Pulp Extracts of Picralima nitida: a Larvicidal Agent in Malaria Vector Control

Abstract

The methanolic and aqueous pulp extracts of Picralima nitida as an eco-friendly alternative in malaria vector control were investigated. The sample yielded a 3.93% extract with methanol and 0.89% with aqueous. The phytochemicals constitutes of crude methanolic and aqueous extracts of P. nitida pulp include the alkaloids, cardiac glycosides, saponins, tannins, flavonoids, terpenes and steroids. Laboratory reared larvae of Anopheles gambiae 4th instar were exposed to varying concentrations of the P. nitida pulp extracts ranging from 0.5 to 5.0mg/ml, according to WHO Bioassay Methods for susceptibility. Probit analysis using statistical package for social sciences version 16.0, at (P<0.05) gave time dependent LC₅₀ and LC₉₅ values of 4.979 mg/ml and 18.541mg/ml, 4.299 mg/ml and 16.008 mg/ml and 2.792 mg/ml and 10.397 mg/ml for aqueous pulp extracts at 24, 48 and 72 hours while methanolic extract values were 12.285 and 96.993 mg/ml, 9.700 and 76.584 mg/ml and 6.490 and 51.236 mg/ml at 24h, 48h and 72 h respectively. The Relative Potency estimate revealed that methanolic extract has 1.525, 1.554 and 1.880 times the potency of aqueous extract at 24 h, 48 h and 72 h respectively.

Keywords: Picralima nitida, Eco-friendly, Insecticides, Resistance, Larvicidal.