Echis Carinatus Sochureki Research Articles

Immunoreactivity and neutralization efficacy of Pakistani Viper Antivenom (PVAV) against venoms of Saw-scaled Vipers (Echis carinatus subspp.) and Western Russell's Vipers (Daboia russelii) from the Indian subcontinent

Snakebite envenoming (SBE) is a priority Neglected Tropical Disease listed by the World Health Organization. South Asia is heavily affected, and virtually all countries in the region import polyvalent antivenom products from India for clinical use. The imported antivenoms, however, have suboptimal effectiveness due to geographical venom variation. Recently, a domestic bivalent product, named Pakistani Viper Antivenom (PVAV) has been developed specifically for Pakistani vipers, Echis carinatus sochureki and Daboia russelii. As a bivalent viperid antivenom, it is unknown yet if PVAV exhibits higher immunological binding and neutralization activities against viper venoms from distant locales compared with polyvalent antivenoms manufactured in India. This study thus examined the preclinical efficacy of PVAV against venoms of Western Russell's Vipers and Saw-scaled Viper subspecies from selected locales in the Indian subcontinent. PVAV generally outperformed the commonly used VINS polyvalent antivenom (VPAV, manufactured in India) in binding toward venoms, and showed superior or comparable neutralization efficacy against the venom procoagulant and hemorrhagic effects of Saw-scaled Vipers as well as Russell's Vipers from Pakistan and Sri Lanka. Based on normalized potency values, PVAV is far more potent than VPAV in neutralizing the lethality of all viper venoms, except that of the Indian Russell's Viper. The study shows conserved antigenicity of toxins responsible for major toxicity across these viperid venoms, and suggests the feasible production of a viper-specific antivenom with higher potency and broader geographical utility for the region.

Analysis and Identification of Putative Novel Peptides Purified from Iranian Endemic Echis Carinatus Sochureki Snake Venom by MALDI-TOF Mass Spectrometry.

The Iranian Echis Carinatus (IEC) venom is an exclusive natural source of bio-substances for a wide range of purposes in the blood coagulation cascade. The present study for the first time was aimed to assess novel pro-coagulant, anti-coagulant and anti-platelet proteins, named EC1.5 (a), EC5.1 (b) and EC4 (a) from Iranian Echis Carinatus (IEC) venom. These peptides were purified by multi-step chromatography methods. Hematological properties were measured using activated clotting tests, platelet aggregation studies, and hemorrhage assessment. Subsequently, these proteins were identified through both their intact molecular mass and peptide mass fingerprint (PMF) using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Multiple sequence alignments were performed by ClustalW, Bioedit software. Molegro Data Modeller (MDM) 3.0 software was used to predict the putative tertiary structure of proteins.EC1.5 (a), a single-band protein with a molecular mass of 66 and 55 kDa, was observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis as a reduced and non-reduced state, respectively. Based on the Mascot results, we considered that EC1.5 (a) is a metalloproteinase of group ΙΙ which exhibited potent pro-coagulant activity. It is predicted that the EC1.5 (a) with hemorrhagic activity, potentially is a metalloproteinase/disintegrin region that constitutes the disintegrin-like domains. Our findings demonstrate that the disintegrin domain of EC1.5 (a) lacks platelet aggregation inhibitory activity. On the contrary, this factor shows the property of a platelet aggregation inducer. Also, the EC5.1 (b) was observed as a single-band protein with a molecular mass of 7.5 kDa. EC5.1 (b) showed both anti-coagulant and anti-platelet properties. Additionally, the structure of the EC5.1 (b) fraction is expected to be similar to that of phospholipase A2, while EC4 (a) structure is potentially very similar to that of Echistatin with 5 kDa molecular mass. We introduce the predicted structure of P-II snake venom metalloproteinase/ disintegrin domains, phospholipase A2 and Echistatin-like fractions. Further research is therefore needed to determine the complete structure of these novel fractions and elucidate their mechanism of action and future therapeutic applications of cardiovascular and homeostasis disorders.

