Oxidative stress and micronutrient therapy in malaria: an in vivo study in Plasmodium berghei infected mice.

Free radical production from oxidative stress induced by malaria infection plays a major role in the pathogenesis of malaria. However, the use of agents with antioxidant activity may interfere with malaria progression. The study involves an in vivo evaluation of the role of some antioxidant micronutrients in the modulation of malaria infection. Rodent malaria model using Plasmodium berghei NK-65 strain (chloroquine sensitive) was used for the study. Forty five mice of either sex weighing 20.05 +/- 0.02 g were procured for the study. Forty mice were inoculated intraperitoneally with 1 x 10(7) million Plasmodium berghei infected erythrocyte and were administered with 0.2 mL of distilled water, 0.2 mL of vehicle; Tween 80 (control and vehicle group), chloroquine 25 mg kg(-1) and artesunate 4 mg kg(-1) (standard drug group), vitamin A 60 mg kg(-1), vitamin E 100 mg kg(-1), selenium 1 mg kg(-1), zinc 100 mg kg(-1) (test group F, G, H and I, respectively) 72 hours post inoculation. Antioxidant micronutrients demonstrated significant (p < 0.05) schizonticidal activity when compared with negative control during the 4 day curative test. Erythrocyte membrane disability was most markedly elevated in the tween 80 group (426.15%), followed closely by the chloroquine (373.85%) treated group and artesunate group (329.23%) and least in the zinc treated group (32.31%). There was no significant (p > 0.05) difference in MCFI values (0.115 +/- 0.002; 0.114 +/- 0.002 g dL(-1)) between vitamin A treated group and selenium treated group respectively. However, this was significant (p < 0.05) between the micronutrient treated groups and the control (negative, positive and vehicle). Conclusively, antioxidant micronutrients have antimalarial activity which may be due potentiation of erythrocyte membrane stabilization.