anti-giardial activity of chloroformic extract of tanacetum parthenium and artemisia annua in vitro

background: giardiasis is a one of the most prevalent intestinal parasitic diseases in human, treatment of this disease through medicinal plants is very important since parasite resistance to chemical drugs exists. thus, in this study, the in vitro anti-giardial activity of chloroformic extract of tanacetum parthenium and artemisia annua on cyst and trophozoite of giardia lamblia were separately investigated.materials and methods: in this experimental study chloroformic extracts of artemisia annua and tanacetum parthenium on cyst and trophozoite of g. lamblia in vitro were prepared in 1, 10, 50 and 100 mg∕ml concentrations for 5, 10, 30, 60 and 180 min. purified cysts were used for encystations and culture in tyi-s-33 medium. then, 2 ml of each solution was placed in test tubes, to which 10,000 washed cysts and trophozoites were added. the contents of the tubes were gently mixed and incubated. the percentages of dead parasites were determined by counting 500 cysts. non treated parasites were considered a control group in each experiment and the viability of the parasites checked with eeosin staining and statistical analysis were done. results: the results showed that chloroformic extracts of a. annua at 100 mg/ml concentration affected on gardia cyst 86% and 100% trophozoite after 1 hour. t. parthenium at 50mg/ml concentration killed cysts (83%) and trophozite (100%) after 1 hour, respectively. t. parthenium chloroformic extract had a better effect on cyst and trophozoite of giardia at 50 mg/ml after 1 hour exposure than a. annua extract. conclusion: according to this study, a. annua and t. parthenium chlorofomic extracts could be considered as a more effective anti-giardial agent. chloroformic extract of t. parthenium was also shown the anti-giardial activity compared with a. annua and control groups at all exposure times. therefore, in the future research using these plants are recommended against giardia in low concentration in the in vivo, also to find fractions of the pharmacological effects of these plants.