Analysis and Identification of Putative Novel Peptides Purified from Iranian Endemic Echis Carinatus Sochureki Snake Venom by MALDI-TOF Mass Spectrometry

The Iranian Echis Carinatus (IEC) venom is an exclusive natural source of bio-substances for a wide range of purposes in the blood coagulation cascade. The present study for the first time was aimed to assess novel pro-coagulant, anti-coagulant and anti-platelet proteins, named EC1.5 (a), EC5.1 (b) and EC4 (a) from Iranian Echis Carinatus (IEC) venom.These peptides were purified by multi-step chromatography methods. Hematological properties were measured using activated clotting tests, platelet aggregation studies, and hemorrhage assessment. Subsequently, these proteins were identified through both their intact molecular mass and peptide mass fingerprint (PMF) using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Multiple sequence alignments were performed by ClustalW, Bioedit software. Molegro Data Modeller (MDM) 3.0 software was used to predict the putative tertiary structure of proteins.EC1.5 (a), a single-band protein with a molecular mass of 66 and 55 kDa, was observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis as a reduced and non-reduced state, respectively. Based on the Mascot results, we considered that EC1.5 (a) is a metalloproteinase of group ΙΙ which exhibited potent pro-coagulant activity. It is predicted that the EC1.5 (a) with hemorrhagic activity, potentially is a metalloproteinase/disintegrin region that constitutes the disintegrin-like domains. Our findings demonstrate that the disintegrin domain of EC1.5 (a) lacks platelet aggregation inhibitory activity. On the contrary, this factor shows the property of a platelet aggregation inducer. Also, the EC5.1 (b) was observed as a single-band protein with a molecular mass of 7.5 kDa. EC5.1 (b) showed both anti-coagulant and anti-platelet properties. Additionally, the structure of the EC5.1 (b) fraction is expected to be similar to that of phospholipase A2, while EC4 (a) structure is potentially very similar to that of Echistatin with 5 kDa molecular mass. We introduce the predicted structure of P-II snake venom metalloproteinase/ disintegrin domains, phospholipase A2 and Echistatin-like fractions. Further research is therefore needed to determine the complete structure of these novel fractions and elucidate their mechanism of action and future therapeutic applications of cardiovascular and homeostasis disorders.

Proteomic Analysis, Immuno-Specificity and Neutralization Efficacy of Pakistani Viper Antivenom (PVAV), a Bivalent Anti-Viperid Antivenom Produced in Pakistan.

Snakebite envenoming is a neglected tropical disease prevalent in South Asia. In Pakistan, antivenoms are commonly imported from India despite the controversy over their effectiveness. To solve the problem, the locals have developed the Pakistani Viper Antivenom (PVAV), raised against Sochurek's Saw-scaled Viper (Echis carinatus sochureki) and Russell's Viper (Daboia russelii) of Pakistani origin. This study is set to evaluate the composition purity, immuno-specificity and neutralization efficacy of PVAV. Chromatographic and electrophoretic profiling coupled with proteomic mass spectrometry analysis showed PVAV containing high-purity immunoglobulin G with minimum impurities, notably the absence of serum albumin. PVAV is highly immuno-specific toward the venoms of the two vipers and Echis carinatus multisquamatus, which are indigenous to Pakistan. Its immunoreactivity, however, reduces toward the venoms of other Echis carinatus subspecies and D. russelii from South India as well as Sri Lanka. Meanwhile, its non-specific binding activities for the venoms of Hump-nosed Pit Vipers, Indian Cobras and kraits were extremely low. In the neutralization study, PVAV effectively mitigated the hemotoxic and lethal effects of the Pakistani viper venoms, tested in vitro and in vivo. Together, the findings suggest the potential utility of PVAV as a new domestic antivenom for the treatment of viperid envenoming in Pakistan.

