Biochemical and biological characterization of the venoms of and from Myanmar and neutralization effects of BPI cobra antivenom.

Snakebite is a neglected public health issue, with many scientific and medical issues to be solved. Cobras are among the most common venomous snakes in Myanmar and are responsible for a considerable number of severe snakebite envenoming. There are three species of cobra (, and ) in Myanmar. The study aims to characterize the and venoms and to investigate the efficacy of anti-cobra antivenom (BPI) against the two venoms. Protein components and fibrinogenolytic activity were determined by SDS-PAGE. Enzymatic activities for PLA, protease and acetylcholinesterase were determined by spectrophotometric method. Anticoagulant activity was determined by recalcification time of citrated human plasma. Myotoxicity, necrotizing activity, median lethal dose (LD) and median effective dose (ED) were determined by WHO recommended methods. The SDS-PAGE displayed the proteins and enzymes containing in two venoms were different. venom exhibited more in PLA, acetylcholinesterase, anticoagulant, fibrinogenolytic and necrotizing activities than venom. mandalayensis venom had more protease activity and myotoxicity than venom. The median lethal dose (LD) of and venom was 4.33 μg/mouse and 5.04 μg/mouse respectively. Both venoms induced fibrinogen Aα chain degradation in 30 min () and in 6 h (). The same median effective dose (ED) (19.56 μg/mouse) showed that anti-NK antivenom can neutralize against lethal effect of venom. It can also neutralize the protease activity, anticoagulant activity and fibrinogenolytic activity of both venoms. Immunodiffusion and immunoblotting studies showed that the antivenom recognized its homologous venom () and cross-reacted against the heterologous venom (). The anti-NK antivenom is suitable to use for bite if monospecific antivenom is not available.