Quast, U.; Cook, N.S.
The effect of the crude venom of the Israeli scorpion Leiurus quinquestriatus hebraeus on the 86 Rb + efflux stimulated by the K + channel opener BRL 34915 in the rat portal vein was examined. Applied alone, the venom greatly increased the spontaneous mechanical activity of and the concomitant 86 Rb + efflux from the vessel. When the excitability of the vein was suppressed by the dihydropyridine calcium antagonist, PN 200-110, the 86 Rb + efflux stimulated by BRL 34915 could be shown to be inhibited by the venom. From the concentration dependence of this inhibition an IC 50 value of 0.17 +/- 0.01 mg/ml was estimated. This venom is thus the most potent blocker of BRL 34915-evoked 86 Rb + efflux reported so far. 17 references, 2 figures
Abd Rabo, H.A.M.
Unlike the amphibians, birds, mammals and reptiles, scorpions have no back bone, as they are invertebrates. Scorpions belong to the phylum arthropoda, their bodies are segmented and their legs are jointed. They belong to the class arachnida, because they have eight legs, two pedipalps, two chelicerae and a body composed of eighteen segments. The most important species of Buthidae family are Buthotus tamulus, Leiurus quinquestriatus, Androctonus crassicauda, Androctonus australis, Tityus serrulatus, and Centruroides suffusus (Minton, 2010). Scorpions are found in East Africa, Middle East, India, as well as Central and South America. Classification of scorpions from Africa and Middle East, has been summarized by Vachon, (1966). Unlike snakes, all scorpions are venomous. The venom is injected by means of a stinger found at the tip of the telson, the terminal structure of the tail. The smallest adults may range from approximately 2 to 3 cm and the largest between 15 to 25 cm (Bucherl, 1971). Scorpions have quite variable life spans. The age range appears to be approximately 4–25 years. Scorpions prefer to live in areas where the temperatures range from 20 °C to 37 °C, but may survive from freezing temperatures to the desert heat (Hadley, 1970; Hannah's et al., 2006). The death stalker (Leiurus quinquestriatus), is a member of the Buthidae family. It is also known as Palestine yellow scorpion, Omdurman scorpion, Israeli desert scorpion and numerous other colloquial names. To eliminate confusion, especially with potentially dangerous species, the scientific name is normally used to refer to them. The name Leiurus quinquestriatus roughly translates into English as f ive-striped smooth-tail . Other species of the genus Leiurus are often referred to as d eathstalkers a s well (Werness, 2004; Minton, 2010).
Full Text Available Venom of Leiurus abdullahbayrami (Scorpiones: Buthidae is an extremely toxic one and it stimulates voltage-gated sodium and potassium channels. In case of a stung by this scorpion; excessive catecholamine release occur and it impairs left ventricle contractility and consequently a heart failure occurs (scorpion sting-related cardiomyopathy. In addition to this cardiac-induced acute pulmonary, edema may occur in severe cases too. An 11-year-old male child who was stung by a scorpion (species: Leiurus abdullahbayrami consulted to the Emergency Room. Even after 7 h of scorpion envenomation he was confused and having hallucinations. Besides he was dyspneic, tachycardic, hypotensive and got worse in overall situation due to cardiogenic pulmonary edema. These clinical findings are concordant with the Level III scorpion envenomation (major systemic manifestations. Positive inotropic agents, diuretics and antiagregant agents used on supportive therapy in his treatment. After 2 weeks he get recovered and discharged from the pediatric intensive care unit. This research is conducted by thinking emergency physicians should learn that Leiurus abdullahbayrami envenomation can cause scorpion-related cardiomyopathy and acute pulmonary edema especially in children. Keywords: Leiurus, Scorpionism, Cardiomyopathy, Pulmonary edema
Song, Weizhong; Du, Yuzhe; Liu, Zhiqi; Luo, Ningguang; Turkov, Michael; Gordon, Dalia; Gurevitz, Michael; Goldin, Alan L; Dong, Ke
Scorpion β-toxins bind to the extracellular regions of the voltage-sensing module of domain II and to the pore module of domain III in voltage-gated sodium channels and enhance channel activation by trapping and stabilizing the voltage sensor of domain II in its activated state. We investigated the interaction of a highly potent insect-selective scorpion depressant β-toxin, Lqh-dprIT(3), from Leiurus quinquestriatus hebraeus with insect sodium channels from Blattella germanica (BgNa(v)). Like other scorpion β-toxins, Lqh-dprIT(3) shifts the voltage dependence of activation of BgNa(v) channels expressed in Xenopus oocytes to more negative membrane potentials but only after strong depolarizing prepulses. Notably, among 10 BgNa(v) splice variants tested for their sensitivity to the toxin, only BgNa(v)1-1 was hypersensitive due to an L1285P substitution in IIIS1 resulting from a U-to-C RNA-editing event. Furthermore, charge reversal of a negatively charged residue (E1290K) at the extracellular end of IIIS1 and the two innermost positively charged residues (R4E and R5E) in IIIS4 also increased the channel sensitivity to Lqh-dprIT(3). Besides enhancement of toxin sensitivity, the R4E substitution caused an additional 20-mV negative shift in the voltage dependence of activation of toxin-modified channels, inducing a unique toxin-modified state. Our findings provide the first direct evidence for the involvement of the domain III voltage-sensing module in the action of scorpion β-toxins. This hypersensitivity most likely reflects an increase in IIS4 trapping via allosteric mechanisms, suggesting coupling between the voltage sensors in neighboring domains during channel activation.
