In vivo antimalarial activity of the crude leaf extract and solvent fractions of Croton macrostachyus Hocsht. (Euphorbiaceae) against Plasmodium berghei in mice

BACKGROUND The issue of resistance in malarial infection makes development of novel drugs a necessity. An alternative source for discovering such drugs is natural products. Croton macrostachyus H. (Euphorbiaceae) is used in Ethiopian folklore medicine for the treatment of malaria and found to possess antimalarial activity in vitro. However, no further scientific investigations have been carried out to substantiate the claim. This study therefore aimed at investigating the in vivo antiplasmodial activity of 80% methanol extract and solvent fractions of the leaves of Croton macrostachyus H. in rodent model of malaria. METHODS A rodent malaria parasite, Plasmodium berghei, was used to inoculate healthy male Swiss Albino mice of age 6-8 weeks and weight 23-27 g. A hydro-alcoholic crude extract and the solvent fractions (chloroform, methanol and aqueous) were administered at different doses 200, 400 and 600 mg/kg. Parameters, including parasitemia, survival time, body weight, temperature, and packed cell volume were then determined using standard tests such as Peter's and Rane's test. RESULTS Chemoprotective effect exerted by the crude extract and fractions ranged between 44-91% and 12-76%, respectvely. The chemotherapeutic effect of the crude extract and chloroform fraction was in the range of 39-83% and 66-82%, respectively. Maximum effect in both tests was observed with the larger dose of the crude extract and chloroform fraction. The crude extract prevented loss of weight and reduction in temperature but did not affect packed cell volume. However, the chloroform fraction did also reverse reduction in packed cell volume due to the absence of saponins in the fraction. CONCLUSIONS The results collectively indicate that the plant has a promising antiplasmodial activity against Plasmodium berghei, which upholds the earlier in vitro findings as well as its folkloric use. Thus, it could be considred as a potential source to develop new antimalarial agents.