基于PI3K/AKT信号通路研究草果知母汤对锂-匹罗卡品诱导的癫痫大鼠的神经保护作用

Neuroprotective Effect of Caoguo Zhimu Decoction Against Lithium-PilocarpineInduced Epilepsy in Rats: An Exploration Based on PI3K/AKT Signaling Pathway

目的:研究草果知母汤对锂-匹罗卡品诱导的癫痫大鼠的神经保护作用及对磷脂酰肌醇激酶(PI3K)/蛋白激酶B(AKT)信号通路的调节作用。方法:采用锂-匹罗卡品诱导建立癫痫大鼠模型,大鼠随机分为模型对照组、草果知母汤2.5、5、10 g/kg组及丙戊酸钠65 mg/kg组,另设正常对照组,各组灌胃给予相应药物或生理盐水,1次/d,连续4 w,测定大鼠海马组织丙二醛(MDA)、肿瘤坏死因子α(TNF-α)、白介素-6(IL-6)、白介素-1β(IL-1β)水平、超氧化物歧化酶(SOD)活性,Morris水迷宫测定大鼠学习记忆能力,苏木精-伊红(HE)染色检查大鼠海马组织CA1区病理学变化,Western blot检测大鼠海马组织PI3K、p-PI3K、AKT、p-AKT蛋白表达。结果:与正常对照组比较,模型对照组大鼠海马组织MDA、TNF-α、IL-6、IL-1β水平及Racine评分、逃避潜伏期明显升高(P<0.05),SOD活性、60 s内靶象限停留时间及穿过平台次数、海马组织p-PI3K/PI3K、p-AKT/AKT比值明显降低(P<0.05);与模型对照组比较,草果知母汤各剂量组大鼠海马组织MDA、TNF-α、IL-6、IL-1β水平及Racine评分、逃避潜伏期显著降低(P<0.05),SOD活性、60 s内靶象限停留时间及穿过平台次数、海马组织p-PI3K/PI3K、p-AKT/AKT比值明显升高(P<0.05),海马组织CA1区组织病理学改善。结论:草果知母汤能够改善锂-匹罗卡品诱导的癫痫大鼠的神经损伤,其机制可能与调节PI3K/AKT信号通路有关。

Objective: To study the neuroprotective effect of Caoguo Zhimu Decoction on lithium-pilocarpine-induced epilepsy in rats and its regulation of phosphatidylinositol 3-kinase(PI3 K)/protein kinase B(AKT) signaling pathway. Methods: The rats were exposed to lithium-pilocarpine to induce epilepsy and then randomized into the model group, sodium valproate(65 mg/kg) group, and low-(2.5 mg/kg), medium-(5 mg/kg), and high-dose(10 mg/kg) Caoguo Zhimu Decoction groups. The normal control group was also set up. Rats in each group were orally administrated with corresponding drugs or normal saline, once a day, for four successive weeks. The levels of malondialdehyde(MDA), tumor necrosis factor α(TNF-α), interleukin-6(IL-6), and interleukin-1β(IL-1β) and superoxide dismutase(SOD) activity in rat hippocampus were measured. The learning and memory ability of rats was tested using the Morris water maze. The pathological changes in hippocampal CA1 region were detected by hematoxylin-eosin(HE) staining. The protein expression levels of PI3 K, p-PI3 K, AKT and p-AKT in hippocampal tissue were assayed by Western blotting. Results: Compared with the normal control group, the model group exhibited significantly increased MDA, TNF-α, IL-6 and IL-1 β, Racine score, and escape latency(P<0.05) while decreased SOD activity, residence time in the target quadrant within 60 s, number of crossing the platform, p-PI3 K/PI3 K and p-AKT/AKT in hippocampus(P<0.05). Compared with the model group, Caoguo Zhimu Decoction at each dose significantly lowered the levels of MDA, TNF-α, IL-6 and IL-1 β, Racine score and escape latency in hippocampus(P<0.05), but elevated the SOD activity, residence time in the target quadrant within 60 s, number of crossing the platform, p-PI3 K/PI3 K and p-AKT/AKT(P<0.05). Besides, the pathological changes in hippocampal CA1 region were alleviated. Conclusion: Caoguo Zhimu Decoction ameliorates the nerve injury of epileptic rats induced by lithium-pilocarpine, which may be related to its regulation of PI3 K/AKT signaling pathway.