Abu-Sinna, Gamal. Vol 2 (2000) - Articles Effect of Leiurus quinquestriatus venom and venom fractions on cells cultured in vitro. Abstract PDF. ISSN: 1110-6859. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and ...
Al Asmari AK
Full Text Available Abdulrahman K Al Asmari, Abdul Quaiyoom Khan Research Centre, Prince Sultan Military Medical City, Riyadh, Saudi Arabia Abstract: Cancer is the leading cause of morbidity and mortality all over the world in spite of the advances made in its management. In this study, we investigated the in vivo antitumorigenic potential of the venom obtained from a medically important scorpion species Leiurus quinquestriatus on chemically induced skin cancer in mice. Animals were divided into five groups, with 13 animals in each group. All the treatments were given topically on the shaved dorsal surface of the skin. Animals in Group 1 received vehicle only (0.2 mL acetone. Moreover, 7,12-dimethylbenz[a]anthracene (DMBA, 400 nmol per mouse was applied to all the animals in the remaining four groups. After 1 week, different concentrations of venom (17.5 µg, 35 µg, and 52.5 µg per animal were applied to each animal in the Groups III–V. Thirty minutes after the application of venom, croton oil was applied on the same position where venom was administered to the animals of Groups III–V. Animals in Group II were treated as the positive control (without venom and received croton oil as in Groups III–V. The findings of this study revealed that venom extract of L. quinquestriatus inhibits DMBA + croton oil-induced mouse skin tumor incidence and tumor multiplicity. Venom treatment also decreased the expression of proinflammatory cytokines. Immunohistochemistry results showed a downregulation of the expression of molecular markers such as Ki-67, nuclear factor kappa-B, cyclooxygenase-2, B-cell lymphoma-2, and vascular endothelial growth factor, in venom-treated animals. Our findings suggest that the venom of L. quinquestriatus possesses in vivo anticancer potential and may be used in the development of anticancer molecules. Keywords: Leiurus quinquestriatus, skin cancer, apoptosis, immunosuppression
Smith, C.; Phillips, M.; Miller, C.
Charybdotoxim is a high-affinity specific inhibitor of the high-conductance Ca 2+ -activated K + channel found in the plasma membranes of many vertebrate cell types. Using Ca 2+ -activated K + channels reconstituted into planar lipid bilayer membranes as an assay, the authors have purified the toxin from the venom of the scorpion Leiurus quinquestriatus by a two-step procedure involving chromatofocusing on SP-Sephadex, followed by reversed-phase high-performance liquid chromatography. Charybdotoxin is shown to be a highly basic protein with a mass of 10 kDa. Under the standard assay conditions, the purified toxin inhibits the Ca 2+ -activated K + channel with an apparent dissociation constant of 3.5 nM. The protein is unusually stable, with inhibitory potency being insensitive to boiling or exposure to organic solvents. The toxin's activity is sensitive to chymotrypsin treatment and to acylation of lysine groups. The protein may be radioiodinated without loss of activity
Full Text Available Chlorotoxin is a 36-amino acid peptide derived from Leiurus quinquestriatus (scorpion venom, which has been shown to inhibit low-conductance chloride channels in colonic epithelial cells. Chlorotoxin also binds to matrix metalloproteinase-2 and other proteins on glioma cell surfaces. Glioma cells are considered to require the activation of matrix metalloproteinase-2 during invasion and migration. In this study, for targeting glioma, we designed two types of recombinant chlorotoxin fused to human IgG-Fcs with/without a hinge region. Chlorotoxin fused to IgG-Fcs was designed as a dimer of 60 kDa with a hinge region and a monomer of 30 kDa without a hinge region. The monomeric and dimeric forms of chlorotoxin inhibited cell proliferation at 300 nM and induced internalization in human glioma A172 cells. The monomer had a greater inhibitory effect than the dimer; therefore, monomeric chlorotoxin fused to IgG-Fc was multivalently displayed on the surface of bionanocapsules to develop a drug delivery system that targeted matrix metalloproteinase-2. The target-dependent internalization of bionanocapsules in A172 cells was observed when chlorotoxin was displayed on the bionanocapsules. This study indicates that chlorotoxin fused to IgG-Fcs could be useful for the active targeting of glioblastoma cells.
