effect of achillea millefolium aqueous extract on memory deficit and anxiety caused by stroke in ovariectomized rats

Introduction: some studies indicated that the decrease of estrogen level in menopausal woman results in increasing the risk of stroke. although estrogen is a neuroprotective factor, high consumption of this compound may develop breast cancer and endometriosis. the present study investigated the effect of achilles millefolium extract, containing estrogen-like compounds, on memory impairment and anxiogenic-like behaviors caused by cerebral ischemia in ovariectomized rats. methods: permanent middle cerebral artery ligation was performed, as a model for studying postmenopausal condition, in 48 female wistar rats weighing 200-250 g. the aqueous extract of a. millefolium was prepared and gavaged for 4 weeks after inducing cerebral ischemia. memory and anxiety-like behavior assessments were evaluated by step-through and elevated plus maze apparatus, respectively. result: according to the results, cerebral ischemia in ovariectomized rats induced amnesia and anxiogenic-like behaviors which were restored by 7 mg/kg of a. millefolium aqueous extract. furthermore, inactivation of estrogen receptors (ers) by tamoxifen (100 μg/kg, intraperitoneally) blocked the restoration effect of a. millefolium on behaviors induced by cerebral ischemia. conclusion: it could be concluded that, oral administration of a. millefolium extract is able to restore memory impairment and anxiogenic-like behaviors induced by ischemia via ers in ovariectomized rat.