietary determinants of AA status. In this study, we examined habitual food consumption in relation to plasma concentrations of AA and other PUFAs in population-based studies. We used cross-sectional data from 269 healthy, ethnic Chinese participants (25–80 years old with contrasting intakes of fish and red meat from the Singapore Prospective Study Program and 769 healthy participants (44–74 years old from the Singapore Chinese Health Study as a validation set. Multivariable linear regression was used to examine PUFA intake (% energy and food sources of PUFA (fish, red meat, poultry, soy and cooking oils in relation to plasma PUFAs (AA, LA, dihomo-gamma-linolenic acid (DGLA; 20:3 n − 6, alpha-linolenic acid (ALA; 18:3 n − 3, eicosapentaenoic acid (EPA; 20:5 n − 3, and docosahexaenoic acid (DHA; 22:6 n − 3 concentrations. Higher intake of red meat was associated with higher plasma AA concentrations. High intake of PUFA or PUFA-rich oils was associated with higher plasma ALA but not with plasma AA. Higher intakes of soy were associated with higher ALA and fish with higher DHA and EPA concentrations. These associations were statistically significant (p < 0.05 in both studies. Red meat consumption, but not PUFA or PUFA-rich cooking oil, was associated with circulating AA suggesting that intake of pre-formed AA rather than LA is an important determinant of AA status. A diet high in fish, soy products and polyunsaturated cooking oil, and low in red meat may be associated with an optimal plasma profile of PUFA in this Chinese population.

Acyl-CoA synthetase activity links wild-type but not mutant a-Synuclein to brain arachidonate metabolism

DEFF Research Database (Denmark)

Golovko, Mikhail; Rosenberger, Thad; Færgeman, Nils J.

2006-01-01

Because alpha-synuclein (Snca) has a role in brain lipid metabolism, we determined the impact that the loss of alpha-synuclein had on brain arachidonic acid (20:4n-6) metabolism in vivo using Snca-/- mice. We measured [1-(14)C]20:4n-6 incorporation and turnover kinetics in brain phospholipids using......, our data demonstrate that alpha-synuclein has a major role in brain 20:4n-6 metabolism through its modulation of endoplasmic reticulum-localized acyl-CoA synthetase activity, although mutant forms of alpha-synuclein fail to restore this activity....

Degradation of clofibric acid in UV/chlorine disinfection process: kinetics, reactive species contribution and pathways.

Science.gov (United States)

Tang, Yuqing; Shi, Xueting; Liu, Yongze; Feng, Li; Zhang, Liqiu

2018-02-01

As a potential endocrine disruptor, clofibric acid (CA) was investigated in this study for its degradation kinetics and pathways in UV/chlorine process. The results showed that CA in both UV photolysis and UV/chlorine processes could be degraded via pseudo-first-order kinetics, while it almost could not be degraded in the dark chlorination process. The observed rate constant ( k obs ) in UV photolysis was 0.0078 min -1, and increased to 0.0107 min -1 combining with 0.1 mM chlorine. The k obs increased to 0.0447 min -1 with further increasing the chlorine dosage from 0.1 to 1.0 mM, and reached a plateau at higher dosage (greater than 1.0 mM). The higher k obs was obtained at acid solution rather than basic solution. Moreover, the calculated contributions of radical species to k obs indicated that the HO• contributed significantly to CA degradation in acidic conditions, while the reactive chlorine species and UV direct photolysis dominated in neutral and basic solution. The degradation of CA was slightly inhibited in the presence of [Formula: see text] (1 ∼ 50 mM), barely affected by the presence of Cl - (1 ∼ 200 mM) and greatly suppressed by humic acid (0 ∼ 5 mg l -1 ). Thirteen main degradation intermediates and three degradation pathways of CA were identified during UV/chlorine process.

Formation of N-acyl-phosphatidylethanolamine and N-acylethanolamine (including anandamide) during glutamate-induced neurotoxicity

DEFF Research Database (Denmark)

Hansen, Harald S.; Moesgaard, B.; Hansen, H.H.

1999-01-01

N-acyl-phosphatidylethanolamine (NAPE) is present in very small amounts in mammalian tissues (less than 0.1% of total phospholipids). However, NAPE as well as its degradation production, N-acylethanolamine (NAE), can be formed in certain neuronal tissues in response to increased [Ca ](i). A high...... activation of the N-methyl-D-aspartate-receptor. Both NAPE and, to a lesser extent, NAE accumulate in a linear fashion for many hours while at the same time the neurons are dying. Likewise, in neurons prelabeled with C-arachidonic acid, C-arachidonic acid-labeled NAPE, and anandamide (= N...

Degradable polyphosphazene/poly(alpha-hydroxyester) blends: degradation studies.

Science.gov (United States)

Ambrosio, Archel M A; Allcock, Harry R; Katti, Dhirendra S; Laurencin, Cato T

2002-04-01

Biomaterials based on the polymers of lactic acid and glycolic acid and their copolymers are used or studied extensively as implantable devices for drug delivery, tissue engineering and other biomedical applications. Although these polymers have shown good biocompatibility, concerns have been raised regarding their acidic degradation products, which have important implications for long-term implantable systems. Therefore, we have designed a novel biodegradable polyphosphazene/poly(alpha-hydroxyester) blend whose degradation products are less acidic than those of the poly(alpha-hydroxyester) alone. In this study, the degradation characteristics of a blend of poly(lactide-co-glycolide) (50:50 PLAGA) and poly[(50% ethyl glycinato)(50% p-methylphenoxy) phosphazene] (PPHOS-EG50) were qualitatively and quantitatively determined with comparisons made to the parent polymers. Circular matrices (14mm diameter) of the PLAGA, PPHOS-EG50 and PLAGA-PPHOS-EG50 blend were degraded in non-buffered solutions (pH 7.4). The degraded polymers were characterized for percentage mass loss and molecular weight and the degradation medium was characterized for acid released in non-buffered solutions. The amounts of neutralizing base necessary to bring about neutral pH were measured for each polymer or polymer blend during degradation. The poly(phosphazene)/poly(lactide-co-glycolide) blend required significantly less neutralizing base in order to bring about neutral solution pH during the degradation period studied. The results indicated that the blend degraded at a rate intermediate to that of the parent polymers and that the degradation products of the polyphosphazene neutralized the acidic degradation products of PLAGA. Thus, results from these in vitro degradation studies suggest that the PLAGA-PPHOS-EG50 blend may provide a viable improvement to biomaterials based on acid-releasing organic polymers.

Arachidonic acid alters tomato HMG expression and fruit growth and induces 3-hydroxy-3-methylglutaryl coenzyme A reductase-independent lycopene accumulation

Energy Technology Data Exchange (ETDEWEB)

Rodriguez-Concepcion, M.; Gruissem, W. [Univ. of California, Berkeley, CA (United States). Dept. of Plant and Microbial Biology

1999-01-01

Regulation of isoprenoid end-product synthesis required for normal growth and development in plants is not well understood. To investigate the extent to which specific genes for the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) are involved in end-product regulation, the authors manipulated expression of the HMG1 and HMG2 genes in tomato (Lycopersicon esculentum) fruit using arachidonic acid (AA). In developing young fruit AA blocked fruit growth, inhibited HMG1, and activated HMG2 expression. These results are consistent with other reports indicating that HMG1 expression is closely correlated with growth processes requiring phytosterol production. In mature-green fruit AA strongly induced the expression of HMG2, PSY1 (the gene for phytoene synthase), and lycopene accumulation before the normal onset of carotenoid synthesis and ripening. The induction of lycopene synthesis was not blocked by inhibition of HMGR activity using mevinolin, suggesting that cytoplasmic HMGR is not required for carotenoid synthesis. Their results are consistent with the function of an alternative plastid isoprenoid pathway (the Rohmer pathway) that appears to direct the production of carotenoids during tomato fruit ripening.

In situ ruminal degradation of phytic acid in formaldehyde treated rice bran

NARCIS (Netherlands)

Martin-Tereso, J.; Gonzalez, A.; Laar, van H.; Burbara, C.; Pedrosa, M.; Mulder, K.; Hartog, den L.A.; Verstegen, M.W.A.

2009-01-01

Rice bran has a very high content of phytic acid (IP6), which is a nutritional antagonist of Ca. Microbial phytase degrades IP6, but ruminal degradation of nutrients can be reduced by formaldehyde treatment. Milk fever in dairy cows can be prevented by reducing available dietary Ca to stimulate Ca

Anaerobic degradation of benzene by enriched consortia with humic acids as terminal electron acceptors

Energy Technology Data Exchange (ETDEWEB)

Cervantes, Francisco J., E-mail: fjcervantes@ipicyt.edu.mx [Division de Ciencias Ambientales, Instituto Potosino de Investigacion Cientifica y Tecnologica (IPICyT), Camino a la Presa San Jose 2055, Col. Lomas 4a. Seccion, San Luis Potosi, SLP, 78216 Mexico (Mexico); Mancilla, Ana Rosa; Toro, E. Emilia Rios-del [Division de Ciencias Ambientales, Instituto Potosino de Investigacion Cientifica y Tecnologica (IPICyT), Camino a la Presa San Jose 2055, Col. Lomas 4a. Seccion, San Luis Potosi, SLP, 78216 Mexico (Mexico); Alpuche-Solis, Angel G.; Montoya-Lorenzana, Lilia [Division de Biologia Molecular, Instituto Potosino de Investigacion Cientifica y Tecnologica (IPICyT), Camino a la Presa San Jose 2055, Col. Lomas 4a. Seccion, San Luis Potosi, SLP, 78216 Mexico (Mexico)

2011-11-15

Highlights: {yields} Enriched consortia were able to couple the anaerobic degradation of benzene to the reduction of humic acids. {yields} Electron-equivalents derived from anaerobic benzene oxidation were highly recovered as reduced humic acids. {yields} Several species from classes {beta}-, {delta}- and {gamma}-Proteobacteria were enriched during the anaerobic degradation of benzene. - Abstract: The anaerobic degradation of benzene coupled to the reduction of humic acids (HA) was demonstrated in two enriched consortia. Both inocula were able to oxidize benzene under strict anaerobic conditions when the humic model compound, anthraquinone-2,6-disulfonate (AQDS), was supplied as terminal electron acceptor. An enrichment culture originated from a contaminated soil was also able to oxidize benzene linked to the reduction of highly purified soil humic acids (HPSHA). In HPSHA-amended cultures, 9.3 {mu}M of benzene were degraded, which corresponds to 279 {+-} 27 micro-electron equivalents ({mu}Eq) L{sup -1}, linked to the reduction of 619 {+-} 81 {mu}Eq L{sup -1} of HPSHA. Neither anaerobic benzene oxidation nor reduction of HPSHA occurred in sterilized controls. Anaerobic benzene oxidation did not occur in soil incubations lacking HPSHA. Furthermore, negligible reduction of HPSHA occurred in the absence of benzene. The enrichment culture derived from this soil was dominated by two {gamma}-Proteobacteria phylotypes. A benzene-degrading AQDS-reducing enrichment originated from a sediment sample showed the prevalence of different species from classes {beta}-, {delta}- and {gamma}-Proteobacteria. The present study provides clear quantitative demonstration of anaerobic degradation of benzene coupled to the reduction of HA.

Anaerobic degradation of benzene by enriched consortia with humic acids as terminal electron acceptors

International Nuclear Information System (INIS)

Cervantes, Francisco J.; Mancilla, Ana Rosa; Toro, E. Emilia Rios-del; Alpuche-Solis, Angel G.; Montoya-Lorenzana, Lilia

2011-01-01

Highlights: → Enriched consortia were able to couple the anaerobic degradation of benzene to the reduction of humic acids. → Electron-equivalents derived from anaerobic benzene oxidation were highly recovered as reduced humic acids. → Several species from classes β-, δ- and γ-Proteobacteria were enriched during the anaerobic degradation of benzene. - Abstract: The anaerobic degradation of benzene coupled to the reduction of humic acids (HA) was demonstrated in two enriched consortia. Both inocula were able to oxidize benzene under strict anaerobic conditions when the humic model compound, anthraquinone-2,6-disulfonate (AQDS), was supplied as terminal electron acceptor. An enrichment culture originated from a contaminated soil was also able to oxidize benzene linked to the reduction of highly purified soil humic acids (HPSHA). In HPSHA-amended cultures, 9.3 μM of benzene were degraded, which corresponds to 279 ± 27 micro-electron equivalents (μEq) L -1 , linked to the reduction of 619 ± 81 μEq L -1 of HPSHA. Neither anaerobic benzene oxidation nor reduction of HPSHA occurred in sterilized controls. Anaerobic benzene oxidation did not occur in soil incubations lacking HPSHA. Furthermore, negligible reduction of HPSHA occurred in the absence of benzene. The enrichment culture derived from this soil was dominated by two γ-Proteobacteria phylotypes. A benzene-degrading AQDS-reducing enrichment originated from a sediment sample showed the prevalence of different species from classes β-, δ- and γ-Proteobacteria. The present study provides clear quantitative demonstration of anaerobic degradation of benzene coupled to the reduction of HA.

Biosynthesis, degradation, and pharmacological importance of the fatty acid amides

Science.gov (United States)

Farrell, Emma K.; Merkler, David J.

2008-01-01

The identification of two biologically active fatty acid amides, N-arachidonoylethanolamine (anandamide) and oleamide, has generated a great deal of excitement and stimulated considerable research. However, anandamide and oleamide are merely the best-known and best-understood members of a much larger family of biologically-occurring fatty acid amides. In this review, we will outline which fatty acid amides have been isolated from mammalian sources, detail what is known about how these molecules are made and degraded in vivo, and highlight their potential for the development of novel therapeutics. PMID:18598910

Oxidative degradation of salicylic acid by sprayed WO{sub 3} photocatalyst

Energy Technology Data Exchange (ETDEWEB)

Mohite, S.V.; Rajpure, K.Y., E-mail: rajpure@yahoo.com

2015-10-15

Highlights: • The photoactivity of sprayed WO{sub 3} thin film. • Photoelectrocatalytic degradation of salicylic acid. • Reaction kinetics and mineralization of pollutants by COD. - Abstract: The WO{sub 3} thin films were deposited using spray pyrolysis technique. The prepared WO{sub 3} thin films were characterized using photoelectrochemical (PEC), X-ray diffraction, atomic force microscopy (AFM), and UV–vis absorbance spectroscopy techniques. PEC measurements of WO{sub 3} films deposited at different deposition temperatures were carried out to study photoresponse. The maximum photocurrent (I{sub ph} = 261 μA/cm{sup 2}) was observed for the film deposited at the 225 °C. The monoclinic crystal structure of WO{sub 3} has been confirmed from X-ray diffraction studies. AFM studies were used to calculate particle size and average roughness of the films. Optical absorbance was studied to estimate the bandgap energy of WO{sub 3} thin film which was about 2.65 eV. The photoelectrocatalytic activity of WO{sub 3} film was studied by degradation of salicylic acid with reducing concentrations as function of reaction time. The WO{sub 3} photocatalyst degraded salicylic acid to about 67.14% with significant reduction in chemical oxygen demand (COD) value.

Anti-inflammatory effects of benfotiamine are mediated through the regulation of the arachidonic acid pathway in macrophages.

Science.gov (United States)

Shoeb, Mohammad; Ramana, Kota V

2012-01-01

Benfotiamine, a lipid-soluble analogue of vitamin B1, is a potent antioxidant that is used as a food supplement for the treatment of diabetic complications. Our recent study (U.C. Yadav et al., Free Radic. Biol. Med. 48:1423-1434, 2010) indicates a novel role for benfotiamine in the prevention of bacterial endotoxin, lipopolysaccharide (LPS)-induced cytotoxicity and inflammatory response in murine macrophages. Nevertheless, it remains unclear how benfotiamine mediates anti-inflammatory effects. In this study, we investigated the anti-inflammatory role of benfotiamine in regulating arachidonic acid (AA) pathway-generated inflammatory lipid mediators in RAW264.7 macrophages. Benfotiamine prevented the LPS-induced activation of cPLA2 and release of AA metabolites such as leukotrienes, prostaglandin E2, thromboxane 2 (TXB2), and prostacyclin (PGI2) in macrophages. Further, LPS-induced expression of AA-metabolizing enzymes such as COX-2, LOX-5, TXB synthase, and PGI2 synthase was significantly blocked by benfotiamine. Furthermore, benfotiamine prevented the LPS-induced phosphorylation of ERK1/2 and expression of transcription factors NF-κB and Egr-1. Benfotiamine also prevented the LPS-induced oxidative stress and protein-HNE adduct formation. Most importantly, compared to specific COX-2 and LOX-5 inhibitors, benfotiamine significantly prevented LPS-induced macrophage death and monocyte adhesion to endothelial cells. Thus, our studies indicate that the dual regulation of the COX and LOX pathways in AA metabolism could be a novel mechanism by which benfotiamine exhibits its potential anti-inflammatory response. Copyright © 2011 Elsevier Inc. All rights reserved.

Microwave-assisted degradation of acid orange using a conjugated polymer, polyaniline, as catalyst

Directory of Open Access Journals (Sweden)

Ufana Riaz

2014-01-01

Full Text Available Microwave-assisted photocatalytic degradation of dyes is one of the emerging technologies for waste water remediation. Microwave effectively accelerates photocatalytic degradation, when microwave electrodeless lamp (MEL substitutes traditional UV lamp as light source. This setup can be extremely simplified if MEL and photocatalyst can be replaced by a catalyst which can work under microwave irradiation in the absence of any light source. The present work reports for the first time degradation of acid orange 7 (AO under microwave irradiation using polyaniline (PANI as catalyst in the absence of any UV lamp as light source. The degradation/decolourization was carried out in neutral acidic and basic media and was monitored spectrophotometrically to evaluate the ability of microwave irradiation to degrade AO. Microwave irradiation showed excellent performance as it completely decolourizes AO dye solution in 10 min. With the advantages of low cost and rapid processing, this novel catalyst is expected to gain promising application in the treatment of various dyestuff wastewaters on a large scale.

Fluorescence Spectroscopy Applied to Monitoring Biodiesel Degradation: Correlation with Acid Value and UV Absorption Analyses.

Science.gov (United States)

Vasconcelos, Maydla Dos Santos; Passos, Wilson Espíndola; Lescanos, Caroline Honaiser; Pires de Oliveira, Ivan; Trindade, Magno Aparecido Gonçalves; Caires, Anderson Rodrigues Lima; Muzzi, Rozanna Marques

2018-01-01

The techniques used to monitor the quality of the biodiesel are intensely discussed in the literature, partly because of the different oil sources and their intrinsic physicochemical characteristics. This study aimed to monitor the thermal degradation of the fatty acid methyl esters of Sesamum indicum L. and Raphanus sativus L. biodiesels (SILB and RSLB, resp.). The results showed that both biodiesels present a high content of unsaturated fatty acids, ∼84% (SILB) and ∼90% (RSLB). The SILB had a high content of polyunsaturated linoleic fatty acid (18  :  2), about 49%, and the oleic monounsaturated (18  :  1), ∼34%. On the other hand, RSLB presented a considerable content of linolenic fatty acid (18  :  3), ∼11%. The biodiesel samples were thermal degraded at 110°C for 48 hours, and acid value, UV absorption, and fluorescence spectroscopy analysis were carried out. The results revealed that both absorption and fluorescence presented a correlation with acid value as a function of degradation time by monitoring absorptions at 232 and 270 nm as well as the emission at 424 nm. Although the obtained correlation is not completely linear, a direct correlation was observed in both cases, revealing that both properties can be potentially used for monitoring the biodiesel degradation.

Fluorescence Spectroscopy Applied to Monitoring Biodiesel Degradation: Correlation with Acid Value and UV Absorption Analyses

Directory of Open Access Journals (Sweden)

Maydla dos Santos Vasconcelos

2018-01-01

Full Text Available The techniques used to monitor the quality of the biodiesel are intensely discussed in the literature, partly because of the different oil sources and their intrinsic physicochemical characteristics. This study aimed to monitor the thermal degradation of the fatty acid methyl esters of Sesamum indicum L. and Raphanus sativus L. biodiesels (SILB and RSLB, resp.. The results showed that both biodiesels present a high content of unsaturated fatty acids, ∼84% (SILB and ∼90% (RSLB. The SILB had a high content of polyunsaturated linoleic fatty acid (18  :  2, about 49%, and the oleic monounsaturated (18  :  1, ∼34%. On the other hand, RSLB presented a considerable content of linolenic fatty acid (18  :  3, ∼11%. The biodiesel samples were thermal degraded at 110°C for 48 hours, and acid value, UV absorption, and fluorescence spectroscopy analysis were carried out. The results revealed that both absorption and fluorescence presented a correlation with acid value as a function of degradation time by monitoring absorptions at 232 and 270 nm as well as the emission at 424 nm. Although the obtained correlation is not completely linear, a direct correlation was observed in both cases, revealing that both properties can be potentially used for monitoring the biodiesel degradation.

Long-chain n-3 fatty acids and inflammation: potential application in surgical and trauma patients

Directory of Open Access Journals (Sweden)

Calder P.C.

2003-01-01

Full Text Available Lipids used in nutritional support of surgical or critically ill patients have been based on soybean oil, which is rich in the n-6 fatty acid linoleic acid (18:2n-6. Linoleic acid is the precursor of arachidonic acid (20:4n-6. In turn, arachidonic acid in cell membrane phospholipids is the substrate for the synthesis of a range of biologically active compounds (eicosanoids including prostaglandins, thromboxanes, and leukotrienes. These compounds can act as mediators in their own right and can also act as regulators of other processes, such as platelet aggregation, blood clotting, smooth muscle contraction, leukocyte chemotaxis, inflammatory cytokine production, and immune function. There is a view that an excess of n-6 fatty acids should be avoided since this could contribute to a state where physiological processes become dysregulated. One alternative is the use of fish oil. The rationale of this latter approach is that fish oil contains long chain n-3 fatty acids, such as eicosapentaenoic acid. When fish oil is provided, eicosapentaenoic acid is incorporated into cell membrane phospholipids, partly at the expense of arachidonic acid. Thus, there is less arachidonic acid available for eicosanoid synthesis. Hence, fish oil decreases production of prostaglandins like PGE2 and of leukotrienes like LTB4. Thus, n-3 fatty acids can potentially reduce platelet aggregation, blood clotting, smooth muscle contraction, and leukocyte chemotaxis, and can modulate inflammatory cytokine production and immune function. These effects have been demonstrated in cell culture, animal feeding and healthy volunteer studies. Fish oil decreases the host metabolic response and improves survival to endotoxin in laboratory animals. Recently clinical studies performed in various patient groups have indicated benefit from this approach.

Analysis of hydroxycinnamic acid degradation in Agrobacterium fabrum reveals a coenzyme A-dependent, beta-oxidative deacetylation pathway.

Science.gov (United States)

Campillo, Tony; Renoud, Sébastien; Kerzaon, Isabelle; Vial, Ludovic; Baude, Jessica; Gaillard, Vincent; Bellvert, Floriant; Chamignon, Cécile; Comte, Gilles; Nesme, Xavier; Lavire, Céline; Hommais, Florence

2014-06-01

The soil- and rhizosphere-inhabiting bacterium Agrobacterium fabrum (genomospecies G8 of the Agrobacterium tumefaciens species complex) is known to have species-specific genes involved in ferulic acid degradation. Here, we characterized, by genetic and analytical means, intermediates of degradation as feruloyl coenzyme A (feruloyl-CoA), 4-hydroxy-3-methoxyphenyl-β-hydroxypropionyl-CoA, 4-hydroxy-3-methoxyphenyl-β-ketopropionyl-CoA, vanillic acid, and protocatechuic acid. The genes atu1416, atu1417, and atu1420 have been experimentally shown to be necessary for the degradation of ferulic acid. Moreover, the genes atu1415 and atu1421 have been experimentally demonstrated to be essential for this degradation and are proposed to encode a phenylhydroxypropionyl-CoA dehydrogenase and a 4-hydroxy-3-methoxyphenyl-β-ketopropionic acid (HMPKP)-CoA β-keto-thiolase, respectively. We thus demonstrated that the A. fabrum hydroxycinnamic degradation pathway is an original coenzyme A-dependent β-oxidative deacetylation that could also transform p-coumaric and caffeic acids. Finally, we showed that this pathway enables the metabolism of toxic compounds from plants and their use for growth, likely providing the species an ecological advantage in hydroxycinnamic-rich environments, such as plant roots or decaying plant materials.

Acid-degradable and bioerodible modified polyhydroxylated materials

Energy Technology Data Exchange (ETDEWEB)

Frechet, Jean M. J.; Bachelder, Eric M.; Beaudette, Tristan T.; Broaders, Kyle E.

2017-05-09

Compositions and methods of making a modified polyhydroxylated polymer comprising a polyhydroxylated polymer having reversibly modified hydroxyl groups, whereby the hydroxyl groups are modified by an acid-catalyzed reaction between a polydroxylated polymer and a reagent such as acetals, aldehydes, vinyl ethers and ketones such that the modified polyhydroxylated polymers become insoluble in water but freely soluble in common organic solvents allowing for the facile preparation of acid-sensitive materials. Materials made from these polymers can be made to degrade in a pH-dependent manner. Both hydrophobic and hydrophilic cargoes were successfully loaded into particles made from the present polymers using single and double emulsion techniques, respectively. Due to its ease of preparation, processability, pH-sensitivity, and biocompatibility, of the present modified polyhydroxylated polymers should find use in numerous drug delivery applications.

