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Snakebite is a major public health concern in many parts of the world, including India, where over 58,000 deaths occur annually due to snake envenoming. The common krait (Bungarus caeruleus) is responsible for the second-highest number of snakebite-related mortalities in the country. However, despite its notoriety, little is known about its venom ecology, functions and compositional variation across bioclimatic zones, partly because these nocturnal snakes are highly elusive, making it difficult to find them in the wild. We aim to address this knowledge gap by characterising the venom composition and toxicity profiles of the pan-Indian populations (n = 8) of B. caeruleus using a combination of proteomics, receptor-toxin interaction assays, biochemical experiments, pharmacological tests and preclinical evaluations. We reveal considerable variation in venom composition, functions, and pharmacological activities among the geographically distinct populations of B. caeruleus. Furthermore, toxin-receptor interaction assays provide insights into their feeding ecology and prey-predator interactions. Finally, in vitro and in vivo experiments revealed the poor neutralising potencies of Indian antivenoms towards most populations of the common krait. Our findings highlight the alarming need to develop efficacious snakebite therapy in India to treat bites from this medically most important elapid snake. [ABSTRACT FROM AUTHOR]

Snakebite is a major public health concern in many parts of the world, including India, where over 58,000 deaths occur annually due to snake envenoming. The common krait (Bungarus caeruleus) is responsible for the second-highest number of snakebite-related mortalities in the country. However, despite its notoriety, little is known about its venom ecology, functions and compositional variation across bioclimatic zones, partly because these nocturnal snakes are highly elusive, making it difficult to find them in the wild. We aim to address this knowledge gap by characterising the venom composition and toxicity profiles of the pan-Indian populations (n = 8) of B. caeruleus using a combination of proteomics, receptor-toxin interaction assays, biochemical experiments, pharmacological tests and preclinical evaluations. We reveal considerable variation in venom composition, functions, and pharmacological activities among the geographically distinct populations of B. caeruleus. Furthermore, toxin-receptor interaction assays provide insights into their feeding ecology and prey-predator interactions. Finally, in vitro and in vivo experiments revealed the poor neutralising potencies of Indian antivenoms towards most populations of the common krait. Our findings highlight the alarming need to develop efficacious snakebite therapy in India to treat bites from this medically most important elapid snake.

Introduction Despite the widespread use of antivenom for the treatment of snakebite envenoming in the Indian subcontinent, the ideal dose of antivenom has been a point of contention. Low-dose regimens can economize on a scarce resource in low- and middle-income countries. This study assessed the effectiveness of a low-dose (10 vials) antivenom regimen compared to the usual 20 vials in patients with krait bite neuroparalysis requiring mechanical ventilation. Methods This study was a prospective controlled pilot study conducted in a tertiary-care hospital in north India. Participants were eligible if they were ≥12 years old, had krait bite neurotoxicity, showed severe paralysis requiring mechanical ventilation, and had access to antivenom therapy within 24 h of the bite. The primary outcome was the duration of mechanical ventilation, and the secondary outcomes were the length of hospital stay and in-hospital survival. Results Fifteen patients received 10 vials of antivenom, and 25 received 20 vials. The two treatment groups had similar baseline demographics, clinical and laboratory features, snakebite severity scores, and median time from snakebite to initiation of antivenom therapy. The low-dose regimen was as effective as the standard dose concerning the median duration of mechanical ventilation (41 h vs. 55 h, P  = 0.094), the median length of stay (78 h vs. 85.5 h, P  = 0.360), and in-hospital deaths (1 vs. 3, P  = 1.000). The incidence of ventilator-associated pneumonia was similar between the two groups (1 vs 3, P  = 1.000). Conclusion A low dose of antivenom effectively treats patients with severe krait bite neuroparalysis. [ABSTRACT FROM AUTHOR]

Snakebite envenomation has been one of the major causes of morbidity and mortality around the world. Though intravenous administration of commercial anti-venom systemically neutralizes the toxicity, adverse effects are commonly seen in the post-treatment period. Plant metabolites and their derivatives have been shown to exhibit a wide range of antiophidian properties. In this study, we have investigated the Bungaruscaeruleus venom neutralization potential of Citrus aurantium and Citrus reticulata Blanco peels in terms of phospholipase and hemolytic inhibition. Methanolic extract of C. reticulata exhibited the highest inhibition (93%) of PLA2 activity. However, the extracts of both these Citrus species significantly inhibited the hemolytic activity of the venom (54-82%). Molecular docking indicated the binding of the citrus metabolites to catalytic site residues (TRP19, GLY30, TYR31, GLY32, and HIS48) of PLA2. In vivo studies using Swiss Albino mice confirmed the neutralising capacity of the citrus peel extract, as reflected by the increase in survival time. Therefore, the study reveals that these metabolites in the methanolic extract of the citrus peel can be used as supplements for the management of snake bites. [ABSTRACT FROM AUTHOR]

