Effect of Neocarya macrophylla root on Naja nigricollis venom

Abstract

Background and objective: Snake envenomation remain a public health problem, causing considerable morbidity and mortality especially in South Asia and sub-Saharan Africa. The study evaluated the antisnake venom activity of the methanol root extract, ethylacetate and n-butanol fractions of Neocarya macrophylla against Naja nigricollis venom.

Materials and Methods: The powdered plant material was macerated in 90% methanol and the extract was fractionated into n-hexane, chloroform, ethylacetate and n-butanol fractions. Preliminary phytochemical screening was conducted using standard procedures and acute toxicity was conducted according to Lorke's method. The antivenom studies was evaluated using both in vitro and in vivo studies in mice.

Results: The intraperitoneal LD₅₀ of the methanol root extract, ethylacetate and n-butanol fractions was found to be 118, 565 and 282 mg/kg, respectively. The extract and the two fractions exhibited significant in vitro antivenom activity with 100 % survival rate in mice. The extract and fractions were also able to inhibit the hydrolytic action of phospholipase A₂ enzyme activity. Minimal in vivo activity was observed for the methanol extract and ethylacetate fraction with 20 % survival rate and no protection was observed for the n-butanol fraction.

Conclusion: The results indicated that the root of Neocarya macrophylla possess antisnake venom activity thereby validating the ethnomedicinal claim of the use of the plant in the treatment of snakebite.