Immunoregulatory and anti-inflammatory effects of n-3 polyunsaturated fatty acids

Directory of Open Access Journals (Sweden)

P.C. Calder

1998-04-01

Full Text Available 1. Fish oils are rich in the long-chain n-3 polyunsaturated fatty acids (PUFAs, eicosapentaenoic (20:5n-3 and docosahexaenoic (22:6n-3 acids. Linseed oil and green plant tissues are rich in the precursor fatty acid, a-linolenic acid (18:3n-3. Most vegetable oils are rich in the n-6 PUFA linoleic acid (18:2n-6, the precursor of arachidonic acid (20:4n-6. 2. Arachidonic acid-derived eicosanoids such as prostaglandin E2 are pro-inflammatory and regulate the functions of cells of the immune system. Consumption of fish oils leads to replacement of arachidonic acid in cell membranes by eicosapentaenoic acid. This changes the amount and alters the balance of eicosanoids produced. 3. Consumption of fish oils diminishes lymphocyte proliferation, T-cell-mediated cytotoxicity, natural killer cell activity, macrophage-mediated cytotoxicity, monocyte and neutrophil chemotaxis, major histocompatibility class II expression and antigen presentation, production of pro-inflammatory cytokines (interleukins 1 and 6, tumour necrosis factor and adhesion molecule expression. 4. Feeding laboratory animals fish oil reduces acute and chronic inflammatory responses, improves survival to endotoxin and in models of autoimmunity and prolongs the survival of grafted organs. 5. Feeding fish oil reduces cell-mediated immune responses. 6. Fish oil supplementation may be clinically useful in acute and chronic inflammatory conditions and following transplantation. 7. n-3 PUFAs may exert their effects by modulating signal transduction and/or gene expression within inflammatory and immune cells.

Omega-6 fatty acid biomarkers and incident type 2 diabetes

NARCIS (Netherlands)

Wu, Jason H.Y.; Marklund, Matti; Imamura, Fumiaki; Tintle, Nathan; Ardisson Korat, Andres V.; Goede, de Janette; Zhou, Xia; Yang, Wei Sin; Oliveira Otto, de Marcia C.; Kröger, Janine; Qureshi, Waqas; Virtanen, Jyrki K.; Bassett, Julie K.; Frazier-Wood, Alexis C.; Lankinen, Maria; Murphy, Rachel A.; Rajaobelina, Kalina; Gobbo, Del Liana C.; Forouhi, Nita G.; Luben, Robert; Khaw, Kay Tee; Wareham, Nick; Kalsbeek, Anya; Veenstra, Jenna; Luo, Juhua; Hu, Frank B.; Lin, Hung Ju; Siscovick, David S.; Boeing, Heiner; Chen, Tzu An; Steffen, Brian; Steffen, Lyn M.; Hodge, Allison; Eriksdottir, Gudny; Smith, Albert V.; Gudnason, Vilmunder; Harris, Tamara B.; Brouwer, Ingeborg A.; Berr, Claudine; Helmer, Catherine; Samieri, Cecilia; Laakso, Markku; Tsai, Michael Y.; Giles, Graham G.; Nurmi, Tarja; Wagenknecht, Lynne; Schulze, Matthias B.; Lemaitre, Rozenn N.; Chien, Kuo Liong; Soedamah-Muthu, Sabita S.; Geleijnse, Johanna M.; Sun, Qi; Harris, William S.; Lind, Lars; Ärnlöv, Johan; Riserus, Ulf; Micha, Renata; Mozaffarian, Dariush

2017-01-01

Background: The metabolic effects of omega-6 polyunsaturated fatty acids (PUFAs) remain contentious, and little evidence is available regarding their potential role in primary prevention of type 2 diabetes. We aimed to assess the associations of linoleic acid and arachidonic acid biomarkers with

[Degradation of Acid Orange 7 with Persulfate Activated by Silver Loaded Granular Activated Carbon].

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Wang, Zhong-ming; Huang, Tian-yin; Chen, Jia-bin; Li, Wen-wei; Zhang, Li-ming

2015-11-01

Granular activated carbon with silver loaded as activator (Ag/GAC) was prepared using impregnation method. N2 adsorption, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) were adopted to characterize the Ag/GAC, showing that silver was successfully loaded on granular activated carbon. The oxidation degradation of acid orange 7 (AO7) by the Ag/GAC activated by persulfate (PS) was investigated at ambient temperature. The influences of factors such as Ag loading, PS or Ag/GAC dosages and initial pH on the degradation of AO7 were evaluated. The results demonstrated that the degradation rate of AO7 could reach more than 95.0% after 180 min when the Ag loading content, PS/AO7 molar ratio, the Ag/GAC dosage were 12.7 mg x g(-1), 120: 1, 1.0 g x L(-1), respectively. The initial pH had significant effect on the AO7 degradation, with pH 5.0 as the optimal pH for the degradation of AO7. The possible degradation pathway was proposed for the AO7 degradation by using UV-visible spectroscopy and gas chromatography-mass spectrometry (GG/MS). The azo bond and naphthalene ring in the AO7 were destroyed during the degradation, with phthalic acid and acetophenone as the main degradation products.

Electrochemical assisted photocatalytic degradation of salicylic acid with highly ordered TiO{sub 2} nanotube electrodes

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Zhang, Qian [The State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Zhu, Jinwei [China Aerospace Science and Technology Corporation Fourty-fourth Research Institution (China); Wang, Ying; Feng, Jiangtao [Department of Environmental Science and Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Yan, Wei, E-mail: yanwei@mail.xjtu.edu.cn [The State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Department of Environmental Science and Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Xu, Hao, E-mail: xuhao@mail.xjtu.edu.cn [Department of Environmental Science and Engineering, Xi’an Jiaotong University, Xi’an 710049 (China)

2014-07-01

To explore the kinetics of photoelectrocatalytic degradation of salicylic acid, one of the important PPCPs, highly ordered TiO{sub 2} nanotube arrays (NTs) were prepared by the electrochemical anodization and characterized with scanning electron microscopy and X-ray diffraction techniques. The effect of TiO{sub 2} NTs properties, bias potential, initial salicylic acid concentration and solution pH on the degradation efficiency was studied and carefully analyzed. The results revealed that the salicylic acid degradation follows quasi-first order kinetics in the photoelectrocatalytic process, and the fastest decay kinetics was achieved in acidic environment (pH 2). The result was further interpreted through the electrochemical impedance spectroscopy. It is confirmed that the electrochemical assisted photocatalysis is a synergetic approach to combat stable organic substances with improved efficiency.

Kinetic and mechanistic study of microcystin-LR degradation by nitrous acid under ultraviolet irradiation

International Nuclear Information System (INIS)

Ma, Qingwei; Ren, Jing; Huang, Honghui; Wang, Shoubing; Wang, Xiangrong; Fan, Zhengqiu

2012-01-01

Highlights: ► For the first time, degradation of MC-LR by nitrous acid under UV 365 nm was discovered. ► The effects of factors on MC-LR degradation were analyzed based on kinetic study. ► Mass spectrometry was applied for identification of intermediates and products. ► Special intermediates involved in this study were identified. ► Degradation mechanisms were proposed according to the results of LC–MS analysis. - Abstract: Degradation of microcystin-LR (MC-LR) in the presence of nitrous acid (HNO 2 ) under irradiation of 365 nm ultraviolet (UV) was studied for the first time. The influence of initial conditions including pH value, NaNO 2 concentration, MC-LR concentration and UV intensity were studied. MC-LR was degraded in the presence of HNO 2 ; enhanced degradation of MC-LR was observed with 365 nm UV irradiation, caused by the generation of hydroxyl radicals through the photolysis of HNO 2 . The degradation processes of MC-LR could well fit the pseudo-first-order kinetics. Mass spectrometry was applied for identification of the byproducts and the analysis of degradation mechanisms. Major degradation pathways were proposed according to the results of LC–MS analysis. The degradation of MC-LR was initiated via three major pathways: attack of hydroxyl radicals on the conjugated carbon double bonds of Adda, attack of hydroxyl radicals on the benzene ring of Adda, and attack of nitrosonium ion on the benzene ring of Adda.

Genome Sequence Analysis of the Naphthenic Acid Degrading and Metal Resistant Bacterium Cupriavidus gilardii CR3.

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Xiaoyu Wang

Full Text Available Cupriavidus sp. are generally heavy metal tolerant bacteria with the ability to degrade a variety of aromatic hydrocarbon compounds, although the degradation pathways and substrate versatilities remain largely unknown. Here we studied the bacterium Cupriavidus gilardii strain CR3, which was isolated from a natural asphalt deposit, and which was shown to utilize naphthenic acids as a sole carbon source. Genome sequencing of C. gilardii CR3 was carried out to elucidate possible mechanisms for the naphthenic acid biodegradation. The genome of C. gilardii CR3 was composed of two circular chromosomes chr1 and chr2 of respectively 3,539,530 bp and 2,039,213 bp in size. The genome for strain CR3 encoded 4,502 putative protein-coding genes, 59 tRNA genes, and many other non-coding genes. Many genes were associated with xenobiotic biodegradation and metal resistance functions. Pathway prediction for degradation of cyclohexanecarboxylic acid, a representative naphthenic acid, suggested that naphthenic acid undergoes initial ring-cleavage, after which the ring fission products can be degraded via several plausible degradation pathways including a mechanism similar to that used for fatty acid oxidation. The final metabolic products of these pathways are unstable or volatile compounds that were not toxic to CR3. Strain CR3 was also shown to have tolerance to at least 10 heavy metals, which was mainly achieved by self-detoxification through ion efflux, metal-complexation and metal-reduction, and a powerful DNA self-repair mechanism. Our genomic analysis suggests that CR3 is well adapted to survive the harsh environment in natural asphalts containing naphthenic acids and high concentrations of heavy metals.

Regulation of the arachidonic acid mobilization in macrophages by combustion-derived particles

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Weiss Carsten

2011-08-01

Full Text Available Abstract Background Acute exposure to elevated levels of environmental particulate matter (PM is associated with increasing morbidity and mortality rates. These adverse health effects, e.g. culminating in respiratory and cardiovascular diseases, have been demonstrated by a multitude of epidemiological studies. However, the underlying mechanisms relevant for toxicity are not completely understood. Especially the role of particle-induced reactive oxygen species (ROS, oxidative stress and inflammatory responses is of particular interest. In this in vitro study we examined the influence of particle-generated ROS on signalling pathways leading to activation of the arachidonic acid (AA cascade. Incinerator fly ash particles (MAF02 were used as a model for real-life combustion-derived particulate matter. As macrophages, besides epithelial cells, are the major targets of particle actions in the lung murine RAW264.7 macrophages and primary human macrophages were investigated. Results The interaction of fly ash particles with macrophages induced both the generation of ROS and as part of the cellular inflammatory responses a dose- and time-dependent increase of free AA, prostaglandin E2/thromboxane B2 (PGE2/TXB2, and 8-isoprostane, a non-enzymatically formed oxidation product of AA. Additionally, increased phosphorylation of the mitogen-activated protein kinases (MAPK JNK1/2, p38 and ERK1/2 was observed, the latter of which was shown to be involved in MAF02-generated AA mobilization and phosphorylation of the cytosolic phospolipase A2. Using specific inhibitors for the different phospolipase A2 isoforms the MAF02-induced AA liberation was shown to be dependent on the cytosolic phospholipase A2, but not on the secretory and calcium-independent phospholipase A2. The initiation of the AA pathway due to MAF02 particle exposure was demonstrated to depend on the formation of ROS since the presence of the antioxidant N-acetyl-cysteine (NAC prevented the MAF02

Effects of dietary conjugated linoleic acid and linoleic:linolenic acid ratio on polyunsaturated fatty acid status in laying hens.

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Du, M; Ahn, D U; Sell, J L

2000-12-01

A study was conducted to determine the effects of dietary conjugated linoleic acid (CLA) and the ratio of linoleic:linolenic acid on long-chain polyunsaturated fatty acid status. Thirty-two 31-wk-old White Leghorn hens were randomly assigned to four diets containing 8.2% soy oil, 4.1% soy oil + 2.5% CLA (4.1% CLA source), 4.1% flax oil + 2.5% CLA, or 4.1% soy oil + 4.1% flax oil. Hens were fed the diets for 3 wk before eggs and tissues were collected for the study. Lipids were extracted from egg yolk and tissues, classes of egg yolk lipids were separated, and fatty acid concentrations of total lipids, triglyceride, phosphatidylethanolamine, and phosphatidylcholine were analyzed by gas chromatography. The concentrations of monounsaturated fatty acids and non-CLA polyunsaturated fatty acids were reduced after CLA feeding. The amount of arachidonic acid was decreased after CLA feeding in linoleic acid- and linolenic acid-rich diets, but amounts of eicosapentaenoic acid and docosahexaenoic acid were increased in the linolenic-rich diet, indicating that the synthesis or deposition of long-chain n-3 fatty acids was accelerated after CLA feeding. The increased docosahexaenoic acid and eicosapentaenoic acid contents in lipid may be compensation for the decreased arachidonic acid content. Dietary supplementation of linoleic acid increased n-6 fatty acid levels in lipids, whereas linolenic acid increased n-3 fatty acid levels. Results also suggest that CLA might not be elongated to synthesize long-chain fatty acids in significant amounts. The effect of CLA in reducing the level of n-6 fatty acids and promoting the level of n-3 fatty acids could be related to the biological effects of CLA.

Effects of Arachidonic Acid Supplementation on Acute Anabolic Signaling and Chronic Functional Performance and Body Composition Adaptations.

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Eduardo O De Souza

Full Text Available The primary purpose of this investigation was to examine the effects of arachidonic acid (ARA supplementation on functional performance and body composition in trained males. In addition, we performed a secondary study looking at molecular responses of ARA supplementation following an acute exercise bout in rodents.Thirty strength-trained males (age: 20.4 ± 2.1 yrs were randomly divided into two groups: ARA or placebo (i.e. CTL. Then, both groups underwent an 8-week, 3-day per week, non-periodized training protocol. Quadriceps muscle thickness, whole-body composition scan (DEXA, muscle strength, and power were assessed at baseline and post-test. In the rodent model, male Wistar rats (~250 g, ~8 weeks old were pre-fed with either ARA or water (CTL for 8 days and were fed the final dose of ARA prior to being acutely strength trained via electrical stimulation on unilateral plantar flexions. A mixed muscle sample was removed from the exercised and non-exercised leg 3 hours post-exercise.Lean body mass (2.9%, p<0.0005, upper-body strength (8.7%, p<0.0001, and peak power (12.7%, p<0.0001 increased only in the ARA group. For the animal trial, GSK-β (Ser9 phosphorylation (p<0.001 independent of exercise and AMPK phosphorylation after exercise (p-AMPK less in ARA, p = 0.041 were different in ARA-fed versus CTL rats.Our findings suggest that ARA supplementation can positively augment strength-training induced adaptations in resistance-trained males. However, chronic studies at the molecular level are required to further elucidate how ARA combined with strength training affect muscle adaptation.

Degradation of 2,4,5-trichlorophenoxyacetic acid in aqueous solution by 60Co-γ irradiation

International Nuclear Information System (INIS)

Liu Yuanxia; Yu Yuan; Bao Huaying

2010-01-01

2,4,5-trichlorophenoxyacetic acid(2,4,5-T) is one kind of phenoxy-hydroxy-acid herbicides, also is one kind of Endocrine Disrupting Chemicals. The degradation of 2,4,5-T in aqueous solution by 60 Co-γ irradiation was investigated in the paper. The degradation effect of different influencing factors, such as absorbed dose and irradiation aura, was studied respectively. The degradation products were preliminarily analyzed by High Performance Liquid Chromatography, UV-Vis spectrophotometer and Ion Chromatography. The results showed that 2,4,5-T could be effectively degraded in aqueous solutions by 60 Co-γ irradiation. Meanwhile, the Chloride ion was detected in the solution, whose concentration increased with the growth of absorbed dose. It was found that although both e-aq and ·OH originated from water radiolysis could eliminate 2,4,5-T, the dechlorination effect and the degradation products were different. (authors)

Hydrothermal synthesis spherical TiO2 and its photo-degradation property on salicylic acid

International Nuclear Information System (INIS)

Guo Wenlu; Liu Xiaolin; Huo Pengwei; Gao Xun; Wu Di; Lu Ziyang; Yan Yongsheng

2012-01-01

Anatase TiO 2 spheres have been prepared using hydrothermal synthesis. The prepared spheres were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and UV-vis diffuse reflectance spectra (UV-vis DRS). The TiO 2 consisted of well-defined spheres with size of 3-5 μm. The photocatalytic activity of spherical TiO 2 was determined by degradation of salicylic acid under visible light irradiation. It was revealed that the degradation rate of the spherical TiO 2 which was processed at 150 °C for 48 h could reach 81.758%. And the kinetics of photocatalytic degradation obeyed first-order kinetic, which the rate constant value was 0.01716 S -1 of the salicylic acid onto TiO 2 (temperature: 150, time: 48 h). The kinetics of adsorption followed the pseudo-second-order model and the rate constant was 1.2695 g mg -1 of the salicylic acid onto TiO 2 (temperature: 150, time: 48 h).

Characterization of the complete uric acid degradation pathway in the fungal pathogen Cryptococcus neoformans.

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I Russel Lee

Full Text Available Degradation of purines to uric acid is generally conserved among organisms, however, the end product of uric acid degradation varies from species to species depending on the presence of active catabolic enzymes. In humans, most higher primates and birds, the urate oxidase gene is non-functional and hence uric acid is not further broken down. Uric acid in human blood plasma serves as an antioxidant and an immune enhancer; conversely, excessive amounts cause the common affliction gout. In contrast, uric acid is completely degraded to ammonia in most fungi. Currently, relatively little is known about uric acid catabolism in the fungal pathogen Cryptococcus neoformans even though this yeast is commonly isolated from uric acid-rich pigeon guano. In addition, uric acid utilization enhances the production of the cryptococcal virulence factors capsule and urease, and may potentially modulate the host immune response during infection. Based on these important observations, we employed both Agrobacterium-mediated insertional mutagenesis and bioinformatics to predict all the uric acid catabolic enzyme-encoding genes in the H99 genome. The candidate C. neoformans uric acid catabolic genes identified were named: URO1 (urate oxidase, URO2 (HIU hydrolase, URO3 (OHCU decarboxylase, DAL1 (allantoinase, DAL2,3,3 (allantoicase-ureidoglycolate hydrolase fusion protein, and URE1 (urease. All six ORFs were then deleted via homologous recombination; assaying of the deletion mutants' ability to assimilate uric acid and its pathway intermediates as the sole nitrogen source validated their enzymatic functions. While Uro1, Uro2, Uro3, Dal1 and Dal2,3,3 were demonstrated to be dispensable for virulence, the significance of using a modified animal model system of cryptococcosis for improved mimicking of human pathogenicity is discussed.

Mild MPP+ exposure impairs autophagic degradation through a novel lysosomal acidity-independent mechanism.

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Miyara, Masatsugu; Kotake, Yaichiro; Tokunaga, Wataru; Sanoh, Seigo; Ohta, Shigeru

2016-10-01

Parkinson's disease (PD) is the second most common neurodegenerative disorder, but its underlying cause remains unknown. Although recent studies using PD-related neurotoxin MPP + suggest autophagy involvement in the pathogenesis of PD, the effect of MPP + on autophagic processes under mild exposure, which mimics the slow progressive nature of PD, remains largely unclear. We examined the effect of mild MPP + exposure (10 and 200 μM for 48 h), which induces a more slowly developing cell death, on autophagic processes and the mechanistic differences with acute MPP + toxicity (2.5 and 5 mM for 24 h). In SH-SY5Y cells, mild MPP + exposure predominantly inhibited autophagosome degradation, whereas acute MPP + exposure inhibited both autophagosome degradation and basal autophagy. Mild MPP + exposure reduced lysosomal hydrolase cathepsin D activity without changing lysosomal acidity, whereas acute exposure decreased lysosomal density. Lysosome biogenesis enhancers trehalose and rapamycin partially alleviated mild MPP + exposure induced impaired autophagosome degradation and cell death, but did not prevent the pathogenic response to acute MPP + exposure, suggesting irreversible lysosomal damage. We demonstrated impaired autophagic degradation by MPP + exposure and mechanistic differences between mild and acute MPP + toxicities. Mild MPP + toxicity impaired autophagosome degradation through novel lysosomal acidity-independent mechanisms. Sustained mild lysosomal damage may contribute to PD. We examined the effects of MPP + on autophagic processes under mild exposure, which mimics the slow progressive nature of Parkinson's disease, in SH-SY5Y cells. This study demonstrated impaired autophagic degradation through a reduction in lysosomal cathepsin D activity without altering lysosomal acidity by mild MPP + exposure. Mechanistic differences between acute and mild MPP + toxicity were also observed. Sustained mild damage of lysosome may be an underlying cause of Parkinson

The role of the arachidonic acid cascade in the species-specific X-ray-induced inflammation of the rabbit eye

International Nuclear Information System (INIS)

Bito, L.Z.; Klein, E.M.

1982-01-01

To identify the mediator(s) of the apparently species-specific X-ray-induced inflammation of the rabbit eye, inhibitors of the synthesis and/or release of known or putative mediators of ocular inflammation were administered prior to irradiation. The X-ray-induced ocular inflammation, particularly the rise in intraocular pressure, was found to be inhibited by intravenous pretreatment of rabbits with flurbiprofen, indomethacin, or imidazole (1, 10, and 100 mg/kg i.v., respectively), or by combined intravitreal and topical administration of flurbiprofen. Systemic, intravitreal, and/or topical pretreatment with prednisolone or disodium cromoglycate or the retrobulbar injection of ethyl alcohol or capsaicin failed to block the inflammatory response, whereas vitamin E apparently exerted some protective effect. These findings show that the X-ray-induced inflammation of the rabbit eye is mediated, at least in part, by prostaglandins (PGs) and/or related autacoids. In addition, these results suggest that the unique sensitivity of the rabbit eye to X-ray-induced inflammation is due either to the presence in this species of a unique or uniquely effective triggering mechanism for the release of PG precursors or to the greater sensitivity of this species to the ocular inflammatory effects of PGs. Thus the rabbit eye may provide a unique model for studying some aspects of arachidonic acid release or ocular PG effects, but extreme caution must be exercised in generalizing such findings to other species

Safflower and olive oil dietary treatments rescue aberrant embryonic arachidonic acid and nitric oxide metabolism and prevent diabetic embryopathy in rats.

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Higa, R; White, V; Martínez, N; Kurtz, M; Capobianco, E; Jawerbaum, A

2010-04-01

Aberrant arachidonic acid and nitric oxide (NO) metabolic pathways are involved in diabetic embryopathy. Previous works have found diminished concentrations of PGE(2) and PGI(2) in embryos from diabetic rats, and that PGI(2) is capable of increasing embryonic PGE(2) concentrations through the activation of the nuclear receptor PPARdelta. PPARdelta activators are lipid molecules such as oleic and linoleic acids, present in high concentrations in olive and safflower oils, respectively. The aim of this study was to analyze the capability of dietary supplementation with either 6% olive or 6% safflower oils to regulate PGE(2), PGI(2) and NO concentrations in embryos and deciduas from control and diabetic rats during early organogenesis. Diabetes was induced by a single injection of streptozotocin (55 mg/kg) 1 week before mating. Animals were fed with the oil-supplemented diets from Days 0.5 to 10.5 of gestation. PGI(2) and PGE(2) were measured by EIA and NO through the evaluation of its stable metabolites nitrates-nitrites in 10.5 day embryos and deciduas. We found that the olive and safflower oil-supplemented treatments highly reduced resorption and malformation rates in diabetic animals, and that they were able to prevent maternal diabetes-induced alterations in embryonic and decidual PGI(2) and PGE(2) concentrations. Moreover, these dietary treatments prevented NO overproduction in embryos and deciduas from diabetic rats. These data indicate that in maternal diabetes both the embryo and the decidua benefit from the olive and safflower oil supplementation probably through mechanisms that involve the rescue of aberrant prostaglandin and NO generation and that prevent developmental damage during early organogenesis.

Impact of arachidonic versus eicosapentaenoic acid on exotonin-induced lung vascular leakage: relation to 4-series versus 5-series leukotriene generation.

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Grimminger, F; Wahn, H; Mayer, K; Kiss, L; Walmrath, D; Seeger, W

1997-02-01

Escherichia coli hemolysin (HlyA) is a proteinaceous pore-forming exotoxin that is implicated as a significant pathogenicity factor in extraintestinal E. coli infections including sepsis. In perfused rabbit lungs, subcytolytic concentrations of the toxin evoke thromboxane-mediated vasoconstriction and prostanoid-independent protracted vascular permeability increase (11). In the present study, the influence of submicromolar concentrations of free arachidonic acid (AA) and eicosapentaenoic acid (EPA) on the HlyA-induced leakage response was investigated. HlyA at concentration from 0.02 to 0.06 hemolytic units/ml provoked a dose-dependent, severalfold increase in the capillary filtration coefficient (Kfc), accompanied by the release of leukotriene(LT)B4, LTC4, and LTE4 into the recirculating buffer fluid. Simultaneous application of 100 nmol/L AA markedly augmented the HlyA-elicited leakage response, concomitant with an amplification of LTB4 release and a change in the kinetics of cysteinyl-LT generation. In contrast, 50 to 200 nmol/L EPA suppressed in a dose-dependent manner the HlyA-induced increase in Kfc values. This was accompanied by a blockage of 4-series LT generation and a dose-dependent appearance of LTB5, LTC5, and LTE5. In addition, EPA fully antagonized the AA-induced amplification of the HlyA-provoked Kfc increase, again accompanied by a shift from 4-series to 5-series LT generation. We conclude that the vascular leakage provoked by HlyA in rabbit lungs is differentially influenced by free AA versus free EPA, related to the generation of 4- versus 5-series leukotrienes. The composition of lipid emulsions used for parenteral nutrition may thus influence inflammatory capillary leakage.

