The effect of hydrogen peroxide, (H2O2) on Cryptosporidium parvum infection
and the protective function of free radical scavengers were studied in cul
tured bovine fallopian tubes epithelial cells. H2O2 treatment at 500 mu moL
/L and 1 mmol/L significantly inhibited excystation of bleach-treated oocys
ts (p < 0.01). At 48 h postinoculation, H2O2 at 500 and 750 mu mol/L result
ed in a significant (p < 0.01) decrease of C. parvum infection by 35.77% an
d 58.16% respectively in the cultured cells, when compared with the untreat
ed control. Surprisingly, the infection was significantly increased from 22
.21% to 39.33% (p < 0.05) with lower concentration of H2O2 (50 similar to 2
00 mu moL/L). The inhibitory and stimulatory effects of H2O2 treatment on C
. partum infection were, to a certain extent, abolished in the presence of
reduced glutathione or mannitol. These observations indicate that reactive
oxygen species, such as H2O2, may play an important role in C. parvum infec
tion.