In Vitro Neutralization of Naja naja Venom Enzymes by Folk Medicinal Plant Extracts

Medicinal plants are known to possess pharmacologically active compounds which have therapeutic properties and number of plants have been evaluated in disease management including venomous bites. Products of plant extracts are thus gaining importance because of their easy availability, low cost and less side effects and are evaluated for their antidote potential against Indian cobra (Naja naja) venom enzymes. In vitro enzyme inhibitions such as anti-proteolytic, anti-phospholipase, anti-hyaluronidase, anti-acetylcholine esterase and pharmacological studies (anti- hemolytic activity and anti-fibrinogenolytic activity) were evaluated for aqueous ethanolic extracts and organic extracts of Clerodendrum serratum, Azadirachta indica, Aegle marmelos, Aristolochia indica, Citrus limon, Calotropis gigantea, Cryptolepis buchanani and Butea monosperma on N. naja venom. Significant inhibitions were observed by both the extracts. However, it is interesting to note that aqueous extracts significantly inhibited phospholipase activity and organic extracts inhibited fibrinogenolytic activity of venom. The hyaluronidase activity was not observed in the venom. Indirect hemolytic assay revealed the potential of Butea monosperma extracts to completely neutralize the lysis of red blood cells (RBC) induced by cobra venom. The isolation of bioactive principles or a combination of these active principles, from the tested medicinal plants for ex vivo and in vivo anti-venom activity has to be validated by active isolated compound from extract which is responsible for neutralizing toxic snake venom enzymes.