Kinetic and mechanistic study of microcystin-LR degradation by nitrous acid under ultraviolet irradiation

Energy Technology Data Exchange (ETDEWEB)

Ma, Qingwei; Ren, Jing [Department of Environmental Science and Engineering, Fudan University, Shanghai 200433 (China); Huang, Honghui [Key Laboratory of Fisheries Ecology Environment, Ministry of Agriculture, Guangzhou 510300 (China); Wang, Shoubing [Department of Environmental Science and Engineering, Fudan University, Shanghai 200433 (China); Wang, Xiangrong, E-mail: xrxrwang@vip.sina.com [Department of Environmental Science and Engineering, Fudan University, Shanghai 200433 (China); Fan, Zhengqiu, E-mail: zhqfan@fudan.edu.cn [Department of Environmental Science and Engineering, Fudan University, Shanghai 200433 (China)

2012-05-15

Highlights: Black-Right-Pointing-Pointer For the first time, degradation of MC-LR by nitrous acid under UV 365 nm was discovered. Black-Right-Pointing-Pointer The effects of factors on MC-LR degradation were analyzed based on kinetic study. Black-Right-Pointing-Pointer Mass spectrometry was applied for identification of intermediates and products. Black-Right-Pointing-Pointer Special intermediates involved in this study were identified. Black-Right-Pointing-Pointer Degradation mechanisms were proposed according to the results of LC-MS analysis. - Abstract: Degradation of microcystin-LR (MC-LR) in the presence of nitrous acid (HNO{sub 2}) under irradiation of 365 nm ultraviolet (UV) was studied for the first time. The influence of initial conditions including pH value, NaNO{sub 2} concentration, MC-LR concentration and UV intensity were studied. MC-LR was degraded in the presence of HNO{sub 2}; enhanced degradation of MC-LR was observed with 365 nm UV irradiation, caused by the generation of hydroxyl radicals through the photolysis of HNO{sub 2}. The degradation processes of MC-LR could well fit the pseudo-first-order kinetics. Mass spectrometry was applied for identification of the byproducts and the analysis of degradation mechanisms. Major degradation pathways were proposed according to the results of LC-MS analysis. The degradation of MC-LR was initiated via three major pathways: attack of hydroxyl radicals on the conjugated carbon double bonds of Adda, attack of hydroxyl radicals on the benzene ring of Adda, and attack of nitrosonium ion on the benzene ring of Adda.

Protective effect of eicosapentaenoic acid on ouabain toxicity in neonatal rat cardiac myocytes

International Nuclear Information System (INIS)

Hallaq, H.; Leaf, A.; Sellmayer, A.; Smith, T.W.

1990-01-01

Isolated neonatal cardiac myocytes have been utilized as a model for the study of cardiac arrhythmogenic factors. The myocytes respond to the toxic effects of a potent cardiac glycoside, ouabain at 0.1 mM, by an increase in their spontaneous beating rate and a reduction in amplitude of contractions resulting within minutes in a lethal state of contracture. Incubating the isolated myocytes for 3 endash 5 days in culture medium enriched with 5 μM arachidonic acid had no effect on the development of lethal contracture after subsequent exposure to 0.1 mM ouabain. By contrast, incubating the myocytes for 3 endash 5 days with 5 μM eicosapentaenoic acid completely prevented the toxic effects of ouabain at 0.1 mM. No differences in bumetanide-inhibitable 86 Rb flux were observed between the three preparations. However, measurements with fura-2 of cytosolic free calcium levels indicated that control and arachidonic acid-enriched myocytes developed toxic cytosolic calcium concentrations of 845 ± 29 and 757 ± 64 nM, respectively, on exposure to 0.1 mM ouabain, whereas in eicosapentaenoic acid-enriched myocytes, physiologic calcium levels were preserved. Incubating the myocytes with eicosapentaenoic acid for 3 endash 5 days resulted in a small reduction of arachidonic acid and a small but significant increase of eicosapentaenoic acid in membrane phospolipids of the myocytes

Liver conversion of docosahexaenoic and arachidonic acids from their 18-carbon precursors in rats on a DHA-free but α-LNA-containing n-3 PUFA adequate diet.

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Gao, Fei; Kim, Hyung-Wook; Igarashi, Miki; Kiesewetter, Dale; Chang, Lisa; Ma, Kaizong; Rapoport, Stanley I

2011-01-01

The long-chain polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid (EPA, 20:5n-3), docosahexaenoic acid (DHA, 22:6n-3), and arachidonic acid (AA, 20:4n-6), are critical for health. These PUFAs can be synthesized in liver from their plant-derived precursors, α-linolenic acid (α-LNA, 18:3n-3) and linoleic acid (LA, 18:2n-6). Vegetarians and vegans may have suboptimal long-chain n-3 PUFA status, and the extent of the conversion of α-LNA to EPA and DHA by the liver is debatable. We quantified liver conversion of DHA and other n-3 PUFAs from α-LNA in rats fed a DHA-free but α-LNA (n-3 PUFA) adequate diet, and compared results to conversion of LA to AA. [U-(13)C]LA or [U-(13)C]α-LNA was infused intravenously for 2h at a constant rate into unanesthetized rats fed a DHA-free α-LNA adequate diet, and published equations were used to calculate kinetic parameters. The conversion coefficient k(⁎) of DHA from α-LNA was much higher than for AA from LA (97.2×10(-3) vs. 10.6×10(-3)min(-1)), suggesting that liver elongation-desaturation is more selective for n-3 PUFA biosynthesis on a per molecule basis. The net daily secretion rate of DHA, 20.3μmol/day, exceeded the reported brain DHA consumption rate by 50-fold, suggesting that the liver can maintain brain DHA metabolism with an adequate dietary supply solely of α-LNA. This infusion method could be used in vegetarians or vegans to determine minimal daily requirements of EPA and DHA in humans. Published by Elsevier B.V.

Poly(ethylene glycol) (PEG)-lactic acid nanocarrier-based degradable hydrogels for restoring the vaginal microenvironment

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Rajan, Sujata Sundara; Turovskiy, Yevgeniy; Singh, Yashveer; Chikindas, Michael L.; Sinko, Patrick J.

2014-01-01

Women with bacterial vaginosis (BV) display reduced vaginal acidity, which make them susceptible to associated infections such as HIV. In the current study, poly(ethylene glycol) (PEG) nanocarrier-based degradable hydrogels were developed for the controlled release of lactic acid in the vagina of BV-infected women. PEG-lactic acid (PEG-LA) nanocarriers were prepared by covalently attaching lactic acid to 8-arm PEG-SH via cleavable thioester bonds. PEG-LA nanocarriers with 4 copies of lactic acid per molecule provided controlled release of lactic acid with a maximum release of 23% and 47% bound lactic acid in phosphate buffered saline (PBS, pH 7.4) and acetate buffer (AB, pH 4.3), respectively. The PEG nanocarrier-based hydrogels were formed by cross-linking the PEG-LA nanocarriers with 4-arm PEG-NHS via degradable thioester bonds. The nanocarrier-based hydrogels formed within 20 min under ambient conditions and exhibited an elastic modulus that was 100-fold higher than the viscous modulus. The nanocarrier-based degradable hydrogels provided controlled release of lactic acid for several hours; however, a maximum release of only 10%–14% bound lactic acid was observed possibly due to steric hindrance of the polymer chains in the cross-linked hydrogel. In contrast, hydrogels with passively entrapped lactic acid showed burst release with complete release within 30 min. Lactic acid showed antimicrobial activity against the primary BV pathogen Gardnerella vaginalis with a minimum inhibitory concentration (MIC) of 3.6 mg/ml. In addition, the hydrogels with passively entrapped lactic acid showed retained antimicrobial activity with complete inhibition G. vaginalis growth within 48 h. The results of the current study collectively demonstrate the potential of PEG nanocarrier-based hydrogels for vaginal administration of lactic acid for preventing and treating BV. PMID:25223229

Reaction pathway of the degradation of the p-hydroxybenzoic acid by sulfate radical generated by ionizing radiations

International Nuclear Information System (INIS)

Criquet, Justine; Leitner, Nathalie Karpel Vel

2015-01-01

The degradation of p-hydroxybenzoic acid (HBA) in aqueous solutions by ionizing radiation was studied. The phenolic pollutant was easily removed by the electron beam irradiation, as more than 80% of the initial 100 µM introduced was degraded for a dose of 600 Gy. It was shown that the addition of persulfate, producing the sulfate radical as additional reactive species, induced a change in the reaction pathway. LC–MS analyses were performed in order to identify the different by-products formed. In the absence of persulfate, the main by-product formed was 3,4-dihydroxybenzoic acid, while in presence of persulfate, 1,4-benzoquinone was detected and the hydroxylated by-products were not present. A reaction pathway of HBA degradation by hydroxyl and sulfate radicals was proposed from the identification of the chemical structure of the different by-products detected. The influences of pH and dissolved oxygen were also studied. A high decline of HBA degradation was observed at pH 11 compared to pH 4.5, this decrease was minimized in the presence of persulfate. The dissolved oxygen concentration was found to be a limiting parameter of HBA degradation, however an excess of dissolved oxygen in solution did not improve the degradation to a large extent. - Highlights: • p-Hydroxybenzoic acid (HBA) is easily removed by e-beam irradiation. • The sulfate radicals formed from persulfate induce loss of the benzoic acid skeleton. • The dissolved oxygen concentration is a limiting parameter of the HBA degradation. • The effect of pH is minimized in presence of persulfate

Docosahexaenoic acid and other fatty acids induce a decrease in pHi in Jurkat T-cells

OpenAIRE

Aires, Virginie; Hichami, Aziz; Moutairou, Kabirou; Khan, Naim Akhtar

2003-01-01

Docosahexaenoic acid (DHA) induced rapid (t1/2=33 s) and dose-dependent decreases in pHi in BCECF-loaded human (Jurkat) T-cells. Addition of 5-(N,N-dimethyl)-amiloride, an inhibitor of Na+/H+ exchanger, prolonged DHA-induced acidification as a function of time, indicating that the exchanger is implicated in pHi recovery.Other fatty acids like oleic acid, arachidonic acid, eicosapentaenoic acid, but not palmitic acid, also induced a fall in pHi in these cells.To assess the role of calcium in t...

Chronic dietary n-6 PUFA deprivation leads to conservation of arachidonic acid and more rapid loss of DHA in rat brain phospholipids.

Science.gov (United States)

Lin, Lauren E; Chen, Chuck T; Hildebrand, Kayla D; Liu, Zhen; Hopperton, Kathryn E; Bazinet, Richard P

2015-02-01

To determine how the level of dietary n-6 PUFA affects the rate of loss of arachidonic acid (ARA) and DHA in brain phospholipids, male rats were fed either a deprived or adequate n-6 PUFA diet for 15 weeks postweaning, and then subjected to an intracerebroventricular infusion of (3)H-ARA or (3)H-DHA. Brains were collected at fixed times over 128 days to determine half-lives and the rates of loss from brain phospholipids (J out). Compared with the adequate n-6 PUFA rats, the deprived n-6-PUFA rats had a 15% lower concentration of ARA and an 18% higher concentration of DHA in their brain total phospholipids. Loss half-lives of ARA in brain total phospholipids and fractions (except phosphatidylserine) were longer in the deprived n-6 PUFA rats, whereas the J out was decreased. In the deprived versus adequate n-6 PUFA rats, the J out of DHA was higher. In conclusion, chronic n-6 PUFA deprivation decreases the rate of loss of ARA and increases the rate of loss of DHA in brain phospholipids. Thus, a low n-6 PUFA diet can be used to target brain ARA and DHA metabolism. Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

Degradation of protein translation machinery by amino acid starvation-induced macroautophagy

DEFF Research Database (Denmark)

Gretzmeier, Christine; Eiselein, Sven; Johnson, Gregory R.

2017-01-01

, unbiased approaches relying on quantitative mass spectrometry-based proteomics. Macroautophagy is induced by rapamycin treatment, and by amino acid and glucose starvation in differentially, metabolically labeled cells. Protein dynamics are linked to image-based models of autophagosome turnover. Depending...... on the inducing stimulus, protein as well as organelle turnover differ. Amino acid starvation-induced macroautophagy leads to selective degradation of proteins important for protein translation. Thus, protein dynamics reflect cellular conditions in the respective treatment indicating stimulus-specific pathways...

Degradation of Poly (lactic acid under Simulated Landfill Conditions

Directory of Open Access Journals (Sweden)

Chomnutcha Boonmee

2017-03-01

Full Text Available In this study, the physical and chemical properties change of poly(lactic acid after burying in the mixture of soil and sludge under thermophilic (61 °C oxygen limited conditions were investigated using various analytical techniques. The environmental factors under these setting conditions and microbial activities accelerated the degradation process of PLA. Under tested conditions, PLA loss their weight about 90% at the burying time of 90 days. During the degradation process, PLA samples were continuously broken to small fragile fragments and showed the size less than 1 mm at the end of degradation test. Change of the surface morphology change was revealed by scanning electron microscopy (SEM. Many pores, cracks and irregular roughness were presented on the PLA surface. Thermal decomposition was decreased from 387.8 to 289.2 °C. The percentage of carbon content in molecular structure decreased from 49.46% to 45.42%. In addition, the Fourier transformed infrared spectroscopy (FTIR revealed the change of ester bonds. This study can be used for developing PLA waste management process.

Omega-6 and trans fatty acids in blood cell membranes: a risk factor for acute coronary syndromes?

Science.gov (United States)

Block, Robert C; Harris, William S; Reid, Kimberly J; Spertus, John A

2008-12-01

Although fatty acid intake has been associated with risk of coronary disease events, the association between blood omega-6 and trans fatty acids (FAs) at the time of an acute coronary syndrome (ACS) is unknown. The relationship of blood FA composition to ACS was analyzed in 768 incident cases and 768 controls (matched on age, sex, and race). Compared to controls, ACS cases' blood cell membrane content of linoleic acid was 13% lower (P 3 times the odds for being a case (odds ratio [OR] 3.23, 95% confidence interval [CI] 2.63-4.17). The relationship of arachidonic acid to ACS was U shaped; compared to the first quartile of arachidonic acid, the ORs for case status in the second, third, and fourth quartiles were 0.73 (95% CI 0.47-1.13), 0.65 (95% CI 0.41-1.04), and 2.32 (95% CI 1.39-3.90), respectively. The OR for a 1-SD increase in trans oleic acid was 1.24 (95% CI 1.06-1.45), and for trans-trans linoleic acid, 1.1 (95% CI 0.93-1.30). All associations were independent of membrane omega-3 FA content. High blood levels of linoleic acid but low levels of trans oleic acid are inversely associated with ACS. The relationship of arachidonic acid to ACS appears more complex.

Characterization of arachidonate 5-lipoxygenase and leukotriene A4 synthetase from RBL-1 cells

International Nuclear Information System (INIS)

Cook, M.; Hogaboom, G.K.; Sarau, H.M.; Foley, J.J.; Crooke, S.T.

1986-01-01

5-lipoxygenase (LO) and leukotriene (LT) A4 synthetase from RBL-1 high speed (105,000 x g for 60 min) supernatants were partially purified by protein-high performance liquid chromatography (HPLC) and characterized in detail. The partially purified preparation contained only 5-LO and LTA4 synthetase and was isolated from 12-LO, peroxidase and LTA4 hydrolase activities. Reaction products were separated by reversed phase HPLC and quantitated by absorption spectrophotometry and radiochemical detection. The enzyme preparation rapidly converted [ 14 C]arachidonate to [ 14 C]5-hydroperoxyeicosatetraenoic acid (HPETE) and [ 14 C]5,12-dihydroperoxyeicosatetraenoic acids (diHETEs). The 5,12-diHETEs were primarily non-enzymatic breakdown products of LTA4 (e.g., 6-trans-LTB4 and 6-trans-12-epi-LTB4). Both the 5-LO and LTA4 synthetase activities were Ca 2+- and ATP-dependent. For both enzyme activities, the CA 2+ stimulation required the presence of ATP. The fatty acid hydroperoxides, 5-,12-, and 15-HPETE, both stimulated ([ 3 μM]) 5-LO and LTA4 synthetase activities. The rapid isolation and subsequent characterization of 5-LO and LTA4 synthetase provide the bases for the further understanding of the role of the LO pathway in biological processes

Selective remodeling of cardiolipin fatty acids in the aged rat heart

Directory of Open Access Journals (Sweden)

Rapoport Stanley I

2006-01-01

Full Text Available Abstract Background The heart is rich in cardiolipin, a phospholipid acylated in four sites, predominately with linoleic acid. Whether or not aging alters the composition of cardiolipin acyl chains is controversial. We therefore measured the fatty acid concentration of cardiolipin in hearts of 4, 12 and 24 month old rats that consumed one diet, adequate in fatty acids for the duration of their life. Results The concentration (nmol/g of linoleic acid was decreased in 24 month old rats (3965 ± 617, mean ± SD vs 4 month old rats (5525 ± 656, while the concentrations of arachidonic and docosahexaenoic acid were increased in 24 month old rats (79 ± 9 vs 178 ± 27 and 104 ± 16 vs 307 ± 68 for arachidonic and docosahexaenoic acids, 4 months vs 24 months, respectively. Similar changes were not observed in ethanolamine glycerophospholipids or plasma unesterified fatty acids, suggesting specificity of these effects to cardiolipin. Conclusion These results demonstrate that cardiolipin remodeling occurs with aging, specifically an increase in highly unsaturated fatty acids.

Experimental investigation of coating degradation during simultaneous acid and erosive particle exposure

DEFF Research Database (Denmark)

Møller, Victor Buhl; Dam-Johansen, Kim; Frankær, Sarah Maria

When used in industrial processes, such as stirred acid leaching in the mineral industry, thermoset coatings are exposed to a combination of aggressive chemicals and erosive particlewear. While each exposure condition has been studied separately, no research has been presented on the effects...... of a simultaneous exposure. To investigate this, a pilot-scale stirred acid leaching tank, containing erosive particles and acidic solutions, has been designed and constructed. Resin types considered are amine-cured novolac epoxy and vinyl ester. Transient coating degradation is mapped through visual inspection...

Polylactic acid coating on a biodegradable magnesium alloy: An in vitro degradation study by electrochemical impedance spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Alabbasi, Alyaa; Liyanaarachchi, S.; Kannan, M. Bobby, E-mail: bobby.mathan@jcu.edu.au

2012-09-30

Polylactic acid (PLA) was coated on a biodegradable magnesium alloy, AZ91, using spin coating technique for temporary implant applications. The degradation behaviour of the coated alloy samples was evaluated using electrochemical impedance spectroscopy (EIS) method in simulated body fluid (SBF). EIS results suggested that the PLA coating enhanced the degradation resistance of the alloy significantly. Increase in the PLA coating thickness was found to increase the degradation resistance, but resulted in poor adhesion. Long-term EIS experiments of the PLA coated samples suggested that their degradation resistance gradually decreased with increase in SBF exposure time. However, the degradation resistance of the PLA coated samples was significantly higher than that of the bare metal even after a 48 h exposure to SBF. - Highlights: Black-Right-Pointing-Pointer Polylactic acid (PLA) was coated on a magnesium-based alloy. Black-Right-Pointing-Pointer PLA coating enhanced the in vitro degradation resistance of the alloy. Black-Right-Pointing-Pointer Increase in the PLA coating thickness improved the alloy degradation resistance. Black-Right-Pointing-Pointer Thin film PLA coating exhibited both good degradation resistance and adhesion.

Polylactic acid coating on a biodegradable magnesium alloy: An in vitro degradation study by electrochemical impedance spectroscopy

International Nuclear Information System (INIS)

Alabbasi, Alyaa; Liyanaarachchi, S.; Kannan, M. Bobby

2012-01-01

Polylactic acid (PLA) was coated on a biodegradable magnesium alloy, AZ91, using spin coating technique for temporary implant applications. The degradation behaviour of the coated alloy samples was evaluated using electrochemical impedance spectroscopy (EIS) method in simulated body fluid (SBF). EIS results suggested that the PLA coating enhanced the degradation resistance of the alloy significantly. Increase in the PLA coating thickness was found to increase the degradation resistance, but resulted in poor adhesion. Long-term EIS experiments of the PLA coated samples suggested that their degradation resistance gradually decreased with increase in SBF exposure time. However, the degradation resistance of the PLA coated samples was significantly higher than that of the bare metal even after a 48 h exposure to SBF. - Highlights: ► Polylactic acid (PLA) was coated on a magnesium-based alloy. ► PLA coating enhanced the in vitro degradation resistance of the alloy. ► Increase in the PLA coating thickness improved the alloy degradation resistance. ► Thin film PLA coating exhibited both good degradation resistance and adhesion.

From labdanes to drimanes. Degradation of the side chain of dihydrozamoranic acid.

Science.gov (United States)

Rodilla, Jesús M L; Díez, D; Urones, J G; Rocha, Pedro M

2004-04-30

A new route for the degradation of the saturated side chain of dihydrozamoranic acid has been devised, giving an advanced intermediate, compound 14, useful for the synthesis of insect antifeedants such as warburganal and polygodial.

Arginine-vasopressin stimulates the formation of phosphatidic acid in rat Leydig cells

DEFF Research Database (Denmark)

Nielsen, J.R.; Hansen, Harald S.; Jensen, B.

1987-01-01

Arginine-vasopressin (AVP) stimulated the formation of labelled phosphatidic acid (PA) in [C]arachidonic acid-prelabelled rat Leydig cells. After addition of 10 M AVP [C]arachidonoylphosphatidic acid reached a maximum within 2 min. The increase was dose-dependent (10-10 M). No change in labelling...

Degradation of Acid Orange 7 in an Atmospheric-Pressure Plasma-Solution System (Gliding Discharge)

International Nuclear Information System (INIS)

NI Mingjiang; YANG Huan; CHEN Tong; ZHANG Hao; WU Angjian; DU Changming; LI Xiaodong

2015-01-01

In this work, a plasma-solution system was applied to the degradation of Acid Orange 7 (AO7). The effects of initial concentration and type of feed gases (air, oxygen, nitrogen or argon) were studied. As the initial concentration increased from 100 mg/L to 160 mg/L, the discolouration rate of AO7 decreased from 99.3% to 95.9%, whereas the COD removal rate decreased from 37.9% to 22.6%. Air provided the best discolouration and COD removal rates (99.3% and 37.9%, respectively). In the presence of a zero-valent iron (ZVI) catalyst, the AO7 COD removal rate increased to 76.4%. The degradation products were analysed by a GC-MS, revealing that the degradation of the dye molecule was initiated through the cleavage of the -N=N- bond before finally being converted to organic acids. (paper)

Degradation of trans-ferulic acid in acidic aqueous medium by anodic oxidation, electro-Fenton and photoelectro-Fenton

Energy Technology Data Exchange (ETDEWEB)

Flores, Nelly; Sirés, Ignasi; Garrido, José Antonio; Centellas, Francesc; Rodríguez, Rosa María; Cabot, Pere Lluís; Brillas, Enric, E-mail: brillas@ub.edu

2016-12-05

Highlights: • trans-Ferulic acid degradation by EAOPs using a stirred BDD/air-diffusion cell. • Slow substrate abatement and poor mineralization by AO-H{sub 2}O{sub 2}. • 98% Mineralization by PEF, but with rapid and similar substrate decay than by EF. • Quicker degradation by SPEF due to the more potent photolytic action of sunlight. • Reaction pathway with four primary aromatic products and three final carboxylic acids. - Abstract: Solutions of pH 3.0 containing trans-ferulic acid, a phenolic compound in olive oil mill wastewater, have been comparatively degraded by anodic oxidation with electrogenerated H{sub 2}O{sub 2} (AO-H{sub 2}O{sub 2}), electro-Fenton (EF) and photoelectro-Fenton (PEF). Trials were performed with a BDD/air-diffusion cell, where oxidizing ·OH was produced from water discharge at the BDD anode and/or in the solution bulk from Fenton’s reaction between cathodically generated H{sub 2}O{sub 2} and added catalytic Fe{sup 2+}. The substrate was very slowly removed by AO-H{sub 2}O{sub 2}, whereas it was very rapidly abated by EF and PEF, at similar rate in both cases, due to its fast reaction with ·OH in the bulk. The AO-H{sub 2}O{sub 2} process yielded a slightly lower mineralization than EF, which promoted the accumulation of barely oxidizable products like Fe(III) complexes. In contrast, the fast photolysis of these latter species under irradiation with UVA light in PEF led to an almost total mineralization with 98% total organic carbon decay. The effect of current density and substrate concentration on the performance of all treatments was examined. Several solar PEF (SPEF) trials showed its viability for the treatment of wastewater containing trans-ferulic acid at larger scale. Four primary aromatic products were identified by GC–MS analysis of electrolyzed solutions, and final carboxylic acids like fumaric, acetic and oxalic were detected by ion-exclusion HPLC. A reaction sequence for trans-ferulic acid mineralization

Biodegradation of dimethyl phthalate by Sphingomonas sp. isolated from phthalic-acid-degrading aerobic granules.

Science.gov (United States)

Zeng, Ping; Moy, Benjamin Yan-Pui; Song, Yong-Hui; Tay, Joo-Hwa

2008-10-01

Phthalic acid esters (PAEs) contamination in water, air, and soil is one of the major environmental concerns in many countries. Besides the PAE biodegradation process, the PAE degrading bacteria have become one of the focuses of study. This study reports the successful isolation of one kind of indigenous bacterium PA-02 from phthalic acid (PA)-degrading aerobic granules. Based on its 16S ribosomal DNA sequence, isolate PA-02 was identified as Sphingomonas genus with 100% similarity to Sphingomonas sp. strain D84532. Strain PA-02 was a Gram-negative, rod-shaped bacterium with strong auto-aggregation ability. In particular, the strain PA-02 possessed PAE-degrading ability without acclimation. Results of growth tests showed that strain PA-02 could degrade dimethyl phthalate (DMP), dibutyl phthalate, and diethylhexyl phthalate. The specific degradation rates of DMP and PA were concentration-dependent with maximum values of 0.4 g-DMP g(-1) biomass h(-1) and 1.3 g-PA g(-1) biomass h(-1), respectively. Kinetic studies also revealed that PA-02 was robust under high concentrations of DMP and PA. Even when the PA concentration was increased to 1,000.0 mg l(-1), the specific PA degradation rate was about 0.25 g-PA g(-1) biomass h(-1). The corresponding value for DMP was 0.067 g-DMP g(-1) biomass h(-1) at 1,000 mg l(-1).

Chronic sucrose intake decreases concentrations of n6 fatty acids, but not docosahexaenoic acid in the rat brain phospholipids.

