Abstract:
Background: Resistances to currently available drugs and insecticides, significant drug toxicities and costs and lack of vaccines currently complicated the treatment of malaria. A continued search for safe, effective and affordable plant-based antimalarial agents, as evident from history, thus becomes crucial and vital in the face of these difficulties.
Objective: To evaluate the antimalarial activity of 80% methanolic extract of the seeds of Brassica nigra against Plasmodium berghei infection in mice.
Method: The seed of Brassica nigra was extracted by 80% methanol using maceration method. Chloroquine sensitive Plasmodium berghei (ANKA strain) was used to test the antimalarial activity of the extract. In suppressive and prophylactic models, Swiss albino mice of either sex were randomly grouped into five groups of five mice each. Group I mice were treated with the vehicle (distilled water, 10 ml/kg), group II, III and IV were treated with 100, 200, and 400 mg/kg of the extract, respectively and the last group (V) mice were treated with chloroquine (10 mg/kg). The level of parasitemia, survival time and variation in weight of mice were used to determine the antimalarial activity of the extract.
Results: Chemosuppressive activities produced by the extract of the seeds of Brassica nigra were 21.88%, 50.00% (P < 0.01) and 53.13% (P < 0.01) suppression, while the chemoprophylactic activities were 17.42%, 21.21% and 53.79% (P < 0.05) suppression at 100, 200 and 400 mg/kg of the extract, respectively as compared to the negative control. The extract treated mice were significantly (P < 0.05) lived longer and gained weight as compared to negative control at 200 and 400 mg/kg of the extract in suppressive test.
Conclusion: From this study, it can be concluded that the seed of Brassica nigra showed good chemosuppressive and moderate chemoprophylactic activities and the plant may contain biologically active principles which are relevant in the treatment and prophylaxis of malaria, thus supporting further studies of the plant for its active components.
