Occurrence of non-protein low molecular weight cardiotoxin in Indian King Cobra (<i style="">Ophiophagus hannah</i>) Cantor 1836, venom

Abstract

Pathophysiology due to snakebite is a combined effect of various actions of the complex venom constituents. Importance of protein toxins in snake envenomation is well known. The present investigation reports the existence of non-protein/nonpetide low molecular weight toxin in Indian King Cobra venom, which plays an important role in envenomation consequences in experimental animal models. A group of non-peptidic toxins (OH-NPT1) was isolated from Indian King Cobra <i style="">Ophiophagus hannah</i> by thin layer chromatography and silica gel column chromatography. UV, IR, NMR and (ESI) TOF-MS studies characterized the OH-NPT1 as a mixture of aliphatic acids having molecular weights 256, 326 and 340Da.<b style=""> </b>The minimum lethal dose of OH-NPT1 was found to be 2.5 <img src='/image/spc_char/micro.gif'>g/20g (iv) and 4<img src='/image/spc_char/micro.gif'>g/20g (ip) in male albino mice. The cardiotoxic property of OH-NPT1 was established through studies on isolated guinea pig heart and auricle preparations, ECG studies in albino rat and estimation of LDH1/LDH and CPK-MB/CPK ratio in Swiss albino mice. Commercial antiserum failed to neutralize the lethality and cardiotoxicity of the toxin. However, calcium and magnesium effectively neutralized the lethal action.