Science.gov (United States)

Mašek, Tomislav; Starčević, Kristina

2017-07-13

We investigated the influence of high sucrose intake, administered in drinking water, on the lipid profile of the brain and on the expression of SREBP1c and Δ-desaturase genes. Adult male rats received 30% sucrose solution for 20 weeks (Sucrose group), or plain water (Control group). After the 20th week of sucrose treatment, the Sucrose group showed permanent hyperglycemia. Sucrose treatment also increased the amount of total lipids and fatty acids in the brain. The brain fatty acid profile of total lipids as well as phosphatidylethanolamine, phosphatidylcholine and cardiolipin of the Sucrose group was extensively changed. The most interesting change was a significant decrease in n6 fatty acids, including the important arachidonic acid, whereas the content of oleic and docosahexaenoic acid remained unchanged. RT-qPCR revealed an increase in Δ-5-desaturase and SREBP1c gene expression. In conclusion, high sucrose intake via drinking water extensively changes rat brain fatty acid profile by decreasing n6 fatty acids, including arachidonic acid. In contrast, the content of docosahexaenoic acid remains constant in the brain total lipids as well as in phospholipids. Changes in the brain fatty acid profile reflect changes in the lipid metabolism of the rat lipogenic tissues and concentrations in the circulation. Copyright © 2017 Elsevier B.V. All rights reserved.

The role of nanoparticulate agglomerates in TiO{sub 2} photocatalysis: degradation of oxalic acid

Energy Technology Data Exchange (ETDEWEB)

Ivanova, Irina [Leibniz Universitaet Hannover, Institut fuer Technische Chemie (Germany); Mendive, Cecilia B., E-mail: cbmendive@mdp.edu.ar [Universidad Nacional de Mar del Plata, Facultad de Ciencias Exactas y Naturales, Departamento de Química (Argentina); Bahnemann, Detlef [Leibniz Universitaet Hannover, Institut fuer Technische Chemie (Germany)

2016-07-15

The simultaneous bimodal study of the photocatalytic oxalic acid degradation by aqueous TiO{sub 2} suspensions revealed that particular systems possess the capacity to protect a certain amount of oxalic acid from oxidation, thus hindering, to some extent, the photocatalytic reaction. While measurements of the oxalic acid concentration in the bulk liquid phase indicated full photocatalytic degradation; in situ pH-stat measurements allowed the quantification of the amount of oxalic acid remaining in the part of the nanoparticulate agglomerates where light could apparently not access. An explanation for this phenomenon takes into account the possibility of the formation of TiO{sub 2} agglomerates in which these molecules are hidden from the effect of the light, thus being protected from photocatalytic degradation. Studies of different TiO{sub 2} materials with different particle sizes allowed a deeper exploration of this phenomenon. In addition, because this property of encapsulating pollutant molecules by photocatalytic systems is found to be a reversible phenomenon, P25 appears to be more convenient and advantageous as compared to the use of large surface area photocatalysts.Graphical AbstractFig.: Deaggregation of TiO{sub 2} particle agglomerates upon UV illumination.

Degradation characteristics of 2,4-dichlorophenoxyacetic acid in electro-biological system

Energy Technology Data Exchange (ETDEWEB)

Zhang, JingLi, E-mail: jinglizhangczp@126.com [Tianjin Key Laboratory of Aquatic Science and Technology, Tianjin Institute of Urban Construction, Tianjin 300384 (China); Cao, ZhanPing; Zhang, HongWei [School of Environmental and Chemical Engineering, Tianjin Polytechnic University, Tianjin 300387 (China); Zhao, LianMei [Tianjin Key Laboratory of Aquatic Science and Technology, Tianjin Institute of Urban Construction, Tianjin 300384 (China); Sun, XuDong; Mei, Feng [School of Environmental and Chemical Engineering, Tianjin Polytechnic University, Tianjin 300387 (China)

2013-11-15

Highlights: • The 2,4-D reductive degradation was studied in an electro-biological system. • The electric auxiliary accelerates 2,4-D microbial degradation. • A electron transfer is achieved between the electrode, bacteria and the pollutants. • The paper provides a promising way for the degradation of persistent organics. -- Abstract: The reductive degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) was studied in an electro-biological system, a biological system and an electric catalytic system, respectively. Electrochemical characteristics were monitored by cyclic voltammetry and the intermediate products of 2,4-D degradation were determined by high speed liquid chromatography (HPLC). The results showed that all 2,4-D degradations in the three systems conformed to the kinetics characteristics of one-order reaction, and the degradation kinetics constants were 28.74 × 10{sup −2} h{sup −1}, 19.73 × 10{sup −2} h{sup −1} and 3.54 × 10{sup −2} h{sup −1}, respectively. The kinetics constant in the electro-biological system was higher than the sum in the other two systems by 19%. The electrochemical assistance provided the electrons and accelerated the electron transfer rate in the microbial degradation of 2,4-D. The degradation resulted from the microbial reduction strengthened by the electrochemical assistance. The electron transfer existed between the electrode, cytochrome, NAD and the pollutants. A long-range electron transfer process could be achieved on the multi-phase interfaces between the electrode, bacteria and the pollutants.

Degradation of 3-phenoxybenzoic acid by a filamentous fungus Aspergillus oryzae M-4 strain with self-protection transformation.

Science.gov (United States)

Zhu, Yuanting; Li, Jianlong; Yao, Kai; Zhao, Nan; Zhou, Kang; Hu, Xinjie; Zou, Likou; Han, Xinfeng; Liu, Aiping; Liu, Shuliang

2016-11-01

A novel filamentous fungus M-4 strain was isolated from soy sauce koji and identified as Aspergillus oryzae (Collection number: CGMCC 11645) on the basis of morphological characteristics and internal transcribed spacer sequence. M-4 could degrade 80.62 % of 3-phenoxybenzoic acid (3-PBA; 100 mg L -1 ) within 5 days. 3-PBA degradation occurred in accordance with first-order kinetics. The degradation metabolites of 3-PBA were identified through high-performance liquid chromatography-mass spectrometry (HPLC-MS). Relevant enzymatic activities and substrate utilization were also investigated, which indicated that M-4 could effectively degrade the intermediates of 3-PBA. Base on analysis of these metabolites, a novel biochemical pathway for the degradation of 3-PBA was proposed. There exists a mutual transformation between 3-phenoxy-benzyl alcohol and 3-PBA, which was firstly reported about the degradation of 3-PBA and may be attributed to self-protection transformation of M-4; subsequently, 3-PBA was gradually transformed into phenol, 3-hydroxy-5-phenoxy benzoic acid, protocatechuic acid and gallic acid. The safety of M-4 was evaluated via an acute toxicity test in vivo. The biodegradation ability of M-4 without toxic effects reveals that this fungus may be likely to be used for eliminating 3-PBA from contaminated environment or fermented foods.

n-3 fatty acids reduce plasma 20-hydroxyeicosatetraenoic acid and blood pressure in patients with chronic kidney disease.

Science.gov (United States)

Barden, Anne E; Burke, Valerie; Mas, Emilie; Beilin, Lawrence J; Puddey, Ian B; Watts, Gerald F; Irish, Ashley B; Mori, Trevor A

2015-09-01

Metabolism of arachidonic acid by cytochrome P450 ω-hydroxylase leads to the formation of 20-hydroxyeicosatetraenoic acid (20-HETE) that regulates vascular function, sodium homeostasis and blood pressure (BP). Supplementation with n-3 fatty acids is known to alter arachidonic acid metabolism and reduce the formation of the lipid peroxidation products F2-isoprostanes, but the effect of n-3 fatty acids on 20-HETE has not been studied. We previously reported a significant effect of n-3 fatty acids but not coenzyme Q10 (CoQ) to reduce BP in a double-blind, placebo-controlled intervention, wherein patients with chronic kidney disease (CKD) were randomized to n-3 fatty acids (4 g), CoQ (200 mg), both supplements or control (4 g olive oil), daily for 8 weeks. This study examined the effect of n-3 fatty acids on plasma and urinary 20-HETE in the same study, as well as plasma and urinary F2-isoprostanes, and relate these to changes in BP. Seventy-four patients completed the 8-week intervention. n-3 fatty acids but not CoQ significantly reduced plasma 20-HETE (P = 0.001) and F2-isoprostanes (P fatty acids. This is the first report that n-3 fatty acid supplementation reduces plasma 20-HETE in humans and that this associates with reduced BP. These results provide a plausible mechanism for the reduction in BP observed in patients with CKD following n-3 fatty acid supplementation.

From Labdanes to Drimanes. Degradation of the Side Chain of Dihydrozamoranic Acid.

Directory of Open Access Journals (Sweden)

Pedro M. Rocha

2004-04-01

Full Text Available A new route for the degradation of the saturated side chain of dihydrozamoranic acid has been devised, giving an advanced intermediate, compound 14, useful for the synthesis of insect antifeedants such as warburganal and polygodial.

Syntrophomonas zehnderi sp. nov., an anaerobe that degrades long-chain fatty acids in co-culture with Methanobacterium formicicum.

Science.gov (United States)

Sousa, Diana Z; Smidt, Hauke; Alves, M Madalena; Stams, Alfons J M

2007-03-01

An anaerobic, mesophilic, syntrophic fatty-acid-oxidizing bacterium, designated strain OL-4(T), was isolated as a co-culture with Methanobacterium formicicum DSM 1535(NT) from an anaerobic expanded granular sludge bed reactor used to treat an oleate-based effluent. Strain OL-4(T) degraded oleate, a mono-unsaturated fatty acid, and straight-chain fatty acids C(4 : 0)-C(18 : 0) in syntrophic association with Methanobacterium formicicum DSM 1535(NT). Even-numbered fatty acids were degraded to acetate and methane whereas odd-numbered fatty acids were degraded to acetate, propionate and methane. Branched-chain fatty acids were not degraded. The bacterium could not grow axenically with any other substrate tested and therefore is considered to be obligately syntrophic. Fumarate, sulfate, thiosulfate, sulfur and nitrate could not serve as electron acceptors for strain OL-4(T) to degrade oleate or butyrate. Cells of strain OL-4(T) were curved rods, formed spores and showed a variable response to Gram staining. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain OL-4(T) was most closely related to the fatty-acid-oxidizing, syntrophic bacterium Syntrophomonas sp. TB-6 (95 % similarity), Syntrophomonas wolfei subsp. wolfei DSM 2245(T) (94 % similarity) and Syntrophomonas erecta DSM 16215(T) (93 % similarity). In addition to this moderate similarity, phenotypic and physiological characteristics, such as obligate syntrophy, spore formation and utilization of a broader substrate range, differentiated strain OL-4(T) from these Syntrophomonas species. Therefore strain OL-4(T) represents a novel species, for which the name Syntrophomonas zehnderi sp. nov. is proposed. The type strain is OL-4(T) (=DSM 17840(T)=JCM 13948(T)).

Isonicotinic acid-ligated cobalt (II phthalocyanine-modified titania as photocatalyst for benzene degradation via fluorescent lamp

Directory of Open Access Journals (Sweden)

Joey Andrew A. Valinton

2016-06-01

Full Text Available The utilization of bis(isonicotinic acidphthalocyaninatocobalt (II [CoPc(isa2] incorporated on TiO2 has been studied as a photocatalyst to degrade benzene vapor under fluorescent lamp (indoor light conditions. The photocatalytic activity of [CoPc(isa2]-TiO2 compared to TiO2 showed an increase in the extent of degradation. The axial isonicotinic acid ligand attached to CoPc improved the degradation rate of benzene as compared with unligated CoPc-TiO2 which may be attributed to the enhancement of electronic structure in the complex due to the additional isonicotinic acid ligand and its possible attachment to the TiO2 surface through the carboxylic acid moiety. Therefore, covalently-linked CoPc(isa2 to TiO2 can enhance the extent of photodegradation of benzene and other common volatile organic compounds under indoor lighting conditions.

FT-IR study of gamma-radiation induced degradation of polyvinyl alcohol (PVA) and PVA/humic acids blends

International Nuclear Information System (INIS)

Ilcin, M.; Hola, O.; Bakajova, B.; Kucerik, J.

2010-01-01

Samples of pure polyvinyl alcohol (PVA) and PVA doped with humic acids were exposed to gamma radiation. Gamma rays induced the degradation of the pure polymer. Degradation changes were observed using ATR FT-IR equipment. Dehydration, double bond creation, and their subsequent oxidation (surrounding atmosphere was air) were found out. Also, other degradation reactions (e.g. chain scission, cyclization) occur simultaneously. Formation of C=C and C=O bonds is apparent from FT-IR spectra. In contrast the presence of humic acids in the PVA sample showed stabilizing effect on PVA structure within the concentration range 0.5-10%. (author)

Characterisation of (R-2-(2-Fluorobiphenyl-4-yl-N-(3-Methylpyridin-2-ylPropanamide as a Dual Fatty Acid Amide Hydrolase: Cyclooxygenase Inhibitor.

Directory of Open Access Journals (Sweden)

Sandra Gouveia-Figueira

Full Text Available Increased endocannabinoid tonus by dual-action fatty acid amide hydrolase (FAAH and substrate selective cyclooxygenase (COX-2 inhibitors is a promising approach for pain-relief. One such compound with this profile is 2-(2-fluorobiphenyl-4-yl-N-(3-methylpyridin-2-ylpropanamide (Flu-AM1. These activities are shown by Flu-AM1 racemate, but it is not known whether its two single enantiomers behave differently, as is the case towards COX-2 for the parent flurbiprofen enantiomers. Further, the effects of the compound upon COX-2-derived lipids in intact cells are not known.COX inhibition was determined using an oxygraphic method with arachidonic acid and 2-arachidonoylglycerol (2-AG as substrates. FAAH was assayed in mouse brain homogenates using anandamide (AEA as substrate. Lipidomic analysis was conducted in unstimulated and lipopolysaccharide + interferon γ- stimulated RAW 264.7 macrophage cells. Both enantiomers inhibited COX-2 in a substrate-selective and time-dependent manner, with IC50 values in the absence of a preincubation phase of: (R-Flu-AM1, COX-1 (arachidonic acid 6 μM; COX-2 (arachidonic acid 20 μM; COX-2 (2-AG 1 μM; (S-Flu-AM1, COX-1 (arachidonic acid 3 μM; COX-2 (arachidonic acid 10 μM; COX-2 (2-AG 0.7 μM. The compounds showed no enantiomeric selectivity in their FAAH inhibitory properties. (R-Flu-AM1 (10 μM greatly inhibited the production of prostaglandin D2 and E2 in both unstimulated and lipopolysaccharide + interferon γ- stimulated RAW 264.7 macrophage cells. Levels of 2-AG were not affected either by (R-Flu-AM1 or by 10 μM flurbiprofen, either alone or in combination with the FAAH inhibitor URB597 (1 μM.Both enantiomers of Flu-AM1 are more potent inhibitors of 2-AG compared to arachidonic acid oxygenation by COX-2. Inhibition of COX in lipopolysaccharide + interferon γ- stimulated RAW 264.7 cells is insufficient to affect 2-AG levels despite the large induction of COX-2 produced by this treatment.

Gestational age in relation to marine n-3 fatty acids in maternal erythrocytes

DEFF Research Database (Denmark)

Olsen, S.F.; Hansen, Harald S.; Sommer, S.

1991-01-01

Gestation is longer in Faroese than Danish women, possibly because of the high intake of marine long-chain n-3 fatty acids that down regulates formation of prostaglandins from arachidonic acid. Polyunsaturated fatty acids were quantified in erythrocytes obtained within 2 days of delivery from...... randomly selected groups of 62 Faroese and 37 Danish women with an assessable gestational age. Average ratio of long-chain n-3 fatty acids to arachidonic acid [(3/6) ratio] was 0.73 (SD = 0.11) in Faroese women and 0.61 (SD = 0.12) in Danish women (p ...-3 fatty acids in the Faroes. A 20% increase in the (3/6) ratio was associated with an increase in pregnancy duration of 5.7 days in Danish women (95% confidence interval, 1.4 to 10.1 days; p = 0.02) and 0.7 days in Faroese women (95% confidence interval, -2.0 to 3.3; p = 0.6). The hypothesized...

FATTY ACID COMPOSITION AND PROSTAGLANDIN CONTENT OF THE RED SEAWEED Gracilaria sp. FROM INDONESIA

Directory of Open Access Journals (Sweden)

Muhammad Ikbal Illijas

2012-06-01

Full Text Available High content of polyunsaturated fatty acids (PUFAs such as arachidonic and eicosapentaenoic acids are typical for the red alga. Analysis of fatty acid composition and prostaglandin content was conducted in the red alga Gracilaria sp. from Indonesia. Total lipid of the alga was extracted with CHCl3-MeOH (2:1, v/v. Analysis of the fatty acids composition was performed on gas chromatography (GC equipped with omega wax column (30 m x 0,32 mm i.d., Supelco, PA, USA and analysis of prostaglandins were carried out by HPLC on ODS column (Mightysil RP-18 GP, 250 mm x 4.6 mm, 5 μm. The content of fatty acids high for were palmitic acid (50% and arachidonic acid (26.9%, whereas prostaglandin E2 was identified and found lower concentration (44.2 μg/gram total lipid.

Identification of major degradation products of 5-aminosalicylic acid formed in aqueous solutions and in pharmaceuticals

DEFF Research Database (Denmark)

Jensen, J.; Cornett, Claus; Olsen, C. E.

1992-01-01

of polymeric species by oxidative self-coupling of 5-ASA moieties. These results indicate that the degradation of 5-ASA follows the same mechanism as observed for the autooxidation of 4-aminophenol and 1,4-phenylenediamine. Some of the identified degradation products were found in 5-ASA......The formation of four major degradation products of 5-aminosalicylic acid (5-ASA) in buffered solutions at pH 7.0 was demonstrated by gradient HPLC analysis. The isolation and structural elucidation of the resulting degradation products showed that the degradation of 5-ASA led to the formation...

Acidic nanoparticles are trafficked to lysosomes and restore an acidic lysosomal pH and degradative function to compromised ARPE-19 cells.

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Gabriel C Baltazar

Full Text Available Lysosomal enzymes function optimally in acidic environments, and elevation of lysosomal pH can impede their ability to degrade material delivered to lysosomes through autophagy or phagocytosis. We hypothesize that abnormal lysosomal pH is a key aspect in diseases of accumulation and that restoring lysosomal pH will improve cell function. The propensity of nanoparticles to end up in the lysosome makes them an ideal method of delivering drugs to lysosomes. This study asked whether acidic nanoparticles could traffic to lysosomes, lower lysosomal pH and enhance lysosomal degradation by the cultured human retinal pigmented epithelial cell line ARPE-19. Acidic nanoparticles composed of poly (DL-lactide-co-glycolide (PLGA 502 H, PLGA 503 H and poly (DL-lactide (PLA colocalized to lysosomes of ARPE-19 cells within 60 min. PLGA 503 H and PLA lowered lysosomal pH in cells compromised by the alkalinizing agent chloroquine when measured 1 hr. after treatment, with acidification still observed 12 days later. PLA enhanced binding of Bodipy-pepstatin-A to the active site of cathepsin D in compromised cells. PLA also reduced the cellular levels of opsin and the lipofuscin-like autofluorescence associated with photoreceptor outer segments. These observations suggest the acidification produced by the nanoparticles was functionally effective. In summary, acid nanoparticles lead to a rapid and sustained lowering of lysosomal pH and improved degradative activity.

Hydrothermal synthesis spherical TiO{sub 2} and its photo-degradation property on salicylic acid

Energy Technology Data Exchange (ETDEWEB)

Guo Wenlu, E-mail: liu287856624@163.com [School of Biology and Chemical Engineering, Jiangsu University of Science and Technology, Mengxi Road 2, Zhenjiang 212003 (China); Liu Xiaolin [School of Biology and Chemical Engineering, Jiangsu University of Science and Technology, Mengxi Road 2, Zhenjiang 212003 (China); Huo Pengwei; Gao Xun; Wu Di; Lu Ziyang; Yan Yongsheng [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China)

2012-07-01

Anatase TiO{sub 2} spheres have been prepared using hydrothermal synthesis. The prepared spheres were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and UV-vis diffuse reflectance spectra (UV-vis DRS). The TiO{sub 2} consisted of well-defined spheres with size of 3-5 {mu}m. The photocatalytic activity of spherical TiO{sub 2} was determined by degradation of salicylic acid under visible light irradiation. It was revealed that the degradation rate of the spherical TiO{sub 2} which was processed at 150 Degree-Sign C for 48 h could reach 81.758%. And the kinetics of photocatalytic degradation obeyed first-order kinetic, which the rate constant value was 0.01716 S{sup -1} of the salicylic acid onto TiO{sub 2} (temperature: 150, time: 48 h). The kinetics of adsorption followed the pseudo-second-order model and the rate constant was 1.2695 g mg{sup -1} of the salicylic acid onto TiO{sub 2} (temperature: 150, time: 48 h).

Dietary Linoleic and a-Linolenic Acid Affect Anxiety-Related Responses and Exploratory Activity in Growing Pigs

NARCIS (Netherlands)

Clouard, C.M.; Gerrits, W.J.J.; Kerkhof, van I.; Smink, W.; Bolhuis, J.E.

2015-01-01

Background: Growing evidence suggests that the dietary ratio of linoleic acid (LA) to a-linolenic acid (ALA), the precursors of arachidonic acid (AA) and docosahexaenoic acid (DHA), respectively, may affect behavior in mammals. Objective: This study aimed at evaluating the impact of dietary LA and

Effect of perfluorosulfonic acid membrane equivalent weight on degradation under accelerated stress conditions

International Nuclear Information System (INIS)

Rodgers, Marianne P.; Pearman, Benjamin P.; Mohajeri, Nahid; Bonville, Leonard J.; Slattery, Darlene K.

2013-01-01

The equivalent weight of proton exchange membranes has a large effect on their properties and can impact performance and durability in hydrogen fuel cells. For example, increasing the EW increases the crystallinity of perfluorosulfonic acid membranes, while water content and glass transition temperature decrease. The length of the sulfonic acid side chain also impacts membrane properties. Perfluorosulfonic acid membranes with shorter sulfonic acid side chains, though they exhibit similar gas permeability, have been shown to have higher crystallinity, higher glass transition temperature, slightly lower water content, and lower proton conductivity than membranes with longer sulfonic acid side chains for a given EW. Although many reports have investigated cell performance for membranes as a function of low EW and side chains length, their impact on cell durability is not well understood. Because side chain attack by radicals formed during fuel cell operation is a major source of membrane degradation, it is reasonable to hypothesize that membranes with lower EW and, therefore, more sulfonic acid side chains, would have lower durability. This study evaluates membrane degradation for cells containing PFSA membranes with 750 EW, 950 EW, and 1100 EW. The 750 EW membrane contained short sulfonic acid side-chains while the 950 EW and 1100 EW membranes were Nafion ® -based with long sulfonic acid side-chains. Membranes were tested in fuel cells for 100 h under open circuit voltage, at 90 °C and 30% relative humidity. Diagnostic tests conducted on the cells included hydrogen crossover, fluoride emission, catalyst electrochemical surface area, posttest membrane scanning electron microscopy/transmission electron microscopy evaluation, and defect identification in membranes. The 950 EW cell had the highest decay metrics including fluoride emission, voltage decay, loss in ECA, and loss in cell performance. In all cases, the 1100 EW cell showed the lowest degradation. This has

The characterization of mechanical and surface properties of poly (glycerol-sebacate-lactic acid) during degradation in phosphate buffered saline

Energy Technology Data Exchange (ETDEWEB)

Sun Zhijie [Center for biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China)], E-mail: zhijiesun2005@yahoo.com.cn; Wu Lan; Lu Xili; Meng Zhaoxu; Zheng Yufeng [Center for biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China); Dong Deli [Department of Pharmacology, Harbin Medical University, Bio-pharmaceutical Key Laboratory of Heilongjiang Province, Harbin 150081 (China)

2008-11-15

The present study synthesized a poly (glycerol-sebacate-lactic acid) (PGSL) with 1:1:0.5 mole ratio of glycerol, sebacate and lactic acid and investigated the degradation characteristics of the polymer in phosphate buffered saline (PBS) at 37 deg. C in vitro by means of mass loss tests, geometry, differential scanning calorimeter (DSC) measurements, tensile analysis and scanning electron microscopy (SEM). The maintained geometry, linear mass loss, and minor crack formation on the surface during degradation characterized both the bulk degradation and surface erosion of the polymer. By day 30 of degradation, the mass lost reached 16%. The elastic modulus, tensile strength and elongation at breakage of PGSL were correlative to the period of degradation.

Time-related fatty acid profiles of plasma and lymph after gastric administration of fats to rats fed high-fat diets

DEFF Research Database (Denmark)

Porsgaard, Trine; Straarup, E. M.; Brand, C. L.

2000-01-01

investigated. Although decreasing during the early absorptive phase a continuous contribution of endogenous trans-C18:I and arachidonic acid was observed in plasma. Small differences were observed between the 4 dietary fats. In lymph, the transport of trans-C18:1 rose markedly after butter administration...... partly caused by the content of this fatty acid in butter, while the transport of trans-C18:1 after R/C10 was unchanged although still transported at a reasonable high rate. The transport of arachidonic acid increased after administration of both butter and R/C10. Minor changes were observed in plasma...

Prediction of the ageing of commercial lager beer during storage based on the degradation of iso-α-acids.

Science.gov (United States)

Blanco, Carlos A; Nimubona, Dieudonné; Caballero, Isabel

2014-08-01

Iso-α-acids and their chemically modified variants are responsible for the bitterness of beer and play a disproportionately large role in the final quality of beer. The current study was undertaken to predict the degradation of commercial lager beers related to changes in the concentration of trans-iso-α-acids during storage by using high-pressure liquid chromatography. In the analysed beers the concentration of isohumulone (average concentration 28 mg L(-1)) was greater than that of isocohumulone (20 mg L(-1)) and isoadhumulone (10 mg L(-1)). The kinetic parameters, activation energy and rate constant, of the trans-iso-α-acids were calculated. In the case of dark beers, the activation energy for the degradation of trans-isocohumulones was found to be higher than for trans-isohumulones and trans-isoadhumulones, whereas in pale and alcohol-free beers activation energies for the degradation of the three trans isomers were similar. The loss of iso-α-acids can be calculated using the activation energy of the degradation of trans-iso-α-acids and the temperature profile of the accelerated ageing. The results obtained in the investigation can be used in the beer industry to predict the alteration of the bitterness of beer during storage. © 2013 Society of Chemical Industry.

