Venom Of Saw-scaled Viper Research Articles

ASSESSMENT OF SNAKE ANTIVENOM ACTIVITY OF TAMARINDUS INDICA SEED COAT EXTRACT

Snakebite is a life-threatening medical emergency, and globally responsible for millions of deaths. In snakebites accidents only deaths are not a concern, it leads to more morbidities. Due to scanty healthcare facilities in rural areas of India, many people seek alternative treatment available in ethnic practices. Tamarindus Indica (TI) plant is rich in medicinal value and used to treat many diseases including snakebite treatment traditionally. In view of this TI seed coat extract (TISCE) was evaluated for antivenom activity. The phytochemical screening of TISCE was performed to understand its chemical composition. TISCE was evaluated for antivenom activity against Indian cobra venom (ICV), common krait venom (CKV), Russells viper venom (RVV), and saw-scaled viper venom (SCV) for phospholipase A2 (PLA-2), haemorrhagic in vitro and in vivo, procoagulant, proteolytic activity, and lethality studies. TISCE majorly contains saponins, glycosides, alkaloids, and phenolic compounds. Minimum indirect haemorrhagic dose (MIHD) observed for ICV (12.5 µg), CKV (5.0 µg),RVV (10.0 µg), and SVV (12.5 µg). TISCE inhibits the procoagulant activity of all venoms at a concentration of 18.0 µg. It also shows the neutralization of proteolytic enzymes of venom in a dose-dependent manner. A pre-incubated mixture containing five lethal dose 50 (LD50) of venom and TISCE was injected intravenously, all mice survived as venom neutralized by TISCE. The present study demonstrates the ability of TISCE to neutralize snake venom using suitable in vivo and in vitro methods. Further studies required to unravelling the specific active chemical constituent of TISCE that may used as novel alternative snakebite treatment. TISCE was able to prolong the deaths during the simulation study and may be used in the topical pharmaceutical formulation that will reduce local venom reactions causing much morbidity, which will collectively with Anti-snake venom (ASV), used to treat envenomed patients more effectively.

Snake Venoms in Diagnostic Hemostasis and Thrombosis.

Snake venoms have evolved primarily to immobilize and kill prey, and consequently, they contain some of the most potent natural toxins. Part of that armory is a range of hemotoxic components that affect every area of hemostasis, which we have harnessed to great effect in the study and diagnosis of hemostatic disorders. The most widely used are those that affect coagulation, such as thrombin-like enzymes unaffected by heparin and direct thrombin inhibitors, which can help confirm or dispute their presence in plasma. The liquid gold of coagulation activators is Russell's viper venom, since it contains activators of factor X and factor V. It is used in a range of clotting-based assays, such as assessment of factor X and factor V deficiencies, protein C and protein S deficiencies, activated protein C resistance, and probably the most important test for lupus anticoagulants, the dilute Russell's viper venom time. Activators of prothrombin, such as oscutarin C from Coastal Taipan venom and ecarin from saw-scaled viper venom, are employed in prothrombin activity assays and lupus anticoagulant detection, and ecarin has a valuable role in quantitative assays of direct thrombin inhibitors. Snake venoms affecting primary hemostasis include botrocetin from the jararaca, which can be used to assay von Willebrand factor activity, and convulxin from the cascavel, which can be used to detect deficiency of the platelet collagen receptor, glycoprotein VI. This article takes the reader to every area of the diagnostic hemostasis laboratory to appreciate the myriad applications of snake venoms available in diagnostic practice.

Complex target SELEX-based identification of DNA aptamers against Bungarus caeruleus venom for the detection of envenomation using a paper-based device

Complex target SELEX always have been an intriguing approach to the scientific community, as it offers the potential discovery of novel biomarkers. We herein successfully performed SELEX on Bungarus caeruleus venom to develop a panel of highly affine aptamers that specifically recognizes the B. caeruleus (common krait) venom and was able to discriminate the B. caeruleus venom from Cobra, Russell's, and Saw-scaled viper's venom. The aptamers generated against the crude venom also lead to the identification of the specific component of the venom, which is β-Bungarotoxin, a toxin uniquely present in the B. caeruleus venom. The best performing aptamer candidates were used as a molecular recognition element in a paper-based device and were able to detect as low as 2 ng krait venom in human serum background. The developed aptamer-based paper device can be used for potential point-of-care venom detection applications due to its simplicity and affordability.

Potential of herbal cocktail of medicinal plant extracts against ‘big four’ snake venoms from India

BackgroundVenomous snake bites cause acute medical emergencies and are fatal. India accounts for large proportion of snake-bite deaths globally. Medically important ‘BIG FOUR’ snakes of India are Bungarus caeruleus (krait), Naja naja (cobra), Echis carinatus (saw-scaled viper) and Daboia russelii (Russell's viper). Polyherbal formulations have been proved to be effective in treatment of diseases than a single formulation. Objective(s)To evaluate aqueous ethanolic extract cocktail of Azadirachata indica, Butea monosperma, Citrus limon, Clerodendrum serratum and Areca catechu for antidote potential against BIG FOUR venoms in ex vivo and in vivo model. Materials and methodsAnti-hemorrhagic and venom neutralization studies were performed in seven-day old chick embryo model for ex vivo studies. In vivo studies were performed using male Swiss albino mice for antivenom potential of herbal cocktail by performing anti-edematic, anti-hemorrhagic, anti-myotoxic activity, and venom neutralization. ResultsHerbal cocktail exhibited differential venom inhibition potential against four venoms tested. Hemorrhagic activity was completely neutralized by the herbal cocktail; myotoxic activities of krait and Russell's viper venom were neutralized; while anti-edematic activity was observed for krait and cobra venom. Herbal cocktail completely neutralized venom lethality (3∗LD50) of krait and saw-scaled viper venom. ConclusionInhibitions of various venom components of all four venoms suggests presence of phytochemicals in herbal cocktail with therapeutic properties. Further studies would help in the development of a formulation as a first-aid towards treatment of snake bite victims.