Venom-induced consumptive coagulopathy leading to thrombotic microangiopathy following Echis carinatus sochureki bite: is snake antivenom effective?

The incidence of thrombotic microangiopathy (TMA) following snake bite is reported to be ranging from 3.6 to 15%. We report a 10-year-old boy who developed TMA and due to venom-induced consumptive coagulopathy (VICC) despite receiving adequate and timely doses of snake antivenom following a bite of saw-scaled viper (Echis carinatus sochureki). VICC was managed by plasmapheresis. Though snake bite envenomation-associated renal complications are not uncommon, possibility of TMA should be considered early during management. Our patient developed TMA with subsequent acute cortical necrosis after saw-scaled viper bite despite an adequate and timely dose of snake antivenom which emphasizes the ineffectiveness of antivenom against the venom of given snake species leading to long-term complications.

Correction to: A case report of a patient with visual hallucinations following snakebite

The original version of this article unfortunately contained mistakes. This is a correction to "J Surg Trauma. 2018;6(2):73-76." In the originally published version of this paper, there was an error in the abstract and main content. In this report, the offending snake was mistakenly mentioned an adder snake (3rd sentence in the "Abstract" and 1st paragraph in the "Case" part). However, the offending snake was actually a Saw scaled viper (Echis carinatus sochureki). The authors express their apologies for this error, and state that this correction does not affect the findings and does not change the scientific conclusions of the article in any way.

Ophiotaenia echidis n. sp. (Cestoda: Proteocephalidae) from the saw-scaled viper, Echis carinatus sochureki Stemmler (Ophidia: Viperidae), one of the world's deadliest snakes, from the United Arab Emirates.

Ophiotaenia echidis n. sp. (Cestoda: Proteocephalidae) is described from the intestine of one of the world's deadliest snakes, the saw-scaled viper Echis carinatus sochureki Stemmler (Ophidia: Viperidae) in the United Arab Emirates. The new species differs from other species of the non-monophyletic Ophiotaenia by the position of testes in two longitudinal lines on both sides of the uterus, and by the large size of an embryophore (diameter of 44–55 μm versus less than 40 μm in other species). Phylogenetic reconstructions based on lsrDNA and concatenated lsrDNA + COI datasets place the new species among proteocephalids from unrelated zoogeographical realms but mostly infecting venomous snakes. In all analyses, O. echidis n. sp. exhibited a strongly supported sister relationship with O. lapata Rambeloson, Ranaivoson et de Chambrier, 2012, a parasite of a pseudoxyrhophiid snake endemic to Madagascar. Despite a shared close evolutionary history between these taxa, morphological synapomorphies remain unclear, which impedes the erection of a new genus to accommodate them. A list of the 71 tapeworms of the former, non-monophyletic subfamily Proteocephalinae, parasitising snakes and lizards, including species inquirendae, and the phylogenetically closely related Thaumasioscolex didelphidis from opossum, with selected characteristics, is also provided, together with a checklist of helminth parasites reported from E. carinatus.

Venom Gland Mass Spectrometry Imaging of Saw-Scaled Viper, Echis carinatus sochureki, at High Lateral Resolution.

The snake venom gland is the place for the synthesis, storage, and secretion of a complex mixture of proteins and peptides, i.e., the venom. The morphology of the gland has been revealed by classical histology and microscopic studies. However, knowledge about the gland's cellular secretory and functional processes is still incomplete and has so far been neglected by the omics disciplines. We used autofocusing atmospheric-pressure matrix-assisted laser desorption/ionization (AP-SMALDI) mass spectrometry imaging (MSI) to investigate endogenous biomolecular distributions in the venom glands of the saw-scaled viper, Echis carinatus sochureki, employing different sample preparation methods. Fresh-freezing and formalin-fixation were tested for the gland to obtain intact tissue sections. Subsequently, MSI was conducted with 12 μm pixel resolution for both types of preparations, and the lateral distributions of the metabolites were identified. Experiments revealed that lipids belonging to the classes of PC, SM, PE, PS, PA, and TG are present in the venom gland. PC (32:0) and SM (36:1) were found to be specifically located in the areas where cells are present. The snake venom metalloprotease inhibitor pEKW (m/z 444.2233) was identified in the venom by top-down LC-MS/MS and localized by MALDI-MSI in the gland across secretory epithelial cells. The peptide can inhibit the venom's enzymatic activity during long-term storage within the venom gland. With a high degree of spectral similarities, we concluded that formalin-fixed tissue, in addition to its high ability to preserve tissue morphology, can be considered as an alternative method to fresh-frozen tissue in the case of lipid and peptide MS imaging in venom gland tissues.

