Neutralization Effect of <i>Tithonia diversifolia</i> (Hemsl.) A. Gray against Bitis arietans and <i>Naja nigricollis</i> venoms-induced toxicity

Abstract

Leaf methanol extract and fractions of Tithonia diversifolia (Hemsl.) A. Gray (Asteraceae) used in traditional medicine was evaluated for neutralization of toxicity induced by Bitis arietans and Naja nigricollis snake venoms in mice and rats. Inhibition of adenosine diphosphate-induced platelet aggregation, antioxidant activity, total phenol content and neutralization of venom-induced toxicity were evaluated by standard methods. The methanol extract was the most active inhibitor of platelet aggregation (66.7 - 84.8%) in the B. arietans model at 100 - 500 μg/ml. The methanol extract and fractions appear to be equipotent  in inhibiting platelet aggregation (68 - 74%) induced by N. nigricollis. The aqueous fraction was more active against B. arietans venom at 500 μg/ml as an inhibitor of platelet aggregation (59.4% inhibition), while the dichloromethane (DCM) fraction was more potent against N. nigricollis (70.97% inhibition). The methanol extract showed highest DPPH radical scavenging activity followed by the aqueous and DCM fractions. Total phenolic content was in the order: methanol extract > DCM fraction > aqueous fraction. The aqueous fraction was a better antivenin agent in both B. arietans (complete protection at 24 h) and N. nigricollis-envenomed mice and rat models. Anti-snake venom activity was more prominent at 24 h. The results herein, being the very first report, indicate the potential antiophidic activity of T. diversifolia leaf particularly against B. arietans-induced toxicity.