Jarrar, Bashir M.; Al-Rowaily, Meshref A.
Information on scorpion stings is available for many parts of SaudiArabia, but not for the Al-Jouf Province. We reviewed and analyzed 1449 casesof scorpion stings that presented to the emergency department of thehospitals and medical centers in Al-Jouf Province during a 2-year period(2005-2006). The majority of patients (92.7%) manifested class I envenomationwith local pain at the sting site as the primary complaint. Systemic toxicitywas noticed in 7.3% of cases but no deaths were reported. Scorpion stingswere recorded throughout the year with the highest seasonal incidence in thesummer (64.3%) and the lowest during the winter (10.6%). The highest monthlyincidence was in June (21.5%) and the lowest in December (1.5%). Most of thepatients were male (77.3%) and the age of 44.2% of victims ranged between 15to 30 years. Diurnal stings exceeded the nocturnal ones with a ratio of 3:2and most of the stings were located mainly on the exposed limbs (88.6%),especially the lower limbs (51.7%). Leiurus quinquestriatus and Androctouscrassicauda were incriminated in most recorded cases. Our findings indicatethat scorpion stings are common in Al-Jouf Province, especially during thesummer. The overall threat to human health was found to be low. (author)
M. K. Al-Sadoon
Full Text Available This investigation evaluated the epidemiological aspects of scorpion stings in different areas of Saudi Arabia. A total of 72,168 cases of scorpion stings recorded in Ministry of Health Medical Centers in 11 selected areas of Saudi Arabia were analyzed based on area, age, sex, time of sting, sting site, treatment outcome, time of year, and scorpion species. Stings occurred throughout the year; the highest frequency was in June (15.08%, the lowest in February (2.52%. Most patients were male (61.8%; the majority of which were more than 15 years old (65.4%. Nocturnal envenomation (47.74% was more common than diurnal (43.91%; most stings were in exposed limbs (90.95%, mainly in the lower limbs (63%. Most envenomings were mild (74.48% and all evolved to cure, except for one death. Envenomation was characterized by local pain, erythema, headache, vomiting, and anxiety. This study found that the Leiurus quinquestriatus (Ehrenberg 1828, Androctonus crassicauda (Olivier 1807, and Apistobuthus pterygocercus (Finnegan 1807 were responsible for most of the stings, indicating their medical importance in Saudi Arabia. The study shows low threat to life despite the high number of stings; this is a result of the availability of medical facilities and the multi-center antivenom use in different areas of Saudi Arabia.
Tang, C M; Strichartz, G R; Orkand, R K
Experiments investigating both the binding of radioactively labelled saxitoxin (STX) and the electrophysiological response to drugs that increase the sodium permeability of excitable membranes were conducted in an effort to detect sodium channels in glial cells of the optic nerve of Necturus maculosa, the mudpuppy. Glial cells in nerves from chronically enucleated animals, which lack optic nerve axons, show no saturable uptake of STX whereas a saturable uptake is clearly present in normal optic nerves. The normal nerve is depolarized by aconitine, batrachotoxin, and veratridine (10(-6)-10(-5) M), whereas the all-glial preparation is only depolarized by veratridine and at concentrations greater than 10(-3) M. Unlike the depolarization caused by veratridine in normal nerves, the response in the all-glial tissue is not blocked by tetrodotoxin nor enhanced by scorpion venom (Leiurus quinquestriatus). In glial cells of the normal nerve, where axons are also present, the addition of 10(-5) M veratridine does lead to a transient depolarization; however, it is much briefer than the axonal response to veratridine in this same tissue. This glial response to veratridine could be caused by the efflux of K+ from the drug-depolarized axons, and is similar to the glial response to extracellular K+ accumulation resulting from action potentials in the axon.
Ottea, J.A.; Payne, G.T.; Soderlund, D.M.
