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The amino acid sequence of beta super(I)-globin chain from Sindhi Krait (Bungarus sindanus sindanus) was determined to study the molecular evolution among snakes. The hemoglobin was isolated from the red blood cells and was analyzed by ion-exchange chromatography (IEX). The crude globin was subjected to reversed phased-high performance liquid chromatography (RP-HPLC) using C4 column. The N-terminal sequences of intact globin chains and tryptic peptides were determined by Edman degradation in a pulsed liquid gas phase sequencer using an online Phenylthiohydantoin analyzer. Sindhi Krait is expected to express three hemoglobin components that are composed of beta super(II), beta super(I), alpha super(D) and alpha super(A)-globin chains, as apparent by IEX, RP-HPLC and N-terminal sequence analyses. Sequence alignment and phylogenetic analyses of beta super(I) globin chain from Sindhi Krait showed closest relationship with beta super(I) globin chain from Rattlesnake, Water snake and Indigo snake. Interestingly, comparison of primary sequence of beta super(I) globin chain of Sindhi Krait with human beta chain revealed 63 % similarity along with the retention of all heme contact points. Variations among the two sequences were prominent at alpha beta contact points and in regions directly not important for function.

The banded krait, Bungarus fasciatus is a widespread elapid snake, likely to comprise several distinct species in different geographic regions of Asia. Therefore, based on molecular phylogenetics and comparative morphology data, we present an overview of the systematic composition of the species to delimit potential biogeographic boundaries. Our phylogenetic analyses, based on four mitochondrial genes, reveal the existence of at least three evolutionary lineages within B. fasciatus , corresponding to Indo-Myanmar, Sundaic and eastern Asian lineages. We are convinced that there are at least three taxonomic entities within the nomen B. fasciatus and restrict the distribution of B. fasciatus sensu stricto to the Indo-Myanmar region. We also provide additional natural history data of the taxon from eastern India. Finally, we advocate further studies to establish the degree of reproductive isolation among these diverging evolutionary lineages and to reassess the systematic status of this species complex especially the Sundaic and eastern Asian lineages.

In majority of snakebite cases, the snake responsible for the bite remains unidentified. The traditional snakebite diagnostics method relies upon clinical symptoms and blood coagulation assays that do not provide accurate diagnosis which is important for epidemiological as well as diagnostics point of view. On the other hand, high batch-to-batch variations in antibody performance limit its application for diagnostic assays. In recent years, nucleic acid aptamers have emerged as a strong chemical rival of antibodies due to several obvious advantages, including but not limited to in vitro generation, synthetic nature, ease of functionalization, high stability and adaptability to various diagnostic formats. In the current study, we have rationally truncated an aptamer developed for α-Toxin of Bungarus multicinctus and demonstrated its utility for the detection of venom of Bungarus caeruleus . The truncated aptamer α-Tox-T2 (26mer) is found to have greater affinity than its 40-mer parent counterpart α-Tox-FL. The truncated aptamers are characterized and compared with parent aptamer for their binding, selectivity, affinity, alteration in secondary structure and limit of detection. Altogether, our findings establish the cross-species application of a DNA aptamer generated for α-Toxin of Bungarus multicinctus (a snake found in Taiwan and China) for the reliable detection of venom of Bungarus caeruleus (a snake found in the Indian subcontinent).

Bungarus multicinctus (many-banded krait) ranks among the world’s most medically significant venomous snakes. Its venom, predominantly composed of α-bungarotoxin neurotoxins in a complex mixture, induces life-threatening respiratory paralysis, pulmonary failure, and often multi-organ dysfunction following envenomation. Building upon our discovery that the chemical dye Cy7-SE attenuates the toxicity of Bungarus multicinctus venom, this study employed network pharmacology to analyze molecular docking parameters between Cy7-SE and α-bungarotoxin. We subsequently applied computational virtual screening to identify natural small molecules alleviating symptoms of B. multicinctus envenomation, followed by comprehensive in vitro and in vivo validation. Molecular docking revealed that Cy7-SE forms a stable complex with α-bungarotoxin through five hydrogen bonds, exhibiting a binding energy of -8. 49 kcal/mol. Using optimized GridBox parameters derived from this interaction, we performed batch molecular docking against the ZINC database, identifying 3, 118, 296 potential α-bungarotoxin-binding molecules. Through sequential filtering—binding energy ≤ -7 kcal/mol, ADMET prediction analysis, Lipinski’s rule screening, weighted refinement via Pandas library analysis, and final prioritization using PyMOL visualization—coupled with literature mining, the natural compound cyanidin-3-glucoside (C3G) was identified as a promising therapeutic candidate. Molecular dynamics simulations confirmed the stable binding of C3G to α-bungarotoxin. Surface plasmon resonance demonstrated that C3G and α-bungarotoxin have a strong binding affinity. In vivo studies showed that co-injection of high-dose C3G (300-fold molar equivalent to venom) with B. multicinctus venom significantly enhanced murine survival rates. Moreover, immediate post-envenomation administration of C3G at this dosage improved 24-hour survival and alleviated histopathological damage in diaphragmatic and pulmonary tissues. Notably, the protective effect of C3G relies on an extremely high molar excess and is mainly limited to co-administration or immediate post-envenomation intervention; this compound acts as a symptomatic ameliorating agent to delay disease progression and mitigate secondary tissue damage, rather than exerting direct or clinically significant venom neutralization, distinguishing it from antivenom.