Integrating Top-Down and Bottom-Up Mass Spectrometric Strategies for Proteomic Profiling of Iranian Saw-Scaled Viper, Echis carinatus sochureki, Venom.

Saw-scaled or carpet vipers (genus Echis) are considered to cause a higher global snakebite mortality than any other snake. Echis carinatus sochureki (ECS) is a widely distributed snake species, also found across the thirteen provinces of Iran, where it is assumed to be responsible for the most snakebite envenomings. Here, we collected the Iranian specimens of ECS from three different geographically distinct populations, investigated food habits, and performed toxicity assessment and venom proteome profiling to better understand saw-scaled viper life. Our results show that the prey items most commonly found in all populations were arthropods, with scorpions from the family Buthidae particularly well represented. LD50 (median lethal dose) values of the crude venom demonstrate highly comparable venom toxicities in mammals. Consistent with this finding, venom characterization via top-down and bottom-up proteomics, applied to both crude venoms and size-exclusion chromatographic fractions, revealed highly comparable venom compositions among the different populations. By combining all proteomics data, we identified 22 protein families from 102 liquid chromatography and tandem mass spectrometry (LC-MS/MS) raw files, including the most abundant snake venom metalloproteinases (SVMPs, 29-34%); phospholipase A2 (PLA2s, 26-31%); snake venom serine proteinases (SVSPs, 11-12%); l-amino acid oxidases (LAOs, 8-11%), C-type lectins/lectin-like (CTLs, 7-9%) protein families, and many newly detected ones, e.g., renin-like aspartic proteases (RLAPs), fibroblast growth factors (FGFs), peptidyl-prolyl cis-trans isomerases (PPIs), and venom vasodilator peptides (VVPs). Furthermore, we identified and characterized methylated, acetylated, and oxidized proteoforms relating to the PLA2 and disintegrin toxin families and the site of their modifications. It thus seems that post-translational modifications (PTMs) of toxins, particularly target lysine residues, may play an essential role in the structural and functional properties of venom proteins and might be able to influence the therapeutic response of antivenoms, to be investigated in future studies.

First Case Report of an Unusual Echis genus (Squamata: Ophidia: Viperidae) Body Pattern Design in Iran.

Three families of venomous snakes exist in Iran including Viperidae, Elapidae, and Hydrophidae. Viperidae family is the only family with a widespread distribution. Saw-scaled vipers are important poisonous snakes in Asia and Africa. This name is given to this snake due to the presence of obliquely keeled and serrated lateral body scales. Distribution of this genera is mostly reported in the central and southern regions of Iran. This genus has four main clades: the Echis carinatus, E. coloratus, E. ocellatus, and E. pyramidum. Design pattern in Echis species plays an important role in camouflage and variety of habitat. In the present report, we investigated a specimen from the eastern region of Iran; we examined 25 specimens of Echis that were collected from the eastern region of our country. Among them, only one specimen with a different pattern was found compared with the other 24 specimens by surveying meristic, mensural, and design pattern characters using valid key identifiers. The similarities between the specific Echis with a different pattern and other 24 specimens were also studied and compared. The results of this investigation clearly showed that although the pattern of the lateral white line and block on dorsal body of the specific Echis snake was different, since the meristic and mensural characters were similar to other Echis snakes it can be concluded that this specimen is not a different species; the difference in these patterns may be due to a minor genetic mutation of that specimen. It is the first case report of Echis carinatus sochureki Stemmler, 1969 from Iran with a different pattern.

