Varthemia persica DC. is an aromatic plant, from the Asteraceae family, wildly growing in the central provinces of Iran. Sesquiterpene lactones that are found in Varthemia species have protective effect against organophosphates toxicity. This study aimed to assess the Effect of Varthemia persica extract on acetylcholinesterase (AChE) activity. In this study, 0.4 mg normal saline was injected intra peritoneally in 12 control rats. 0.4 ml ethyl paraoxon was injected intraperitoneally in the reference group. In positive control group, after ethyl paraoxon injection, 0.4 ml pralidoxime was injected. In the first group (test 1) ethanolic Varthemia persica suspension was injected. In the second group (test 2), during the 6 days before toxin injection, daily injection of Varthemia persica was made. In test 3 group, suspension injection was repeated in 5 following days. In test 4 group, dichloroethanic suspension was injected. And in the last group (test 5) a high dose of suspension (1g/ml) was injected. The blood sample was collected 30 minutes after final injection. AChE activity was measure. The results showed that AChE activity was significantly improved only in the second and third groups and in other test groups, Varthemia persica suspension don’t improved AChE activity. Based on the present finding it seems that the Varthemia persica extract is only effective if it used frequently and a single dose even in high dose is not effective.