Bungarus multicinctus is one of the most venomous and lethal snake species in mainland China, with envenomation resulting in a mortality rate as high as 23%. Currently, antivenin against B. multicinctus remains the gold standard for treating bites from this species. However, in remote mountainous areas or rural regions of China, access to antivenin may be delayed or unavailable following a bite. The lethal components of B. multicinctus venom include α-, β-, γ- and κ-bungarotoxins, which act on either the presynaptic or postsynaptic membrane, thereby altering acetylcholine levels in the synaptic cleft. This study aims to evaluate pharmaceutical agents that confer prophylactic or protective effects against bungarotoxins and neurotoxin-rich snake venoms. Based on theoretical considerations, we postulate that certain anticholinergic or anticholinesterase agents may exhibit potential protective efficacy against these venom components. This study investigated the protective effects of clinically standard anticholinergic and anticholinesterase agents-scopolamine, neostigmine methylsulfate, bethanechol chloride, pilocarpine hydrochloride, and atropine sulfate-against different bungarotoxins and wide distribution neurotoxin-rich crude snake venoms (B. multicinctus, Naja atra and Ophiophagus hannah). Our results showed that neostigmine methylsulfate and atropine sulfate exerted significant protective effects (P < 0.01) against three-finger toxins contained in B. multicinctus venom, including α-bungarotoxin, γ-bungarotoxin, α-bungarotoxin+γ-bungarotoxin combinations, β-bungarotoxin+α-bungarotoxin combinations, and β-bungarotoxin+γ-bungarotoxin combinations. In mice animal models treated with B. multicinctus antivenin, neostigmine methylsulfate and atropine sulfate retained profound protective effects (P < 0.01) against β-bungarotoxin+α-bungarotoxin and β-bungarotoxin+γ-bungarotoxin mixtures. However, these clinic-used drugs showed no significant protective effect against B. multicinctus crude venom, with only modest survival time prolongation without statistical significance observed. Under the same conditions, theses drugs showed no effects on king cobra venoms and significantly prompted the death of the tested animals. Present investigation provides a scientific basis for the treatment of B. multicinctus bites in remote mountainous areas or rural regions of southern China. Upon confirming victims were bitten by B. multicinctus, administering atropine sulfate or neostigmine methylsulfate as emergency treatment might provide supplementary benefits for subsequent care. Importantly, the administration of clinic used drugs does not interfere with the efficacy of B. multicinctus antivenin in later treating stages.

Snakebite in India is a severe problem as it causes a mortality rate of 58,000 and a disability rate of 140,000 every year which is the highest among any other country. Antivenom is the primary therapy for snakebite, and its manufacturing techniques have essentially stayed unaltered for over a century. Indian polyvalent antivenom, a scientifically validated medicine for treating the toxic effects of snakebites, is available against the venom of the so-called Big Four snakes namely Spectacled cobra (Naja naja), Saw-scaled viper (Echis carinatus), Russell’s viper (Daboia russelli) and the Common krait (Bungarus caeruleus), responsible for majority of the deaths in India. India hosts many other species of snakes, including cobras, kraits, saw-scaled vipers, sea snakes, and pit vipers, responsible for clinically severe envenomation. Neutralization strategy has been applied to access the efficacy of antivenoms, crucial for reducing snake bite deaths and disabilities. This review aims to conduct a systematic review and meta-analysis on the neutralization efficiency of the Polyvalent Antivenom (PAV) and focus on the factors that may contribute to the poor recognition of the antivenom towards the venom toxins. Reports focusing on the investigation of antivenom efficacy were searched and collected from several databases. Preclinical studies that reported the neutralization efficacy of the commercial antivenom against the medically important snakes of India were included. The articles were screened based on the inclusion criteria and 8 studies were shortlisted for meta-analysis. Pooled proportion was calculated for the antivenom efficacy reported by the studies and was found to be statistically significant with a 95% confidence interval. The heterogenicity in the venom toxicity and neutralization potency of the antivenom was evident in the overall estimate (proportion) and individual data. We provide comprehensive evidence on antivenom efficacy against medically important snakes from various parts of India which may aid in identifying the gaps in snake envenomation therapy and the need for novel potentially improved treatment of snakebites.