Analysis of effectiveness of Iranian snake antivenom on Viper venom induced effects including analysis of immunologic biomarkers in the Echis carinatus sochureki envenomed victims

Snakebite is an important toxicologic emergency with the potential of triggering local and systemic inflammation. Antivenom has remained the mainstay of treatment for snakebite envenomation. In this study we sought to investigate the effectiveness of Iranian antivenom in a series of 44 viper envenomed patients through analysis of changes in clinical severity and the levels of inflammatory markers. Clinical envenomation severity assessed by snakebite severity score (SSS) and laboratory exams of the patients were recorded before (baseline visit) and after antivenom therapy. During 12-h antivenom therapy, the median (range) score of SSS significantly decreased from 3.5 (2–10) on admission to 1 (0–5) in the last visit (P < 0.001). Moreover, a significant decrease in prothrombin time and international normalized ratio was found (P = 0.006 and 0.008; respectively). Plasma concentrations of interleukin (IL) 1-β, IL-6, IL-8, tumor necrosis factor α (TNF-α), complement hemolytic activity (CH50) were also measured in 10 severely Echis carinatus sochureki envenomed victims and 10 age and gender-matched healthy controls. Except IL-8, the baseline levels of IL-1β, IL-6 and TNF-α in victims were significantly higher than healthy controls (P = 0.005, <0.001 and < 0.001, respectively). Moreover, the baseline level of CH50 was significantly lower in the patients compared to healthy controls (P < 0.001). After 12-h antivenom therapy, the plasma levels of IL-1β, IL-6 and TNF-α significantly decreased (P = 0.032, 0.006 and 0.003, respectively), the levels of IL-8 remained relatively unchanged and the CH50 significantly increased (P = 0.011). Iranian snake antivenom was effective in treating viper bite envenomation as it reversed clinical venom effects and restored near normal underlying inflammatory status. This study is the first to ascertain and report the effectiveness of this antivenom in human subjects.

Epidemiologic prediction of snake bites in tropical south Iran: Using seasonal time series methods

BackgroundSnakebite envenomation is a vital status necessitating immediate treatment following case detection. Many cases of snakebites are recorded every year due to the suitable climatic conditions for the existence and survival of snakes in south Iran. MethodsIn the present retrospective cross-sectional study, 195 snake (Reptilia: Squamata: Viperidae; Echis carinatus sochureki) bite cases referred to 10 rural health centers, two health care stations and the Haji-Abad Central Hospital of Hormozgan University of Medical Sciences (HUMS) were surveyed during 2012–2016. Seasonal time series models were applied to fit a linear model to describe and predict the monthly trend of snakebite cases. ResultsAmong these patients, males (70%, 136) from rural areas (79.5%, 155) were mostly recorded. The mean (±SD) age of victims was 33 (±17.0) years old and the most common age group was 20–29years (32%). Most snakebites took place outdoors (80%), on hands and legs (97%), and among unemployed people and farmers (61.0%). Snakebites often happened between midnight and 6 am (32%); also 51% of them occurred during summer. Most (70%) patients had pain at the bite sites. The location of being bitten (indoors or outdoors) had a significant difference with patient’s sex (χ2=7.764, P=0.021). ConclusionsTime series analysis proposed a mixed seasonal autoregressive moving average, ARMA (1,0)×(1,1)12 as the best process for the monthly trend of snakebite and to predict the incidence of snakebites. Local residents should be more cautious on snakebites during warm seasons.

