Abstract
The Russell's viper (Daboia russelii) has recently become a significant threat to human life in Bangladesh. Given its wide distribution across South Asia, the venom characteristics and lethality can vary by region with different toxicological properties. Hence, we investigated the characteristics of Bangladeshi Russell's viper venom (BRVV) through SDS-PAGE profiling, reverse-phase HPLC analysis, along with assessments of phospholipase A(2) (PLA(2)), edema-inducing, hemolytic, hemorrhagic, and coagulant activities, histopathology, and blood biochemistry, following established protocols. We also studied the neutralization efficacy of polyvalent antivenom from VINS Bio Products Ltd., India (VPAV) against BRVV. RP-HPLC analysis of BRVV displayed 15 peaks, and SDS-PAGE showed high-intensity protein bands within the 15-70 kDa range. The median lethal dose (LD(50)) for mice was found to be 0.33 mg/kg intraperitoneally (i.p.), and venom exposure resulted in neurotoxic symptoms such as limb paralysis, respiratory difficulties, and sluggishness. BRVV exhibited strong PLA(2), procoagulant, hemorrhagic, indirect hemolytic, and edema-inducing activities but poor direct hemolytic activity. Venom administration also significantly increased levels of alanine aminotransferase (ALT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), cholesterol, total protein, uric acid, blood urea nitrogen (BUN), and creatinine in mouse serum, indicating organ damage. Histopathological examination revealed cell vacuolization, congestion, hemorrhage, inflammatory infiltrations, and necrosis in venom-exposed tissues, validating the abnormal serum biochemistry. The neutralization study revealed that VPAV had limited efficacy against BRVV, suggesting the presence of venom proteins not fully neutralized by the antivenom. Altogether, these findings suggest that the Russell's viper is a medically significant venomous snake in Bangladesh, and VPAV is only partially effective in reducing the venom's toxic effects. Therefore, region-specific venoms must be considered in antivenom development for more effective treatment in envenomation cases.