Areca catechu seeds and their extract/s are currently used to treat various ailments and infections including snakebites. The purpose of this investigation was to assess the inhibiting/neutralizing effect of ethyl acetate and aqueous ethanolic seed extracts of A. catechu on Bungarus caeruleus (krait) venom. The enzyme activities and their inhibition were evaluated using standard procedures (in vitro). In vivo studies were conducted using chick embryos and murine models. The extracts inhibited hyaluronidase and phospholipase A2 activities. Protease activity was neutralized by the aqueous ethanolic extract only. The IC50 value of aqueous ethanolic extract for hyaluronidase was 0.001 g/mL, while that for the ethyl acetate extract for phospholipase A2 was 0.006 g/mL. In addition, both the extracts neutralized the indirect hemolysis and fibrinogenolytic activity induced by B. caeruleus venom. The LD50 for the chick embryos was 4.9 µg/egg. The 50 and 100 µg aqueous ethanolic extracts neutralized the LD50 and the challenging dose (3LD50) of venom effectively in the chick embryo model. The LD50 of B. caeruleus venom in mice was 0.1927 µg/kg; the extract extended the survival time of the mice from 25 min to 30 and 35 min in 1:10 and 1:20 ((w/w) venom:extract) ratios, respectively. The extract also neutralized myotoxic activity. The A. catechu seed extract showed promising inhibitory properties against B. caeruleus venom. In this regard, academia and industries should work collaboratively to develop and formulate a cost-effective first-aid drug. [ABSTRACT FROM AUTHOR]

Background: Venomous 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 methods: Anti-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. Results: Herbal 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. Conclusion: Inhibitions 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.

Anti-snake venom therapy is the only treatment for snake bite but leads to acute and chronic conditions which may be severe. The medicinal plants have gained importance over years to find an effective alternative to anti-snake venom. The present study focused on evaluating the potential of Clerodendrum serratum for the anti-snake venom activity. Phytochemicals were extracted from the C. serratum with different solvents. The ethyl acetate and methanolic extracts were found to neutralize the major enzyme toxins (phospholipase A2, protease and hyaluronidase) of Bungarus caeruleus and Daboia russelii venom at a concentration of 100 µg/mL. The fibrinogenolytic activity of both the venoms were neutralized. The study proves that the plant C. serratum possesses certain compounds which inhibit the toxins present in the venom of B. caeruleus and D. russelii. Video Clip of Methodology: Hyaluronidase assay: 3 min 30 sec Full Screen Alternate

Purpose: Three species in the genus Bungarus inhabit Thailand. Among these, Bungarus candidus (Malayan krait) is the most common and deadliest. Currently, the clinical manifestations of patients envenomed by kraits, especially Bungarus fasciatus (banded krait), have not been thoroughly investigated. This study was performed to elucidate the clinical manifestations and outcomes of patients bitten by kraits in Thailand.Materials and Methods: The data of krait envenomation cases that occurred during a 9-year period were obtained from the Ramathibodi Poison Center Toxic Exposure Surveillance System and retrospectively analyzed.Results: In total, 78 cases of krait envenomation were included. Most patients were male (59.0%) and the median age was 28 years. All had minimal local effects. The median duration from the bite to the onset of neurological manifestations was 3 hours (range, 0.5-8 hours). Besides neurological effects, the patients also developed high blood pressure (67.4%), tachycardia (61.7%), hypokalemia (55.3%), and hyponatremia (17.6%). Severe hyponatremia (<120 mEq/L) was noted in four pediatric patients. Other clinical manifestations were bradycardia, abdominal pain, and rhabdomyolysis. The mortality rate was 6.4%, and all deaths occurred from B. candidus bites. Eighty-six percent of patients received antivenom. Most patients (75.6%) were intubated and underwent assisted ventilation for a median of 6 days (range, 1-37 days). The median length of hospital stay was 7 days. Some patients developed complications during hospitalization; the most common was pneumonia. These in-hospital complications were significantly associated with death.Conclusion: Although krait bites caused only minimal local effects, the mortality rate was still high, particularly from Malayan krait bites. Besides neurological effects, other clinical manifestations were high blood pressure, tachycardia, hypokalemia, and hyponatremia. Thus, vital signs and electrolytes should be frequently and closely monitored in these patients. Apart from antivenom treatment, adequate supportive care including management of complications might help to decrease the mortality rate. [ABSTRACT FROM AUTHOR]

