Evaluation of the antiplasmodial activity of Curcuma longa (turmeric - Zingiberaceae) on Plasmodium berghei in laboratory mice.

Malaria is a leading cause of morbidity and mortality worldwide, especially in developing countries and in sub-Saharan Africa where most malaria cases and deaths occur. The resistance of malaria parasites to most anti-malaria drugs, coupled with the high cost and the toxic effects of some drugs has posed a challenge for the search of new effective anti-malarial compounds of low cost. The study aims to determine the antiplasmodial activity of Curcuma longa against Plasmodium berghei in rodents. A total of 110 Swiss albino mice weighing 18-30 grams were used for the study: 35 for the toxicity test and 75 for the antimalarial study. For each test, 25 mice were inoculated with drug-sensitive Nk65 Plasmodium berghei and divided into five groups of five animals each and each group was administered one of the following: 120mg/kg of ethanol extract, 120mg/kg water extract, 120mg/kg nHexane extracts of C. longa, 1.2mg/kg of pyrimethamine or 5mg/kg of Chloroquine (positive control) and 0.2mls of normal saline (negative control). The lethal dose concentration was above 1500mg/kg and the extracts showed significant (P<0.05) antimalarial activity with the highest percentage inhibition (67.49%) recorded in the group treated with ethanol in the curative test, followed by the group given water in the suppressive test with (65.03%) and nHexane in the prophylactic test with percentage inhibition of 64.98%. There was a slight difference in the antimalarial activities of the extracts of different solvents which all had lower activities compared with the standard drugs (Chloroquine administered at 5mg/kg or pyrimethamine, 1.2mg/kg/day) but no total clearance of the parasite was recorded. C. longa possesses considerable antiplasmodial activity, which can be exploited in malaria therapy.