原花青素对大鼠蛛网膜下腔出血后脑血管痉挛的保护作用

Protective effect of proanthocyanidins on cerebral vasospasm after subarachnoid hemorrhage in rats

目的:探讨原花青素(PC)对大鼠蛛网膜下腔出血(SAH)后脑血管痉挛(CVS)的保护作用。方法:将32只健康SPF级Wistar大鼠随机分为正常对照组、SAH模型组、PC低剂量组(PC 50 mg/kg)和PC高剂量组(PC 100 mg/kg),采用枕大池注入自体动脉血法建立SAH模型,PC组通过灌胃给予上述浓度的PC 5 d,其余组给予相同体积的生理盐水。采用丙二醛(MDA)和总抗氧化能力(TAC)试剂盒测定大鼠脑组织中MDA和TAC水平。神经行为学评分检测大鼠行为学改变,通过对基底动脉(BA)切片的苏木精-伊红(HE)染色进行病理组织学检查以及测量管腔直径和壁厚分析大鼠血管痉挛程度。蛋白免疫印迹法检测Nrf2和HO-1的蛋白表达。结果:与正常对照组比较,SAH模型组大鼠MDA水平升高(P<0.01),TAC水平下降(P<0.05),神经行为学评分降低(P<0.001)。与SAH模型组比较,PC低高剂量组大鼠MDA水平下降,神经行为学评分升高(P<0.01),而在TAC水平上比较,差异无统计学意义(P>0.05)。此外,SAH模型组大鼠较正常对照组大鼠BA平均壁厚增加,平均管腔直径减小并伴随一定程度的内皮肿胀伴局灶性脱屑,而PC低高剂量组较SAH模型组动脉壁更薄,管腔直径更大(P<0.05)。与正常对照组比较,SAH模型组的Nrf2及其下游蛋白HO-1表达显著下调(P<0.001);与SAH模型组比较,PC低剂量组和PC高剂量组均可显着上调Nrf2/HO-1信号通路(P<0.01),且高剂量组效果更好(P<0.001)。结论:PC可能通过其抗氧化功效对大鼠SAH后CVS有保护作用,而抗氧化作用可能与Nrf2及HO-1信号通路有关。

Objective:To investigate the protective effect of proanthocyanidins(PC)on cerebral vasospasm(CVS)after subarachnoid hemorrhage(SAH)in rats.Methods:32 healthy SPF Wistar rats were randomly divided into normal control group,SAH model group,PC low-dose group(PC 50 mg/kg),and PC high-dose group(PC 100 mg/kg).The SAH model was established by cisterna magna injection of autologous arterial blood.The PC groups were given PC at the above concentrations for 5 days by intragastric administration,and the other groups were given the same volume of normal saline.Malondialdehyde(MDA)and total antioxidant capacity(TAC)kits were used to determine the MDA and TAC levels in rat brain tissues.Neurobehavioral score was used to detect the behavioral changes of rats.Hematoxylin-eosin(HE)staining of basilar artery(BA)sections was used for histopathological examination and measurement of lumen diameter and wall thickness to analyze the degree of vasospasm in rats.Western blotting was used to detect the protein expression of Nrf2 and HO-1.Results:Compared with the normal control group,the MDA level was increased(P<0.01),the TAC level was decreased(P<0.05),and the neurobehavioral score was decreased(P<0.001)in the SAH model group.Compared with the SAH model group,the MDA level of rats was decreased,and the neurobehavioral score was increased(P<0.01)in the PC low-dose and highdose groups,but there was no significant difference in terms of TAC level among SAH model group,PC low-dose and high-dose groups(P>0.05).In addition,the average wall thickness of BA was increased,and the average lumen diameter was decreased accompanied by a certain degree of endothelial swelling with focal desquamation in the SAH model group compared with the normal control group.Compared with the SAH model group,the BA wall in the PC lowdose and high-dose groups was thinner and the lumen diameter was larger(P<0.05).Compared with the normal control group,the expression of Nrf2 and its downstream protein HO-1 in the SAH model group were significantly down-regulated(P<0.001);compared with the model group,both the PC low-dose group and the PC highdose group could significantly up-regulate the Nrf2/HO-1 pathway(P<0.01),especially in the high-dose group(P<0.001).Conclusion:PC may have a protective effect on CVS after SAH in rats through its antioxidant effect,and the antioxidant effect may be related to the Nrf2/HO-1 signaling pathway.