The anti-malarial and biochemical studies of microglossa pyrifolia (lam.) ktze and trimeria grandifolia (hochst.) warb from Lake Victoria Basin, Kenya(Lam.) Ktze and Trimeria grandifolia (Hochst.) Warb from Lake Victoria Basin, Kenya

Abstract

ABSTRACT Malaria continues to kill over a million people each year, with more than 90% of these cases found in sub-Saharan Africa. In this work, two plants used as traditional medicine in the Lake Victoria basin; Microglossa pyrifolia (Lam.) Ktze. (compositae) and Trimeria grandifolia (Hochst.) Warb. (Flacourtiaceae),were investigated for their anti-plasmodial and biochemical principles. On the anti-plasmodial assay, aerial parts of M. pyrifolia methanol extract had the highest anti-plasmodial activity against P. falciparum chloroquine sensitive, D6 strain (IC50 1.59 ± 0.07 μg/ml) and chloroquine resistant, W2 strain (2.50 ± 0.15 μg/ml) strains. Similarly, the methanol extract of T. grandifolia showed activity (IC50 17.16 ± 0.03 μg/ml) and (IC50 19.21 ± 2.18 μg/ml) on D6 and W2 strains. All extracts subjected to cytotoxicity assay did not show any cytotoxic effect on Vero 199 cells (CC50 > 20 μg/ml). Extracts of M. pyrifolia and T. grandifolia were subjected to bioassay-guided fractionation. Pure and semi-pure compounds obtained were also subjected to antiplasmodial assay. Compound TGC 2 had activity on both D6 (IC50 9.78 ± 3.2 μg/ml) and W2 (14.4 ± 1.35 μg/ml) strains. Compound MPC 3 also showed activity on CQ sensitive D6 strain (IC50 11.12 ± 2.31 μg/ml). MPC 2 had a higher activity on CQ resistant strain W2 (IC50 24.22 ± 2.51 μg/ml) compared to CQ sensitive strain D6 (IC50 27.11 ± 1.18 μg/ml) although both activities were generally low according to KEMRI criteria. An interaction study was carried out using compound TGC 2 and chloroquine diphosphate. An additive interaction effect was observed with Fraction Inhibition Concentration [sum FIC (≥1 - <2)] Structure elucidation of T. grandifolia showed three compounds Idesin [6-hydroxy-2- (hydroxymethyl)phenyl β-D-glucopyranoside] TGC2 (61) of which is reported here for the first time, Lupenone [Lup-20(29)-en-3-one] TG 4 (62) and β- sitosterol [TGP 33 (63)] and one compound Friedelanol [MP24 (64)] from Microglossa pyrifolia