Phase II Clinical Trial to Establish Efficacy of a Locally Appropriate Bivalent Anti Snake Venom in Pakistan

Objective: This study was conducted to determine the efficacy of Snake anti-venom Immunoglobulin [IgG] manufactured by Anti-Snake Venom [ASV]/Anti-Rabies [ARV] Serology Laboratory, Health Department, Government of Sindh. Methods: The prospective, observational single arm study was conducted after the approval of IRB. Study included six patients with viper [Echis carinatus sochureki] snakebites referred to the emergency ward of Peoples University of Medical &amp; Health Sciences Hospital, Nawabshah and District Headquarter Hospital Mithi, Sindh, Pakistan with consultation of Clinical and Principal investigator. The study was conducted over a period of three months [August 2015 to November 2015]. All patients were given IV infusion of 10 mL [1 vial] investigational ASV diluted in 100 mL normal saline except one patient who received 5 mL management dose and 5 mL subsequent dose for the recovery of coagulopathy. The efficacy was assessed by Primary and secondary efficacy endpoints, i.e. the dose at which maximum no of patients were treated [permanent restoration of normal blood coagulation tested by 20-minute whole blood clotting test [20-minute WBCT] with minimum toxicity. Results: All patients recovered from coagulopathy after receiving IV infusion of 10 mL investigational ASV diluted in 100 mL normal saline tested by 20-minute WBCT. Mean Recovery time was 9:15 ± 3:25 hours. Conclusion: Safety and efficacy was assessed for the Bivalent Anti venom Immunoglobulin-NQ1 [IgG] manufactured by ASV/ARV Serology Laboratory, Health Department, Government of Sindh.

Production and preclinical assessment of camelid immunoglobulins against Echis sochureki venom from desert of Rajasthan, India

Snakebite is a significant cause of death and disability in subsistent farming populations of rural India. Antivenom is the most effective treatment of envenoming and is manufactured from IgG of venom-immunised horses. Because of complex fiscal reasons, the production, testing and delivery of antivenoms designed to treat envenoming by the most medically-important snakes in the region has been questioned time to time. In this study, we report successful immunisation of dromedaries (Camelus dromedarius) against the venom of Indian saw-scaled Viper- Echis carinatus sochureki. This study assessed the specificity and potential of camels immunised with venom of medically most important snake of Western India, the saw-scaled viper (Echis c. sochureki). Using WHO standard pre-clinical in vivo tests the neutralisation of the venom responsible for the lethal, haemorrhagic, coagulant and local necrotizing activities were measured, since these are the most significant effects that characterize envenoming by this species. The anti-venom was found significantly effective in the neutralisation of all these effects tested and thus, revealed further an immunological perspective, that camel IgG anti-venom (monospecific) would be as efficacious as specific equine anti-venoms or even of better choice in treating snake specific envenoming.

Anti-angiogenic activities of snake venom CRISP isolated from Echis carinatus sochureki

BackgroundCysteine-rich secretory protein (CRISP) is present in majority of vertebrate including human. The physiological role of this protein is not characterized. We report that a CRISP isolated from Echis carinatus sochureki venom (ES-CRISP) inhibits angiogenesis. MethodsThe anti-angiogenic activity of purified ES-CRISP from snake venom was investigated in vitro using endothelial cells assays such as proliferation, migration and tube formation in Matrigel, as well as in vivo in quail embryonic CAM system. The modulatory effect of ES-CRISP on the expression of major angiogenesis factors and activation of angiogenesis pathways was tested by qRT-PCR and Western blot. ResultsThe amino acid sequence of ES-CRISP was found highly similar to other members of this snake venom protein family, and shares over 50% identity with human CRISP-3. ES-CRISP supported adhesion to endothelial cells, although it was also internalized into the cytoplasm in a granule-like manner. It blocked EC proliferation, migration and tube formation in Matrigel. In the embryonic quail CAM system, ES-CRISP abolished neovascularization process induced by exogenous growth factors (bFGF, vpVEGF) and by developing gliomas. CRISP modulates the expression of several factors at the mRNA level, which were characterized as regulators of angiogenesis and blocked activation of MAPK Erk1/2 induced by VEGF. ConclusionsES-CRISP was characterized as a negative regulator of the angiogenesis, by direct interaction with endothelial cells. General significanceThe presented work may lead to the development of novel angiostatic therapy, as well as contribute to the identification of the physiological relevance of this functionally uncharacterized protein.

