Evaluation of Bioactive Composition and Larvicidal activities of Garcinia kola Seeds on F2 Anopheles gambiae Complex Larvae (Diptera: Culicidae)

Abstract

Concerns of emerging and re-emerging mosquito-borne diseases has made control at larval stage primal. This study investigates the larvicidal biopotency of crude ethanolic and partially purified fractions of Garcinia kola seeds (GKs) on second filial (F2) progeny of A. gambiae larvae with a view to providing a pre-control data that would be useful in malaria and other mosquito-borne diseases’control strategies. Ethanolic extraction was done by maceration of chopped and dried GKs (35-45°C). Partial purification was performed using thin layer chromatography (TLC) cum column chromatography. Partially purified fractions were pulled into two (FA and FB), on the basis of salient chromatographic factors. Collection, culturing and identification of A. gambiae larvae complex larvae; determination of appropriate larvicidal concentrations for crude/partially purified fractions (FA and FB) and susceptibility of mosquito larvae, were all performed by WHO standardized protocols. Chemical characterization of GKs fractions (GCMS and FTIR) provided data on bioactive components of GKs. Larvicidal biopotency of Garcinia kola seeds peaked in Fraction B, (FB, LC50 = 608.097 μg/ml, LC90 = 859.763 μg/ml) compared to Fraction A (FA, LC50 = 842.748 μg/ml, LC90 = 924.651 μg/ml) and crude extract (LC50 = 1213.38 μg/ml, LC90 of 1616.14 μg/ml). GC-MS showed a relative abundance of Oleic acid (38.21 %), n-Propyl-9, 12-Octadedecadienoate (29.60 %) and Quinoline (2.63 %) over other compounds. FTIR presented variety of functional groups (-OH, -NH2, -OR, -C-C-,-C=C-,-C=C-). Our findings showed that fractions of GKs has effective larvicidal properties against A. gambiae complex larvae and may serve as alternative biocontrol remedy against mosquitoes at larval stage.