IN VIVO ANTIMALARIAL ACTIVITIES OF PLANTS USED IN ETHIOPIAN TRADITIONAL MEDICINE, DELOMENNA, SOUTHEAST ETHIOPIA

Abstract

BACKGROUND: Malaria constitutes one of the major health problems in Ethiopia. One of the reasons attributed for the upsurge was the development of resistance of Plasmodium falciparum and the emergence of multi-resistant strains of the parasite to antimalarial drugs. A continued search for other effective, safe and cheap plant-based antimalarial agents thus becomes imperative in the face of these difficulties. The objective of the present study was therefore to evaluate in vivo antimalarial activities and acute toxicity profiles of the aqueous and methanolic extracts of nine medicinal plants. METHODS: Nine plants which are commonly used for the treatment of malaria in the community were identified. The nine medicinal plants species Cissampelos mucronata, Clerodendrum myricoides, Gnidia stenophylla, Vernonia bipontini, Euclea scimperi, Solanum incanum, Plumbago zylanica, Warburgia ugandensis and Kalanchoe petitiana were evaluated for their antimalarial activity in vivo, in 4-day suppressive assays against Plasmodium berghei Anka strain in mice. RESULTS: No toxic effect or mortality was observed in mice treated orally with any of the extracts as a single dose of 1000mg/kg/day. At oral doses of 400mg/kg/day, the lyophilized aqueous root extract of Gnidia stenophylla, leaf extract of Vernonia bipontini, root extract of Euclea scimperi, Cissampelos mucronata, and Clerodendrum myricoides and methanolic leaf extract of Vernonia bipontini presented relatively high activities, among which three extracts reduced parasitemia by >50% when tested at an oral dose of 400mg/kg/day indicating that the plants are promising for further investigation. CONCLUSION: The results justify the use of these plants as traditional medicines for the treatment of malaria. Except the leaf extract of Cissampelos mucronata, the methanol extract of Clerodendrum myricoides and aqueous extract of Kalanchoe petitiana have inhibition of parasitemia above 10%. Further detailed pharmacological and toxicological studies are recommended for drug development.