Efficacy of nitazoxanide, tizoxanide and tizoxanide glucuronide against Cryptosporidium parvum development in sporozoite-infected HCT-8 enterocytic cells

The effects of nitazoxanide and its metabolites, tizoxanide and tizoxanide glucuronide, on the development of the asexual and sexual stages of Cryptos poridium parvum in differentiated human enterocytic HCT-8 cells were evalua ted in a quantitative alkaline phosphatase immunoassay. Nitazoxanide, tizox anide and tizoxanide glucuronide were inhibitory for up to 46 h when added after sporozoite invasion (MIC50 1.2, 22.6 and 2.2 mg/L, respectively). Tiz oxanide had only limited activity, but nitazoxanide and tizoxanide glucuron ide strongly inhibited asexual and sexual stages, respectively.