An agonist of CXCR4 induces a rapid recovery from the neurotoxic effects of Vipera ammodytes and Vipera aspis venoms.

People bitten by Alpine vipers are usually treated with antivenom antisera to prevent the noxious consequences caused by the injected venom. However, this treatment suffers from a number of drawbacks and additional therapies are necessary. The venoms of Vipera ammodytes and of Vipera aspis are neurotoxic and cause muscle paralysis by inducing neurodegeneration of motor axon terminals because they contain a presynaptic acting sPLA2 neurotoxin. We have recently found that any type of damage to motor axons is followed by the expression and activation of the intercellular signaling axis consisting of the CXCR4 receptor present on the membrane of the axon stump and of its ligand, the chemokine CXCL12 released by activated terminal Schwann cells. We show here that also V. ammodytes and V. aspis venoms cause the expression of the CXCL12-CXCR4 axis. We also show that a small molecule agonist of CXCR4, dubbed NUCC-390, induces a rapid regeneration of the motor axon terminal with functional recovery of the neuromuscular junction. These findings qualify NUCC-390 as a promising novel therapeutics capable of improving the recovery from the paralysis caused by the snakebite of the two neurotoxic Alpine vipers.

Pro-inflammatory cytokines gene expression in liver and kidneys of rats exposed to a sub-lethal dose of Bitis arietans snake venom.

Bitis arietans (Puff adder) is a poisonous snake and its bite causes pain, edema, blistering, tissue damage and neutrophilia. There are limited studies on inflammatory process involved in Bitis arietans envenomation. We therefore investigated the role of proinflammatory cytokines in Bitis arietans venom (BAV)-induced liver and kidney toxicities in rats. Adult male Sprague Dawley rats were treated with BAV (0.5 mg/kg) and were sacrificed after specific time intervals (2 h, 24 h, 1 week). Blood samples were collected for liver and renal function tests and tissues were collected for histopathology and gene expression analysis of IL-1ß, IL-6, and TNF-α in liver and kidneys. There was no significant difference in serum ALT activities among different treatment groups. Serum AST was significantly increased at 24 h following BAV injection. In both organs, injection of BAV resulted in mild inflammatory cell infiltration at 2 h post-dosing which normalized after 1 week. In liver, there was a significant increase in IL-1ß expression in BAV-treated rats at 2 and 24 h post-dosing that reduced after one week. Significant increases in IL-6 and TNF-α were observed at 24 h and 1 week after BAV exposure. In kidneys, there were significant increases in IL-1ß and TNF-α expression at 24 h that subsided after 1 week. In conclusion, a single sub-lethal dose of BAV caused an acute phase inflammation in liver and kidneys. It is most probable that a higher dose of BAV may result in greater and irreversible damage to these organs.

Unraveling the Reaction Mechanism of Russell's Viper Venom Factor X Activator: A Paradigm for the Reactivity of Zinc Metalloproteinases?

Snake venom metalloproteinases (SVMPs) are important drug targets against snakebite envenoming, the neglected tropical disease with the highest mortality worldwide. Here, we focus on Russell's viper (Daboia russelii), one of the "big four" snakes of the Indian subcontinent that, together, are responsible for ca. 50,000 fatalities annually. The "Russell's viper venom factor X activator" (RVV-X), a highly toxic metalloproteinase, activates the blood coagulation factor X (FX), leading to the prey's abnormal blood clotting and death. Given its tremendous public health impact, the WHO recognized an urgent need to develop efficient, heat-stable, and affordable-for-all small-molecule inhibitors, for which a deep understanding of the mechanisms of action of snake's principal toxins is fundamental. In this study, we determine the catalytic mechanism of RVV-X by using a density functional theory/molecular mechanics (DFT:MM) methodology to calculate its free energy profile. The results showed that the catalytic process takes place via two steps. The first step involves a nucleophilic attack by an in situ generated hydroxide ion on the substrate carbonyl, yielding an activation barrier of 17.7 kcal·mol-1, while the second step corresponds to protonation of the peptide nitrogen and peptide bond cleavage with an energy barrier of 23.1 kcal·mol-1. Our study shows a unique role played by Zn2+ in catalysis by lowering the pKa of the Zn2+-bound water molecule, enough to permit the swift formation of the hydroxide nucleophile through barrierless deprotonation by the formally much less basic Glu140. Without the Zn2+ cofactor, this step would be rate-limiting.

