BackgroundDue to increasing problems of inadequate and unreliable medical treatments for Cryptosporidium enteritis, alternative therapies are being sought. ObjectiveThe current study was designed to evaluate the prophylactic and therapeutic efficacy of Allium sativum (garlic) against Cryptosporidium infection in experimentally infected immunocompetent and immunosuppressed mice. MethodsForty eight male Swiss albino mice were divided equally into control and experimental groups. Each group was further subdivided into four equal subgroups; two immunosuppressed and two immunocompetent. Cryptosporidial oocysts were isolated from human stools, and were used to infect the mice. The experimental subgroups received garlic orally two days before infection or one day following infection, and continued daily till the end of the study. Two weeks following garlic administration, mice stools were examined for counting the cryptosporidial oocysts, then the animals were sacrificed; their small intestines were processed and were examined for detection of the pathological lesions and for counting of the parasites. Also, myeloperoxidase (MPO) activity was measured in jejunal sections. ResultsThe results showed that the infected immunosuppressed subgroups of mice; showed a statistically significant increase in the number of cryptosporidial oocysts in stool and ileal sections, as well as an increase in the MPO activity when compared to the corresponding immunocompetent subgroups. Garlic successfully eradicated the Cryptosporidium oocysts from stool and intestinal sections of the infected immunocompetent subgroup of mice receiving garlic two days before the infection. Besides, the oocysts were significantly reduced in all other infected experimental subgroups in comparison to the corresponding infected control subgroups. The intestinal sections of all subgroups received garlic before or after the infection, revealed a more or less normal architecture. Reduction in the level of MPO activity was also detected in all experimental subgroups. ConclusionOur findings suggest that garlic is a convenient prophylactic and a promising therapeutic agent for cryptosporidial infection.