Cytotoxic activities of [Ser49]phospholipase A2 from the venom of the saw-scaled vipers Echis ocellatus, Echis pyramidum leakeyi, Echis carinatus sochureki, and Echis coloratus

Fractionation by reversed-phase HPLC of venom from four species of saw-scaled viper: Echis ocellatus, Echis pyramidum leakeyi, Echis carinatus sochureki, and Echis coloratus led to identification in each sample of an abundant protein with cytotoxic activity against human non-small cell lung adenocarcinoma A549 cells. The active component in each case was identified by MALDI-TOF mass fingerprinting of tryptic digests as [Ser49]phospholipase A2 ([Ser49]PLA2). An isoform of [Ser49]PLA2 containing the single Ala18 → Val substitution and a partially characterized [Asp49]PLA2 were also present in the E. coloratus venom. LC50 values against A549 cells for the purified [Ser49]PLA2 proteins from the four species are in the range 2.9–8.5 μM. This range is not significantly different from the range of LC50 values against human umbilical vein endothelial HUVEC cells (2.5–12.2 μM) indicating that the [Ser49]PLA2 proteins show no differential anti-tumor activity. The LC50 value for [Ser49]PLA2 from E. ocellatus against human erythrocytes is >100 μM and the MIC values against Escherichia coli and Staphylococcus aureus are >100 μM. It is suggested that the [Ser49]PLA2 proteins play a major role in producing local tissue necrosis and hemorrhage at the site of envenomation.

The snake fauna of Khabr National Park, southeast of Iran

Khabr National Park and Ruchun Wildlife Refuge are situated in the southeast of Iran, Kerman Province. Although snakes are an important group in the studied area, little is known regarding their diversity. The present study was carried out from March 2009 to late summer 2010. In this study, 74 specimens were collected (or observed) and identified, belonging to four families, 14 genera, and 17 species, including Typhlopidae: Typhlops vermicularis; Colubridae: Boiga trigonatum melanocephala, Hemorrhois ravergieri, Lytorhynchus diadema gaddi, Lytorhynchus ridgewayi, Platyceps rhodorachis ladacensis, Platyceps ventromaculatus ventromaculatus, Psammophis schokari, Pseudocyclophis persicus, Spalerosophis diadema cliffordii, Spalerosophis microlepis, Telescopus rhinopoma, Eirenis punctatolineatus; Viperidae: Echis carinatus sochureki, Macrovipera lebetina cernovi, Pseudocerastes persicus; Elapidae: Walterinnesia morgani. The records of Spalerosophis microlepis, Lytorhynchus diadema gaddi, Pseudocyclophis persicus and Walterinnesia morgani are reported for the first time from southeast of Iran.

Neutralization of Haemorrhagic Activity of Viper Venoms by 1-(3-Dimethylaminopropyl)-1-(4-Fluorophenyl)-3-Oxo-1,3-Dihydroisobenzofuran-5-Carbonitrile

