藏红花素预处理对大鼠全脑缺血再灌注损伤保护作用及机制研究

Protective effect of crocin pretreatment on global cerebral ischemia reperfusion injury in rats

目的研究藏红花素预处理对大鼠全脑缺血再灌注损伤的保护作用及其机制。方法采用四动脉阻断法复制全脑缺血再灌注大鼠模型;藏红花素低、中、高剂量组分别于术前7 d开始1次/d ip给予10、20、40 mg/kg藏红花素,另设假手术组、模型组和尼莫地平(阳性药,1 mg/kg)组。测定脑电图恢复时间和翻正反射恢复时间;术后24 h评卒中指数和神经功能缺失评分;干湿比重法测定脑组织含水量;伊文氏蓝法检测血脑屏障(BBB)通透性;HE染色法行大脑皮层神经元病理学检查并进行病变分级;末端标记法(TUNEL)观察皮层神经元凋亡状况并计算凋亡指数;生化分析法测定氧自由基(ROS)、丙二醛(MDA)含量及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性;酶联免疫吸附法(ELISA)测定白介素(IL)-1β、肿瘤坏死因子(TNF-α)、IL-6、干扰素-γ(IFN-γ)水平。结果与模型组比较,藏红花素中、高剂量或尼莫地平预处理均明显缩短全脑缺血性脑损伤大鼠脑电图恢复时间和翻正反射恢复时间,降低卒中指数和神经功能缺失评分,抑制脑组织含水量升高和伊文氏蓝渗入,抑制缺血大脑皮层神经元病理性形态结构改变和病变等级的升高,抑制缺血大脑皮层神经元凋亡、降低凋亡指数,抑制ROS、MDA含量升高和SOD、CAT活性降低,抑制TNF-α、IL-1β、IL-6、IFN-γ含量升高,差异均具有统计学意义(P<0.05、0.01)。结论藏红花素预处理对大鼠全脑缺血再灌注损伤具有保护作用,机制可能与抑制氧化应激损伤和抑制炎症级联反应有关。

Objective To study the protective effect and mechanism of crocin pretreatment on global cerebral ischemia reperfusion in rats.Methods Four-artery occlusion was used to duplicate the rat model of cerebral ischemic injury.7 days before operation,the low,medium and high dose crocin pretreatment groups were given 10,20 and 40 mg/kg by ip injection once a day;another sham operation group,model group and nimodipine pretreatment group(positive drug,1 mg/kg)were set up.The electroencephalogram recovery time and the righting reflex recovery time were measured;24 h after operation,the stroke score and neurological symptom score were performed,the water content in brain tissue were determined by dry-wet specific gravity method,the permeability of blood brain barrier(BBB)was detected by evans blue method,the pathological examination of cerebral cortical neurons by HE staining and the pathological grading was carried out,the apoptosis of cortical neurons was detected by TUNEL and the apoptosis indes was calculated;the content of oxygen free radicals(ROS),MDA and the activities of superoxide dismutase(SOD)and catalase(CAT)were determined by biochemical analysis;the inflammatory cytokines content of IL-1β,TNF-α,IL-6,IFN-γwere determined by ELISA.Results Compared with model control group,the pretreatment of crocin with medium,high dose or nimodipine could shorten the recovery time of EEG and righting reflex in rats with cerebral ischemic injury,reduce stroke score and neurological symptom score,inhibit the increase of brain tissue water content and the infiltration of evans blue,inhibit pathological morphological and structural changes of cerebral cortical neurons on ischemic side,inhibit the apoptosis of ischemic cerebral neuronal and reduce the apoptosis index,inhibit the increase of ROS,MDA content and the decrease of SOD,CAT activities,Inhibit the increase of TNF-α,IL-1β,IL-6,IFN-γcontent;all of the difference was statistically significant(P<0.05 or 0.01).Conclusion crocin pretreatment has a protective effect on global cerebral ischemic reperfusion injury,and the mechanism may be related to inhibition of oxidative stress injury and inhibition of inflammatory response.