Evaluation of the in-vivo Antiplasmodial Activities of Ochna membranacea (Oliv) Ochnaceae Leaves and Stembark extracts in mice

Abstract

Malaria is an infectious disease with high mortality rate in Africa. Development of resistance to antimalarial drugs in current clinical use such as chloroquine and Artemisinin; along with poor health systems and funding shortfalls have elevated the importance of continuous search for novel antimalarial agents. The lead compounds from which chloroquine and artemisinin were derived were isolated from plants. Therefore, there is high potential for the discovery of new and effective treatment from plants. Ochna membranacea (Oliv) Ochnaceae is among several plants used traditionally against infectious diseases including malaria with no scientific validation. This study investigated the antiplasmodial effect of the crude methanol leaves extract and crude methanol stembark extract of Ochna membranacea coded OMCLE and OMCSE respectively against Plasmodium berghei chloroquine-resistant strain. Acute toxicity studies were carried out using standard protocol. The prophylactic, suppressive and curative effects of the extracts were evaluated at the doses of 500, 1000 and 1500 mg/kg using Ryley and Peters’ method. Chloroquine (5 mg/kg) and artesunate (5 mg/kg) were used as standard drugs in the suppressive and curative tests, while 1.2 mg/kg pyrimethamine was used as standard in the prophylactic test. The oral median lethal dose (LD₅₀) was estimated to be > 5000 mg/kg. All graded doses of OMCLE gave a statistically significant (P<0.05) prophylactic effect. Only the median and highest doses of OMCSE gave significant inhibition of parasitaemia. In the suppressive test, all tested doses of both extracts exhibited significant suppression of parasitaemia compared to the negative control. In conclusion, the study suggests that O. membranaceapossesses antiplasmodial activity making it a potent candidate in the search for newer antimalarials.