A beneficial role for immunoglobulin E in host defense against honeybee venom.

Allergies are widely considered to be misdirected type 2 immune responses, in which immunoglobulin E (IgE) antibodies are produced against any of a broad range of seemingly harmless antigens. However, components of insect venoms also can sensitize individuals to develop severe IgE-associated allergic reactions, including fatal anaphylaxis, upon subsequent venom exposure. We found that mice injected with amounts of honeybee venom similar to that which could be delivered in one or two stings developed a specific type 2 immune response that increased their resistance to subsequent challenge with potentially lethal amounts of the venom. Our data indicate that IgE antibodies and the high affinity IgE receptor, FcεRI, were essential for such acquired resistance to honeybee venom. The evidence that IgE-dependent immune responses against venom can enhance survival in mice supports the hypothesis that IgE, which also contributes to allergic disorders, has an important function in protection of the host against noxious substances.

Isolated Ptosis Following a Vipera aspis Bite.

In Spain, snakebites are uncommon medical emergencies that cause barely 100 hospitalizations annually. Most of the venomous bites are by snakes of the Viperidae family. Venom from Vipera snakes is reported to have cytotoxic and hematotoxic effects, and neurological effects have also been described. Ptosis (cranial nerve III palsy) is the most common sign, although any cranial nerve can be affected. We describe isolated ptosis, which was very likely after a Vipera aspis bite in the East Catalonian Pyrenees. No antivenom was administered. The ptosis resolved spontaneously within 10 h. Although neurologic findings are usually mild, they indicate a moderate or severe envenomation. Treating snakebites can be challenging for clinicians, especially when there are uncommon clinical manifestations. A toxicologist at a poison center should be consulted to help guide management. Development of local protocols may provide clinical support.

VENOMOUS SNAKEBITES IN CROATIA, CLINICAL PRESENTATION, DIAGNOSIS AND TREATMENT.

Venomous snake bites are recognized as a major public health problem, affecting mostly poor, underdeveloped areas in the tropical and subtropical areas. Every year, more than three million bite cases and about 100,000 deaths are registered worldwide. Over the past years, 632 people have been hospitalized in Croatia with only 3 deaths due to venomous snake bites. Favorable geographic position, warm climate and great biodiversity of Croatia have resulted in the development of a total of 15 species of snakes, of which only 3 are venomous: horned viper (Vipera ammodytes), the common European viper (Vipera berus) and meadow viper (Vipera ursinii macrops). Snake venom envenomation is called ophidism (greek ofis=snake). Snake venoms are complex mixtures of proteins and toxins that have a wide range of toxic effects. The clinical presentation of ophidism is due to hematotoxic, neurotoxic, myotoxic (cardiotoxic) and cytotoxic effects of venom. There is currently no test to identify patients with a systemic spread of the venom, the diagnosis is made by a combination of diagnostic tests, clinical symptoms and sings of systemic envenomation. Ophidism is a medical condition that requires urgent treatment. Following first aid given at the scene, the patient should be transported to the closest medical facility to assess the severity of the clinical presentation in a timely manner and take the necessary treatment measures.

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.

Viper venoms drive the macrophages and hepatocytes to sequester and clear platelets: novel mechanism and therapeutic strategy for venom-induced thrombocytopenia.

