Pomegranate seed hydroalcoholic extract improves memory deficits in ovariectomized rats with permanent cerebral hypoperfusion /ischemia

OBJECTIVES Estrogen deficit following menopause results in cognitive behaviors impairment. This study aimed to evaluate the effects of pomegranate seed extract (PGSE) on avoidance memories after permanent bilateral common carotid arteries occlusion (2CCAO) in ovariectomized (OVX) rats. MATERIALS AND METHODS Adult female Wistar rats were divided randomly into eight groups with 8 rats in each group: 1) Sham-operated for ovaries and 2CCAO (ShO); 2) OVX and sham operated for ischemia (OShI); 3-7) OVX with 2CCAO (OI) received PGSE (100, 200, 400 and 800 mg/2ml/kg or normal saline, orally) for 14 days (OI+E100, 200, 400, 800 or OI+Veh); 8) OShI received most effective dose of PGSE (200 and 400 mg/kg for passive and active avoidance memories respectively). Active and passive avoidance tasks were measured in Y-maze and two-way shuttle box respectively. Data were analyzed with one-way and RM-ANOVA followed by HSD post-hoc test. RESULTS Sensorimotor impaired in OShI+Veh and OI+Veh (P<0.001 vs. ShO). PGSE improved it significantly in dose dependently manner (P<0.001 vs. OI+Veh). Both types of memories were significantly impaired in OVX rats before and after 2CCAO (P<0.001). PGSE treatment significantly improved memories in OI groups (P<0.05, P<0.01 and P<0.001) compared with OI+Veh. No toxicity was observed with PGSE consumption (800 mg/kg, 2 weeks, orally). CONCLUSION PGSE exhibits therapeutic potential for avoidance memories, which is most likely related at least in part to its phytoestrogenic and also antioxidative actions.