白苏油改善自然衰老小鼠学习记忆的可能机制

Possible mechanism underlying the improvement of learning and memory by Baisu oil in naturally aging mice

目的:研究白苏油改善自然衰老小鼠学习记忆的可能机制。方法:使用超临界CO2萃取法提取的白苏油,按照0.8,1.6,2.4 g.kg-1.d-1的剂量给22月龄的老年小鼠灌胃给药,qd,连续灌胃10周后,使用开场实验,避暗实验和通道式水迷宫实验方法测定小鼠的学习记忆功能,再测定小鼠脑组织中抗氧化指标[超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)、丙二醛(MDA)]和部分单胺类神经递质等指标[一氧化氮(NO)、乙酰胆碱酯酶(AchE)、单胺氧化酶(MAO)、多巴胺(DA)]。实验同时设立22月龄老年小鼠的模型对照组和5月龄青年小鼠的正常对照组,均灌胃给予等体积的菜籽油(白苏油的溶剂)。结果:与正常对照(青年小鼠)比较,模型组(老年溶剂对照组)小鼠的学习和记忆能力显著降低(P<0.01),脑组织中SOD,GSH-Px和CAT酶活性均显著降低(P<0.01),MDA含量显著增加(P<0.01),脑组织DA和NO含量明显减少(P<0.01),AchE和MAO活性明显增加(P<0.01)。白苏油能逆转老年小鼠的学习和记忆能力的下降,以及小鼠脑组织中抗氧化酶(SOD,GSH-Px)和单胺类神经递质[NO,AchE,MAO,DA]等相关指标的改变,并呈现一定的剂量依赖性(P<0.05或P<0.01)。结论:白苏油改善自然衰老小鼠的学习记忆能力与其增强抗氧化酶的活性和提高部分单胺类神经递质的含量有关。

Objective： To investigate the possible mechanism underlying the improvement of learning and memory by Baisu oil in naturally aging mice. Methods： Baisu oil was prepared by supercritical CO2 extraction. The old Kunming mice （22 months＇ age） were orally received Baisu oil （0.8, 1.6 and 2.4 g. kg^-1.d^-1 ）, once a day, for successive 10 weeks. The learning and memory were observed using open field test, step-through test, and passageway water maze test; the antioxidant indexes [ superoxide dismutase （SOD）, glutathione peroxidase （GSH- Px） , catalase（CAT） and malonyldialdehyde（MDA） ] and monoamine neurotransmitters [ nitric oxide（NO） , acetylcholinesterase（AchE） , monoamine oxidase（MAO）, dopamine（DA） ] in the brain were determined. As the controls, old or young mice （5 months＇ age） fed rape oil （the solvent of Baisu oil）. Results：As compared with the young control, the learning and memory of the old mice were markedly impaired. The activities of SOD, GSH-Px, CAT and the level of DA and NO decreased; and the level of MDA, and the activity of AchE and MAO significantly increased in the brain of old mice. Baisu oil dose-dependently reversed the changes in learning and memory, antioxidant indexes and monoamine neurotransmitters in old mice （ P 〈 0.05 or P 〈 0.01 ）. Conclusion ： Baisu oil can improve the learning and memory in naturally aging mice ; this effect relates to modulation of antioxidant ability and monoamine neurotransmitters.