Snake envenomations have been a serious yet often overlooked public health threat especially in tropical and subtropical countries, including Southeast Asia. The medically important venomous land snakes in Southeast Asia include snakes from the Elapidae and Crotalidae families. Among the elapids, there are only 12 species that are considered of medical importance, represented by the kraits (Bungarus caeruleus, B. candidus, B. fasciatus, B. flaviceps and B. multicinctus). The incidence of snakebite is high in India. Apart from mortality, the morbidity is due to various complications. The common krait (Bungarus caeruleus) is the most toxic snake found commonly in the plains of throughout the India and the number of snakebites in the rural areas of India was recorded by this snake. The present article highlights the prevalence and the clinical complications of Indian common krait envenomation among the rural populations of India. [ABSTRACT FROM AUTHOR]

Snake venoms are mixtures of biologically-active proteins and peptides, and several studies have described the characteristics of some of these toxins. However, complete proteomic profiling of the venoms of many snake species has not yet been done. The Indian cobra ( Naja naja ) and common krait ( Bungarus caeruleus ) are elapid snake species that are among the ‘Big Four’ responsible for the majority of human snake envenomation cases in India. As understanding the composition and complexity of venoms is necessary for successful treatment of envenomation in humans, we utilized three different proteomic profiling approaches to characterize these venoms: i) one-dimensional SDS-PAGE coupled with in-gel tryptic digestion and electrospray tandem mass spectrometry (ESI-LC-MS/MS) of individual protein bands; ii) in-solution tryptic digestion of crude venoms coupled with ESI-LC-MS/MS; and iii) separation by gel-filtration chromatography coupled with tryptic digestion and ESI-LC-MS/MS of separated fractions. From the generated data, 81 and 46 different proteins were identified from N. naja and B. caeruleus venoms, respectively, belonging to fifteen different protein families. Venoms from both species were found to contain a variety of phospholipases A 2 and three-finger toxins, whereas relatively higher numbers of snake venom metalloproteinases were found in N. naja compared to B. caeruleus venom. The analyses also identified less represented venom proteins including L-amino acid oxidases, cysteine-rich secretory proteins, 5’-nucleotidases and venom nerve growth factors. Further, Kunitz-type serine protease inhibitors, cobra venom factors, phosphodiesterases, vespryns and aminopeptidases were identified in the N. naja venom, while acetylcholinesterases and hyaluronidases were found in the B. caeruleus venom. We further analyzed protein coverage (Lys/Arg rich and poor regions as well as potential glycosylation sites) using in-house software. These studies expand our understanding of the proteomes of the venoms of these two medically-important species. [ABSTRACT FROM AUTHOR]

The Indian krait ( Bungarus caeruleus ) is one of the “Big Four” venomous snakes widely distributed in South Asia. The present venomic study reveals that its venom (Sri Lankan origin) is predominated by phospholipases A 2 (64.5% of total proteins), in which at least 4.6% are presynaptically-acting β-bungarotoxin A-chains. Three-finger toxins (19.0%) are the second most abundant, comprising 15.6% κ-neurotoxins, the potent postsynaptically-acting long neurotoxins. Comparative chromatography showed that venom samples from Sri Lanka, India and Pakistan did not exhibit significant variation. These venoms exhibited high immunoreactivity toward VINS Indian Polyvalent Antivenom (VPAV). The Pakistani krait venom, however, had a relatively lower degree of binding, consistent with its moderate neutralization by VPAV (potency = 0.3 mg venom neutralized per ml antivenom) while the Sri Lankan and Indian venoms were more effectively neutralized (potency of 0.44 mg/ml and 0.48 mg/ml, respectively). Importantly, VPAV was able to neutralize the Sri Lankan and Indian venoms to a comparable extent, supporting its use in Sri Lanka especially in the current situation where Sri Lanka-specific antivenom is unavailable against this species. The findings also indicate that the Pakistani B. caeruleus venom is immunologically less comparable and should be incorporated in the production of a pan-regional, polyspecific antivenom. Biological significance The Indian krait or blue krait, Bungarus caeruleus , is a highly venomous snake that contributes to the snakebite envenoming problem in South Asia. This is a less aggressive snake species but its accidental bite can cause rapid and severe neurotoxicity, in which the patient may succumb to paralysis, respiratory failure and death within a short frame of time. The proteomic analysis of its venom (sourced from Sri Lanka) unveils its content that well correlates to its envenoming pathophysiology, driven primarily by the abundant presynaptic and postsynaptic neurotoxins (β-bungarotoxins and κ-neurotoxins, respectively). The absence of cytotoxins in the venom proteome also correlates with the lack of local envenoming sign (pain, swelling), and explains why the bite may be insidious until later stage when paralysis sets in. The muscarinic toxin-like proteins in the venom may be the cause of severe abdominal pain that precedes paralysis in many cases, and justifies the need of closely monitoring this symptom in suspected cases. Venom samples from Sri Lanka, India and Pakistan exhibited no remarkable variation in protein profiling and reacted immunologically toward the VINS Indian Polyvalent Antivenom, though to a varying extent. The antivenom is effective in neutralizing the Sri Lankan and Indian venoms, confirming its clinical use in the countries. The antivenom efficacy against the Pakistani venom, however, may be further optimized by incorporating the Pakistani venom in the antivenom production. [ABSTRACT FROM AUTHOR]