Venomous snakebites cause clinical manifestations that range from local to systemic and are considered a significant global health challenge. Persistent or refractory thrombocytopenia has been frequently reported in snakebite patients, especially in cases caused by viperidae snakes. Viper envenomation-induced thrombocytopenia may persist in the absence of significant consumption coagulopathy even after the antivenom treatment, yet the mechanism remains largely unknown. Our study aims to investigate the mechanism and discover novel therapeutic targets for coagulopathy-independent thrombocytopenia caused by viper envenomation. Here we found that patients bitten by Protobothrops mucrosquamatus and Trimeresurus stejnegeri, rather than Naja. atra may develop antivenom-resistant and coagulopathy-independent thrombocytopenia. Crude venoms and the derived C-type lectin-like proteins from these vipers significantly increased platelet surface expression of neuraminidase and platelet desialylation, therefore led to platelet ingestion by both macrophages and hepatocytes in vitro, and drastically decreased peripheral platelet counts in vivo. Our study is the first to demonstrate that desialylation-mediated platelet clearance is a novel mechanism of viper envenomation-induced refractory thrombocytopenia and C-type lectin-like proteins derived from the viper venoms contribute to snake venom-induced thrombocytopenia. The results of this study suggest the inhibition of platelet desialylation as a novel therapeutic strategy against viper venom-induced refractory thrombocytopenia.

A Genus-Wide Bioactivity Analysis of Daboia (Viperinae: Viperidae) Viper Venoms Reveals Widespread Variation in Haemotoxic Properties.

The snake genus Daboia (Viperidae: Viperinae; Oppel, 1811) contains five species: D. deserti, D. mauritanica, and D. palaestinae, found in Afro-Arabia, and the Russell's vipers D. russelii and D. siamensis, found in Asia. Russell's vipers are responsible for a major proportion of the medically important snakebites that occur in the regions they inhabit, and their venoms are notorious for their coagulopathic effects. While widely documented, the extent of venom variation within the Russell's vipers is poorly characterised, as is the venom activity of other species within the genus. In this study we investigated variation in the haemotoxic activity of Daboia using twelve venoms from all five species, including multiple variants of D. russelii, D. siamensis, and D. palaestinae. We tested the venoms on human plasma using thromboelastography, dose-response coagulometry analyses, and calibrated automated thrombography, and on human fibrinogen by thromboelastography and fibrinogen gels. We assessed activation of blood factors X and prothrombin by the venoms using fluorometry. Variation in venom activity was evident in all experiments. The Asian species D. russelii and D. siamensis and the African species D. mauritanica possessed procoagulant venom, while D. deserti and D. palaestinae were net-anticoagulant. Of the Russell's vipers, the venom of D. siamensis from Myanmar was most toxic and D. russelli of Sri Lanka the least. Activation of both factor X and prothrombin was evident by all venoms, though at differential levels. Fibrinogenolytic activity varied extensively throughout the genus and followed no phylogenetic trends. This venom variability underpins one of the many challenges facing treatment of Daboia snakebite envenoming. Comprehensive analyses of available antivenoms in neutralising these variable venom activities are therefore of utmost importance.

Venom-Induced Consumption Coagulopathy Unresponsive to Antivenom After Echis carinatus sochureki Envenoming.

Snakebite envenoming is a serious and life-threatening but neglected problem in the tropics. The focus in the Indian subcontinent is usually on the Indian cobra (Naja naja), common krait (Bungarus caeruleus), Russell's viper (Daboia russelii), and Indian saw-scaled viper (Echis carinatus). The Indian polyvalent antivenom contains hyperimmunized horse antibodies against only these 4 species. However, regional intraspecific variations are important in viper envenomings, leading to marked differences in clinical presentation and response to the available polyvalent antivenom. Echis carinatus sochureki, a subspecies of Echis carinatus, has been linked to serious morbidity in the Thar Desert regions of Rajasthan, although consistent reports are lacking. We report a patient with prolonged venom-induced consumption coagulopathy owing to Echis carinatus sochureki envenoming who did not respond to Indian polyvalent antivenom in Jodhpur, India. Features of local and hemotoxic envenoming resolved after a week with supportive care. Echis sochureki venom has been shown to be different from Echis carinatus in terms of composition and in vitro neutralization by antivenom. Clinicians in the tropical desert regions must suspect Echis sochureki envenoming in the setting of nonresponsiveness to Indian polyvalent antivenom. This will help optimize antivenom use in these patients, preventing potentially life-threatening antivenom associated reactions. Because the usefulness of Indian polyvalent antivenom appears to be limited in this setting, there is an urgent need to advocate for region-specific antivenom or monovalent antivenom for this area.

