Abstract
BACKGROUND: Malaria is one of the most important tropical diseases and the greatest cause of hospitalization and death. Recurring problems of drug resistance are reinforcing the need for finding new antimalarial drugs. In this respect, natural plant products are the main sources of biologically active compounds and have potential for the development of novel antimalarial drugs. A study was conducted to evaluate extracts of the leaves of Croton macrostachyus and Acokanthera schimperi for their in vivo antimalarial activity. METHODS: The plants were selected based on their ethnomedicinal information. Acute and sub- acute toxicity studies of the crude extracts were carried out in Swiss albino mice. To assess the effect of extracts of the plants on the parasite, a 4-day suppressive standard test was performed using Plasmodium berghei (ANKA strain). Data were analyzed using paired t-test and ANOVA. RESULTS: In acute toxicity study, the two plants extracts did not show any sign of toxicity up to 2000 mg/kg. In sub-acute toxicity study, both plants did not exhibit any hematological change and mortality throughout the observation period up to the highest dose of 1000 mg/kg given daily. Extracts of the leaves of both plants significantly (P < 0.05) suppressed parasitaemia in dose dependent manner at all dose levels. CONCLUSIONS: The findings may support the traditional use of the plants to treat malaria. Further pharmacological, toxicological and phytochemical studies are, however, required to evaluate the potential of the plants towards the development of new antimalarial agent.