Codon bias study in an organism gains significance in understanding the molecular mechanism as well as the functional conservation of gene expression during the course of evolution. The prime focus in this study is to compare the codon usage patterns among the four species belonging to the genus Bungarus ( B . multicinctus , B . fasciatus , B . candidus and B . flaviceps ) using several codon bias parameters. Our results suggested that relatively low codon bias exists in the coding sequences of the selected species. The compositional constraints together with gene expression level might influence the patterns of codon usage among the genes of Bungarus species. Both natural selection and mutation pressure affect the codon usage pattern in Bungarus species as evident from correspondence analysis. Neutrality plot indicates that natural selection played a major role while mutation pressure played a minor role in codon usage pattern of the genes in Bungarus species. [ABSTRACT FROM AUTHOR]

The Ceylon krait ( Bungarus ceylonicus ) is a deadly venomous elapid snake endemic to Sri Lanka. Its habitat is mainly in the wet zone of the island. Despite its frequent encounters in and near human dwellings, reports of envenoming are rare and limited to four in the literature. The first and last fatal reports envenoming by B. ceylonicus was in 1993. After over two decades, we report two confirmed cases of B. ceylonicus bites-one a dry bite and the other with signs and symptoms of moderate envenoming. The envenoming occurred at night while the victim was asleep, causing tightness in the chest and dyspnoea on waking up, followed by neuromuscular paralysis that did not cause respiratory failure and complete recovery was observed three days following the bite. [ABSTRACT FROM AUTHOR]

Snake venoms are rich in enzymes such as phospholipase A2, proteolytic enzymes, hyaluronidases and phosphodiesterases, which are well characterized. However, L-amino acid oxidase (LAO EC.1.4.3.2) from snake venoms has not been extensively studied. A novel L-amino acid oxidase from Bungarus caeruleus venom was purified to homogeneity using a combination of ion-exchange by DEAE-cellulose chromatography and gel filtration on Sephadex® G-100 column. The purified monomer of LAO showed a molecular mass of 55 ±1 kDa estimated by SDS-PAGE. The specific activity of purified LAO was 6,230 ± 178 U/min/mg, versus 230 ± 3.0 U/min/mg for the whole desiccated venom, suggesting a 27-fold purification with a 25% yield. Optimal pH and temperature for maximum purified enzyme activity were 6.5 and 37ºC, respectively. Platelet aggregation studies show that purified LAO inhibited ADP-induced platelet aggregation dose-dependently at 0.01 to 0.1 µM with 50% inhibitory concentration (IC50) of 0.04 µM, whereas at a 0.08 µM concentration it did not induce appreciable aggregation on normal platelet-rich plasma (PRP). The purified protein catalyzed oxidative deamination of L-amino acids while the most specific substrate was L-leucine. The purified LAO oxidizes only L-forms, but not D-forms of amino acids, to produce H2O2. The enzyme is important for the purification and determination of certain amino acids and for the preparation of α-keto acids.

