Role of anti-oxidant preparation (oxi-guard) on Cryptosporidium parvum infection in albino mice.

: Oxi-guard is a commercial anti-oxidant preparation in the form of capsules. One hundred and twenty albino mice were divided into three groups, first (50 mice) received oxi-guard for one week before infection with Cryptosporidium oocysts and continued for 50 days post-infection (P.I.), second (50 mice) did not receive oxi-guard and infected with Cryptosporidium oocysts and third (20 mice) was neither infected, nor receiving oxi-guard, a control group. Histopathological examination of small intestines and counting of endogenous stages of Cryptosporidium in the epithelial surface were done. Malonyldialdehyde (MDA) levels in small intestines were measured in all mice. It had been observed that the administration of oxi-guard led to significant increase in the numbers of endogenous stages of Cryptosporidium in the small intestines of group (1) in comparison with group (2). MDA levels showed a significant increase on the 15th, 20th and 25th days P.I. in group (2) and they did not show any significant changes in group (1) in comparison with the control group. As regards the activity of endogenous anti-oxidant enzymes in Cryptosporidium parvum oocysts, there was a significant increase in superoxide dismutase in group (2) of mice compared with its level in group (1). Finally, it can be concluded that the administration of oxi-guard had led to eradication of free radicals which in turn prevented their lethal effects on the parasite leading to increased parasitic colonization in the small intestine of mice.