Potential effect of methanol leaf extracts from three Podocarpus species on experimental cryptosporidiosis.

Cryptosporidiosis causes diarrhea in both immunocompetent and immunocompromised individuals, with acute manifestations occurring particularly in children and the elderly. Up till now, there is no curative therapy for cryptosporidiosis, so discovery of new classes of drugs are of great importance. This study aimed to examine the effect of methanol leaves extracts of the three Podocarpus species; P. macrophyllus (Thunb.), P. gracilior (Pilg.) and P. elongatus (Aiton) L' Hér. ex Pers and their combination on Cryptosporidium parvum (C. parvum) in experimentally infected mice in comparison with the commercially used drug, Nitazoxanide. As well as spectrophotometric estimation of the total phenolic and flavonoid content of these extracts was done. Results revealed that treatment with these three Podocarpus extracts and their combination showed a significant reduction of the number of C. parvum oocyst shed in the stool of infected mice compared to infected control group and Nitazoxanide- infected treated group at P < 0.001. The combination of the three Podocarpus extracts was the most effective treatment showing the lowest number of oocysts shedding in comparison with other used extracts and Nitazoxanide. Histopathological inspection of sections from ilium and colon displayed signs of improvement after treatment with P. macrophyllus and P. gracilior extracts and more remarkable improvement when the three extracts were combined. It was concluded that the three Podocarpus species extracts used in this study had a promising anti-Cryptosporidium activity especially when they were combined.