Snake venom hyaluronidases known as “spreading factor” are not extensively studied. Recently, it is argued that beyond its role as a spreading factor, venom hyaluronidase (HYL) deserves to be explored as a possible therapeutic target for inhibiting the systemic distribution of venom/toxins and also for minimizing local tissue destruction. In this context, in the present study, a low-molecular weight HYL has been isolated fromBungarus caeruleus(Indian krait) venom by single step chromatography on HPLC system. The apparent molecular weight determined by SDS-PAGE is 14 ± 2 kDa, as confirmed by zymogen study and LC–MS as well. The enzyme had optimal pH 6 and temperature 37°C. The Michaelis–Menten constant (Km) was found to be 8.48 µg/mL at 37°C. The activity of purified enzyme was completely inhibited by Ba2+metal ion andN-acetyl imidazole group-specific agents. This work yielded a highly active HYL fromB. caeruleusthe first one to be isolated. Further studies on its pharmacological actions will be interesting to develop lead molecules for better management of snakebite. [ABSTRACT FROM PUBLISHER]

Objective: We aimed to investigate neurophysiological and clinical effects of common krait envenoming, including the time course and treatment response. Methodology: Patients with definite common krait (Bungarus caeruleus) bites were recruited from a Sri Lankan hospital. All patients had serial neurological examinations and stimulated concentric needle single-fibre electromyography (sfEMG) of orbicularis oculi in hospital at 6wk and 6–9mth post-bite. Principal Findings: There were 33 patients enrolled (median age 35y; 24 males). Eight did not develop neurotoxicity and had normal sfEMG. Eight had mild neurotoxicity with ptosis, normal sfEMG; six received antivenom and all recovered within 20–32h. Seventeen patients developed severe neurotoxicity with rapidly descending paralysis, from ptosis to complete ophthalmoplegia, facial, bulbar and neck weakness. All 17 received Indian polyvalent antivenom a median 3.5h post-bite (2.8–7.2h), which cleared unbound venom from blood. Despite this, the paralysis worsened requiring intubation and ventilation within 7h post-bite. sfEMG showed markedly increased jitter and neuromuscular blocks within 12h. sfEMG abnormalities gradually improved over 24h, corresponding with clinical recovery. Muscle recovery occurred in ascending order. Myotoxicity was not evident, clinically or biochemically, in any of the patients. Patients were extubated a median 96h post-bite (54–216h). On discharge, median 8 days (4–12days) post-bite, patients were clinically normal but had mild sfEMG abnormalities which persisted at 6wk post-bite. There were no clinical or neurophysiological abnormalities at 6–9mth. Conclusions: Common krait envenoming causes rapid onset severe neuromuscular paralysis which takes days to recover clinically consistent with sfEMG. Subclinical neuromuscular dysfunction lasts weeks but was not permanent. Antivenom effectively cleared venom but did not prevent worsening or reverse neuromuscular paralysis. [ABSTRACT FROM AUTHOR]

The neurotoxin purified from the venom of Bungarus caeruleus causes a neuromuscular blockade on acetylcholine-induced muscle twitch response in isolated frog rectus abdominis muscle preparation. Neuromuscular blockade produced by d-tubocurarine on acetylcholine-induced muscle twitch response in an isolated frog rectus abdominis muscle preparation was reversed to normal muscle twitch response in presence of neostigmine. Whereas the purified neurotoxin produced an irreversible neuromuscular blockade in presence of the same strength of neostigmine. As it is already known, botulinum toxin, which also brings about neuromuscular blockade, is effectively used as a drug in the treatment of painful movement disorders. Since the purified toxin also causes paralysis of the muscle, we propose its possible efficacy in the treatment of neuromuscular disorders.

Background: The hump-nosed pit viper (Hypnale hypnale) is the commonest cause for venomous snakebites in Sri Lanka. Previously, it was thought to cause only local envenomation. However recently, several systemic effects and even mortality has been reported. Along with other snakes, such as the Indian cobra (Naja naja), the common krait (Bungarus caeruleus), the Russell's viper (Daboia russelii) and the saw-scaled viper (Echis carinatus), the hump-nosed viper is now also considered capable of causing lethal envenomation. Unlike other snake species, the systemic manifestations occurring through the bite of a hump-nosed viper, such as acute renal failure, thrombotic microangiopathy etc are rare and unpredictable. Case presentation: A 49-year-old Sri Lankan Tamil male presented with a hump-nosed viper bite, which had resulted in a cardiac arrest within half an hour of envenomation. On arrival to the Emergency Treatment Unit, he was unconscious and without spontaneous breathing. Electrocardiography monitoring revealed ST elevation in leads II, III and aVF with reciprocal changes in leads I and aVL—indicating inferior wall infarction—as well as atrial fibrillation. Glasgow Coma Scale was 7/15, which indicated severe brain injury and electroencephalogram on day 10 revealed a low amplitude pattern compatible with diffuse brain damage. Conclusion: This case describes an authenticated case of myocardial infarction in a 49-year-old male following envenomation by a hump-nosed viper in Sri Lanka. This systemic effect of this viper's bite has not previously been described in the literature. This case report is intended to increase the vigilance for myocardial infarction following hump-nosed viper envenomation. [ABSTRACT FROM AUTHOR]