Nepal has one of the highest snakebite fatality rates in south Asia. A study in the country in 2001 indicated an annual incidence, in the study area, of 162 snakebite-related deaths per 100 000 population. If the numbers of out-of-hospital deaths caused by snakebite are to be reduced in Nepal, there needs to be improvements in the public awareness of the benefits of snakebite treatment in hospital and in the pre-hospital care of snakebite - as seen, for example, in Sri Lanka. The corresponding in-hospital mortality will only be reduced by increasing the availability of safe and effective antivenoms and improving critical care for people bitten by snakes. Until Nepal is able to produce antivenom of high quality, antivenoms will need to be imported from other Asian countries or elsewhere. As a temporary measure, i.e. until local production is ready in terms of capacity and funding, antivenoms produced by competent non-profit institutions, e.g. in Brazil or Costa Rica, could be imported.

The common krait (Bungarus caeruleus) and the endemic Sri Lankan krait (B. ceylonicus) are two species of krait responsible for envenomings in Sri Lanka that result in progressive neuromuscular paralysis. We characterised the in vitro neurotoxicity of B. ceylonicus and B. caeruleus venoms and studied their neutralisation by two commercially available Indian polyvalent antivenoms (i.e., VINS and BHARAT), Thai banded krait antivenom and Australian polyvalent antivenom using the chick biventer cervicis nerve-muscle preparation. Both venoms displayed concentration-dependent neurotoxicity, showing equipotent pre-synaptic neurotoxicity at 0.03 μg/mL. At a higher concentration (1 μg/mL), both venoms showed post-synaptic neurotoxicity, with B. ceylonicus venom being more potent. VINS was unable to neutralise the neurotoxicity of B. ceylonicus venom, but neutralised both pre- and post-synaptic neurotoxicity of B. caeruleus venom. BHARAT neutralised in vitro pre- and post-synaptic activity of both B. ceylonicus and B. caeruleus venoms. Banded krait antivenom and Australian polyvalent antivenoms were unable to fully neutralise the neurotoxicity of either venom at tested concentrations. In conclusion, B. ceylonicus venom shows pre- and post-synaptic neurotoxicity similar to B. caeruleus venom. BHARAT effectively neutralises both pre- and post-synaptic neurotoxicity of B. ceylonicus venom. Both Indian polyvalent antivenoms effectively neutralise neurotoxicity induced by B. caeruleus venom.

Animal movement can impact human–wildlife conflict by influencing encounter and detection rates. We assess the movement and space use of the highly venomous and medically important Malayan krait ( Bungarus candidus ) on a suburban university campus. We radio-tracked 14 kraits for an average of 114 days (min: 19, max: 218), during which we located individuals an average of 106 times (min: 21, max: 229) each. Most individuals displayed some level of attraction to buildings (n = 10) and natural areas (n = 12); we identified a similar unambiguous pattern of attraction to buildings and natural areas at the population level (of our sample). Snakes remained in shelter sites for long durations (max: 94 days) and revisited sites on average every 15.45 days. Over 50% of locations were within human settlements and 37.1% were associated with buildings. We found generally seasonal patterns of activity, with higher activity in wet seasons, and lower activity in the hot season. These results show frequent proximity between Malayan kraits and humans at the university; thereby, suggesting a near constant potential for human-wildlife conflict. Despite the fact that no snakebites from this species occurred at the university during our study period, substantial education and awareness training should be considered to ensure continued coexistence on campus.

We aimed to investigate neurophysiological and clinical effects of common krait envenoming, including the time course and treatment response. 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 6 wk and 6-9 mth post-bite. There were 33 patients enrolled (median age 35 y; 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 20-32 h. 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 3.5 h post-bite (2.8-7.2 h), which cleared unbound venom from blood. Despite this, the paralysis worsened requiring intubation and ventilation within 7 h post-bite. sfEMG showed markedly increased jitter and neuromuscular blocks within 12 h. sfEMG abnormalities gradually improved over 24 h, 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 96 h post-bite (54-216 h). On discharge, median 8 days (4-12 days) post-bite, patients were clinically normal but had mild sfEMG abnormalities which persisted at 6 wk post-bite. There were no clinical or neurophysiological abnormalities at 6-9 mth. 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.