In vitro and in vivo antiplasmodial activity of extracts from Polyalthia suaveolens, Uvaria angolensis and Monodora tenuifolia (Annonaceae)
The present study aimed at investigating the in vitro and in vivo susceptibility of malaria parasites to crude extracts and fractions from Polyalthia suaveolens, Uvaria angolensis, and Monodora tenuifolia. The ethanolic extracts were partitioned using water, dichloromethane, hexane, and methanol. The most promising fraction was subjected to column chromatography. The antiplasmodial effect of extracts, fractions and subfractions against P. falciparum Chloroquine resistant (PfK1) strain was determined using SYBR green florescence assay. The promising fraction was assessed for cytotoxicity against Human Foreskin Fibroblast (HFF) cells and further for safety in Swiss albino mice and suppressive effect against P. berghei. The methanol sub-fraction of P. suaveolens [PStw(Ace)] showed the highest potency with IC50 of 3.24 μg/mL. Sub-fraction PS8 from PStw(Ace) was the most active with IC50 of 4.42 μg/mL. Oral administration of PStw(Ace) at 5000 mg/kg b.w in mice showed no signs of toxicity. Also, it exerted the highest suppressive effect against P. berghei at 400 mg/kg b.w throughout the 4 days experiment. Overall, the results achieved supported the use of the three plants in the traditional treatment of malaria in Cameroon. More interestingly, the PStw(Ace) fraction might be of interest in future development of an antimalarial phytodrug.
Keywords: Polyalthia suaveolens, Uvaria angolensis, Monodora tenuifolia, Plasmodium falciparum K1, Toxicity, Antimalarial.