Novel extracellular PHB depolymerase from Streptomyces ascomycinicus: PHB copolymers degradation in acidic conditions.

Directory of Open Access Journals (Sweden)

Javier García-Hidalgo

Full Text Available The ascomycin-producer strain Streptomyces ascomycinicus has been proven to be an extracellular poly(R-3-hydroxybutyrate (PHB degrader. The fkbU gene, encoding a PHB depolymerase (PhaZ Sa , has been cloned in E. coli and Rhodococcus sp. T104 strains for gene expression. Gram-positive host Rhodococcus sp. T104 was able to produce and secrete to the extracellular medium an active protein form. PhaZ Sa was purified by two hydrophobic interaction chromatographic steps, and afterwards was biochemically as well as structurally characterized. The enzyme was found to be a monomer with a molecular mass of 48.4 kDa, and displayed highest activity at 45°C and pH 6, thus being the first PHB depolymerase from a gram-positive bacterium presenting an acidic pH optimum. The PHB depolymerase activity of PhaZ Sa was increased in the presence of divalent cations due to non-essential activation, and also in the presence of methyl-β-cyclodextrin and PEG 3350. Protein structure was analyzed, revealing a globular shape with an alpha-beta hydrolase fold. The amino acids comprising the catalytic triad, Ser(131-Asp(209-His(269, were identified by multiple sequence alignment, chemical modification of amino acids and site-directed mutagenesis. These structural results supported the proposal of a three-dimensional model for this depolymerase. PhaZ Sa was able to degrade PHB, but also demonstrated its ability to degrade films made of PHB, PHBV copolymers and a blend of PHB and starch (7∶3 proportion wt/wt. The features shown by PhaZ Sa make it an interesting candidate for industrial applications involving PHB degradation.

Novel extracellular PHB depolymerase from Streptomyces ascomycinicus: PHB copolymers degradation in acidic conditions.

Science.gov (United States)

García-Hidalgo, Javier; Hormigo, Daniel; Arroyo, Miguel; de la Mata, Isabel

2013-01-01

The ascomycin-producer strain Streptomyces ascomycinicus has been proven to be an extracellular poly(R)-3-hydroxybutyrate (PHB) degrader. The fkbU gene, encoding a PHB depolymerase (PhaZ Sa ), has been cloned in E. coli and Rhodococcus sp. T104 strains for gene expression. Gram-positive host Rhodococcus sp. T104 was able to produce and secrete to the extracellular medium an active protein form. PhaZ Sa was purified by two hydrophobic interaction chromatographic steps, and afterwards was biochemically as well as structurally characterized. The enzyme was found to be a monomer with a molecular mass of 48.4 kDa, and displayed highest activity at 45°C and pH 6, thus being the first PHB depolymerase from a gram-positive bacterium presenting an acidic pH optimum. The PHB depolymerase activity of PhaZ Sa was increased in the presence of divalent cations due to non-essential activation, and also in the presence of methyl-β-cyclodextrin and PEG 3350. Protein structure was analyzed, revealing a globular shape with an alpha-beta hydrolase fold. The amino acids comprising the catalytic triad, Ser(131)-Asp(209)-His(269), were identified by multiple sequence alignment, chemical modification of amino acids and site-directed mutagenesis. These structural results supported the proposal of a three-dimensional model for this depolymerase. PhaZ Sa was able to degrade PHB, but also demonstrated its ability to degrade films made of PHB, PHBV copolymers and a blend of PHB and starch (7∶3 proportion wt/wt). The features shown by PhaZ Sa make it an interesting candidate for industrial applications involving PHB degradation.

Suppression of Remodeling Behaviors with Arachidonic Acid Modification for Enhanced in vivo Antiatherogenic Efficacies of Lovastatin-loaded Discoidal Recombinant High Density Lipoprotein.

Science.gov (United States)

He, Hongliang; Zhang, Mengyuan; Liu, Lisha; Zhang, Shuangshuang; Liu, Jianping; Zhang, Wenli

2015-10-01

A series of in vitro evaluation in our previous studies had proved that arachidonic acid (AA) modification could suppress the remodeling behaviors of lovastatin-loaded discoidal reconstituted high density lipoprotein (LT-d-rHDL) by restraining the reactivity with lecithin cholesterol acyltransferase (LCAT) for reducing undesired drug leakage. This study focuses on the investigation of AA-modified LT-d-rHDL (AA-LT-d-rHDL) in atherosclerotic New Zealand White (NZW) rabbit models to explore whether AA modification could enhance drug targeting delivery and improve antiatherogenic efficacies in vivo. After pharmacokinetics of AA-LT-d-rHDL modified with different AA amount were investigated in atherosclerotic NZW rabbits, atherosclerotic lesions targeting property was assessed by ex vivo imaging of aortic tree and drug distribution. Furthermore, their antiatherogenic efficacies were elaborately evaluated and compared by typical biochemical indices. With AA modification amount augmenting, circulation time of AA-LT-d-rHDL was prolonged, and drug accumulation in the target locus was increased, eventually the significant appreciation in antiatherogenic efficacies were further supported by lower level of bad cholesterol, decreased atherosclerotic lesions areas and mean intima-media thickness (MIT), markedly attenuated matrix metalloproteinase-9 (MMP-9) protein expression and macrophage infiltration. This proof-of-concept study demonstrated that AA-LT-d-rHDL could enhance drug accumulation in atherosclerotic lesion and impede atherosclerosis progression more effectively.

Clofibric acid degradation in UV254/H2O2 process: effect of temperature.

Science.gov (United States)

Li, Wenzhen; Lu, Shuguang; Qiu, Zhaofu; Lin, Kuangfei

2010-04-15

The degradation of clofibric acid (CA) in UV(254)/H(2)O(2) process under three temperature ranges, i.e. T1 (9.0-11.5 degrees C), T2 (19.0-21.0 degrees C) and T3 (29.0-30.0 degrees C) was investigated. The effects of solution constituents including NO(3)(-) and HCO(3)(-) anions, and humic acid (HA) on CA degradation were evaluated in Milli-Q waters. CA degradation behaviors were simulated with the pseudo-first-order kinetic model and the apparent rate constant (k(ap)) and half-life time (t(1/2)) were calculated. The results showed that higher temperature would favor CA degradation, and CA degradation was taken place mostly by indirect oxidation through the formation of OH radicals in UV(254)/H(2)O(2) process. In addition, the effects of both NO(3)(-) and HCO(3)(-) anions at two selected concentrations (1.0x10(-3) and 0.1 mol L(-1)) and HA (20 mg L(-1)) on CA degradation were investigated. The results showed that HA had negative effect on CA degradation, and this effect was much more apparent under low temperature condition. On the other hand, the inhibitive effect on CA degradation at both lower and higher concentrations of bicarbonate was observed, and this inhibitive effect was much more apparent at higher bicarbonate concentration and lower temperature condition. While, at higher nitrate concentration the inhibitive effect on CA degradation under three temperature ranges was observed, and with the temperature increase this negative effect was apparently weakened. However, at lower nitrate concentration a slightly positive effect on CA degradation was found under T2 and T3 conditions. Moreover, when using a real wastewater treatment plant (WWTP) effluent spiked with CA over 99% of CA removal could be achieved under 30 degrees C within only 15 min compared with 40 and 80 min under 20 and 10 degrees C respectively, suggesting a significant promotion in CA degradation under higher temperature condition. Therefore, it can be concluded that temperature plays an

Efficient photocatalytic degradation of perfluorooctanoic acid by a wide band gap p-block metal oxyhydroxide InOOH

Science.gov (United States)

Xu, Jingjing; Wu, Miaomiao; Yang, Jingwen; Wang, Zhengmei; Chen, Mindong; Teng, Fei

2017-09-01

In this work, we prepared a new wide band gap semiconductor, p-block metal oxyhydroxide InOOH, which exhibits efficient activity for perfluorooctanoic acid (PFOA) degradation under mild conditions and UV light irradiation. The apparent rate constant for PFOA degradation by InOOH is 27.6 times higher than that for P25 titania. Results show that ionized PFOA (C7F15COO-) can be adsorbed much more efficiently on the surface of InOOH than P25. Then, the adsorbed C7F15COO- can be decomposed directly by photo-generated holes to form C7F15COOrad radicals. This process is the key step for the photocalytic degradation of PFOA. Major degradation intermediates, fluoride ions and perfluorinated carboxylic acids (PFCAs) with shorter chain lengths were detected during PFOA degradation. A possible pathway for photocatalytic degradation of PFOA is proposed based on the experimental results. Therefore, this studies indicates a potential new material and method for the efficient treatment of PFCA pollutants under mild conditions.

Prostaglandin E2 and the protein kinase A pathway mediate arachidonic acid induction of c-fos in human prostate cancer cells

Science.gov (United States)

Chen, Y.; Hughes-Fulford, M.

2000-01-01

Arachidonic acid (AA) is the precursor for prostaglandin E2 (PGE2) synthesis and increases growth of prostate cancer cells. To further elucidate the mechanisms involved in AA-induced prostate cell growth, induction of c-fos expression by AA was investigated in a human prostate cancer cell line, PC-3. c-fos mRNA was induced shortly after addition of AA, along with a remarkable increase in PGE2 production. c-fos expression and PGE2 production induced by AA was blocked by a cyclo-oxygenase inhibitor, flurbiprofen, suggesting that PGE2 mediated c-fos induction. Protein kinase A (PKA) inhibitor H-89 abolished induction of c-fos expression by AA, and partially inhibited PGE2 production. Protein kinase C (PKC) inhibitor GF109203X had no significant effect on c-fos expression or PGE2 production. Expression of prostaglandin (EP) receptors, which mediate signal transduction from PGE2 to the cells, was examined by reverse transcription polymerase chain reaction in several human prostate cell lines. EP4 and EP2, which are coupled to the PKA signalling pathway, were expressed in all cells tested. Expression of EP1, which activates the PKC pathway, was not detected. The current study showed that induction of the immediate early gene c-fos by AA is mediated by PGE2, which activates the PKA pathway via the EP2/4 receptor in the PC-3 cells.

Co-metabolic formation of substituted phenylacetic acids by styrene-degrading bacteria

Directory of Open Access Journals (Sweden)

Michel Oelschlägel

2015-06-01

The styrene-degrading strains Rhodococcus opacus 1CP, Pseudomonas fluorescens ST, and the novel isolates Sphingopyxis sp. Kp5.2 and Gordonia sp. CWB2 were investigated with respect to their applicability to co-metabolically produce substituted phenylacetic acids. Isolates were found to differ significantly in substrate tolerance and biotransformation yields. Especially, P. fluorescens ST was identified as a promising candidate for the production of several phenylacetic acids. The biotransformation of 4-chlorostyrene with cells of strain ST was shown to be stable over a period of more than 200 days and yielded about 38 mmolproduct gcelldryweight−1 after nearly 350 days. Moreover, 4-chloro-α-methylstyrene was predominantly converted to the (S-enantiomer of the acid with 40% enantiomeric excess.

Natural Formation and Degradation of Chloroacetic Acids and Volatile Organochlorines in Forest Soil

Czech Academy of Sciences Publication Activity Database

Laturnus, F.; Fahimi, I.; Gryndler, Milan; Hartmann, A.; Heal, M. R.; Matucha, M.; Schöler, H. F.; Schroll, R.; Svensson, T.

2005-01-01

Roč. 12, č. 4 (2005), s. 233-244 ISSN 0944-1344 Institutional research plan: CEZ:AV0Z50200510 Keywords : chloroacetic acids * degradation * fores decline Subject RIV: EE - Microbiology, Virology Impact factor: 1.518, year: 2005

Agdc1p - a Gallic Acid Decarboxylase Involved in the Degradation of Tannic Acid in the Yeast Blastobotrys (Arxula) adeninivorans.

Science.gov (United States)

Meier, Anna K; Worch, Sebastian; Böer, Erik; Hartmann, Anja; Mascher, Martin; Marzec, Marek; Scholz, Uwe; Riechen, Jan; Baronian, Kim; Schauer, Frieder; Bode, Rüdiger; Kunze, Gotthard

2017-01-01

Tannins and hydroxylated aromatic acids, such as gallic acid (3,4,5-trihydroxybenzoic acid), are plant secondary metabolites which protect plants against herbivores and plant-associated microorganisms. Some microbes, such as the yeast Arxula adeninivorans are resistant to these antimicrobial substances and are able to use tannins and gallic acid as carbon sources. In this study, the Arxula gallic acid decarboxylase (Agdc1p) which degrades gallic acid to pyrogallol was characterized and its function in tannin catabolism analyzed. The enzyme has a higher affinity for gallic acid (K m -0.7 ± 0.2 mM, k cat -42.0 ± 8.2 s -1 ) than to protocatechuic acid (3,4-dihydroxybenzoic acid) (K m -3.2 ± 0.2 mM, k cat -44.0 ± 3.2 s -1 ). Other hydroxylated aromatic acids, such as 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid and 2,5-dihydroxybenzoic acid are not gallic acid decarboxylase substrates. A. adeninivorans G1212/YRC102-AYNI1-AGDC1, which expresses the AGDC1 gene under the control of the strong nitrate inducible AYNI1 promoter achieved a maximum gallic acid decarboxylase activity of 1064.4 U/l and 97.5 U/g of dry cell weight in yeast grown in minimal medium with nitrate as nitrogen source and glucose as carbon source. In the same medium, gallic acid decarboxylase activity was not detected for the control strain G1212/YRC102 with AGDC1 expression under the control of the endogenous promoter. Gene expression analysis showed that AGDC1 is induced by gallic acid and protocatechuic acid. In contrast to G1212/YRC102-AYNI1-AGDC1 and G1212/YRC102, A. adeninivorans G1234 [Δ agdc1 ] is not able to grow on medium with gallic acid as carbon source but can grow in presence of protocatechuic acid. This confirms that Agdc1p plays an essential role in the tannic acid catabolism and could be useful in the production of catechol and cis,cis -muconic acid. However, the protocatechuic acid catabolism via Agdc1p to catechol seems to be

Degradation of 2,4-dichlorophenoxyacetic acid by a halotolerant strain of Penicillium chrysogenum: antibiotic production.

Science.gov (United States)

Ferreira-Guedes, Sumaya; Mendes, Benilde; Leitão, Ana Lúcia

2012-01-01

The extensive use of pesticides in agriculture has prompted intensive research on chemical and biological methods in order to protect contamination of water and soil resources. In this paper the degradation of the pesticide 2,4-dichlorophenoxyacetic acid by a Penicillium chrysogenum strain previously isolated from a salt mine was studied in batch cultures. Co-degradation of 2,4-dichlorophenoxyacetic acid with additives such as sugar and intermediates of pesticide metabolism was also investigated. Penicillium chrysogenum in solid medium was able to grow at concentrations up to 1000 mg/L of 2,4-dichlorophenoxyacetic acid (2,4-D) with sucrose. Meanwhile, supplementation of the solid medium with glucose and lactose led to fungal growth at concentrations up to 500 mg/L of herbicide. Batch cultures of 2,4-D at 100 mg/L were developed under aerobic conditions with the addition of glucose, lactose and sucrose, showing sucrose as the best additional carbon source. The 2,4-D removal was quantified by liquid chromatography. The fungus was able to use 2,4-D as the sole carbon and energy source under 0%, 2% and 5.9% NaCl. The greatest 2,4-D degradation efficiency was found using alpha-ketoglutarate and ascorbic acid as co-substrates under 2% NaCl at pH 7. Penicillin production was evaluated in submerged cultures by bioassay, and higher amounts of beta-lactam antibiotic were produced when the herbicide was alone. Taking into account the ability of P. chrysogenum CLONA2 to degrade aromatic compounds, this strain could be an interesting tool for 2,4-D herbicide remediation in saline environments.

Organic matter degradation in Chilean sediments - following nature's own degradation experiment

DEFF Research Database (Denmark)

Langerhuus, Alice Thoft; Niggemann, Jutta; Lomstein, Bente Aagaard

ORGANIC MATTER DEGRADATION IN CHILEAN SEDIMENTS – FOLLOWING NATURE’S OWN DEGRADATION EXPERIMENT Degradation of sedimentary organic matter was studied at two stations from the shelf of the Chilean upwelling region. Sediment cores were taken at 1200 m and 800 m water depth and were 4.5 m and 7.5 m...... in length, respectively. The objective of this study was to assess the degradability of the organic matter from the sediment surface to the deep sediments. This was done by analysing amino acids (both L- and D-isomers) and amino sugars in the sediment cores, covering a timescale of 15.000 years. Diagenetic...... indicators (percentage of carbon and nitrogen present as amino acid carbon and nitrogen, the ratio between a protein precursor and its non-protein degradation product and the percentage of D-amino acids) revealed ongoing degradation in these sediments, indicating that microorganisms were still active in 15...

Oxidative degradation of acid doped polybenzimidazole membranes and fuel cell durability in the presence of ferrous ions

DEFF Research Database (Denmark)

Liao, Jianhui; Yang, Jingshuai; Li, Qingfeng

2013-01-01

Phosphoric acid doped polybenzimidazole membranes have been explored as proton exchange membranes for high temperature polymer electrolyte membrane fuel cells. Long-term durability of the membrane is of critical concern and has been evaluated by accelerated degradation tests under Fenton conditions...... of the polymer. Fuel cell durability tests with contaminations of ferrous ions did show considerable performance degradation, however, primarily due to the catalyst deterioration rather than the membrane degradation........ In this study effects of phosphoric acid and ferrous ions were investigated by measurements of the weight loss, intrinsic viscosity and size exclusion chromatography (SEC) of the polymer membranes. Ferrous ions resulted in, as expected, catalytic formation of peroxide radicals and hence the accelerated polymer...

Proximate composition, amino acid and fatty acid composition of fish maws.

Science.gov (United States)

Wen, Jing; Zeng, Ling; Xu, Youhou; Sun, Yulin; Chen, Ziming; Fan, Sigang

2016-01-01

Fish maws are commonly recommended and consumed in Asia over many centuries because it is believed to have some traditional medical properties. This study highlights and provides new information on the proximate composition, amino acid and fatty acid composition of fish maws of Cynoscion acoupa, Congresox talabonoides and Sciades proops. The results indicated that fish maws were excellent protein sources and low in fat content. The proteins in fish maws were rich in functional amino acids (FAAs) and the ratio of FAAs and total amino acids in fish maws ranged from 0.68 to 0.69. Among species, croaker C. acoupa contained the most polyunsaturated fatty acids, arachidonic acid, docosahexaenoic acid and eicosapntemacnioc acid, showing the lowest value of index of atherogenicity and index of thrombogenicity, showing the highest value of hypocholesterolemic/hypercholesterolemic ratio, which is the most desirable.

Kinetic and mechanistic study of microcystin-LR degradation by nitrous acid under ultraviolet irradiation.

Science.gov (United States)

Ma, Qingwei; Ren, Jing; Huang, Honghui; Wang, Shoubing; Wang, Xiangrong; Fan, Zhengqiu

2012-05-15

Degradation of microcystin-LR (MC-LR) in the presence of nitrous acid (HNO(2)) under irradiation of 365nm ultraviolet (UV) was studied for the first time. The influence of initial conditions including pH value, NaNO(2) concentration, MC-LR concentration and UV intensity were studied. MC-LR was degraded in the presence of HNO(2); enhanced degradation of MC-LR was observed with 365nm UV irradiation, caused by the generation of hydroxyl radicals through the photolysis of HNO(2). The degradation processes of MC-LR could well fit the pseudo-first-order kinetics. Mass spectrometry was applied for identification of the byproducts and the analysis of degradation mechanisms. Major degradation pathways were proposed according to the results of LC-MS analysis. The degradation of MC-LR was initiated via three major pathways: attack of hydroxyl radicals on the conjugated carbon double bonds of Adda, attack of hydroxyl radicals on the benzene ring of Adda, and attack of nitrosonium ion on the benzene ring of Adda. Copyright © 2012 Elsevier B.V. All rights reserved.

An approach for degradation of grape seed and skin proanthocyanidin polymers into oligomers by sulphurous acid.

Science.gov (United States)

Luo, Lanxin; Cui, Yan; Cheng, Jinhui; Fang, Bairui; Wei, Zongmin; Sun, Baoshan

2018-08-01

To develop an efficient method for degradation of grape seed and skin proanthocyanidins polymers into oligomers, an optimized sulphurous acid degradation conditions for grape seed with the temperature of 60 °C, reaction time of 60 min and sample-sulphurous acid ratio of 1:0.2, and for grape skin with the temperature of 40 °C, reaction time of 60 min and sample-sulphurous acid ratio of 1:0.2, were established. Afterwards, HSCCC and prep-HPLC were used to fractionate and isolate individual proanthocyanidin oligomers from the degradation products. Total of ten dimeric or trimeric procyanidins were obtained, and most of them presented high yield (from 0.7 mg to 13.6 mg per run in grape seed and from 0.5 mg to 4.1 mg per run in grape skin) and high purity (over 90%). The proposed method provides a new way for large preparation of oligomeric proanthocyanidins from naturally abundant and wasted polymeric ones. Copyright © 2018 Elsevier Ltd. All rights reserved.

Microbial dynamics in anaerobic enrichment cultures degrading di-n-butyl phthalic acid ester

DEFF Research Database (Denmark)

Trably, Eric; Batstone, Damien J.; Christensen, Nina

2008-01-01

losses were observed in the sterile controls (20-22%), substantial DBP biodegradation was found in the enrichment cultures (90-99%). In addition, significant population changes were observed. The dominant bacterial species in the DBP-degrading cultures was affiliated to Soehngenia saccharolytica...... in enrichment cultures degrading phthalic acid esters under methanogenic conditions. A selection pressure was applied by adding DBP at 10 and 200 mg L(-1) in semi-continuous anaerobic reactors. The microbial dynamics were monitored using single strand conformation polymorphism (SSCP). While only limited abiotic...

Inhibition of epoxy-eicosanoid degradation improves the tocolytic effects of indomethacin in the uterus from pregnant women.

Science.gov (United States)

Corriveau, Stéphanie; Berthiaume, Maryse; Rousseau, Eric; Pasquier, Jean-Charles

2011-11-01

The incidence of preterm birth is an increasing problem. Indomethacin, a non-specific cyclooxygenase inhibitor, has been largely used as tocolytic in the treatment of preterm labor. The aim of the present study was to assess a putative synergistic tocolytic effect between the inhibition of the production of prostanoids and stabilization of epoxides fatty acids, particularly arachidonate on spontaneous uterine contractile activity. The experimental work was performed on uterine biopsies from consenting women undergoing elective cesarean delivery at term. Isometric tension measurements were performed on fresh human myometrial strips. Contractile activities have been monitored upon individual and combined treatments of indomethacin, DDMS, an inhibitor of hydroxy-eicosanoids production and AUDA, an inhibitor of epoxy-eicosanoids degradation. Interestingly, a significant and consistent synergic effect was observed when indomethacin and AUDA were simultaneously added, raising the possibility of a combined clinical use of cyclooxygenase and sEH inhibitors in attempt to treat preterm labor. Copyright © 2011 Elsevier Inc. All rights reserved.

Degradation of hyaluronic acid, poly- and monosaccharides, and model compounds by hypochlorite

DEFF Research Database (Denmark)

Hawkins, C L; Davies, Michael Jonathan

1998-01-01

the site(s) of HOCl/ClO- attack, the intermediates formed, or the mechanism(s) of polymer degradation. In this study reaction of HOCl/ClO- with amides, sugars, polysaccharides, and hyaluronic acid has been monitored by UV-visible (220-340 nm) and EPR spectroscopy. UV-visible experiments have shown...

Modification of essential fatty acid composition in broodstock of cultured European eel Anguilla anguilla L

DEFF Research Database (Denmark)

Støttrup, Josianne; Jacobsen, Charlotte; Tomkiewicz, Jonna

2013-01-01

Farmed eels had lower levels of arachidonic acid (20:4 n-6) (ARA) and higher ratios of eicosapentaenoic acid (20:5 n-3) (EPA):ARA compared to wild European eels collected from the Baltic Sea and southern Norwegian coast. Eels fed a formulated feed (JD) with a distribution of essential fatty acids...... and docosahexaenoic acid (22:6 n-3) (DHA) had accumulated in ovarian polar lipids......Farmed eels had lower levels of arachidonic acid (20:4 n-6) (ARA) and higher ratios of eicosapentaenoic acid (20:5 n-3) (EPA):ARA compared to wild European eels collected from the Baltic Sea and southern Norwegian coast. Eels fed a formulated feed (JD) with a distribution of essential fatty acids...... (EFA) resembling wild European eel were sampled after 0, 5, 10, 14 and 44 weeks of feeding to examine changes in fatty acid composition (FAC) in ovaries, visceral fat and muscle. The results showed a slow but steady incorporation of EFA. Lipids are incorporated in the oocytes early in oogenesis...

Measurement of 12(S)-hydroxy-5Z,8E,10E-heptadecatrienoic acid and its metabolite 12-oxo-5Z,8E,10E-heptadecatrienoic acid in human plasma by gas chromatography/negative ion chemical ionization mass spectrometry

International Nuclear Information System (INIS)

Hofmann, U.; Seefried, S.; Meese, C.O.; Mettang, T.; Huebel, E.K.; Kuhlmann, U.

