The Effect of Vitamins C and E on Nitric Oxide Elevation to enhance killing of phagocytised Tachizoites of Toxoplasma gondii in BALB/c mice

Toxoplasma gondii is an obligatory intracellular parasite causes toxoplasmosis. The parasite has two forms, noninvasive bradizoites and invasive tachizoites. The present study, for the first time, aimed to evaluate the effect of vitamins C and E on nitric oxide (NO) elevation to promote killing invasive tachizoites by macrophages in susceptible BALB/c mice.

Seventy BALB/c mice were recruited and randomly divided into fourteen groups of five (n=5). Control groups: one group left intact. Two groups were given saline or methanol. Two groups were infected with 104 or 5×104 parasites. The other groups were administrated only vitamin C, E, or both. The rest of sample and control groups were infected with either 104 or 5×104 tachizoites and supplemented with 100 µl vitamin E every other day, or 200 µl of vitamin C daily. Vitamins were intraperitoneally administered up to five days. On sixth day mice were intraperitoneally infected with tachyzoites. The blood samples were taken three days post infection, serum collected and stored at - 20 Cº until examinations. The peritoneal macrophages were isolated for counting phagocytised tachyzoites and nitric oxide assays.

Tachyzoites were significantly decreased after vitamin C & E administration in the infected mice compared to the controls. In mice supplemented vitamins NO levels were significantly higher compared to controls.

Our findings showed that administration of vitamin C, E or both significantly enhanced killing invasive parasites through NO elevation produced by activated macrophages and may have therefore, complementary therapeutic effects.