Introduction: Giardia lamblia, an intestinal flagellate, is a common cause of diarrhea in human, especially in school age children throughout the world. It is usually treated chemically by one of the three drugs of metronidazole, tinidazole or furazolidon, which have several side effects. On the other hand, garlic contains various chemical components, the therapeutic effects of which have been already proved on various diseases. The present study aimed at evaluating the effects of chloroformic garlic (Allium sativum) extract on Giardia lamblia as well as Giardia muris, both in vitro and in vivo.

Methods: Four and 8 mg of garlic extract was added to 1 ml of a suspensions containing 2000 G. muris and G. lamblia cysts separately and kept at 37° C. The cyst viability percentage was measured at 60 minute intervals using 0.1% eosin, until all cysts in test groups were dead. Furthermore, laboratory white mice were infected with Giardia cyst and divided into five groups of test and control. The test groups were fed with different doses of garlic extract, and then the therapeutic effects were evaluated by stool examination as well as autopsy for direct examine of mice intestines.

Results: The results showed that, garlic extract is completely effective on Giardia cyst. The cysts of G. lamblia were more sensitive to garlic extract than G. muris. Although, the infected mice in the test groups were not cured by the doses of 20 and 40 mg/kg body weight, they were compeletly cyst- free with the dose of 80 mg/kg within three days.

Hakim Research Journal 2006 9(3): 58 - 64.