1990-01-01

Thromboxane A2, the predominant product of arachidonic acid metabolism in the blood platelet, is a potent vasoconstrictor and platelet agonist. During its biosynthesis from cyclic endoperoxide, 12(S)-hydroxy-5Z,8E,10E-heptadecatrienoic acid (HHT) is formed in equal amounts. The further metabolism of HHT, catalyzed by 15-hydroxyprostaglandin dehydrogenase, leads to 12-oxo-5Z,8E,10E-heptadecatrienoic acid (Oxo-HT). Sample workup procedures are described which allow for the sensitive and reproducible determination of these two arachidonic acid metabolites in human plasma by gas chromatography-mass spectrometry in the presence of deuterated analogues as internal standards. HHT is derivatized to the pentafluorobenzyl ester tert-butyldimethylsilyl ether. In order to enable quantification of low concentrations of about 10 pg/ml in nonstimulated human plasma, the samples have to be purified by HPLC. Oxo-HT is derivatized to the pentafluorobenzyl ester, which is purified by HPLC, and then derivatized to the trimethylsilyloxime. The method allows quantification of Oxo-HT in concentrations down to 10 pg/ml plasma. The reported methods have been used to measure HHT and Oxo-HT in stimulated platelet rich plasma and to quantify HHT in nonstimulated plasma. Determination of endogenous levels of these two arachidonic acid metabolites may give new insights into the overall biosynthesis of thromboxane A2 in man

Systematic Analysis Reveals that Cancer Mutations Converge on Deregulated Metabolism of Arachidonate and Xenobiotics

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Francesco Gatto

2016-07-01

Full Text Available Mutations are the basis of the clonal evolution of most cancers. Nevertheless, a systematic analysis of whether mutations are selected in cancer because they lead to the deregulation of specific biological processes independent of the type of cancer is still lacking. In this study, we correlated the genome and transcriptome of 1,082 tumors. We found that nine commonly mutated genes correlated with substantial changes in gene expression, which primarily converged on metabolism. Further network analyses circumscribed the convergence to a network of reactions, termed AraX, that involves the glutathione- and oxygen-mediated metabolism of arachidonic acid and xenobiotics. In an independent cohort of 4,462 samples, all nine mutated genes were consistently correlated with the deregulation of AraX. Among all of the metabolic pathways, AraX deregulation represented the strongest predictor of patient survival. These findings suggest that oncogenic mutations drive a selection process that converges on the deregulation of the AraX network.

Omega-3 fatty acids for breast cancer prevention and survivorship.

Science.gov (United States)

Fabian, Carol J; Kimler, Bruce F; Hursting, Stephen D

2015-05-04

Women with evidence of high intake ratios of the marine omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) relative to the omega-6 arachidonic acid have been found to have a reduced risk of breast cancer compared with those with low ratios in some but not all case-control and cohort studies. If increasing EPA and DHA relative to arachidonic acid is effective in reducing breast cancer risk, likely mechanisms include reduction in proinflammatory lipid derivatives, inhibition of nuclear factor-κB-induced cytokine production, and decreased growth factor receptor signaling as a result of alteration in membrane lipid rafts. Primary prevention trials with either risk biomarkers or cancer incidence as endpoints are underway but final results of these trials are currently unavailable. EPA and DHA supplementation is also being explored in an effort to help prevent or alleviate common problems after a breast cancer diagnosis, including cardiac and cognitive dysfunction and chemotherapy-induced peripheral neuropathy. The insulin-sensitizing and anabolic properties of EPA and DHA also suggest supplementation studies to determine whether these omega-3 fatty acids might reduce chemotherapy-associated loss of muscle mass and weight gain. We will briefly review relevant omega-3 fatty acid metabolism, and early investigations in breast cancer prevention and survivorship.

Electron autoradiographic study of intracellular conversion of fatty acids into glycogen in rats with alloxan diabetes

International Nuclear Information System (INIS)

Lebkova, N.P.; Bobkov, Y.I.; Gorbonova, V.D.; Kolesova, O.E.

1985-01-01

An electron-autoradiographic study was undertaken of the intracellular distribution of hydrogen of fatty acids in alloxan diabetes. Alloxan diabetes was induced in rats; between 2 weeks and 2 months after development of the disease 0.1 ml of tritium-oleic or tritium-arachidonic acid was injected into the caudel vein of the rats. After decapitation, myocardial tissue from the subendocardial zone of the left ventricle, liver tissue, and glycogen isolated from the liver by a biochemical method, were taken for electron-autoradiographic investigation. Analysis of the data showed that a radioactive isotope, injected into the blood stream of the animals in the form of oleic or arachidonic acids, is incorporated into various structures of hepatocytes and cardiomyocytes. Direct proof is obtained to show that glycogen in hepatocytes and cardiomyoctyes of diabetic rats may be formed from fatty acids

Inhibitors of the 5-lipoxygenase arachidonic acid pathway induce ATP release and ATP-dependent organic cation transport in macrophages.

Science.gov (United States)

da Silva-Souza, Hercules Antônio; Lira, Maria Nathalia de; Costa-Junior, Helio Miranda; da Cruz, Cristiane Monteiro; Vasconcellos, Jorge Silvio Silva; Mendes, Anderson Nogueira; Pimenta-Reis, Gabriela; Alvarez, Cora Lilia; Faccioli, Lucia Helena; Serezani, Carlos Henrique; Schachter, Julieta; Persechini, Pedro Muanis

2014-07-01

We have previously described that arachidonic acid (AA)-5-lipoxygenase (5-LO) metabolism inhibitors such as NDGA and MK886, inhibit cell death by apoptosis, but not by necrosis, induced by extracellular ATP (ATPe) binding to P2X7 receptors in macrophages. ATPe binding to P2X7 also induces large cationic and anionic organic molecules uptake in these cells, a process that involves at least two distinct transport mechanisms: one for cations and another for anions. Here we show that inhibitors of the AA-5-LO pathway do not inhibit P2X7 receptors, as judged by the maintenance of the ATPe-induced uptake of fluorescent anionic dyes. In addition, we describe two new transport phenomena induced by these inhibitors in macrophages: a cation-selective uptake of fluorescent dyes and the release of ATP. The cation uptake requires secreted ATPe, but, differently from the P2X7/ATPe-induced phenomena, it is also present in macrophages derived from mice deficient in the P2X7 gene. Inhibitors of phospholipase A2 and of the AA-cyclooxygenase pathway did not induce the cation uptake. The uptake of non-organic cations was investigated by measuring the free intracellular Ca(2+) concentration ([Ca(2+)]i) by Fura-2 fluorescence. NDGA, but not MK886, induced an increase in [Ca(2+)]i. Chelating Ca(2+) ions in the extracellular medium suppressed the intracellular Ca(2+) signal without interfering in the uptake of cationic dyes. We conclude that inhibitors of the AA-5-LO pathway do not block P2X7 receptors, trigger the release of ATP, and induce an ATP-dependent uptake of organic cations by a Ca(2+)- and P2X7-independent transport mechanism in macrophages. Copyright © 2014 Elsevier B.V. All rights reserved.

Melatonin prevents maternal fructose intake-induced programmed hypertension in the offspring: roles of nitric oxide and arachidonic acid metabolites.

Science.gov (United States)

Tain, You-Lin; Leu, Steve; Wu, Kay L H; Lee, Wei-Chia; Chan, Julie Y H

2014-08-01

Fructose intake has increased globally and is linked to hypertension. Melatonin was reported to prevent hypertension development. In this study, we examined whether maternal high fructose (HF) intake causes programmed hypertension and whether melatonin therapy confers protection against the process, with a focus on the link to epigenetic changes in the kidney using next-generation RNA sequencing (NGS) technology. Pregnant Sprague-Dawley rats received regular chow or chow supplemented with HF (60% diet by weight) alone or with additional 0.01% melatonin in drinking water during the whole period of pregnancy and lactation. Male offspring were assigned to four groups: control, HF, control + melatonin (M), and HF + M. Maternal HF caused increases in blood pressure (BP) in the 12-wk-old offspring. Melatonin therapy blunted the HF-induced programmed hypertension and increased nitric oxide (NO) level in the kidney. The identified differential expressed gene (DEGs) that are related to regulation of BP included Ephx2, Col1a2, Gucy1a3, Npr3, Aqp2, Hba-a2, and Ptgs1. Of which, melatonin therapy inhibited expression and activity of soluble epoxide hydrolase (SEH, Ephx2 gene encoding protein). In addition, we found genes in arachidonic acid metabolism were potentially involved in the HF-induced programmed hypertension and were affected by melatonin therapy. Together, our data suggest that the beneficial effects of melatonin are attributed to its ability to increase NO level in the kidney, epigenetic regulation of genes related to BP control, and inhibition of SEH expression. The roles of DEGs by the NGS in long-term epigenetic changes in the adult offspring kidney require further clarification. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Degradation and contamination of perfluorinated sulfonic acid membrane due to swelling-dehydration cycles

DEFF Research Database (Denmark)

Andersen, Shuang Ma; Morgen, Per; Skou, Eivind Morten

Formation of sulfonic anhydride S-O-S (from the condensation of sulfonic acids) was known one of the important degradation mechanisms [i] for Nafion membrane under hydrothermal aging condition, which is especially critical for hydrogen fuel cells. Similar mechanism would also have be desirable...... to the membrane degradation in direct methanol fuel cells (DMFCs), where liquid water has direct contact with the electrolyte. An ex-situ experiment was established with swelling-dehydration cycles on the membrane. However, formation of sulfonic anhydride was not detected during the entire treatment; instead...

Thermal degradation kinetics of ascorbic acid, thiamine and riboflavin in rosehip (Rosa canina L nectar

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Çetin KADAKAL

2017-10-01

Full Text Available Abstract In this paper, the loss of L-ascorbic acid, thiamine and riboflavin in rosehip nectar with the heating periods (0, 5, 10, 15, 20 and 30 min at temperatures ranging from 70 to 95 °C is analyzed and experimental results are presented. Firstly, dried rosehip fruits were processed to rosehip nectar and then thermal treatment is performed. Liquid chromatographic (HPLC method was used for the analysis of the contents of L-ascorbic acid, thiamine and riboflavin and examined compounds are thoroughly separated within 25 min. During thermal processing, degradation of L-ascorbic acid, thiamine and riboflavin in rosehip nectar were fitted to a first-order reaction kinetic model. Arrhenius relationship was used for the description of temperature dependence of reaction. Activation energies for L-ascorbic acid, thiamine and riboflavin between 70 to 95 ºC were found to be 55.30, 36.38 and 37.15 kJ/mol, respectively. To the best of the author’s knowledge, due to lack of study on the thermal degradation of L-ascorbic acid, thiamine and riboflavin in rosehip nectar, this manuscript will be the first reported study to enable future analysis.

Heterogeneous photocatalytic degradation of p-toluenesulfonic acid using concentrated solar radiation in slurry photoreactor

International Nuclear Information System (INIS)

Kamble, Sanjay P.; Sawant, Sudhir B.; Pangarkar, Vishwas G.

2007-01-01

In this work, the photocatalytic degradation (PCD) of p-toluenesulfonic acid (p-TSA) in batch reactor using concentrated solar radiation was investigated. The effect of the various operating parameters such as initial concentration of substrate, catalyst loading, solution pH and types of ions on photocatalytic degradation has been studied in a batch reactor to derive the optimum conditions. The rate of photocatalytic degradation was found to be maximum at the self pH (pH 3.34) of p-TSA. It was also observed that in the presence of anions and cations, the rate of PCD decreases drastically. The kinetics of photocatalytic degradation of p-TSA was studied. The PCD of p-TSA was also carried at these optimized conditions in a bench scale slurry bubble column reactor using concentrated solar radiation

Transport and degradation of 2-14C abscicine acid in the coleus rehneltianus berger sprout

International Nuclear Information System (INIS)

Klaska, A.

1979-01-01

1 μg ABA-2- 14 C aqueous solution was injected into the youngest or into a fully grown leaf of young and older coleus plants. The activity quantity in the various sprout parts is investigated after 2, 24 and 72 h; as well as which labelled substances other than abscisic acid (ABA) occur. The activity in the ethanol extracts was detected with the help of liquid scintillation measurements. Thin layer chromatography and gas chromatography were used to characterize the radioactive substances. The results show that ABA is degraded into three metabolites which are characterized by their relative Rsub(F) values using chromatography with LM 2 as substance 0.2, 0.5a, 0.5b and 0.8. Comparing with the literature shows that it could be 6'-hydroxy methyl ABA, ABA glucoside, phaseic acid and dihydrophaseic acid. Young and old leaves in older plants have the same ability to degrade ABA taking the occurence of the 0.8 metabolite as standard. The degradation in younger plants is firstly very slight. However, within 72 h the ability of ABA degradation is induced in older leaves of younger plants, so that finally the degradation rate is as big as in older plants. Activity is essentially exported by adult leaves of older plants. The basipetal transport is considerably greater than the acropetal one. Results show that mainly ABA is transported in the acropetal test, whereas ABA and fraction 0.5 are transported in the basipetal direction. A reversed transport direction is observed after applying ABA to a young leaf. The transport basipetal is polarized in the first two hours, after 72 hours of transport there is a definite acropetal polarity. (orig./MG) [de

Radiolytic degradation of gallic acid and its derivatives in aqueous solution

International Nuclear Information System (INIS)

Melo, R.; Leal, J.P.; Takacs, E.; Wojnarovits, L.

2009-01-01

Polyphenols, like gallic acid (GA) released in the environment in larger amount, by inducing some unwanted oxidations, may constitute environmental hazard: their concentration in wastewater should be controlled. Radiolytic degradation of GA was investigated by pulse radiolysis and final product techniques in dilute aqueous solution. Subsidiary measurements were made with 3,4,5-trimethoxybenzoic acid (TMBA) and 3,4,5-trihydroxy methylbenzoate (MGA). The hydroxyl radical and hydrogen atom intermediates of water radiolysis react with the solute molecules yielding cyclohexadienyl radicals. The radicals formed in GA and MGA solutions in acid/base catalyzed water elimination decay to phenoxyl radicals. This reaction is not observed in TMBA solution. The hydrated electron intermediate of water decomposition adds to the carbonyl oxygen, the anion thus formed protonates on the ring forming cyclohexadienyl radical or on the carbonyl group forming carbonyl centred radical. The GA intermediates formed during reaction with primary water radicals in presence of oxygen transform to non-aromatic molecules, e.g., to aliphatic carboxylic acids.

Radiolytic degradation of gallic acid and its derivatives in aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Melo, R. [Instituto Tecnologico e Nuclear, UCQR, Estrada Nacional No. 10, Apartado 21, 2686-953, Sacavem (Portugal); Leal, J.P. [Instituto Tecnologico e Nuclear, UCQR, Estrada Nacional No. 10, Apartado 21, 2686-953, Sacavem (Portugal); Centro Quimica e Bioquimica, Faculdade de Ciencias da Universidade de Lisboa, 1749-016 Lisboa (Portugal); Takacs, E., E-mail: takacs@iki.kfki.hu [Institute of Isotopes, Hungarian Academy of Sciences, P.O. Box 77, H-1525 Budapest (Hungary); Wojnarovits, L. [Institute of Isotopes, Hungarian Academy of Sciences, P.O. Box 77, H-1525 Budapest (Hungary)

2009-12-30

Polyphenols, like gallic acid (GA) released in the environment in larger amount, by inducing some unwanted oxidations, may constitute environmental hazard: their concentration in wastewater should be controlled. Radiolytic degradation of GA was investigated by pulse radiolysis and final product techniques in dilute aqueous solution. Subsidiary measurements were made with 3,4,5-trimethoxybenzoic acid (TMBA) and 3,4,5-trihydroxy methylbenzoate (MGA). The hydroxyl radical and hydrogen atom intermediates of water radiolysis react with the solute molecules yielding cyclohexadienyl radicals. The radicals formed in GA and MGA solutions in acid/base catalyzed water elimination decay to phenoxyl radicals. This reaction is not observed in TMBA solution. The hydrated electron intermediate of water decomposition adds to the carbonyl oxygen, the anion thus formed protonates on the ring forming cyclohexadienyl radical or on the carbonyl group forming carbonyl centred radical. The GA intermediates formed during reaction with primary water radicals in presence of oxygen transform to non-aromatic molecules, e.g., to aliphatic carboxylic acids.

Agdc1p – a Gallic Acid Decarboxylase Involved in the Degradation of Tannic Acid in the Yeast Blastobotrys (Arxula adeninivorans

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Anna K. Meier

2017-09-01

Full Text Available Tannins and hydroxylated aromatic acids, such as gallic acid (3,4,5-trihydroxybenzoic acid, are plant secondary metabolites which protect plants against herbivores and plant-associated microorganisms. Some microbes, such as the yeast Arxula adeninivorans are resistant to these antimicrobial substances and are able to use tannins and gallic acid as carbon sources. In this study, the Arxula gallic acid decarboxylase (Agdc1p which degrades gallic acid to pyrogallol was characterized and its function in tannin catabolism analyzed. The enzyme has a higher affinity for gallic acid (Km −0.7 ± 0.2 mM, kcat −42.0 ± 8.2 s−1 than to protocatechuic acid (3,4-dihydroxybenzoic acid (Km −3.2 ± 0.2 mM, kcat −44.0 ± 3.2 s−1. Other hydroxylated aromatic acids, such as 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid and 2,5-dihydroxybenzoic acid are not gallic acid decarboxylase substrates. A. adeninivorans G1212/YRC102-AYNI1-AGDC1, which expresses the AGDC1 gene under the control of the strong nitrate inducible AYNI1 promoter achieved a maximum gallic acid decarboxylase activity of 1064.4 U/l and 97.5 U/g of dry cell weight in yeast grown in minimal medium with nitrate as nitrogen source and glucose as carbon source. In the same medium, gallic acid decarboxylase activity was not detected for the control strain G1212/YRC102 with AGDC1 expression under the control of the endogenous promoter. Gene expression analysis showed that AGDC1 is induced by gallic acid and protocatechuic acid. In contrast to G1212/YRC102-AYNI1-AGDC1 and G1212/YRC102, A. adeninivorans G1234 [Δagdc1] is not able to grow on medium with gallic acid as carbon source but can grow in presence of protocatechuic acid. This confirms that Agdc1p plays an essential role in the tannic acid catabolism and could be useful in the production of catechol and cis,cis-muconic acid. However, the protocatechuic acid catabolism via Agdc1p to

Agdc1p – a Gallic Acid Decarboxylase Involved in the Degradation of Tannic Acid in the Yeast Blastobotrys (Arxula) adeninivorans

Science.gov (United States)

Meier, Anna K.; Worch, Sebastian; Böer, Erik; Hartmann, Anja; Mascher, Martin; Marzec, Marek; Scholz, Uwe; Riechen, Jan; Baronian, Kim; Schauer, Frieder; Bode, Rüdiger; Kunze, Gotthard

2017-01-01

Tannins and hydroxylated aromatic acids, such as gallic acid (3,4,5-trihydroxybenzoic acid), are plant secondary metabolites which protect plants against herbivores and plant-associated microorganisms. Some microbes, such as the yeast Arxula adeninivorans are resistant to these antimicrobial substances and are able to use tannins and gallic acid as carbon sources. In this study, the Arxula gallic acid decarboxylase (Agdc1p) which degrades gallic acid to pyrogallol was characterized and its function in tannin catabolism analyzed. The enzyme has a higher affinity for gallic acid (Km −0.7 ± 0.2 mM, kcat −42.0 ± 8.2 s−1) than to protocatechuic acid (3,4-dihydroxybenzoic acid) (Km −3.2 ± 0.2 mM, kcat −44.0 ± 3.2 s−1). Other hydroxylated aromatic acids, such as 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid and 2,5-dihydroxybenzoic acid are not gallic acid decarboxylase substrates. A. adeninivorans G1212/YRC102-AYNI1-AGDC1, which expresses the AGDC1 gene under the control of the strong nitrate inducible AYNI1 promoter achieved a maximum gallic acid decarboxylase activity of 1064.4 U/l and 97.5 U/g of dry cell weight in yeast grown in minimal medium with nitrate as nitrogen source and glucose as carbon source. In the same medium, gallic acid decarboxylase activity was not detected for the control strain G1212/YRC102 with AGDC1 expression under the control of the endogenous promoter. Gene expression analysis showed that AGDC1 is induced by gallic acid and protocatechuic acid. In contrast to G1212/YRC102-AYNI1-AGDC1 and G1212/YRC102, A. adeninivorans G1234 [Δagdc1] is not able to grow on medium with gallic acid as carbon source but can grow in presence of protocatechuic acid. This confirms that Agdc1p plays an essential role in the tannic acid catabolism and could be useful in the production of catechol and cis,cis-muconic acid. However, the protocatechuic acid catabolism via Agdc1p to catechol seems to be

Immunoregulation of antitumor response; differential secretion of arachidonic acid metabolites by macrophages during stimulation ''in vitro'' with BCG and ''Corynebacterium parvum''

International Nuclear Information System (INIS)

Tomecki, Jaroslaw; Sukiennik, Jadwiga; Kordowiak, Anna

1993-01-01

The level of arachidonic acid (AA) metabolites in the supernatants of cultures peritoneal exudate cells (PEC) were studied under various conditions using BCG and ''Corynebacterium parvum'' as stimulators. The metabolite levels were analyzed by thin layer chromatography (TLC). The degree of macrophage cytotoxic/cytostatic activity was dependent on the dose and character of stimulators used and the source of macrophages. The application of micro cytotoxicity assay for the evaluation of tumor cell lysis (lung sarcoma SaL-1) ''in vitro'' revealed that peritoneal macrophages from healthy and tumor bearing BALB/c mice may affect the degree of antitumor response. In the supernatants of cultured PEC from tumor bearing mice AA level increased (by 10-fold) in comparison with PEC from healthy mice. Stimulation with BCG induced over a double level of AA in PEC isolated from tumor bearing mice non-stimulated or stimulated with ''C.parvum''. A lower level of prostaglandins (PGs) was found in the supernatants of cultured PEC isolated from healthy mice (stimulated and non-stimulated), but the highest level of PGs was observed in the supernatants of cultured PEC isolated from tumor bearing mice stimulated with BCG. The unique metabolite of AA was found only in the supernatants form non-stimulated PEC from tumor bearing mice. PEC from tumor bearing mice produced metabolites of AA which were not detected in control group. These results suggest that macrophages also play a regulatory role by secretion of AA. This process can be modified by bacterial antigens. (author). 21 refs, 7 figs

Evidence for the essentiality of arachidonic and docosahexaenoic acid in the postnatal maternal and infant diet for the development of the infant's immune system early in life.

Science.gov (United States)

Richard, Caroline; Lewis, Erin D; Field, Catherine J

2016-05-01

Long-chain polyunsaturated fatty acids (LCPUFA), especially the balance between arachidonic (AA) and docosahexaenoic (DHA) acids are known to have important immunomodulatory roles during the postnatal period when the immune system is rapidly developing. AA and DHA are required in infant formula in many countries but are optional in North America. The rationale for adding these LCPUFA to full-term formula is based on their presence in breast milk and randomized controlled studies that suggest improved cognitive function in preterm infants, but results are more variable in full-term infants. Recently, the European Food Safety Authority has proposed, based on a lack of functional evidence, that AA is not required in infant formula for full-term infants during the first year of life but DHA should remain mandatory. The purpose of this review is to review the evidence from epidemiological and intervention studies regarding the essentiality of AA and DHA in the postnatal infant and maternal diet (breast-feeding) for the immune system development early in life. Although studies support the essentiality of DHA for the immune system development, more research is needed to rule out the essentiality of AA. Nevertheless, intervention studies have demonstrated improvement in many markers of immune function in infants fed formula supplemented with AA and DHA compared with unsupplemented formula, which appears to consistently result in beneficial health outcomes including reduction in the risk of developing allergic and atopic disease early in life.

Tissue levels of fish fatty acids and risk of colorectal adenomas: a case-control study (Netherlands).

NARCIS (Netherlands)

Busstra, M.C.; Siezen, C.L.; Grubben, M.J.A.L.; Kranen, H.J. van; Nagengast, F.M.; Veer, P. van 't

2003-01-01

Epidemiological and animal studies have suggested that a high ratio of n-3 fish fatty acids to arachidonic acid (AA), might protect against colorectal carcinogenesis. Competition of n-3 and n-6 fatty acids, especially AA, for the enzyme cyclooxygenase-2 may be responsible for this effect. To examine

Tissue levels of fish fatty acids and risk of colorectal adenomas: a case-control study (Netherlands)

NARCIS (Netherlands)

Busstra, M.C.; Siezen, C.L.E.; Grubben, M.J.A.L.; Kranen, H.J.; Nagengast, F.M.; Veer, van 't P.

2003-01-01

Epidemiological and animal studies have suggested that a high ratio of n-3 fish fatty acids to arachidonic acid (AA), might protect against colorectal carcinogenesis. Competition of n-3 and n-6 fatty acids, especially AA, for the enzyme cyclooxygenase-2 may be responsible for this effect. To examine

Volatile fatty acid degradation kinetics in anaerobic process; Cinetica de la degradacion de acidos grasos volatiles en procesos anaerobios

Energy Technology Data Exchange (ETDEWEB)

Riscado, S.; Osuna, B.; Iza, J.; Ruiz, E. [Universidad del Pais Vasco. Bilbao (Spain)

1998-10-01

While searching for the optimal substrate load for anaerobic toxicity assays, the inhibition caused by the propionic acid has been addressed. Lab scale experiments have been carried out to assess the effects of different loads and acid ratios. Results bad been subjected to kinetic analysis and show the degradation follows a first order kinetic, and acetic is easier to degrade than propionic acid. The optimal load for a 100 ml vial assay is composed of 158 mg COD of the 3:1:1 HAc:HPr:HBu mixture. (Author) 9 refs.

Effects of global change factors on fatty acids and mycosporine-like amino acid production in Chroothece richteriana (Rhodophyta).

