Allahtavakoli Mohammad, Honari Najmeh, Pourabolli Iran, Kazemi Arababadi Mohammad, Ghafarian Hossein, Roohbakhsh Ali, Esmaeili Nadimi Ali, Shamsizadeh Ali
Physiology- Pharmacology Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran.
Department of Biology, School of Basic Sciences, Shahid Bahonar University of Kerman, Kerman, Iran.
Basic Clin Neurosci. 2015 Jul;6(3):185-92.
Lower level of estrogen hormone is considered as an important factor for loss of learning and memory in postmenopausal women. Although estrogen replacement therapy is used for compensation, but long-term usage of estrogen is associated with a higher risk of hormone-dependent cancers. Phytoestrogens, due to fewer side effects, have been proposed to prevent menopause-related cognitive decline.
24 female Wistar rats weighing 180-220 g were used in this study. The animals were ovariectomized and randomly divided into four groups including, control and two groups which received 8 and 80 mg/kg Vitex agnus castus (VAC) ethanolic extract orally. The last groups were treated with 40 μg/kg of estradiol valerat. Step-through passive avoidance (STPA) test was used for the evaluation of learning and memory. The hippocampal estrogen receptor α (ERα) expression was measured using Real-Time PCR.
The results demonstrated that VAC extract or estradiol had better performance on step-through passive avoidance test than control group (all P<0.05). Moreover, administration of either estradiol or VAC extract increased the hippocampal mRNA level of ERα and prevented the decrease in uterine weight of ovariectomized rats.
Based on our data, VAC extract improves learning and memory in ovariectomized rats. The positive effect of VAC extract on learning and memory is possibly associated with an increase in ERα gene expression in the hippocampal formation.
雌激素水平降低被认为是绝经后女性学习和记忆丧失的一个重要因素。尽管雌激素替代疗法被用于补偿，但长期使用雌激素会增加激素依赖性癌症的风险。由于副作用较少，植物雌激素已被提议用于预防与更年期相关的认知衰退。
本研究使用了24只体重180 - 220克的雌性Wistar大鼠。将这些动物进行卵巢切除，并随机分为四组，包括对照组以及两组分别口服8毫克/千克和80毫克/千克的贞洁树（VAC）乙醇提取物的组。最后一组用40微克/千克的戊酸雌二醇进行治疗。采用穿梭箱被动回避（STPA）试验来评估学习和记忆。使用实时定量聚合酶链反应（Real-Time PCR）测量海马体雌激素受体α（ERα）的表达。
结果表明，VAC提取物或雌二醇在穿梭箱被动回避试验中的表现优于对照组（所有P<0.05）。此外，给予雌二醇或VAC提取物均增加了ERα的海马体mRNA水平，并防止了去卵巢大鼠子宫重量的减轻。
根据我们的数据，VAC提取物可改善去卵巢大鼠的学习和记忆。VAC提取物对学习和记忆的积极作用可能与海马结构中ERα基因表达的增加有关。
