Comparison of the effect of different concentrations of hydroalcoholic extracts of Sahendian savory (Satureja sahandica Bornm.) and oregano (Origanum vulgare L.) with metronidazole on giardia (Giardia lamblia) cysts in vitro

Giardiasis is an intestinal infection caused by the flagellate protozoan Giardia lamblia (synonyms: Giardia intestinalis and Giardia duodenalis). The characteristic of this disease are including worldwide distribution, high prevalence, and significant morbidity. Different studies relieved that the thymol content available in some medicinal plants has anti-giardiasis effect. Hence, based on adequate thymol in contents of both, Satureja sahandica and Origanum vulgare extracts, the aim of present research was comparison the effect of Satureja sahandica and Origanum vulgare Extracts with metronidazole on Giardia lamblia in vitro condition. In this experimental-laboratory study, 500 µl of each of 10, 100 and 200 mg/L concentrations of extracts and 125 mg/L of metronidazole was added to 500 µl of purified giardia cysts, respectively. In control groups normal saline used whereas these agents. The giardicidal activity of the extracts was measured 30, 60 and 120 min (s) after exposure through 0.1% eosin dye staining and microscopic enumeration method. Minimum, maximum and means lethal concentrations of treatments were calculated after three times in each group. Results relieved that anti-giardicidal effects of both extracts significantly increased due to rising the concentration and time. Based on present study findings and in accordance with others, it seems thymol content of SS and OV extracts were responsible for their anti-giardial activity. Meanwhile, further studies needed for clarify their exact mechanism of actions.