金钗石斛对衰老模型大鼠术后认知功能的影响及机制研究

Study on the effect of Dendrobium nobile lindl on postoperative cognitive function and mechanism of aging model rats

摘要:

目的 探讨金钗石斛（DNL）对衰老模型大鼠术后认知功能的影响及机制。方法 选择4月龄SD雄性大鼠60只，连续42 d颈背部皮下注射10% D-半乳糖0.125 g/（kg·d）复制衰老模型大鼠，随机分为对照组、POCD+DNL组及POCD组，每组20只。对照组不作处理，POCD+DNL组及POCD组在七氟烷麻醉下行单侧肾切除术。大鼠于麻醉苏醒2 h后灌胃，POCD+DNL组以10 g/（kg·d） DNL水煎剂进行连续灌胃，POCD组与对照组给予相同体积生理盐水灌胃。依据术后不同灌胃时间每组再分为7 d、14 d两个亚组，每亚组10只。采用Morris水迷宫观察各组大鼠行为学表现；采用HE染色观察大鼠海马神经元细胞形态变化；采用ELISA法检测大鼠血清IL-1β、IL-6、TNF-α水平；采用Western blotting检测大鼠海马NF-κB、IκBα蛋白表达。结果 与对照组及POCD+DNL组比较，POCD组大鼠的逃避潜伏期延长（P <0.05）；大鼠海马HE染色结果显示，与对照组及POCD+DNL组比较，POCD组海马神经元细胞排列松散，细胞形态不规则，细胞核固缩，染色较深；与对照组及POCD+DNL组比较，POCD组血清IL-1β、IL-6、TNF-α水平升高（P <0.05）；与对照组及POCD+DNL组同时间点比较，POCD组海马NF-κB蛋白相对表达量升高（P <0.05）；与对照组及POCD+DNL组同时间点比较，POCD组海马IκBα蛋白相对表达量降低（P <0.05）。结论 DNL连续灌胃可改善衰老模型大鼠术后认知功能障碍、减轻神经细胞的损伤程度，降低炎症因子水平，这可能是通过抗炎作用及抑制NF-κB信号通路来减轻神经炎症、改善术后认知功能障碍。

Abstract:

Objective To explore the effect and mechanism of Dendrobium nobile lindl on postoperative cognitive function in aging model rats.Methods Sixty 4-month-old male SD rats were selected and subcutaneously injected with 10% D-galactose 0.125 g/ (kg·d) on the back of the neck for 42 consecutive days (d) to establish an aging rat model. Then they were randomly divided into control group, treatment group, and model group, with 20 rats in each group. The control group was not treated with modeling, and the model group and the treatment group underwent unilateral nephrectomy under sevoflurane anesthesia. Then, the rats were given intragastric administration 2 hours (h) after awakening from anesthesia. The treatment group was given the decoction [10 g/ (kg·d) ] of Dendrobium nobile lindl for continuous intragastric administration. The model group and the control group were given the same volume of normal saline for intragastric administration. According to the different time of gastric perfusion after operation, the rats were divided into two subgroups: 7 d and 14 d groups, with 10 rats in each subgroup. Morris water maze was used to observe the behavioral performance of the rats in each group. HE staining was used to observe the morphological changes of rats' hippocampal neurons. ELISA was used to detect the levels of inflammatory factors in rat serum. Western blot was used to detect the expression of NF-κB and IκBα protein in rat hippocampus.Results Compared with the control group and the treatment group, the escape latency of the rats from the model group was significantly prolonged (P < 0.05). According to the results of HE staining, compared with the control group and the treatment group, the hippocampal neurons in the model group were loosely arranged and the cell morphology was irregular. Nucleus was pyknosis with drak staining was detected. Compared with the control group and the treatment group, the serum inflammatory factor levels in the model group were significantly increased (P < 0.05). Compared with the control group and the treatment group at the same time point, the hippocampal NF-κB protein expression of the model group was significantly increased (P < 0.05). Compared with the control group and the treatment group at the same time point, the hippocampal IκBα protein expression of the model group was significantly decreased (P < 0.05).Conclusion Continuous intragastric administration of Dendrobium nobile lindl can significantly improve postoperative cognitive function damage and reduce nerve cellular injury and inflammatory factor levels in aging rats. It may play an important role in reducing neuroinflammation and improving postoperative cognitive disorders (POCD) through anti-inflammation and inhibition of NF-κB signaling pathway.