Background: The alpha-delta bungartoxin-4 (α-δ-Bgt-4) is a potent neurotoxin produced by highly venomous snake species, Bungarus caeruleus, mainly targeting neuronal acetylcholine receptors (nAchRs) and producing adverse biological malfunctions leading to respiratory paralysis and mortality. Objective: In this study, we predicted the three-dimensional structure of α-δ-Bgt-4 using homology modeling and investigated the conformational changes and the key residues responsible for nAchRs inhibiting activity. Materials and Methods: From the selected plants, which are traditionally used for snake bites, the active compounds are taken and performed molecular interaction studies and also used for modern techniques like pharmacophore modeling and mapping and absorption, distribution, metabolism, elimination and toxicity analysis which may increase the possibility of success. Results: Moreover, 100's of drug-like compounds were retrieved and analyzed through computational virtual screening and allowed for pharmacokinetic profiling, molecular docking and dynamics simulation. Conclusion: Finally the top five drug-like compounds having competing level of inhibition toward α-δ-Bgt-4 toxin were suggested based on their interaction with α-δ-Bgt-4 toxin. [ABSTRACT FROM AUTHOR]

Background: Bungarus caeruleus (common krait) bite during monsoon season is common in northwest India. Respiratory failure is responsible for high mortality in the victims. In this study we report our experience with manual ventilation using bag valve mask (BVM) in patients with neuroparalysis due to common krait bite. Methods: This prospective study was conducted between June 2009 and December 2009. All consecutive patients with diagnosis of common krait bite who were manually ventilated by BVM were studied. The duration of ventilation and complications associated with ventilation were noted. Polyvalent anti snake venom was administered as per the "national snake bite protocol" and patients were followed up until final outcome. Results: Thirty-four patients (70.6% men) were studied. All patients except two came from rural areas and they were hospitalized between June and September. Majority of patients were bitten during the night while sleeping on the floor. The mean time interval between bite and arrival to hospital was 4.4 hours. Ptosis (100%) was he most common clinical finding followed by ophtalmoplegia (80%) and limb muscle weakness (74%). Twenty-four patients (70%) developed respiratory symptoms and 20 (59%) were intubated and manually ventilated by BVM. Mean duration of assisted ventilation was 34.6 ± 12.8 hours. Hoarseness of voice and throat pain were noted in all intubated patients following extubation, which responded to conservative therapeutic measures. The mean duration of hospitalization was 6 ± 1.6 days. All patients except one survived. Conclusion: Manual ventilation with BVM in patients with neuroparalysis due to common krait bite is a safe and effective modality in resource constraint settings. [ABSTRACT FROM AUTHOR]

Objective: This study aims to analyze and predict the possibility of designing a vaccine that could make humans immune to krait toxin. Materials and Methods: Bungarus caeruleus or common Indian krait is a member of the venomous big four snake species. Its venom contains a neurotoxic protein alpha-delta-bungarotoxin-4 and is found to be responsible for human death 4-8 h after the snake bite. Antigenicity of this protein was determined by Hopp and Woods and Kolaskar and Tangaonkar method. We predicted major histocompatibility complex (MHC) Class I and MHC Class II binding peptides of antigenic protein from alpha-deltabungarotoxin-4, which are an important determinant for protection of host from snake bite. Fragments selected through this study revealed higher efficiency binders. Result: Higher percentages of their atoms are directly involved in binding in comparison with larger molecules. These potential fragments, therefore can be a novel tool in the arena of cross protection to develop host specific antibodies in different objectives. We operated AllerHunter for predicting allergenicity based on the structural and physiochemical properties of whole alpha-delta-bungarotoin-4, and it was found to be nonallergen. The potential epitopes of alpha-delta-bungarotoxin-4 were found to be located at sequences "GENLCYTKM" and "FCSSRGKVI" and these were found to be sufficient for eliciting the desired immune response. In this study, a hypothetical immunization is developed, which demands more validation and study. It can be emphasized that such predictive in silico study requires an in vivo experiments comprehensibly, which must be assured to validate such approaches. Hence, our goal was to identify a conformationally biased epitope sequence, which aims to provide a new paradigm to design epitope-based peptide vaccines in order to alleviate immunological infections from Krait neurotoxin. Conclusion: Computational techniques manifest the attention of Krait neurotoxin as crucial immunodiagnostic tool for fatal venom proved that most snake venoms are in poorly characterized although they are biologically important proteins with therapeutic potentialities. [ABSTRACT FROM AUTHOR]