Nine synthetic N-alkylamides were examined as inhibitors of the specific binding of [ 3 H]batrachotoxinin A 20α-benzoate ([ 3 H]BTX-B) to sodium channels and as activators of sodium uptake in mouse brain synaptoneurosomes. In the presence of scorpion (Leiurus quinquestriatus) venom, the six insecticidal analogues were active as both inhibitors of [ 3 H]BTX-B binding and stimulators of sodium uptake. These findings are consistent with an action of these compounds at the alkaloid activator recognition site (site 2) of the voltage-sensitive sodium channel. The three noninsecticidal N-alkylamides also inhibited [ 3 H]BTX-B binding but were ineffective as activators of sodium uptake. Concentration-response studies revealed that some of the insecticidal amides also enhanced sodium uptake through a second, high-affinity interaction that does not involve site 2, but this secondary effect does not appear to be correlated with insecticidal activity. The activities of N-alkylamides as sodium channel activators were influenced by the length of the alkenyl chain and the location of unsaturation within the molecule. These results further define the actions of N-alkylamides on sodium channels and illustrate the significance of the multiple binding domains of the sodium channel as target sites for insect control agents
Moran, Yehu; Kahn, Roy; Cohen, Lior; Gur, Maya; Karbat, Izhar; Gordon, Dalia; Gurevitz, Michael
Av3 is a short peptide toxin from the sea anemone Anemonia viridis shown to be active on crustaceans and inactive on mammals. It inhibits inactivation of Na(v)s (voltage-gated Na+ channels) like the structurally dissimilar scorpion alpha-toxins and type I sea anemone toxins that bind to receptor site-3. To examine the potency and mode of interaction of Av3 with insect Na(v)s, we established a system for its expression, mutagenized it throughout, and analysed it in toxicity, binding and electrophysiological assays. The recombinant Av3 was found to be highly toxic to blowfly larvae (ED50=2.65+/-0.46 pmol/100 mg), to compete well with the site-3 toxin LqhalphaIT (from the scorpion Leiurus quinquestriatus) on binding to cockroach neuronal membranes (K(i)=21.4+/-7.1 nM), and to inhibit the inactivation of Drosophila melanogaster channel, DmNa(v)1, but not that of mammalian Na(v)s expressed in Xenopus oocytes. Moreover, like other site-3 toxins, the activity of Av3 was synergically enhanced by ligands of receptor site-4 (e.g. scorpion beta-toxins). The bioactive surface of Av3 was found to consist mainly of aromatic residues and did not resemble any of the bioactive surfaces of other site-3 toxins. These analyses have portrayed a toxin that might interact with receptor site-3 in a different fashion compared with other ligands of this site. This assumption was corroborated by a D1701R mutation in DmNa(v)1, which has been shown to abolish the activity of all other site-3 ligands, except Av3. All in all, the present study provides further evidence for the heterogeneity of receptor site-3, and raises Av3 as a unique model for design of selective anti-insect compounds.
., O. hamistrius (Schmidt, 1893 comb. n., O. impressicollis sp. n., O. intersectus sp. n., O. montanus sp. n., O. nubosus sp. n., O. pichinchensis sp. n., O. propinquus sp. n., O. quinquestriatus sp. n., O. rubidus (Hinton, 1935 comb. n., O. rufescens sp. n., O. troglodytes sp. n.], O. plicicollis group [O. cephalicus sp. n., O. longidens sp. n., O. plicicollis (Schmidt, 1893], O. fossipygus group [O. disconnectus sp. n., O. fossipygus (Wenzel, 1944, O. foveipygus (Bickhardt, 1918, O. fungicolus (Wenzel & Dybas, 1941, O. gibbulus (Schmidt, 1889 comb. n., O. olivensis sp. n., O. simplicipygus sp. n., O. subdepressus (Schmidt, 1889, O. therondi (Wenzel, 1976], O. impunctipennis group [O. chamelensis sp. n., O. foveiventris sp. n., O. granulipectus sp. n., O. impunctipennis (Hinton, 1935 comb. n., O. latifoveatus sp. n., O. lissipygus sp. n., O. maesi sp. n., O. mangiferus sp. n., O. marginipennis sp. n., O. nicodemus sp. n., O. nitidus sp. n., O. pacificus sp. n., O. pauperculus sp. n., O. punctissipygus sp. n., O. subviridis sp. n., O. tripartitus sp. n., O. vorax sp. n.], O. marginellus group [O. ashei sp. n., O. baylessae sp. n., O. dentatus sp. n., O. formicatus sp. n., O. hintoni sp. n., O. marginellus (J.E. LeConte, 1860 comb. n., O. orchidophilus sp. n., O. selvorum sp. n., O. striatellus (Fall, 1917 comb. n.], incertae sedis: O. teapensis (Marseul, 1853 comb. n., O. punctulatus sp. n., O. lama Mazur, 1988, O. florifaunensis sp. n., O. bosquesecus sp. n., O. arnaudi Dégallier, 1982, O. subsphaericus sp. n., O. latipygus sp. n., O. elongatus sp. n., O. rupicolus sp. n., O. punctipleurus sp. n., O. falini sp. n., O. peregrinus sp. n., O. brooksi sp. n., O. profundipygus sp. n., O. punctatissimus sp. n., O. cavisternus sp. n., O. siluriformis sp. n., O. parallelus sp. n., O. abbreviatus sp. n., O. pygidialis (Lewis, 1908, O. faltistrius sp. n., O. limonensis sp. n., O. wenzeli sp. n., O. iheringi (Bickhardt, 1917, O. angustisternus (Wenzel, 1944, O. shorti sp. n. We