Annual Research & Review in Biology

Antimalarial resistance is a major challenge for effective control of malaria. This triggered the need to monitor the efficacy of Azadirachta indica and Ocimum gratissimum in the disease management. The present study compared antimalarial activities of the leaf extracts of the individual plants and evaluated their combined effects on malaria infected mice. The leaves of the different plants were extracted with absolute ethanol (BDL 95%) for the test. Clean albino mice were experimentally infected intraperitoneally with chloroquine-sensitive Plasmodium berghei Nk65 strain. Parasitaemia level was determined before parasite inoculation and at 24 hours post treatment period. Efficacy of the leaf extracts was tested on the infected mice using Peter’s 4-days suppressive and curative tests, and secondary biological assessment procedures.The lethal median dose (LD₅₀) recorded for neem and clove basil leaf extracts were 31.62 and 1246.9 mg/kg body weight, respectively. Infected mice treated with leaf extracts of the plants and their combinations produced significant dose- dependent activity against the parasite (P<0.05). Highest reduction of parasitaemia was observed on day 4. Maximum parasitaemia reduction (78.65%) was attained with 30mg/kg of the combination of the extracts on the 7^th day. These observations indicate better anti-malarial activity of the combination therapy as compared with the individual extracts of the plants, and also show their good antimalarial potentials.