Highlights: [•] BCV showed cytotoxic activity on promastigote and amastigote of Leishmania donovani in in vitro condition. [•] BCV activated macrophages and increased cytokine productions in in vitro experiments. [•] BCV treatment decreased parasite count both in liver and spleen of infected BALB/c mice. [•] BCV treatment increased production of TNF-α, IFN-γ, ROS, NO in infected mice. [•] Liver and spleen structure was partially restored due to BCV treatment in infected mice. [Copyright &y& Elsevier]

Abstract: Bungarus caeruleus (Common Krait) is a nocturnal venomous snake that is responsible for many snakebites in India. In the present study, we report the biochemical parameters involved in the neurotoxicity of the venom. The purpose of this study was to characterize the toxic enzymes and proteins in crude krait venom. The results of this study indicate that crude venom consists of proteases esterases, oxidases and nucleotidases enzymes. The highly prominent enzymes responsible for toxicity was found to be hyaluronidases and phospholipases. Crude venom on electrophoresis under reduced conditions showed more number of low molecular weight proteins than high molecular weight proteins. [Copyright &y& Elsevier]

Unlike Naja naja, Bungarus caeruleus, Echis carinatus, and Daboia/Vipera russellii venoms, Ophiophagus hannah venom is medically ignored in the Indian subcontinent. Being the biggest poisonous snake, O. hannah has been presumed to inject several lethal doses of venom in a single bite. Lack of therapeutic antivenom to O. hannah bite in India makes any attempt to save the victim a difficult exercise. This study was initiated to compare O. hannah venom with the above said venoms for possible interference in hemostasis. Ophiophagus hannah venom was found to actively interfere in hemostatic stages such as fibrin clot formation, platelet activation/aggregation, and fibrin clot dissolution. It decreased partial thromboplastin time (aPTT), prothrombin time (PT), and thrombin clotting time (TCT). These activities are similar to that shown by E. carinatus and D. russellii venoms, and thus O. hannah venom was found to exert procoagulant activity through the common pathway of blood coagulation, while N. naja venom increased aPTT and TCT but not PT, and hence it was found to exert anticoagulant activity through the intrinsic pathway. Venoms of O. hannah, E. carinatus, and D. russellii lack plasminogen activation property as they do not hydrolyze azocasein, while they all show plasmin-like activity by degrading the fibrin clot. Although N. naja venom did not degrade azocasein, unlike other venoms, it showed feeble plasmin-like activity on fibrin clot. Venom of E. carinatus induced clotting of human platelet rich plasma (PRP), while the other three venoms interfered in agonist-induced platelet aggregation in PRP. Venom of O. hannah least inhibited the ADP induced platelet aggregation as compared to D. russellii and N. naja venoms. All these three venoms showed complete inhibition of epinephrine-induced aggregation at varied doses. However, O. hannah venom was unique in inhibiting thrombin induced aggregation. [ABSTRACT FROM AUTHOR]

In this article, the author discusses sex chromosomes morphological differentiation in snakes. The author mentions his observation of the presence of W-sex-chromosomespecific satellite DNA in poisonous snake species of Bungarus walliwall and Bungarus caeruleus. He also mentions the in situ hybridization experiment of banded krait minor (Bkm) sequences to determine Bkm's role in sex determination. Moreover, the W chromosome morphological evolution and Bkm sequences accumulations are presented.

Bungarotoxin present in Bungarus caeruleus (BC) causes life threatening respiratory muscle paralysis. Deep coma and hypokalaemia have been observed in a significant proportion of patients, but the cause is unknown. We postulate the likely mechanism behind these two phenomena. We studied clinical details of two patients admitted with deep coma and performed electroencephalograms (EEG) and brain stem auditory and visual evoked potentials (BAEP and VEP). Daily serum potassium was measured along with urinary potassium excretion as a marker of total extracellular body potassium. Both patients had no brain stem reflexes on admission and the EEG revealed absent alpha and delta activity and presence of dominant theta activity. Alpha rhythm returned on the 3rd day in one patient, while in the other it did not, and the latter patient died on the 13th day due to disseminated intravascular coagulation. BAEP were delayed and VEP were absent in the deceased patient. Both had low serum potassium and low urinary potassium excretion. Replacement of potassium (up to 1.5mmol/kg/day) did not improve serum potassium and urinary potassium excretion. Absent alpha and delta activity in EEG and delayed BAEP and absent VEP are suggestive of a central action of the venom on both the cortical and brain stem neurones. Persistently low serum potassium and reduced urinary potassium excretion are suggestive of intracellular shift as the causative mechanism of hypokalaemia. [ABSTRACT FROM AUTHOR]

