知母皂苷Ⅱ对老龄大鼠学习记忆行为及海马区神经元的影响

Effects of Timosaponin B-Ⅱ on learning and memory behavior and hippocampal neurons in aged rats

目的本实验研究知母皂苷BⅡ(Timosaponin B-Ⅱ,TB-Ⅱ)对自然衰老大鼠学习记忆能力的改善及海马区神经元的保护作用。方法 SD大鼠老年对照组(15只)、青年大鼠对照组(15只)、TB-II 1 mg/kg组(15只)、TB-II2 mg/kg组(15只)和TB-II 4 mg/kg组(15只)。Morris水迷宫实验测量动物逃避潜伏时间; Elisa法测定脑脊液IL-6和TNF-α含量; TUNEL法检测海马区凋亡神经元; HPLC法检测多巴胺、去甲肾上腺素和5-羟色胺含量。结果水迷宫实验显示老龄对照组逃避潜伏时间比青年对照组增加,差异有统计学意义(P <0. 05);给药组与老年对照组相比逃避潜伏时间明显缩短,差异有统计学意义(P <0. 05);给药组脑脊液IL-6和TNF-α浓度下降(P <0. 05);给药组海马区神经元凋亡减少(P <0. 05);给药组DA、NE和5-HT含量增加(P <0. 05)。结论知母皂苷BⅡ通过抑制大脑炎症介质生成和抑制海马区神经元凋亡,提高神经递质含量,明显改善自然衰老大鼠的学习和记忆能力。

Objective To investigate the effect of Timosaponin B-Ⅱ(TB-Ⅱ) on learning and memory ability and neuron protection in hippocampus of naturally aging rats.Methods SD rats were divided into the aged control group (15 rats),the young control group (15 rats),TB-Ⅱ 1 mg/kg group (15 rats),TB-Ⅱ 2 mg/kg group (15 rats) and TB-Ⅱ 4 mg/kg group (15 rats).Morris water maze test was used to measure the escape latency time of animals;Elisa method was used to determine the contents of IL-6 and TNF-α in cerebrospinal fluid;TUNEL method was used to detect apoptotic neurons in hippocampus;HPLC method was used to detect the contents of DA,NE and 5-HT.Results The water maze test showed that the escape latency time of the aged control group was longer than that of the young control group (P<0.05).The timosaponin B-Ⅱ group was significantly shortened than the aged control group (P<0.05),the concentration of IL-6 and TNF-alpha in cerebrospinal fluid was decreased (P<0.05),the apoptosis of hippocampal neurons was decreased (P<0.05),and the contents of DA,NE and 5-HT were increased (P<0.05).Conclusion Timosaponin B-Ⅱ could significantly improve the learning and memory abilities of naturally aging rats by inhibiting the production of inflammatory mediators in the brain and inhibiting neuronal apoptosis in the hippocampus.