Anti-malaria activity of bioassay-guided fractionation of the crude ethanol extract of <i>Tithonia diversifolia</i> leaves

Abstract

Malaria has remained one of the most devastating diseases in tropical and sub-tropical regions of the world despite global effort at eradicating it. The use of natural products from plants have been very successful in the therapy of malaria especially in third world countries such as those in Africa where the people cannot afford the costly effective drugs. This study investigates the in vivo suppresstive anti-plasmodial activity of ethanol extract and fractions of T. diversifolia leaves using albino mice infected with Chloroquine-sensitive P. berghei (P. berghei^S) intraperitoneally. Possible effects on the haematological indices were monitored using standard laboratory protocols. Oral administration of the ethanol extract of T. diversifolia leaves to mice caused no death at doses ranging from 10-5,000 mg/kg. The relative presence of the phytochemical contents in the extract were in the order: reducing sugar > alkaloids > steroids > phenol > terpenoids > tannins > soluble carbohydrate. Ethanol crude extract of T. diversifolia at varying doses significantly (p<0.05) reduced parasitaemia compared to the fractions of the extract and chloroquine (10 mg/kg b.w) when administered separately in Plasmodium berghei infected mice. Out of the ten (10) fractions of the crude extract, C70:M30 fraction at 400 mg/kg b.w significantly (p<0.05) reduced parasitaemia compared to the other fractions. A significant (p<0.05) enhancement of the haematological indices was observed in the parasitized mice treated with the ethanol crude extract and C70:M30 fraction of T. diversifolia. The findings of this study suggests that the ethanol crude extract and bioactive fraction (C70:M30) of T. diversifolia leaves demonstrated antiplasmodial activity and boosted haematological indices in malaria infected mice.

Keywords: Malaria; haematology; chloroquine; phytochemicals