姜黄素对三叉神经痛大鼠认知功能障碍的影响

Effect of curcumin on cognitive dysfunction in a rat model of trigeminal neuralgia

目的评价姜黄素对三叉神经痛大鼠认知功能障碍的影响。方法健康成年雄性sD大鼠30只，体重200～250g，采用随机数字表法分为3组（n=10）：假手术组（Sham组）、三叉神经痛组（TN组）和三叉神经痛＋姜黄素组（TN＋Cur组）。TN组和TN＋Cur组于眶下神经鞘处注射蛇毒溶液4μl制备三叉神经痛模型；于造模后15d开始，TN组用花生油1．5m1灌胃，TN＋Cur组用45mg／kg姜黄素（溶于1．5ml花生油中）灌胃，早晚各1次，持续28d。于治疗结束后，采用Morris水迷宫实验检测认知功能，记录逃避潜伏期、游泳速度、目标象限停留时间比率和穿越平台次数，电镜下观察海马CA1区病理学结果，透射电镜下观察海马CA1区神经元、细胞器和突触的超微结构。结果3组间游泳速度比较差异无统计学意义（P〉0．05）；与Sham组比较，TN组第1～4天逃避潜伏期延长，目标象限停留时间比率降低，穿越平台次数减少，TN＋Cur组第3和4天逃避潜伏期延长（P〈0．01）；与TN组比较，TN＋Cur组第2～4天逃避潜伏期缩短，目标象限停留时间比率升高，穿越平台次数增加（P〈O．01），海马组织病理学损伤减轻。结论姜黄素可改善三叉神经痛大鼠认知功能障碍。

Objective To evaluate the effect of curcumin on cognitive dysfunction in a rat model of trigeminal neuralgia. Methods Thirty healthy adult male Sprague-Dawley rats, weighing 200-250 g, were randomly divided into 3 groups （n = 10 each） using a random number table： sham operation group （ Sham group） , trigeminal neuralgia group （ TN group） , and trigeminal neuralgia ＋ curcumin group （TN ＋ Cur group）. Trigeminal neuralgia was produced by injecting cobra venom solution 4μl into the sheath of the infraorbital nerve in TN and TN ＋ Cur groups. Starting from 15 days after establishment of the model, 1.5 ml peanut oil was injected through a gastric tube into stomach twice a day （in the morning and at night） for 28 consecutive days in TN group, and curcumin 45 mg/kg （dissolved in 1.5 ml peanut oil） was injected through a gastric tube into stomach twice a day （in the morning and at night） for 28 consecutive days in TN ＋ Cur group. The cognitive function was assessed using Morris water maze test after the end of treatment. The escape latency, swimming speed, ratio of time of staying at the target quadrant, and the number of times the animals crossing the platform were recorded. The pathological changes in the hippocampal CA 1 region were observed with an electron microscope. The ultrastructure of neurons, organelles and synapses in the hippocampal CA1 region was examined with a transmission electron microscope. Results There was no significant difference in the swimming speed between the three groups （P〉0.05）. Compared with Sham group, the escape latency on lst-4th days was significantly prolonged, the ratio of time of staying at the target quadrant was decreased, and the number of times the animals crossing the platform was decreased in TN group, and the escape latency was significantly prolonged on 3rd and 4th days in TN ＋ Cur group （P〈 0.01 ）. Compared with TN group, the escape latency on 2nd-4th days was significantly shortened, the ratio of time of staying at the target quadrant was increased, the number of times the animals crossing the platform was increased （P〈0.01）, and the pathological changes of hippocampal tissues were attenuated in TN ＋ Cur group. Conclusion Curcumin can improve cognitive dysfunction in a rat model of trigeminal neuralgia.