FREE-RADICALS AND MALARIA

Oxidative stress may affect the malaria parasite at each stage of its development. Ascorbic acid had a stage-dependent effect on the in vitro development of Plasmodium falciparum. Addition of ascorbic acid to the early stage (ring forms) increased hypoxanthine incorporation but prevented the development of trophozoites to mature forms of the plasmodium. We also used DNA degradation to monitor the levels of redox-active iron-containing structures that can catalyse or promote the production of free radicals. We found that DNA was degraded upon incubation with lysates of infected red blood cells. Ascorbic acid was found to enhance the efficiency of degradation whereas the chelating agent diethylnetriaminepentaacetic acid inhibited the effect.