Abstract: In view of the findings that several Kunitz-type protein inhibitors suppress tumor invasion and metastasis, the aim of the present study is to explore whether Bungarus multicinctus protease inhibitor-like protein-2 (PILP-2) and PILP-3 exhibit anti-tumor activity. Although approximately 28% of amino acid substitutions occurred between PILP-2 and PILP-3, molecular modeling suggested that PILP-2 and PILP-3 shared similar folded structures. Unlike PILP-2, PILP-3 showed a notable activity in abolishing migration and invasion of human neuroblastoma SK-N-SH cells. The ability of PILP-3 to inhibit matrix metalloprotease-2 (MMP-2) activity was higher than that of PILP-2. Pull-down assay revealed protein–protein interaction between PILP-3 and MMP-2. In contrast to mutation on N-terminal region, replacement of amino acids at C-terminus attenuated notably the ability of PILP-3 to inhibit cell invasion, cell migration and MMP-2 activity as well as the binding capability of PILP-3 with MMP-2. Molecular docking showed that N-terminal region of PILP-2 and PILP-3 fitted into the cleft around the active site of MMP-2 catalytic domain. In contrast to that of PILP-2, C-terminal region of PILP-3 was suggested to be in close contact with catalytic domain of MMP-2. Collectively, our data indicate that PILP-3 is a MMP-2 inhibitor and shows an activity in inhibiting migration and invasion of neuroblastoma, and suggest that intact C-terminus is crucial to the activities of PILP-3. [Copyright &y& Elsevier]

Ninety-one cases of snakebite were admitted between January 1998 and January 2001 to the general hospital at Mahad, 180 km south of Mumbai in western Maharashtra, India. Twenty-nine (31 · 9%) patients, when admitted to hospital, brought the snakes responsible for the bites (20 kraits, 9 Echis carinatus. Forty-five (49 · 5%) patients had snakebite without envenoming; 27 patients had local fang marks without local and systemic manifestations; 18, reporting 24 h after the bite, had local oedema. Twenty-six (28 · 6%) patients were paralysed. Twenty-five cases who reported between midnight and 08:00 showed no local signs of envenoming. One patient, who reported at 16:00, had local oedema with blebs and a history of cobra bite. Ten (11 · 0%) patients died: 3 on the way to hospital and 7 during treatment. Out of 7 cases transferred for tertiary care, 6 recovered and 1 died on the way to Mumbai. Early administration of anti-snake venom (ASV), endotracheal intubation and timely intervention with manual ventilation by Ambu bag and anticholinesterase treatment for Elapidae (krait and cobra) envenoming are crucial for saving lives. Clinical confirmation of snakebite with envenoming was by identification of the dead snake brought by victims and by clinical signs and symptoms such as paralysis (krait and cobra) and rapid progressive local oedema with active bleeding (E. carinatus and Russell''s viper). The 20-min whole blood clotting test is a simple, rapid and reliable test of coagulopathy. It is also of use in assessing the effectiveness of ASV and is of crucial importance for controlling administration of expensive ASV in relation to restoration of blood coagulability. [Copyright &y& Elsevier]

Information on bungarus caeruleus from Odisha, India including informations related to topics like its diet, the habitat in which it is found, and its physical traits is presented.

We report a case of bilateral parotid enlargement and trismus due to the bite of common krait (Bungarus caeruleus). These clinical findings have not been reported in literature after the bite with this species. [ABSTRACT FROM AUTHOR]

Azima tetracantha Lam. is native to Africa and India. The plant and its parts are used for treating various ailments including snake bites. The different concentrations of ethyl acetate leaf extract of A. tetracantha were used to neutralize the toxic effect of venom through dose dependent enzyme studies and in vivo studies. The extract was able to neutralize the 5' nucleotidase, phospholipase A 2 , Phosphodiesterae, phosphomonoesterase, acetylcholinesterase and hyaluronidase in a dose dependent manner with concentrations ranging from 43.98 -340.1 μg/mL of extract. The extract could retain the lysis of fibrinogen at the concentration of 1:10 (venom: extract, w/w) and also the lysis of lecithin was reduced at a concentration of 1:25 (venom: extract, w/w). The extract was able to neutralize the LD 50 of venom in both mice and embryo and also reduce the myotoxic and edema properties of the venom in mice models. The venom did not show any procoagulant and hemorrhagic effect. The leaf extract possess adequate compounds/phytochemicals that could neutralize the toxic properties/activity of the B. caeruleus venom.