绿茶多酚预防老龄C57BL/6J小鼠学习记忆功能衰退实验研究

Green Tea Polyphenols Prevents the Age-related Decline of Learning and Memory Ability of C57BL/6J Mice

为了研究绿茶多酚对自然衰老的C57BL/6J小鼠学习记忆衰退的预防作用,将14月龄的C57BL/6J小鼠60只随机分为老年对照组和绿茶多酚低、中、高剂量干预组,绿茶多酚掺入小鼠饮水中,剂量分别为0.025%、0.05%和0.1%(W/V),另设1月龄青年对照组。干预6个月后,运用Morris水迷宫、跳台实验检测小鼠的空间学习记忆能力和被动回避记忆能力。结果发现,在Morris水迷宫实验中,0.05%和0.1%剂量的绿茶多酚干预能够明显缩短老年小鼠定位航行实验的逃避潜伏期和游泳距离,显著提高老年小鼠空间探索实验的目标象限持续时间和穿越平台区次数,达到青年对照组水平,并且能够明显提高跳台实验中老年小鼠的跳台记忆潜伏期。同时该两个剂量的绿茶多酚能够提高小鼠血清超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-PX)的活性,增加海马脑区突触后致密物-95(PSD95)和钙离子/钙调素依赖性蛋白激酶II(CaMKII)的蛋白表达。以上结果表明0.05%、0.1%剂量的绿茶多酚能够预防老年C57BL/6J小鼠学习记忆功能的减退,其抗氧化作用和调节神经突触相关蛋白的表达为其可能的作用机制。

To investigate the effect of Green Tea Polyphenols （GTP） on the degeneration of learning and memory ability in aged C57BL/6J mice, 14 month old C57BL/6J mice were randomly divided into aged control group and three GTP administration groups GTP was dissolved into the drinking water with a concentration of 0.025%, 0.05% and 0.1%（W/V）, respectively. After six months, the learning and memory abilities of the mice were checked by Morris water maze and step-down test. Thereafter, the serum of the mice was collected to measure the levels of SOD and GSH-Px. The protein levels of post synaptic density protein 95 （PSD95） and Ca^2＋/calmodulin-dependent protein kinase Ⅱ （CaMKⅡ） were examined using Western blot 0.05% and 0.1% GTP administration can significantly shorten the escape latencies and swim distances of the mice in a place navigation test, increase the time spending in the target quadrant and the crossing numbers in a spatial probe test, and increase the latency to step down in the step-down test. It is shown, 0.5% and 0.1% GTP administrations have significantly raised the activities of SOD and GSH-Px in the serum and prevented the age-related reductions of two representative post synaptic density proteins PSD95 and CaMKⅡ. 0.05% and 0.1% GTP in the drinking water can significantly prevent the decline of learning and memory ability in aged C57BL/6J mice. Besides its antioxidant ability, GTP may also regulate some learning and memory related proteins.