Relative potency of ethanol extracts of stem bark of Sacoglottis gabonensis and seeds of Picralima nitida to larvae of Anopheles gambiae

Abstract

Sacoglottis gabonensis and Picralima nitida are medicinal plants that are of great value in folk medicine in West Africa. This study was aimed at determining the relative potency of ethanol stem bark extract of S. gabonensis and seed extract of P. nitida to mosquito larvae. Potency of extracts was evaluated in static bioassays on fourth instar larvae of Anopheles gambiae at concentrations of 0.45, 0.60 and 0.75%w/v. Observations were made at 24 and 48 hours. Larval mortalities of 100% and 78.33% were recorded for 0.75% w/v of ethanol stem bark of S. gabonensis and seeds of P.nitida respectively at the end of 48 hours. At same exposure period, 0.45 and 0.60%w/v of ethanol stem bark of S. gabonensis resulted in 56.66 and 85.00% mortalities of larvae respectively. The same concentration and exposure period resulted in mortalities of 28.33 and 46.66% using ethanol seed of P. nitida. Ethanol stem bark of S. gabonensis was more potent than ethanol seed extract of P.nitida. Larvae in the controls were agile throughout the duration of experiment. Thus stem bark of S. gabonensis and seed of P.nitida are potential agents for the control of An. gambiae which is one of the vectors of malaria and filariasis.

Key Words: Relative potency, Sacoglottis gabonensis, Picralima nitida, Anopheles gambiae