Occurrence of non-protein low molecular weight cardiotoxin in Indian King Cobra (Ophiophagus hannah) Cantor 1836, venom

摘要

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 nonproteinonpetide 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 Ophiophagus hannah 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. The minimum lethal dose of OH-NPT1 was found to be 2.5 microg/20g (iv) and 4microg/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.