Comparative study of the in vivo toxicity and pathophysiology of envenomation by three medically important Egyptian snake venoms.

Snakebite envenomation is a serious medical problem in many developing tropical and subtropical countries. Envenomation is registered by the World Health Organization as a neglected tropical disease due to critical shortages in the production of antivenom. Envenomation causes more than 100,000 deaths annually. Snakebites result in several effects to include edema, blistering, hemorrhage, necrosis and respiratory paralysis. Antivenom is the preferred treatment for the systemic effects of snakebite envenomation, though these are often ineffective in neutralizing venom toxin-induced local tissue damage. To effectively treat snakebites, it is important to determine the lethal potency and pathophysiological effects induced by specific snake venoms. In the current study, we compared the lethality, and the hemorrhagic and dermonecrotic activities of venoms from three snakes in Egypt that are the primary causes of local tissue necrosis. Our data show that the intraperitoneal median lethal doses (LD50) for Cerastes cerastes, Echis carinatus and Naja nigricollis venoms are 0.946, 1.744 and 0.341 mg/kg mouse body weight, respectively. These results indicated that N. nigricollis venom is the most toxic and significantly accelerated the time of death compared to the other two venoms. However, no hematoma or associated edema appeared upon sub-plantar injection of N. nigricollis venom into the mice hind paw. Two hours following intradermal injection of C. cerastes and E. carinatus venoms, macroscopic analysis of the inner surface of mouse skin showed severe hemorrhagic lesions, whereas only insignificant hemorrhagic lesion appeared in mice injected with the highest dose of N. nigricollis venom. Furthermore, the minimum necrotic doses (MND) for the same venoms were 43.15, and 70.87 µg/mouse, or not observed in the case of N. nigricollis venom, respectively. These LD50 values and pathophysiological results can be used to guide development of antivenom against bites by these dangerous Egyptian snakes.

Lys49 myotoxin from the Brazilian lancehead pit viper elicits pain through regulated ATP release.

Pain-producing animal venoms contain evolutionarily honed toxins that can be exploited to study and manipulate somatosensory and nociceptive signaling pathways. From a functional screen, we have identified a secreted phospholipase A2 (sPLA2)-like protein, BomoTx, from the Brazilian lancehead pit viper (Bothrops moojeni). BomoTx is closely related to a group of Lys49 myotoxins that have been shown to promote ATP release from myotubes through an unknown mechanism. Here we show that BomoTx excites a cohort of sensory neurons via ATP release and consequent activation of P2X2 and/or P2X3 purinergic receptors. We provide pharmacological and electrophysiological evidence to support pannexin hemichannels as downstream mediators of toxin-evoked ATP release. At the behavioral level, BomoTx elicits nonneurogenic inflammatory pain, thermal hyperalgesia, and mechanical allodynia, of which the latter is completely dependent on purinergic signaling. Thus, we reveal a role of regulated endogenous nucleotide release in nociception and provide a detailed mechanism of a pain-inducing Lys49 myotoxin from Bothrops species, which are responsible for the majority of snake-related deaths and injuries in Latin America.

Delayed hypopituitarism following Russell's viper envenomation: a case series and literature review.

PURPOSE: Hypopituitarism (HP) is an uncommon consequence of Russell's viper envenomation (RVE). Delayed hypopituitarism (DHP) presents months to years after recovering from snake bites (SB). The clinical presentation, manifestations, and outcomes of DHP following RVE have not been systematically studied. Here, we present a case series of HP following RVE with delayed diagnosis and conduct a literature review. METHODS: We retrospectively reviewed data of eight DHP cases and literature to outline the presentation, manifestations, hormonal profiles, and radiological features of DHP following RVE. RESULTS: Three men and five women, with a mean age at diagnosis of 39.5 ± 11.6 years, were included. The mean duration between snake bite (SB) and HP diagnosis was 8.1 ± 3.6 years. Secondary hypothyroidism and hypogonadotropic hypogonadism were present in all patients. Growth hormone deficiency (GHD) and secondary hypocortisolism were present in 6 (75%) patients. Magnetic resonance imaging (MRI) revealed empty sella and partially empty sella in three patients each (75%). The literature review revealed additional 20 DHP cases (mean age at diagnosis 32.4 ± 10.8 years), with 65% of patients being men. Fatigue, reduced libido, and loss of weight were the commonest symptoms among men. Secondary amenorrhea, fatigue, and loss of appetite were common manifestations among women. Acute kidney injury, GHD, secondary hypothyroidism, hypogonadism, and adrenal insufficiency were reported in 75%, 79%, 95%, 100%, and 85% of patients, respectively. CONCLUSIONS: DHP is an important complication of RVE, and a delay in its diagnosis is associated with significant morbidity. Patients with RVE should be followed up for a long term to identify DHP.

