Antioxidant activity of the methanol stem bark extract of Uapaca togoensis (pax) in mice exposed to Plasmodium berghei NK65

 Oxidative stress has been linked to the development of systemic complications in malaria infection. Recent approaches in treatment of malaria suggest that the control of oxidative stress in infected patients may be of therapeutic advantage. The stem bark and leaves of Uapaca togoensis are used locally in the treatment of various diseases including malaria. This study aimed to evaluate the antioxidant activities of the methanol stem bark extract of the plant in Plasmodium berghei infected mice. Mice were inoculated intraperitoneally with 0.2 ml of parasitized erythrocytes and parasitemia level assessed after 72 h by the preparation of thin blood films stained with Geimsa stain. The mice were divided into five groups of six mice each. Groups I and V were administered with distilled water (10 ml/kg) and chloroquine (5 mg/kg) orally for four days. The extract at doses of 250, 500 and 1,000 mg/kg were orally administered to groups II, III and IV, respectively, for the same period. Mice were sacrificed under light chloroform. Blood was collected by cardiac puncture and centrifuged at 2,500 rpm for 15 minutes to obtain the serum. The serum was then analyzed to determine the levels of glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and lipid peroxidation product (malondialdehyde - MDA).  Oral median lethal dose of the methanol stem bark extract of Uapacatogoensis was estimated to be greater than 5,000 mg/kg. Administration of the extract to P. berghei infected mice produced a significant (p<0.05) increase in superoxide dismutase, reduced glutathione and catalase levels in. However, a significant (p<0.05) decrease in lipid peroxidation activity in the parasitized mice was observed. The plant possesses antioxidant property which can be exploited in the management of oxidative stress caused by malaria.