Science.gov (United States)

Gonzalez-Silvera, Daniel; Pérez, Sandra; Korbee, Nathalie; Figueroa, Félix L; Asencio, Antonia D; Aboal, Marina; López-Jiménez, José Ángel

2017-10-01

Under natural conditions, Chroothece richteriana synthesizes a fairly high proportion of fatty acids. However, nothing is known about how environmental changes affect their production, or about the production of protective compounds, when colonies develop under full sunshine with high levels of UV radiation. In this study, wild colonies of C. richteriana were subjected to increasing temperature, conductivity, ammonium concentrations and photosynthetically active radiation (PAR), and UV radiations to assess the potential changes in lipid composition and mycosporine-like amino acids (MAAs) concentration. The PERMANOVA analysis detected no differences for the whole fatty acid profile among treatments, but the percentages of α-linolenic acid and total polyunsaturated fatty acids increased at the lowest assayed temperature. The percentages of linoleic and α-linolenic acids increased with lowering temperature. γ-linolenic and arachidonic acids decreased with increasing conductivity, and a high arachidonic acid concentration was related with increased conductivity. The samples exposed to UVB radiation showed higher percentages of eicosapentaenoic acid and total monounsaturated fatty acids, at the expense of saturated fatty acids. MAAs accumulation increased but not significantly at the lowest conductivity, and also with the highest PAR and UVR exposure, while ammonium and temperature had no effect. The observed changes are probably related with adaptations of both membrane fluidity to low temperature, and metabolism to protect cells against UV radiation damage. The results suggest the potential to change lipid composition and MAAs concentration in response to environmental stressful conditions due to climate change, and highlight the interest of the species in future research about the biotechnological production of both compound types. © 2017 Phycological Society of America.

Different Spectrophotometric Methods for Simultaneous Determination of Trelagliptin and Its Acid Degradation Product

Science.gov (United States)

Hassan, Mostafa A.; Zaghary, Wafaa A.

2018-01-01

New spectrophotometric and chemometric methods were carried out for the simultaneous assay of trelagliptin (TRG) and its acid degradation product (TAD) and applied successfully as a stability indicating assay to recently approved Zafatek® tablets. TAD was monitored using TLC to ensure complete degradation. Furthermore, HPLC was used to confirm dealing with one major acid degradation product. The proposed methods were developed by manipulating zero-order, first-derivative, and ratio spectra of TRG and TAD using simultaneous equation, first-derivative, and mean-centering methods, respectively. Using Spectra Manager II and Minitab v.14 software, the absorbance at 274 nm–260.4 nm, amplitudes at 260.4 nm–274.0 nm, and mean-centered values at 287.6 nm–257.2 nm were measured against methanol as a blank for TRG and TAD, respectively. Linearity and the other validation parameters were acceptable at concentration ranges of 5–50 μg/mL and 2.5–25 μg/mL for TRG and TAD, respectively. Using one-way analysis of variance (ANOVA), the optimized methods were compared and proved to be accurate for the simultaneous assay of TRG and TAD. PMID:29629213

Degradation of Acid Orange 7 Dye in Two Hybrid Plasma Discharge Reactors

Science.gov (United States)

Shen, Yongjun; Lei, Lecheng; Zhang, Xingwang; Ding, Jiandong

2014-11-01

To get an optimized pulsed electrical plasma discharge reactor and to increase the energy utilization efficiency in the removal of pollutants, two hybrid plasma discharge reactors were designed and optimized. The reactors were compared via the discharge characteristics, energy transfer efficiency, the yields of the active species and the energy utilization in dye wastewater degradation. The results showed that under the same AC input power, the characteristics of the discharge waveform of the point-to-plate reactor were better. Under the same AC input power, the two reactors both had almost the same peak voltage of 22 kV. The peak current of the point-to-plate reactor was 146 A, while that of the wire-to-cylinder reactor was only 48.8 A. The peak powers of the point-to-plate reactor and the wire-to-cylinder reactor were 1.38 MW and 1.01 MW, respectively. The energy per pulse of the point-to-plate reactor was 0.2221 J, which was about 29.4% higher than that of the wire-to-cylinder reactor (0.1716 J). To remove 50% Acid Orange 7 (AO7), the energy utilizations of the point-to-plate reactor and the wire-to-cylinder reactor were 1.02 × 10-9 mol/L and 0.61 × 10-9 mol/L, respectively. In the point-to-plate reactor, the concentration of hydrogen peroxide in pure water was 3.6 mmol/L after 40 min of discharge, which was higher than that of the wire-to-cylinder reactor (2.5 mmol/L). The concentration of liquid phase ozone in the point-to-plate reactor (5.7 × 10-2 mmol/L) was about 26.7% higher than that in the wire-to-cylinder reactor (4.5 × 10-2 mmol/L). The analysis results of the variance showed that the type of reactor and reaction time had significant impacts on the yields of the hydrogen peroxide and ozone. The main degradation intermediates of AO7 identified by gas chromatography and mass spectrometry (GCMS) were acetic acid, maleic anhydride, p-benzoquinone, phenol, benzoic acid, phthalic anhydride, coumarin and 2-naphthol. Proposed degradation pathways were

Degradation of Acid Orange 7 Dye in Two Hybrid Plasma Discharge Reactors

International Nuclear Information System (INIS)

Shen Yongjun; Ding Jiandong; Lei Lecheng; Zhang Xingwang

2014-01-01

To get an optimized pulsed electrical plasma discharge reactor and to increase the energy utilization efficiency in the removal of pollutants, two hybrid plasma discharge reactors were designed and optimized. The reactors were compared via the discharge characteristics, energy transfer efficiency, the yields of the active species and the energy utilization in dye wastewater degradation. The results showed that under the same AC input power, the characteristics of the discharge waveform of the point-to-plate reactor were better. Under the same AC input power, the two reactors both had almost the same peak voltage of 22 kV. The peak current of the point-to-plate reactor was 146 A, while that of the wire-to-cylinder reactor was only 48.8 A. The peak powers of the point-to-plate reactor and the wire-to-cylinder reactor were 1.38 MW and 1.01 MW, respectively. The energy per pulse of the point-to-plate reactor was 0.2221 J, which was about 29.4% higher than that of the wire-to-cylinder reactor (0.1716 J). To remove 50% Acid Orange 7 (AO7), the energy utilizations of the point-to-plate reactor and the wire-to-cylinder reactor were 1.02 × 10 −9 mol/L and 0.61 × 10 −9 mol/L, respectively. In the point-to-plate reactor, the concentration of hydrogen peroxide in pure water was 3.6 mmol/L after 40 min of discharge, which was higher than that of the wire-to-cylinder reactor (2.5 mmol/L). The concentration of liquid phase ozone in the point-to-plate reactor (5.7 × 10 −2 mmol/L) was about 26.7% higher than that in the wire-to-cylinder reactor (4.5 × 10 −2 mmol/L). The analysis results of the variance showed that the type of reactor and reaction time had significant impacts on the yields of the hydrogen peroxide and ozone. The main degradation intermediates of AO7 identified by gas chromatography and mass spectrometry (GCMS) were acetic acid, maleic anhydride, p-benzoquinone, phenol, benzoic acid, phthalic anhydride, coumarin and 2-naphthol. Proposed degradation

Investigation of the impact of trace elements on anaerobic volatile fatty acid degradation using a fractional factorial experimental design.

Science.gov (United States)

Jiang, Ying; Zhang, Yue; Banks, Charles; Heaven, Sonia; Longhurst, Philip

2017-11-15

The requirement of trace elements (TE) in anaerobic digestion process is widely documented. However, little is understood regarding the specific requirement of elements and their critical concentrations under different operating conditions such as substrate characterisation and temperature. In this study, a flask batch trial using fractional factorial design is conducted to investigate volatile fatty acids (VFA) anaerobic degradation rate under the influence of the individual and combined effect of six TEs (Co, Ni, Mo, Se, Fe and W). The experiment inoculated with food waste digestate, spiked with sodium acetate and sodium propionate both to 10 g/l. This is followed by the addition of a selection of the six elements in accordance with a 2 6-2 fractional factorial principle. The experiment is conducted in duplicate and the degradation of VFA is regularly monitored. Factorial effect analysis on the experimental results reveals that within these experimental conditions, Se has a key role in promoting the degradation rates of both acetic and propionic acids; Mo and Co are found to have a modest effect on increasing propionic acid degradation rate. It is also revealed that Ni shows some inhibitory effects on VFA degradation, possibly due to its toxicity. Additionally, regression coefficients for the main and second order effects are calculated to establish regression models for VFA degradation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Silage fermentation and ruminal degradation of stylo prepared with lactic acid bacteria and cellulase.

Science.gov (United States)

Li, Mao; Zhou, Hanlin; Zi, Xuejuan; Cai, Yimin

2017-10-01

In order to improve the silage fermentation of stylo (Stylosanthes guianensis) in tropical areas, stylo silages were prepared with commercial additives Lactobacillus plantarum Chikuso-1 (CH1), L. rhamnasus Snow Lact L (SN), Acremonium cellulase (CE) and their combination as SN+CE or CH1 + CE, and the fermentation quality, chemical composition and ruminal degradation of these silages were studied. Stylo silages treated with lactic acid bacteria (LAB) or cellulase, the pH value and NH 3 -N ⁄ total-N were significantly (P fermentation and ruminal degradation than SN+CE treatment. The results confirmed that LAB or LAB plus cellulase treatment could improve the fermentation quality, chemical composition and ruminal degradation of stylo silage. Moreover, the combined treatment with LAB and cellulase may have beneficial synergistic effects on ruminal degradation. © 2017 Japanese Society of Animal Science.

Photocatalytic degradation of clofibric acid, carbamazepine and iomeprol using conglomerated TiO2 and activated carbon in aqueous suspension.

Science.gov (United States)

Ziegmann, Markus; Frimmel, Fritz H

2010-01-01

The combination of powdered activated carbon (PAC) and TiO(2) has been tested for synergistic/antagonistic effects in the photocatalytic degradation of carbamazepine, clofibric acid and iomeprol. Synergistic effects are thought to be caused by rapid adsorption on the PAC surface followed by diffusion to the TiO(2) surface and photocatalytic degradation. The Freundlich constant K(F) was used for comparing the sorption properties of the three substances and it was found that K(F) for clofibric acid was 3 times lower than for carbamazepine and iomeprol, regardless of the kind of PAC used. A PAC with a distinct tendency to form conglomerates was selected so that a high percentage of the PAC surface was in direct proximity to the TiO(2) surface. The photocatalytic degradation of the pharmaceutically active compounds studied followed pseudo-first order kinetics. Synergistic effects only occurred for clofibric acid (factor 1.5) and an inverse relationship between adsorption affinity and synergistic effects was found. High affinity of the target substances to the PAC surface seemed to be counterproductive for the photocatalytic degradation.

Associations of Pseudomonas species and forage grasses enhance degradation of chlorinated benzoic acids in soil

Energy Technology Data Exchange (ETDEWEB)

Siciliano, S. D.

1998-12-01

Using chlorinated benzoic acid (CBA) as a model compound, this study attempted to show that microorganisms and plants can be used as bioremediation agents to clean up contaminated soil sites in a cost effective and environmentally friendly manner. CBA was used because it is present in soils contaminated with polychlorinated biphenyls (PCBs), or chlorinated pesticides. Sixteen forage grasses were screened in combination with 12 bacterial inoculants for their ability to promote the degradation of CBA in soil. Five associations of plants and bacteria were found to degrade CBA to a greater extent than plants without bacterial inoculants. Bacterial inoculants were shown to stimulate CBA degradation by altering the microbial community present on the root surface and thereby increasing the ability of this community to degrade CBA.

Mass spectrometry of oil sands naphthenic acids : degradation in OSPW and wetland plants

Energy Technology Data Exchange (ETDEWEB)

Headley, J. [Environment Canada, Saskatoon, SK (Canada). Water Science and Technology Directorate

2009-07-01

This presentation discussed mass spectrometry of oil sands naphthenic acids and the degradation in OSPW and wetland plants. It presented background information on the Athabasca oil sands and naphthenic acids which involve a mixture of alkanes and cycloalkane carboxylic acids with aliphatic side chains. The presentation also discussed mass spectrometry with electrospray operating in negative ion modes. Loop injection, external standard methods and solid phase extraction were reviewed along with improved analysis by removing background ions. Other topics that were presented included hydroponic test systems and wetland plant toxicity, growth and transpiration. It was concluded that dissipation included species containing oxygen, ozone, O{sub 4}, and O{sub 5}. tabs., figs.

The effect of natural iron oxide and oxalic acid on the photocatalytic degradation of isoproturon: a kinetics and analytical study.

Science.gov (United States)

Boucheloukh, H; Remache, W; Parrino, F; Sehili, T; Mechakra, H

2017-05-17

The photocatalytic degradation of isoproturon, a persistent toxic herbicide, was investigated in the presence of natural iron oxide and oxalic acid and under UV irradiation. The influence of the relevant parameters such as the pH and the iron oxide and oxalic acid concentrations has been studied. The presence of natural iron oxide and oxalic acid in the system effectively allow the degradation of isoproturon, whereas the presence of t-butyl alcohol adversely affects the phototransformation of the target pollutant, thus indicating that an OH radical initiated the degradation mechanism. The degradation mechanism of isoproturon was investigated by means of GC-MS analysis. Oxidation of both the terminal N-(CH 3 ) 2 and isopropyl groups is the initial process leading to N-monodemethylated (NHCH 3 ), N-formyl (N(CH 3 )CHO), and CHCH 3 OH as the main intermediates. The substitution of the isopropyl group by an OH group is also observed as a side process.

Nucleolytic degradation of homologous and heterologous deoxyribonucleic acid molecules at the surface of competent pneumococci

International Nuclear Information System (INIS)

Seto, H.; Lopez, R.; Garrigan, O.; Tomasz, A.

1975-01-01

Competent pneumococci can catalyze the rapid and quantitative degradation of extracellular deoxyribonucleic acid (DNA) molecules through the activity of surface-located nucleases (endo- and, possibly, exonucleases as well). Both homologous and heterologous DNAs are degraded by a mechanism that seems to involve a cyclic process: (i) attachment of DNA to the cell surface followed by (ii) nucleolytic attack, and (iii) release to the medium. Processes (ii) and (iii) are both inhibited by ethylenediaminetetraacetate. Whereas surface nuclease activity is specific for competent cells, the bulk of this activity is not coupled to irreversible DNA uptake (deoxyribonuclease-resistant binding). Pneumococcal DNA treated with ultraviolet irradiation or nitrous acid (cross-linking) is selectively impaired in the ability to irreversibly bind to competent cells, whereas reversible binding is normal. (U.S.)

Degradation of self-compacting concrete (SCC) due to sulfuric acid attack: Experiment investigation on the effect of high volume fly ash content

Science.gov (United States)

Kristiawan, S. A.; Sunarmasto; Tyas, G. P.

2016-02-01

Concrete is susceptible to a variety of chemical attacks. In the sulfuric acid environment, concrete is subjected to a combination of sulfuric and acid attack. This research is aimed to investigate the degradation of self-compacting concrete (SCC) due to sulfuric acid attack based on measurement of compressive strength loss and diameter change. Since the proportion of SCC contains higher cement than that of normal concrete, the vulnerability of this concrete to sulfuric acid attack could be reduced by partial replacement of cement with fly ash at high volume level. The effect of high volume fly ash at 50-70% cement replacement levels on the extent of degradation owing to sulfuric acid will be assessed in this study. It can be shown that an increase in the utilization of fly ash to partially replace cement tends to reduce the degradation as confirmed by less compressive strength loss and diameter change. The effect of fly ash to reduce the degradation of SCC is more pronounced at a later age.

Modification and restriction of T-even bacteriophages. In vitro degradation of deoxyribonucleic acid containing 5-hydroxymethylctosine.

Science.gov (United States)

Fleischman, R A; Cambell, J L; Richardson, C C

1976-03-25

Using the single-stranded circular DNA of bacteriophage fd as template, double-stranded circular DNA has been prepared in vitro with either 5-hydroxymethylcytosine ([hmdC]DNA) or cytosine ([dC]DNA) in the product strand. Extracts prepared from Escherichia coli cells restrictive to T-even phage containing nonglucosylated DNA degrade [hmdC]DNA to acid-soluble material in vitro, but do not degrade [dC]dna. In contrast, extracts prepared from E. coli K12 rglA- rglB-, a strain permissive to T-even phage containing nonglucosylated DNA, do not degrade [hmdC]DNA or [dC]DNA. In addition, glucosylation of the [hmdC]DNA renders it resistant to degradation by extracts from restrictive strains. The conversion of [hmdC]DNA to acid-soluble material in vitro consists of an HmCyt-specific endonucleolytic cleavage requiring the presence of the RglB gene product to form a linear molecule, followed by a non-HmCyt-specific hydrolysis of the linear DNA to acid-soluble fragments, catalyzed in part by exonuclease V. The RglB protein present in extracts of E. coli K12 rglA- rglB+ has been purified 200-fold by complementation with extracts from E. coli K12 rglA- rglB-. The purified RglB protein does not contain detectable HmCyt-specific endonuclease or exonuclease activity. In vitro endonucleolytic cleavage of [hmdC]DNA thus requires additional factors present in cell extracts.

Polymer Film-Based Screening and Isolation of Polylactic Acid (PLA)-Degrading Microorganisms.

Science.gov (United States)

Kim, Mi Yeon; Kim, Changman; Moon, Jungheun; Heo, Jinhee; Jung, Sokhee P; Kim, Jung Rae

2017-02-28

Polylactic acid (PLA) has been highlighted as an alternative renewable polymer for the replacement of petroleum-based plastic materials, and is considered to be biodegradable. On the other hand, the biodegradation of PLA by terminal degraders, such as microorganisms, requires a lengthy period in the natural environment, and its mechanism is not completely understood. PLA biodegradation studies have been conducted using mainly undefined mixed cultures, but only a few bacterial strains have been isolated and examined. For further characterization of PLA biodegradation, in this study, the PLA-degrading bacteria from digester sludge were isolated and identified using a polymer film-based screening method. The enrichment of sludge on PLA granules was conducted with the serial transference of a subculture into fresh media for 40 days, and the attached biofilm was inoculated on a PLA film on an agar plate. 3D optical microscopy showed that the isolates physically degraded the PLA film due to bacterial degradation. 16S rRNA gene sequencing identified the microbial colonies to be Pseudomonas sp. MYK1 and Bacillus sp. MYK2. The two isolates exhibited significantly higher specific gas production rates from PLA biodegradation compared with that of the initial sludge inoculum.

Ligand-functionalized degradable polyplexes formed by cationic poly(aspartic acid)-grafted chitosan-cyclodextrin conjugates

Science.gov (United States)

Song, Hai-Qing; Li, Rui-Quan; Duan, Shun; Yu, Bingran; Zhao, Hong; Chen, Da-Fu; Xu, Fu-Jian

2015-03-01

Polypeptide-based degradable polyplexes attracted considerable attention in drug delivery systems. Polysaccharides including cyclodextrin (CD), dextran, and chitosan (CS) were readily grafted with cationic poly(aspartic acid)s (PAsps). To further enhance the transfection performances of PAsp-based polyplexes, herein, different types of ligand (folic acid, FA)-functionalized degradable polyplexes were proposed based on the PAsp-grafted chitosan-cyclodextrin conjugate (CCPE), where multiple β-CDs were tied on a CS chain. The FA-functionalized CCPE (i.e., CCPE-FA) was obtained via a host-guest interaction between the CD units of CCPE and the adamantane (Ad) species of Ad-modified FA (Ad-FA). The resulting CCPE/pDNA, CCPE-FA/pDNA, and ternary CCPE-FA/CCPE/pDNA (prepared by layer-by-layer assembly) polyplexes were investigated in detail using different cell lines. The CCPE-based polyplexes displayed much higher transfection efficiencies than the CS-based polyplexes reported earlier by us. The ternary polyplexes of CCPE-FA/CCPE/pDNA produced excellent gene transfection abilities in the folate receptor (FR)-positive tumor cells. This work would provide a promising means to produce highly efficient polyplexes for future gene therapy applications.Polypeptide-based degradable polyplexes attracted considerable attention in drug delivery systems. Polysaccharides including cyclodextrin (CD), dextran, and chitosan (CS) were readily grafted with cationic poly(aspartic acid)s (PAsps). To further enhance the transfection performances of PAsp-based polyplexes, herein, different types of ligand (folic acid, FA)-functionalized degradable polyplexes were proposed based on the PAsp-grafted chitosan-cyclodextrin conjugate (CCPE), where multiple β-CDs were tied on a CS chain. The FA-functionalized CCPE (i.e., CCPE-FA) was obtained via a host-guest interaction between the CD units of CCPE and the adamantane (Ad) species of Ad-modified FA (Ad-FA). The resulting CCPE/pDNA, CCPE

Arachidonic acid and lipoxin A4 attenuate alloxan-induced cytotoxicity to RIN5F cells in vitro and type 1 diabetes mellitus in vivo.

Science.gov (United States)

Gundala, Naveen K V; Naidu, Vegi G M; Das, Undurti N

2017-03-01

We studied whether polyunsaturated fatty acids (PUFAs) can protect rat insulinoma (RIN5F) cells against alloxan-induced apoptosis in vitro and type 1 diabetes mellitus (type 1 DM) in vivo and if so, mechanism of this beneficial action. In vitro study was conducted using RIN5F cells while in vivo study was performed in Wistar rats. The effect of PUFAs, cyclo-oxygenase and lipoxygenase inhibitors, various eicosanoids and PUFAs metabolites: lipoxin A4 (LXA4), resolvin D2 and protectin against alloxan-induced cytotoxicity to RIN5F cells and type 1 DM was studied. Expression of PDX1, P65 NF-kB and IKB in RIN5F cells and Nrf2, GLUT2, COX2, iNOS protein levels in the pancreatic tissue and plasma glucose, insulin and tumor necrosis factor-α and antioxidants, lipid peroxides and nitric oxide were measured. Of all, arachidonic acid (AA) was found to be the most effective against alloxan-induced cytotoxicity to RIN5F cells and preventing type 1 DM. Both cyclo-oxygenase and lipoxygenase inhibitors did not block the beneficial actions of AA in vitro and in vivo. Alloxan inhibited LXA4 production by RIN5F cells and in alloxan-induced type 1 DM Wistar rats. AA-treatment restored LXA4 levels to normal both in vitro and in vivo. LXA4 protected RIN5F cells against alloxan-induced cytotoxicity and prevented type 1 DM and restored expression of Nrf2, Glut2, COX2, and iNOS genes and abnormal antioxidants to near normal. AA seems to bring about its beneficial actions against alloxan-induced cytotoxicity and type 1 DM by enhancing the production of LXA4. © 2016 BioFactors, 43(2):251-271, 2017. © 2016 International Union of Biochemistry and Molecular Biology.

Degradation of unglazed rough graphite-aluminium solar absorber surfaces in simulated acid and neutral rain

International Nuclear Information System (INIS)

Konttinen, P.; Lund, P.D.; Salo, T.

2005-01-01

Degradation mechanisms of unglazed solar absorber surfaces based on aluminium substrate were studied. Rough graphite-aluminium surfaces were total-immersion subjected to aerated and de-aerated simulated neutral and acid rain. Test conditions were based on calculated absorber stagnation temperature and global rain acidity measurements. Changes in optical properties, elemental composition and sample mass were examined by spectrometry, energy dispersive X-ray spectrometry and thermogravimetry, respectively. The absorbers exhibited almost no degradation at pH value of 3.5. At pH 5.5 alumina on the surface hydrated significantly degrading the optical properties of the surfaces severely in most cases. Therefore these absorber surfaces can not be recommended to be used in non-glazed applications if they are exposed to rain with pH exceeding ∼ 3.5-4.5. The total-immersion test needs to be developed further as the test results exhibited poor temperature and time dependency thus preventing accurate service lifetime estimates. Still, these tests were useful in determining favourable and non-favourable operating conditions for the absorber surfaces based on aluminium substrate. (author)

Polyunsaturated fatty acids and prostate cancer risk

DEFF Research Database (Denmark)

Khankari, Nikhil K; Murff, Harvey J; Zeng, Chenjie

2016-01-01

BACKGROUND: Prostate cancer is a common cancer worldwide with no established modifiable lifestyle factors to guide prevention. The associations between polyunsaturated fatty acids (PUFAs) and prostate cancer risk have been inconsistent. Using Mendelian randomisation, we evaluated associations...... and prostate cancer risk. However, risk reductions were observed for short-chain PUFAs, linoleic (ORLA=0.95, 95%CI=0.92, 0.98) and α-linolenic acids (ORALA=0.96, 95%CI=0.93, 0.98), among men ...-chain PUFAs (i.e., arachidonic, eicosapentaenoic, and docosapentaenoic acids), increased risks were observed among men

Studies of insulin secretory responses and of arachidonic acid incorporation into phospholipids of stably transfected insulinoma cells that overexpress group VIA phospholipase A2 (iPLA2beta ) indicate a signaling rather than a housekeeping role for iPLA2beta.

Science.gov (United States)

Ma, Z; Ramanadham, S; Wohltmann, M; Bohrer, A; Hsu, F F; Turk, J

2001-04-20

A cytosolic 84-kDa group VIA phospholipase A(2) (iPLA(2)beta) that does not require Ca(2+) for catalysis has been cloned from several sources, including rat and human pancreatic islet beta-cells and murine P388D1 cells. Many potential iPLA(2)beta functions have been proposed, including a signaling role in beta-cell insulin secretion and a role in generating lysophosphatidylcholine acceptors for arachidonic acid incorporation into P388D1 cell phosphatidylcholine (PC). Proposals for iPLA(2)beta function rest in part on effects of inhibiting iPLA(2)beta activity with a bromoenol lactone (BEL) suicide substrate, but BEL also inhibits phosphatidate phosphohydrolase-1 and a group VIB phospholipase A(2). Manipulation of iPLA(2)beta expression by molecular biologic means is an alternative approach to study iPLA(2)beta functions, and we have used a retroviral construct containing iPLA(2)beta cDNA to prepare two INS-1 insulinoma cell clonal lines that stably overexpress iPLA(2)beta. Compared with parental INS-1 cells or cells transfected with empty vector, both iPLA(2)beta-overexpressing lines exhibit amplified insulin secretory responses to glucose and cAMP-elevating agents, and BEL substantially attenuates stimulated secretion. Electrospray ionization mass spectrometric analyses of arachidonic acid incorporation into INS-1 cell PC indicate that neither overexpression nor inhibition of iPLA(2)beta affects the rate or extent of this process in INS-1 cells. Immunocytofluorescence studies with antibodies directed against iPLA(2)beta indicate that cAMP-elevating agents increase perinuclear fluorescence in INS-1 cells, suggesting that iPLA(2)beta associates with nuclei. These studies are more consistent with a signaling than with a housekeeping role for iPLA(2)beta in insulin-secreting beta-cells.