Retrospective Documentation of a Confirmed White-Lipped Green Pit Viper (Trimeresurus albolabris Gray, 1842) Bite in the South-Central Hills of Nepal.

This case report documents envenomation by an arboreal white-lipped green pit viper (Trimeresurus albolabris), a species found in South and Southeast Asia that causes the majority of venomous snakebites among Southeast Asian pit vipers. Clinical features vary from asymptomatic to serious coagulopathy that may progress into life-threatening or fatal hemorrhage. The proven life-threatening cases described in published literature, however, are sparse. Practically, no specific antivenom targeted to pit viper bites is available in Nepal. We report a case (managed with several non-evidence-based interventions) of noticeable coagulopathic envenomation due to confirmed T albolabris bite in Nepal. This is the first known reported case of such a bite in Nepal. This case highlights the urgent need to improve diagnosis, monitoring, and supportive care for bite victims and to study the effectiveness of Thai pit viper antivenoms for the treatment of T albolabris envenomations.

Severe Systemic Envenomation Following Vipera berus Bite Managed with ViperaTAb Antivenom.

Bites by the European adder (Vipera berus) are a rare medical emergency in the UK with 20 to 50% of an estimated 50 to 200 cases per year necessitating treatment with antivenom. We present a case demonstrating both severe systemic and local effects necessitating out of hospital resuscitation, vasopressor support, and prolonged rehabilitation. Hemodynamic stability was restored promptly after administration of ViperaTAb antivenom, the first published case of its use in the UK.

Thrombotic Microangiopathy, Hemolytic Uremic Syndrome, and Thrombotic Thrombocytopenic Purpura Following Hump-nosed Pit Viper (Genus: Hypnale) Envenoming in Sri Lanka.

Thrombotic microangiopathy (TMA), which includes the spectrum of hemolytic uremic syndrome and thrombotic thrombocytopenic purpura, is an uncommon complication of hump-nosed pit viper envenomation. We describe 4 cases of TMA following hump-nosed pit viper (Hypnale spp) bites in Sri Lanka. The first case is a typical TMA that spontaneously resolved with supportive treatments. The second and third cases are related to hemolytic uremic syndrome complicated with acute kidney injury that required hemodialysis. The fourth case is thrombotic thrombocytopenic purpura associated with acute kidney injury that required hemodialysis and therapeutic plasma exchange. For each patient we describe the circumstances of the bite, clinical features, laboratory findings, and management.

Evaluation of different Pakistani medicinal plants for inhibitory potential against Echis carinatus induced Phospholipase A2 toxicity.

Medicinal plants of Pakistan are known for their curative properties against snake bite as rural people have been using natural herbs for such injuries for hundreds to thousands of years. People of rural areas of Pakistan are prone to snakebite, and on the whole death due to snakebite has been increasing worldwide. The objective of this study was to test the neutralizing potential of 17 Pakistani medicinal plant extracts against phospholipase A2 activity in Echis carinatus venom. Plant material was extracted by simple maceration and fractionation of active plant extracts. Venom was collected by manual massage of the venom glands. The PLA2 enzymatic assay was performed to map out the venomous activity of Echis carinatus envenomation. Snake venom released fatty acids at different concentrations (0.1-5 mg/ml) of venom in a dose-dependent manner. Reduction of pH by 01 correlated with 133 µmol of fatty acids released at 5mg/ml of venom. All plants extract inhibited PLA2 activity, however, Curcuma longa, Citrullus colocynthis and Rubia cordifolia inhibited maximum of PLA2 activity (⁓78%) comparable to the standard antidote (p>0.5). Medicinal plants possess secondary metabolites and many active compounds that may have neutralizing or inhibiting properties against the PLA2 activity of Echis venom. Further studies such as compound analysis could provide an alternative against snakebites injuries resulting from Echis carinatus venom.