Viper envenomation undeniably induces brutal local manifestations such as haemorrhage, oedema and necrosis involving massive degradation of extracellular matrix at the bitten region and many a times results in dangerous systemic haemorrhage including pulmonary shock. Snake venom metalloproteases (SVMPs) are being considered to be the primary culprits for the venom-induced haemorrhage. As a consequence, the venom researchers and medical practitioners are in deliberate quest of SVMP inhibitors. In this study, we evaluated the inhibitory effect of 1-(3-dimethylaminopropyl)-1-(4-fluorophenyl)-3-oxo-1,3-dihydroisobenzofuran-5-carbonitrile (DFD) on viper venom-induced haemorrhagic and PLA(2) activities. DFD effectively neutralized the haemorrhagic activity of the medically important viper venoms such as Echis carinatus, Echis ocelatus, Echis carinatus sochureki, Echis carinatus leakeyi and Crotalus atrox in a dose-dependent manner. The histological examinations revealed that the compound DFD effectively neutralizes the basement membrane degradation, and accumulation of inflammatory leucocytes at the site of Echis carinatus venom injection further confirms the inhibition of haemorrhagic activity. In addition, DFD dose dependently inhibited the PLA(2) activities of Crotalus atrox and E. c. leakeyi venoms. According to the docking studies, DFD binds to hydrophobic pocket of SVMP with the ki of 19.26 × 10(-9) (kcal/mol) without chelating Zn(2+) in the active site. It is concluded that the clinically approved inhibitors of haemorrhagins could be used as a potent first-aid agent in snakebite management. Furthermore, a high degree of structural and functional homology between SVMPs and their relatives, the MMPs, suggests that DFD analogues may find immense value in the regulation of multifactorial pathological conditions like inflammation, cancer and wound healing.

Structural Characterization of Myotoxic Ecarpholin S From Echis carinatus Venom

Phospholipase A 2 (PLA 2), a common toxic component of snake venom, has been implicated in various pharmacological effects. Ecarpholin S, isolated from the venom of the snake Echis carinatus sochureki, is a phospholipase A 2 (PLA 2) belonging to the Ser 49-PLA 2 subgroup. It has been characterized as having low enzymatic but potent myotoxic activities. The crystal structures of native ecarpholin S and its complexes with lauric acid, and its inhibitor suramin, were elucidated. This is the first report of the structure of a member of the Ser 49-PLA 2 subgroup. We also examined interactions of ecarpholin S with phosphatidylglycerol and lauric acid, using surface plasmon resonance, and of suramin with isothermal titration calorimetry. Most Ca 2+-dependent PLA 2 enzymes have Asp in position 49, which plays a crucial role in Ca 2+ binding. The three-dimensional structure of ecarpholin S reveals a unique conformation of the Ca 2+-binding loop that is not favorable for Ca 2+ coordination. Furthermore, the endogenously bound fatty acid (lauric acid) in the hydrophobic channel may also interrupt the catalytic cycle. These two observations may account for the low enzymatic activity of ecarpholin S, despite full retention of the catalytic machinery. These observations may also be applicable to other non-Asp 49-PLA 2 enzymes. The interaction of suramin in its complex with ecarpholin S is quite different from that reported for the Lys 49-PLA 2/suramin complex , where the interfacial recognition face (i-face), C-terminal region, and N-terminal region of ecarpholin S play important roles. This study provides significant structural and functional insights into the myotoxic activity of ecarpholin S and, in general, of non-Asp 49-PLA 2 enzymes.

Isolation and Partial Characterization of an Antiviral Proteolytic Fraction from the Venom of Echis Carinatus Sochureki

The venom of the viper Echis carinatus sochureki suppresses the hemolytic activity of Sendai virus on human erythrocytes, when pre-incubated with the virions prior to their binding to cells. A fraction (C1), with an IC50 of 1.25 􀀁g/ml, was isolated from the venom. Fraction C1 possesses strong azocollase, azocaseinase and gelatinase activity. The proteolytic and anti-hemolytic potency of C1 depends on the period and temperature of incubation. Its antiviral activity is inhibited by Sodium-EDTA but not by PMSF. SDS PAGE of Sendai virus incubated with fraction C1 shows disappearance of several of the virion high molecular weight bands. We suggest that inhibition of the hemolytic activity of the virions is probably a result of the cleavage of viral surface proteins, such as the hemagglutinin-neuraminidase glycoprotein found on the virion envelope that mediates the absorption of the virus to cells.