Kinetic study of photocatalytic degradation of carbamazepine, clofibric acid, iomeprol and iopromide assisted by different TiO2 materials--determination of intermediates and reaction pathways.

Science.gov (United States)

Doll, Tusnelda E; Frimmel, Fritz H

2004-02-01

The light-induced degradation of clofibric acid, carbamazepine, iomeprol and iopromide under simulated solar irradiation has been investigated in aqueous solutions suspended with different TiO2 materials (P25 and Hombikat UV100). Kinetic studies showed that P25 had a better photocatalytic activity for clofibric acid and carbamazepine than Hombikat UV100. For photocatalytic degradation of iomeprol Hombikat UV100 was more suitable than P25. The results can be explained by the higher adsorption capacity of Hombikat UV100 for iomeprol. The study also focuses on the identification and quantification of possible degradation products. The degradation process was monitored by determination of sum parameters and inorganic ions. In case of clofibric acid various aromatic and aliphatic degradation products have been identified and quantified. A possible multi-step degradation scheme for clofibric acid is proposed. This study proves the high potential of the photocatalytic oxidation process to transform and mineralize environmentally relevant pharmaceuticals and contrast media in water.

Performance Degradation Tests of Phosphoric Acid Doped Polybenzimidazole Membrane Based High Temperature Polymer Electrolyte Membrane Fuel Cells

DEFF Research Database (Denmark)

Zhou, Fan; Araya, Samuel Simon; Grigoras, Ionela

2015-01-01

Degradation tests of two phosphoric acid (PA) doped PBI membrane based HT-PEM fuel cells were reported in this paper to investigate the effects of start/stop and the presence of methanol in the fuel to the performance degradation of the HT-PEM fuel cell. Continuous tests with pure dry H2 and meth...

Ontogeny of 6-keto-PGF/sub 1α/ synthesis in rabbit aorta and the effect of premature weaning

International Nuclear Information System (INIS)

Bydlowski, S.P.; Yunker, R.L.; Subbiah, M.T.R.

1987-01-01

A systematic study of the ontogeny of aortic 6-ketoprostaglandin F/sub 1α/ synthesis from birth to adult life and the effect of premature weaning on this process was investigated in rabbits. Prostacyclin (PGI 2 ) synthesis by both endogenous and exogenous arachidonic acid and its relation to aortic arachidonic acid content was determined. It was found that 1) PGI 2 synthesis from endogenous arachidonic acid increased with age, whereas 2) PGI 2 synthesis from exogenous arachidonic acid decreased. This correlated with a decrease in the incorporation of [ 14 C]arachidonic acid into phospholipids with age. Aortic arachidonic acid concentration did not change from birth until 3 wk of life but increased markedly by 5 wk of age. Premature weaning caused a decrease in the synthesis of aortic PGI 2 and in aortic arachidonic acid concentration initially, but the changes did not persist in later life. These studies suggest that the utilization of exogenous arachidonic acid by aorta decreases after birth perhaps due to maturity of the enzyme systems that synthesize and utilize endogenous substrates

Scanning electron microscopic study of the hydrolytic degradation of poly(glycolic acid) suture

International Nuclear Information System (INIS)

Chu, C.C.; Campbell, N.D.

1982-01-01

This article reports the morphological observations on the surface changes of poly-(glycolic acid) sutures which have been exposed to various dosages of gamma irradiation (0, 2.5, 5.0, 10, 20 and 40 Mrad) and duration of immersion (0, 7, 14, 28, 48, 60, and 90 days) in a physiological saline buffer. The most important gross morphological characteristics of PGA suture hydrolytic degradation is the formation of surface cracks on the filaments. The regularity of the surface cracks increased with an increase in the gamma irradiation and the duration of hydrolysis. Surface cracks were not observed in irradiated sutures that had not been subjected to hydrolytic degradation. The arrangement of the surface cracks, their orientation on the filaments, and the direction of crack propagation provide very useful information for depicting the mechanism of hydrolytic degradation in this class of fibrous material. The microfibrillar model of fiber structure has been used as the basis for the proposed degradation mechanism of PGA in vitro. It is believed that hydrolysis occurs initially in the amorphous regions sandwiched between two crystalline zones, as tie-chain segments, free chain ends, and chain folds in these regions degrade into fragments. As degradation proceeds, the size of the fragments reaches the stage at which they can be dissolved into the buffer medium. This dissolution removes the fragments from the amorphous regions, and surface cracks appeared

Preparation, Cell Compatibility and Degradability of Collagen-Modified Poly(lactic acid

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Miaomiao Cui

2015-01-01

Full Text Available Poly(lactic acid (PLA was modified using collagen through a grafting method to improve its biocompatibility and degradability. The carboxylic group at the open end of PLA was transferred into the reactive acylchlorided group by a reaction with phosphorus pentachloride. Then, collagen-modified PLA (collagen-PLA was prepared by the reaction between the reactive acylchlorided group and amino/hydroxyl groups on collagen. Subsequently, the structure of collagen-PLA was confirmed by Fourier transform infrared spectroscopy, fluorescein isothiocyanate-labeled fluorescence spectroscopy, X-ray photoelectron spectroscopy, and DSC analyses. Finally, some properties of collagen-PLA, such as hydrophilicity, cell compatibility and degradability were characterized. Results showed that collagen had been grafted onto the PLA with 5% graft ratio. Water contact angle and water absorption behavior tests indicated that the hydrophilicity of collagen-PLA was significantly higher than that of PLA. The cell compatibility of collagen-PLA with mouse embryonic fibroblasts (3T3 was also significantly better than PLA in terms of cell morphology and cell proliferation, and the degradability of PLA was also improved after introducing collagen. Results suggested that collagen-PLA was a promising candidate for biomedical applications.

Effect of ultrasonic degradation of hyaluronic acid extracted from rooster comb on antioxidant and antiglycation activities.

Science.gov (United States)

Hafsa, Jawhar; Chaouch, Mohamed Aymen; Charfeddine, Bassem; Rihouey, Christophe; Limem, Khalifa; Le Cerf, Didier; Rouatbi, Sonia; Majdoub, Hatem

2017-12-01

Recently, low-molecular-weight hyaluronic acid (LMWHA) has been reported to have novel features, such as free radical scavenging activities, antioxidant activities and dietary supplements. In this study, hyaluronic acid (HA) was extracted from rooster comb and LMWHA was obtained by ultrasonic degradation in order to assess their antioxidant and antiglycation activities. Molecular weight (Mw) and the content of glucuronic acid (GlcA) were used as the index for comparison of the effect of ultrasonic treatment. The effects on the structure were determined by ultraviolet (UV) spectra and Fourier transform infrared spectra (FTIR). The antioxidant activity was determined by three analytical assays (DPPH, NO and TBARS), and the inhibitory effect against glycated-BSA was also assessed. The GlcA content of HA and LMWHA was estimated at about 48.6% and 47.3%, respectively. The results demonstrate that ultrasonic irradiation decreases the Mw (1090-181 kDa) and intrinsic viscosity (1550-473 mL/g), which indicate the cleavage of the glycosidic bonds. The FTIR and UV spectra did not significantly change before and after degradation. The IC 50 value of HA and LWMHA was 1.43, 0.76 and 0.36 mg/mL and 1.20, 0.89 and 0.17 mg/mL toward DPPH, NO and TBARS, respectively. Likewise LMWHA exhibited significant inhibitory effects on the AGEs formation than HA. The results demonstrated that the ultrasonic irradiation did not damage and change the chemical structure of HA after degradation; furthermore, decreasing Mw and viscosity of LMWHA after degradation may enhance the antioxidant and antiglycation activity.

Dietary supplementation of essential fatty acids in larval pikeperch (Sander lucioperca); short and long term effects on stress tolerance and metabolic physiology

DEFF Research Database (Denmark)

Lund, Ivar; Skov, Peter Vilhelm; Hansen, Benni Winding

2012-01-01

The present study examined the effects of feeding pike perch larvae Artemia, enriched with either docosahexanoic acid (DHA), arachidonic acid (ARA), oleic acid (OA), olive oil (OO) or a commercial enrichment DHA Selco (DS) on tissue lipid deposition, stress tolerance, growth and development...

Effects of Calcium Lignosulfonate and Silicic Acid on Ammonium Nitrate Degradation

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Ahmet Ozan Gezerman

2014-01-01

Full Text Available Ammonium nitrate salts are the most commonly used nitrogenous fertilizers in industry. However, storage of ammonium nitrate is problematic, since its initial properties can decline because of environmental factors, leading to large economic losses. In this study, in order to prevent the caking and degradation of ammonium nitrate, an alternative composition with additional calcium lignosulfonate and silicic acid was studied. The resulting fertilizer was analyzed by screening analysis, ion chromatography, and electron microscopy methods.

Bacterial populations and environmental factors controlling cellulose degradation in an acidic Sphagnum peat.

Science.gov (United States)

Pankratov, Timofey A; Ivanova, Anastasia O; Dedysh, Svetlana N; Liesack, Werner

2011-07-01

Northern peatlands represent a major global carbon store harbouring approximately one-third of the global reserves of soil organic carbon. A large proportion of these peatlands consists of acidic Sphagnum-dominated ombrotrophic bogs, which are characterized by extremely low rates of plant debris decomposition. The degradation of cellulose, the major component of Sphagnum-derived litter, was monitored in long-term incubation experiments with acidic (pH 4.0) peat extracts. This process was almost undetectable at 10°C and occurred at low rates at 20°C, while it was significantly accelerated at both temperature regimes by the addition of available nitrogen. Cellulose breakdown was only partially inhibited in the presence of cycloheximide, suggesting that bacteria participated in this process. We aimed to identify these bacteria by a combination of molecular and cultivation approaches and to determine the factors that limit their activity in situ. The indigenous bacterial community in peat was dominated by Alphaproteobacteria and Acidobacteria. The addition of cellulose induced a clear shift in the community structure towards an increase in the relative abundance of the Bacteroidetes. Increasing temperature and nitrogen availability resulted in a selective development of bacteria phylogenetically related to Cytophaga hutchinsonii (94-95% 16S rRNA gene sequence similarity), which densely colonized microfibrils of cellulose. Among isolates obtained from this community only some subdivision 1 Acidobacteria were capable of degrading cellulose, albeit at a very slow rate. These Acidobacteria represent indigenous cellulolytic members of the microbial community in acidic peat and are easily out-competed by Cytophaga-like bacteria under conditions of increased nitrogen availability. Members of the phylum Firmicutes, known to be key players in cellulose degradation in neutral habitats, were not detected in the cellulolytic community enriched at low pH. © 2011 Society for

Evaluate the role of organic acids in the protection of ligands from radiolytic degradation

Energy Technology Data Exchange (ETDEWEB)

Miller, Anneka [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mezyk, Stehpen [Idaho National Lab. (INL), Idaho Falls, ID (United States); Peterman, Dean [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2016-08-01

In the Advanced TALSPEAK process, the bis(2-ethylhexyl)phosphoric acid (HDEHP) extractant used in the traditional TALSPEAK process is replaced by the extractant 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]). In addition, the aqueous phase complexant and buffer used in traditional TALSPEAK is replaced with the combination of N-(2-hydroxyethyl)ethylenediamine-N,N’,N’-triacetic acid (HEDTA) and citric acid. In order to evaluate the possible impacts of gamma radiolysis upon the efficacy of the Advanced TALSPEAK flowsheet, aqueous and organic phases corresponding to the extraction section of the proposed flowsheet were irradiated in the INL test loop under an ambient atmosphere. The results of these studies conducted at INL, led INL researchers to conclude that the scarcity of values of rate constants for the reaction of hydroxyl radical with the components of the Advanced TALSPEAK process chemistry was severely limiting the interpretation of the results of radiolysis studies performed at the INL. In this work, the rate of reaction of hydroxyl radical with citric acid at several pH values was measured using a competitive pulse radiolysis technique. This report describes those results and is written in completion of milestone M3FT-16IN030102028, the goal of which was to evaluate the role of organic acids in the protection of ligands from radiolytic degradation. The results reported here demonstrate the importance of obtaining hydroxyl radical reaction rate data for the conditions that closely resemble actual solution conditions expected to be used in an actual solvent extraction process. This report describes those results and is written in completion of milestone M3FT-16IN030102028, the goal of which was to evaluate the role of organic acids in the protection of ligands from radiolytic degradation.

Cadmium Alters the Concentration of Fatty Acids in THP-1 Macrophages.

Science.gov (United States)

Olszowski, Tomasz; Gutowska, Izabela; Baranowska-Bosiacka, Irena; Łukomska, Agnieszka; Drozd, Arleta; Chlubek, Dariusz

2018-03-01

Fatty acid composition of human immune cells influences their function. The aim of this study was to evaluate the effects of known toxicant and immunomodulator, cadmium, at low concentrations on levels of selected fatty acids (FAs) in THP-1 macrophages. The differentiation of THP-1 monocytes into macrophages was achieved by administration of phorbol myristate acetate. Macrophages were incubated with various cadmium chloride (CdCl 2 ) solutions for 48 h at final concentrations of 5 nM, 20 nM, 200 nM, and 2 μM CdCl 2 . Fatty acids were extracted from samples according to the Folch method. The fatty acid levels were determined using gas chromatography. The following fatty acids were analyzed: long-chain saturated fatty acids (SFAs) palmitic acid and stearic acid, very long-chain saturated fatty acid (VLSFA) arachidic acid, monounsaturated fatty acids (MUFAs) palmitoleic acid, oleic acid and vaccenic acid, and n-6 polyunsaturated fatty acids (PUFAs) linoleic acid and arachidonic acid. Treatment of macrophages with very low concentrations of cadmium (5-200 nM) resulted in significant reduction in the levels of arachidic, palmitoleic, oleic, vaccenic, and linoleic acids and significant increase in arachidonic acid levels (following exposure to 5 nM Cd), without significant reduction of palmitic and stearic acid levels. Treatment of macrophages with the highest tested cadmium concentration (2 μM) produced significant reduction in the levels of all examined FAs: SFAs, VLSFA, MUFAs, and PUFAs. In conclusion, cadmium at tested concentrations caused significant alterations in THP-1 macrophage fatty acid levels, disrupting their composition, which might dysregulate fatty acid/lipid metabolism thus affecting macrophage behavior and inflammatory state.

Forced degradation of mometasone furoate and development of two RP-HPLC methods for its determination with formoterol fumarate or salicylic acid

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Ramzia I. El-Bagary

2016-05-01

Full Text Available Two simple, selective and precise stability-indicating reversed-phase liquid chromatographic methods were developed and validated for the determination of mometasone furoate in two binary mixtures, with formoterol fumarate (Mixture 1 and salicylic acid (Mixture 2. Also, a forced degradation study of mometasone furoate was carried out including acid and alkali hydrolysis, oxidation, thermal and photo-degradation. For mixture 1, the method was based on isocratic elution using a mobile phase consisting of (Acetonitrile: 3 mM Sodium lauryl sulfate (60:40, v/v at a flow rate of 1 ml min−1. Quantitation was achieved applying dual wavelength detection where mometasone furoate and its degradation products were detected at 247 nm and formoterol fumarate and its degradation product were detected at 214 nm at 30 °C. For mixture 2 and for the forced degradation study, separation was based on isocratic elution of mometasone furoate, its degradation products and salicylic acid on a reversed phase C8 column using a mobile phase consisting of acetonitrile:water:methanol:glacial acetic acid (60:30:10:0.1, v/v at a flow rate of 2 mL min−1. Quantitation was achieved with UV detection at 240 nm. In addition, products from alkaline forced degradation of mometasone furoate were verified by LC–MS. Linearity, accuracy and precision were found to be acceptable over the concentration range of 10–800 μg mL−1 and 5–60 μg mL−1 for mometasone furoate and formoterol fumarate, respectively and over the concentration range of 5–320 μg mL−1 and 20–1280 μg mL−1 for mometasone furoate and salicylic acid, respectively. The two proposed methods could be successfully applied for the routine analysis of the studied drugs in their pharmaceutical preparations without any preliminary separation step.

Degradation of microbial polyesters.

Science.gov (United States)

Tokiwa, Yutaka; Calabia, Buenaventurada P

2004-08-01

Microbial polyhydroxyalkanoates (PHAs), one of the largest groups of thermoplastic polyesters are receiving much attention as biodegradable substitutes for non-degradable plastics. Poly(D-3-hydroxybutyrate) (PHB) is the most ubiquitous and most intensively studied PHA. Microorganisms degrading these polyesters are widely distributed in various environments. Although various PHB-degrading microorganisms and PHB depolymerases have been studied and characterized, there are still many groups of microorganisms and enzymes with varying properties awaiting various applications. Distributions of PHB-degrading microorganisms, factors affecting the biodegradability of PHB, and microbial and enzymatic degradation of PHB are discussed in this review. We also propose an application of a new isolated, thermophilic PHB-degrading microorganism, Streptomyces strain MG, for producing pure monomers of PHA and useful chemicals, including D-3-hydroxycarboxylic acids such as D-3-hydroxybutyric acid, by enzymatic degradation of PHB.

Amino acid and fatty acid compositions of Rusip from fermented Anchovy fish (Stolephorussp)

Science.gov (United States)

Koesoemawardani, D.; Hidayati, S.; Subeki

2018-04-01

Rusip is a typical food of Bangka Belitung Indonesia made from fermented anchovy. This study aims to determine the properties of chemistry, microbiology, composition of amino acids and fatty acids from fermented fish spontaneously and non spontaneously. Spontaneous rusip treatment is done by anchovy fish (Stolephorussp) after cleaning and added salt 25% (w/w) and palm sugar 10% (w/w). While, non-spontaneous rusip is done by adding a culture mixture of Streptococcus, Leuconostoc, and Lactobacillus bacteria 2% (w/v). The materials are then incubated for 2 weeks. The data obtained were then performed t-test at the level of 5%. Spontaneous and non-spontaneous rusip fermentation process showed significant differences in total acid, reducing sugar, salt content, TVN, total lactic acid bacteria, total mold, and total microbial. The dominant amino acid content of spontaneous and non-spontaneous rusip are glutamic acid and aspartic acid, while the dominant fatty acids in spontaneous and non-spontaneous rusip are docosahexaenoic acid, palmitic acid, oleic acid, arachidonic acid, stearic acid, eicosapentaenoic acid, palmitoleic acid, and myristic acid.

Co-Metabolic Degradation of β-Cypermethrin and 3-Phenoxybenzoic Acid by Co-Culture of Bacillus licheniformis B-1 and Aspergillus oryzae M-4.

Science.gov (United States)

Zhao, Jiayuan; Chi, Yuanlong; Xu, Yingchao; Jia, Dongying; Yao, Kai

2016-01-01

The degradation efficiency of organic contaminants and their associated metabolites by co-culture of microbes is mainly limited by toxic intermediates from co-metabolic degradation. In this study, we investigated the degradation of β-cypermethrin (β-CY) and 3-phenoxybenzoic acid (3-PBA) by co-culture of Bacillus licheniformis B-1 and Aspergillus oryzae M-4, as well as the influences of β-CY and 3-PBA metabolites on their degradation and the growth of strains B-1 and M-4. Our results indicated that 100 mg/L β-CY was degraded by 78.85%, and 3-PBA concentration was 0.05 mg/L after 72 h. Compared with using only strain B-1, the half-life (t1/2) of β-CY by using the two strains together was shortened from 84.53 h to 38.54 h, and the yield coefficient of 3-PBA was decreased from 0.846 to 0.001. At 100 mg/L of 3-PBA and gallic acid, β-CY and 3-PBA degradation were only 17.68% and 40.45%, respectively. As the toxic intermediate derived from co-metabolic degradation of β-CY by strain B-1, 3-PBA was efficiently degraded by strain M-4, and gallic acid, as the toxic intermediate from co-metabolic degradation of 3-PBA by strain M-4, was efficiently degraded by strain B-1. These results provided a promising approach for efficient biodegradation of β-CY and 3-PBA.

Co-Metabolic Degradation of β-Cypermethrin and 3-Phenoxybenzoic Acid by Co-Culture of Bacillus licheniformis B-1 and Aspergillus oryzae M-4.

Directory of Open Access Journals (Sweden)

Jiayuan Zhao

Full Text Available The degradation efficiency of organic contaminants and their associated metabolites by co-culture of microbes is mainly limited by toxic intermediates from co-metabolic degradation. In this study, we investigated the degradation of β-cypermethrin (β-CY and 3-phenoxybenzoic acid (3-PBA by co-culture of Bacillus licheniformis B-1 and Aspergillus oryzae M-4, as well as the influences of β-CY and 3-PBA metabolites on their degradation and the growth of strains B-1 and M-4. Our results indicated that 100 mg/L β-CY was degraded by 78.85%, and 3-PBA concentration was 0.05 mg/L after 72 h. Compared with using only strain B-1, the half-life (t1/2 of β-CY by using the two strains together was shortened from 84.53 h to 38.54 h, and the yield coefficient of 3-PBA was decreased from 0.846 to 0.001. At 100 mg/L of 3-PBA and gallic acid, β-CY and 3-PBA degradation were only 17.68% and 40.45%, respectively. As the toxic intermediate derived from co-metabolic degradation of β-CY by strain B-1, 3-PBA was efficiently degraded by strain M-4, and gallic acid, as the toxic intermediate from co-metabolic degradation of 3-PBA by strain M-4, was efficiently degraded by strain B-1. These results provided a promising approach for efficient biodegradation of β-CY and 3-PBA.

Influence of humic acid addition on the degradation of pharmaceuticals by biofilms in effluent wastewater

DEFF Research Database (Denmark)

Tang, Kai; Escola Casas, Monica; Ooi, Gordon Tze Hoong

2017-01-01

in relation to the biodegradation of pharmaceuticals by suspended biofilm carriers adapted to polishing effluent water from a tertiary sewage treatment plant. Twelve out of 22 investigated pharmaceuticals were significantly biodegradable. The biodegradation rate constants of ten of those compounds were......The degradation of organic micropollutants in wastewater treatment is suspected to depend on co-degradation i.e. be dependent on concentrations of substrate. This complicates predicting and modelling their fate. The effect of humic acid, as a model for complex organic substrate, was investigated...

DENTINE CARIES: ACID-TOLERANT MICROORGANISMS AND ASPECTS ON COLLAGEN DEGRADATION.

Science.gov (United States)

Lager, Anders Hedenbjörk

2014-01-01

Dental caries is a common disease all over the world, despite the fact that it can be both effectively prevented and treated. It is driven by acids produced by oral microorganisms as a consequence of their metabolism of dietary carbohydrates. Given enough acid challenge, eventually the tooth enamel barrier will be broken down, and the carious lesion will extend into underlying hard tissue, forming a macroscopic cavity in the dentine. In comparison to biofilm on enamel, a dentine carious lesion provides a vastly different environment for the residing microorganisms. The environment influences the types and numbers of microorganisms that can colonize the dentine caries lesion. The overall aims for this thesis are to enumerate and further study microorganisms found in established dentine caries lesions and also to illuminate how host-derived proteolytic enzymes might contribute to this degradation, not only to better understand the caries process in dentine but also to find incitements for new methods to influence the natural progression of caries lesions. In Paper I, the numbers of remaining viable microorganisms after completed excavation using two excavation methods were investigated. Samples of carious dentine tissue were collected before and after excavation and cultivated on different agar media in different atmospheres. Analysis was performed by counting the number of colony-forming units (CFUs). Key findings: The number of remaining microorganisms after excavation was low for both methods, but some microorganisms always remained in the cavity floors even when the cavities were judged as caries free using normal clinical criteria. In Paper II, the acid tolerant microbiota in established dentine caries lesions was investigated. Samples were taken as in Paper I, but on three levels (superficial, center of lesion, floor of lesion after completed excavation). The samples were cultivated in anaerobic conditions on solid pH-selective agar media of different acidity

Strecker degradation of amino acids promoted by a camphor-derived sulfonamide

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M. Fernanda N. N. Carvalho

2016-04-01

Full Text Available A camphor-derived sulfonimine with a conjugated carbonyl group, oxoimine 1 (O2SNC10H13O, reacts with amino acids (glycine, L-alanine, L-phenylalanine, L-leucine to form a compound O2SNC10H13NC10H14NSO2 (2 which was characterized by spectroscopic means (MS and NMR and supported by DFT calculations. The product, a single diastereoisomer, contains two oxoimine units connected by a –N= bridge, and thus has a structural analogy to the colored product Ruhemann´s purple obtained by the ninhydrin reaction with amino acids. A plausible reaction mechanism that involves zwitterions, a Strecker degradation of an intermediate imine and water-catalyzed tautomerizations was developed by means of DFT calculations on potential transition states.

Kinetics of degradation of ascorbic acid by cyclic voltammetry method

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Grudić Veselinka V.

2015-01-01

Full Text Available Cyclic voltammetry was used to examine the kinetics of degradation of ascorbic acid (AA at different temperatures. It has been shown that the reduction of the concentration of AA in all temperatures follow the kinetics of the first order reaction. The rate constant of the oxidation reaction increases with temperature as follows: 5x10-5; 2x10-4; 1x10-3 and 3x10-3 min-1 at temperatures of 25°C, 35°C, 65°C and 90°C, respectively. The temperature dependence of the rate constant follows Arrhenius equation, and the value of activation energy of the reaction degradation is 48.2 kJ mol-1 . The effect of storage time at a temperature of 90 °C on AA content in fresh juice of green peppers was investigated. It was shown that AA oxidation reaction in the juice is also the first order reaction, while the lower rate constant in relation to the pure AA (5x10-3 min-1 indicates the influence of other substances present in peppers.

The effect of structure and a secondary carbon source on the microbial degradation of chlorophenoxy acids.

Science.gov (United States)

Evangelista, S; Cooper, D G; Yargeau, V