Proteomic Analysis and Immuno-Profiling of Eastern India Russell's Viper ( Daboia russelii) Venom: Correlation between RVV Composition and Clinical Manifestations Post RV Bite.

The proteomes of Russell's viper venom (RVV) from Burdwan (RVV B) and Nadia (RVV N), the two districts of West Bengal, eastern India (EI), were investigated by gel-filtration chromatography (GFC) followed by tandem mass spectrometry of tryptic fragments of the fractions. A total of 73 and 69 proteins belonging to 15 snake venom protein families were identified in RVV B and RVV N, respectively, by MS/MS search against Viperidae (taxid 8689) protein entries of the nonredundant NCBI database. The minor differences in venom composition of both the EI RV were established unequivocally by their biochemical and pharmacological properties and by SDS-PAGE, gel filtration chromatography, and LC-MS/MS analyses. The composition of EI RVVs was well correlated with published reports on the pathophysiology of RV-envenomed patients from this part of the country. Venom-antivenom cross-reactivity determined by ELISA, Western blotting, and antivenomics approaches demonstrated poor recognition of low molecular mass (<20 kDa) RVV proteins by commercial polyvalent antivenoms, which was substantiated by neutralization of RVV enzymes by antivenom.

Inhibition of Echis carinatus venom by DNA, a promising therapeutic molecule for snakebite management.

BACKGROUND: E. carinatus bite is a serious threat to South-Asian countries including India, as it causes the highest number of deaths and debilitating sustained tissue necrosis at the bite site. One of our previous studies has demonstrated the strong interaction between DNA and E. carinatus venom. Therefore, in this study, the effect of DNA on E. carinatus venom has been examined. METHODS: Here we show that calf thymus DNA interact strongly with E. carinatus venom and inhibits its enzymatic and pharmacological activities such as proteolytic, hemolytic, hyaluronidase, L-amino acid oxidase, NETosis, hemorrhage, pro-coagulant, and lethality. Further, using immunoblots and immunofluorescence, the study demonstrates the inhibition of proteolytic cleavage of several surface receptors on PMNs, PBMCs, and platelets by the DNA. CONCLUSIONS: This study for the first time explored the efficient inhibition of enzymatic, pharmacological and lethal properties of E. carinatus venom by the naked DNA and demonstrates the possible therapeutic application of it during snakebite management. GENERAL SIGNIFICANCE: This study identifies naked DNA as an effective defense weapon that has got the therapeutic potential to inhibit the detrimental effects of E. carinatus bite.

Inhibitory effects of ascorbic acid toward snake venom metalloproteinase (SVMP) from Indian Echis carinatus venom: Insights from molecular modeling and binding studies.

Classical antivenom therapy is unable to shield complications of viper bite and has limitations such as anaphylaxis and serum sickness. Snake venom metalloproteinases are responsible for local tissue damage and hemorrhage at the bitten site in viper envenomation, and this has led to a persistent search for metalloproteinase inhibitors. Here, we report the inhibitory effects of ascorbic acid against metalloproteinase from Echis carinatus venom both in-silico and in-vitro. Ascorbic acid effectively inhibited the proteolytic activity of E. carinatus venom in a dose-dependent manner. Interaction studies of ascorbic acid with purified ecarin using isothermal titration calorimetry showed favorable binding energy and energetics. The molecular docking of ascorbic acid with ecarin revealed important interactions with residues at the active site pocket of ecarin. It was observed that the ligand behaves as a chelating inhibitor. Thus, the backbone structural scaffold of ascorbic acid can find potential use as building blocks in designing drug-like molecules for viper bite management.