Protein toxins of the Echis coloratus viper venom directly activate TRPV1

BackgroundPeptide and protein toxins are essential tools to dissect and probe the biology of their target receptors. Venoms target vital physiological processes to evoke pain. Snake venoms contain various factors with the ability to evoke, enhance and sustain pain sensation. While a number of venom-derived toxins were shown to directly target TRPV1 channels expressed on somatosensory nerve terminals to evoke pain response, such toxins were yet to be identified in snake venoms. MethodsWe screened Echis coloratus saw-scaled viper venom's protein fractions isolated by reversed phase HPLC for their ability to activate TRPV1 channels. To this end, we employed heterologous systems to analyze TRPV1 and NGF pathways by imaging and electrophysiology, combined with molecular biology, biochemical, and pharmacological tools. ResultsWe identified TRPV1 activating proteins in the venom of Echis coloratus that produce a channel-dependent increase in intracellular calcium and outwardly rectifying currents in neurons and heterologous systems. Interestingly, channel activation was not mediated by any of its known toxin binding sites. Moreover, although NGF neurotropic activity was detected in this venom, TRPV1 activation was independent of NGF receptors. ConclusionsEchis coloratus venom contains proteins with the ability to directly activate TRPV1. This activity is independent of the NGF pathway and is not mediated by known TRPV1 toxins' binding sites. General significanceOur results could facilitate the discovery of new toxins targeting TRPV1 to enhance current understanding of this receptor activation mechanism. Furthermore, the findings of this study provide insight into the mechanism through which snakes' venom elicit pain.

CAPILLARY PERMEABILITY RESPONSES TO SNAKE VENOMS.

Abstract Russell’s viper venom is many times more toxic to mice on intravenous administration than is saw-scaled viper venom, and yet on local intradermal injection the two venoms have equal capillary permeability effects in mice, rats, guinea-pigs and rabbits. Their effects are completely prevented by drugs possessing both antihistamine and anti-5-ht properties. It is concluded that the increased capillary permeability induced by the venoms is largely mediated through the release of histamine and 5-ht.

Studies on pharmacological effects of Russell's viper and Saw-scaled viper venom and its neutralization by chicken egg yolk antibodies

Antivenom antibodies were raised in 24-week-old white leghorn chickens against hemotoxic venoms of Russell's viper and Saw-scaled viper snakes. Booster injections of increasing concentrations of venom were given at 14days of time interval to raise the antivenom level in egg yolk. Antibodies were extracted from immunized chicken egg yolk by Polson et al. (Polson A., Von Wechmar M.B., Van Regenmortel M.H.V. Isolation of viral IgY antibodies from yolks of immunized hens. Immunological Communications 1980; 9:475–493.) and further purified by DEAE cellulose ion exchange column chromatography, which gave pure (180–200kDa) specific antibodies against venom. High titre of more than 1:10,000 antibodies were detected by ELISA at the 135th day of observation. The lethal toxicity and various pharmacological activities like hemorrhagic activity, phospholipase activity, edema and procoagulant activities of venom were carried out by both in vivo and in vitro methods. The effectiveness of antivenom in neutralizing these effects was carried out involving pre-incubation type experiments. The median effective dose (ED 50) for Russell's viper venom was 0.96mg/2LD 50/18g mice and for Saw-scaled viper venom it was 1.28mg/2LD 50/18g mice. One millilitre of specific antivenom was effective in neutralizing 0.110mg of Russell's viper and 0.137mg of Saw-scaled viper venoms respectively (PD 50). Antivenom was effective in neutralization assays in a dose dependent manner. The results indicate that antibodies raised in chicken could effectively neutralize the pharmacological effects induced by venoms and chickens therefore present an alternative and cheaper source of specific antibody generation.

Crystal Structure of the Disintegrin Heterodimer from Saw-Scaled Viper (Echis carinatus) at 1.9 Å Resolution

Disintegrins constitute a family of potent polypeptide inhibitors of integrins. Integrins are transmembrane heterodimeric molecules involved in cell-cell and cell-extracellular matrix interactions. They are involved in many diseases such as cancer and thrombosis. Thus, disintegrins have a great potential as anticancer and antithrombotic agents. A novel heterodimeric disintegrin was isolated from the venom of saw-scaled viper (Echis carinatus) and was crystallized. The crystals diffracted to 1.9 A resolution and belonged to space group P4(3)2(1)2. The data indicated the presence of a pseudosymmetry. The structure was solved by applying origin shifts to the disintegrin homodimer schistatin solved in space group I4(1)22 with similar cell dimensions. The structure refined to the final R(cryst)/R(free) factors of 0.213/0.253. The notable differences are observed between the loops, (Gln39-Asp48) containing the important Arg42-Gly43-Asp44, of the present heterodimer and schistatin. These differences are presumably due to the presence of two glycines at positions 43 and 46 that allow the molecule to adopt variable conformations. A comparative analysis of the surface-charge distributions of various disintegrins showed that the charge distribution on monomeric disintegrins occurred uniformly over the whole surface of the molecule, while in the dimeric disintegrins, the charge is distributed only on one face. Such a feature may be important in the binding of two integrins to a single dimeric disintegrin. The phylogenetic analysis developed on the basis of amino acid sequence and three-dimensional structures indicates that the protein diversification and evolution presumably took place from the medium disintegrins and both the dimeric and short disintegrins evolved from them.