贝母甲素对大鼠脑缺血再灌注损伤的保护作用

目的研究贝母甲素对大鼠脑缺血再灌注损伤的作用及其机制。方法将SD大鼠随机分为5组:正常组,模型组,贝母甲素2.5、5、10 mg组,每组15只大鼠。采用大脑中动脉线栓法制局灶性脑缺血模型,贝母甲素给药组大鼠在手术前10 d每日分别灌胃贝母甲素2.5、5、10 mg·kg-1,在手术24 h后再连续3 d分别灌胃贝母甲素2.5、5、10 mg·kg-1。正常组和模型组在同一时间灌胃等量生理盐水。给药结束后进行神经功能评分,HE染色观察脑组织损伤,检测超氧化物歧化酶(SOD)、丙二醛(MDA)和乳酸脱氢酶(LDH)的含量,免疫组化法检测细胞间黏附分子-1(ICAM-1)的表达,ELISA法检测白细胞介素(IL)-6、IL-18和IL-1β的含量,Western blotting法检测caspase-9、caspase-3、bax、bcl-2、LC3Ⅱ/LC3Ⅰ、beclin1、p62、PI3K、Akt和mTOR蛋白的表达。结果正常组大鼠神经功能评分为0分,模型组神经功能评分为(2.8±0.4)分。与模型组相比,贝母甲素2.5、5、10 mg组大鼠的神经功能评分显著降低(P <0.05),脑组织形态得到改善;caspase-9、caspase-3、bax表达显著下调,bcl-2表达显著上调(P <0.05);MDA和LDH含量显著降低,SOD含量显著升高(P <0.05);ICAM-1阳性细胞比率显著降低,IL-6、IL-18和IL-1β的含量明显降低(P <0.05);p62、PI3K、Akt和mTOR表达明显下调,LC3Ⅱ/LC3Ⅰ和beclin1表达明显上调(P <0.05),且效果随着给药量的增加而呈增强趋势。结论贝母甲素对大鼠脑缺血再灌注损伤起保护作用,减轻病理损伤和神经功能障碍,这可能与其抑制细胞凋亡、氧化应激和炎症反应,调节PI3K/Akt/mTOR自噬通路有关。

Protective effect of peimine on cerebral ischemia-reperfusion injury in rats

AIM To investigate the effect and mechanism of peimine on cerebral ischemia-reperfusion injury in rats. METHODS SD rats were randomly divided into 5 groups: normal group, model group and peimine 2.5, 5, 10 mg groups, 15 rats in each group. The focal cerebral ischemia model was replicated by middle cerebral artery occlusion. Before the surgery, rats in the drug-administered groups were administered intragastrically with peimine 2.5, 5 and 10 mg·kg-1 respectively for 10 days, and were administered intragastrically for 3 days after 24 hours of surgery. The normal group and the model group were given the same amount of normal saline at the same time. Then, the neurological function score was performed, the tissue damage was observed by HE staining, the contents of superoxide dismutase(SOD), malondialdehyde(MDA) and lactate dehydrogenase(LDH) were detected by kit, the expression of intercellular adhesion molecule-1(ICAM-1) was detected by immunohistochemistry, the contents of interleukin(IL)-6, IL-18 and IL-1β were detected by ELISA, and the expression of caspase-9, caspase-3, bax, bcl-2, LC3Ⅱ/LC3Ⅰ, beclin1, p62, PI3K, Akt and mTOR protein were detected by Western blotting. RESULTS The neural function score of normal group was 0, and that of model group was(2.8±0.4);compared with the model group, the neural function scores of the rats in the peimine 2.5, 5, and 10 mg groups were all significantly lower(P < 0.05), and the brain morphology was improved. The expressions of caspase-9, caspase-3 and bax were significantly down-regulated, and the expression of bcl-2 was significantly up-regulated(P < 0.05). The contents of MDA and LDH were significantly decreased, and the SOD content was significantly increased(P < 0.05). The ratio of ICAM-1 positive cells and the levels of IL-6, IL-18 and IL-1β were significantly decreased(P < 0.05). The expressions of p62, PI3K, Akt and mTOR were significantly down-regulated, and the expressions of LC3Ⅱ/LC3Ⅰ and beclin1 were significantly up-regulated(P < 0.05). These effects all had an increasing trend with the increase of dose. CONCLUSION Peimine has protective effects on cerebral ischemia-reperfusion injury in rats. This may be related to inhibition of apoptosis, oxidative stress and inflammatory response, reduction of pathological damage and neurological dysfunction, and regulation of the PI3K/Akt/mTOR autophagy pathway.