银杏叶提取物通过UCP2/SIRT3通路改善大鼠脑缺血-再灌注损伤

Ginkgo biloba extract ameliorates cerebral ischemia-reperfusion injury in rats via UCP2/SIRT3 pathway

目的:研究银杏叶提取物(EGb761)能否通过线粒体解偶联蛋白2(UCP2)/去乙酰化酶3(SIRT3)通路改善大鼠脑缺血再灌注(CIRI)损伤。方法:雄性SD大鼠分成以下四组:假手术组(sham)、脑缺血再灌注(CIRI)损伤组(CIRI)、银杏叶提取物组(EGb761)和UCP2抑制剂组(EGb761+Genipin)。对EGb761组和EGb761+Genipin组每天尾静脉注射10 mg/kg EGb761注射液,sham组和CIRI组给予尾静脉注射等剂量生理盐水,连续7 d;在第5~7 d,同时对EGb761+Genipin组每天灌胃50 mg/kg Genipin生理盐水溶液。末次给药次日,通过大脑左侧中动脉闭塞法(MCAO)构建大鼠脑CIRI模型。记录各组大鼠Longa神经功能评分和体重变化,取鼠脑制成石蜡切片,通过HE和尼氏染色并观察脑皮质损伤区病理变化;通过免疫组织化学技术检测脑皮质损伤区UCP2、SIRT3及天冬氨酸蛋白半胱氨酸酶3(caspase-3)的表达;收集动脉血,测定血清中总超氧化物歧化酶(SOD)活力和丙二醛(MDA)浓度。结果:与sham组比较,CIRI组大鼠神经功能评分上升(P<0.01),再灌注后体重减轻(P<0.01),脑组织病理损伤加重,UCP2、SIRT3表达减少,caspase-3表达增加(P<0.01),血清SOD活力下降,MDA浓度上升(P<0.01);与CIRI组比较,EGb761组大鼠神经功能评分下降(P<0.01),再灌注后体重增加(P<0.01),脑组织病理损伤减轻,UCP2、SIRT3表达增加,caspase-3表达减少(P<0.01),血清SOD活力增高,MDA浓度下降(P<0.01);与EGb761组比较,EGb761+Genipin组大鼠神经功能评分增加(P<0.05),再灌注后体重减轻(P<0.05),脑组织病理损伤较严重,UCP2、SIRT3表达减少,caspase-3表达增加(P<0.05),血清SOD活力下降,MDA浓度上升(P<0.01)。结论:EGb761可通过调控UCP2/SIRT3通路改善大鼠脑CIRI损伤。

Objective:To investigate whether Ginkgo biloba extract(EGb761)can ameliorate cerebral ischemiareperfusion(CIRI)injury in rats via the mitochondrial uncoupling protein 2(UCP2)/deacetylase 3(SIRT3)pathway.Methods:Male SD rats were divided into sham operation group(sham),cerebral ischemia reperfusion(CIRI)injury group(CIRI),ginkgo biloba extract group(ECb761)and UCP2 inhibitor group(ECb761+Geninpin).10 mg/kg EGb761 injection was given daily in tail vein for ECb761 group and EGb761+Genipin group,and equal doses of saline were given to the sham and CIRI groups for 7 consecutive days;on days of 5 to 7,50 mg/kg Genipin saline solution was simultaneously gavaged daily to the ECb761+Genipin group.On the day following the final administration,cerebral CI-RI model was constructed by the left middle cerebral artery occlusion method(MCAO).Longa neurobehavioral scores and body weight changes of rats in each group were recorded.Paraffin sections were taken from the brain of rats and pathological changes in the cortical damage area were observed by HE and Nissler staining.The expression of UCP2,SIRT3 and cysteine aspartate protease 3(caspase-3)in the cortical damage area was detected by immunohistochemistry.Arterial blood was collected,and total superoxide dismutase(SOD)activity and malondialdehyde(MDA)concentration in serum were measured.Result:Compared with the Sham group,rats in the CIRI group showed increased neurological deficit scores(P<0.01),decreased body weight after reperfusion(P<0.01),increased brain histopathological damage,decreased expression of UCP2 and SIRT3,increased expression of caspase-3(P<0.01),decreased serum SOD activiy and increased MDA concentration(P<0.O1);compared with the CIRI group,rats in the ECb761 group showed decreased neurological deficit scores(P<0.01),increased body weight after reperfusion(P<0.01),reduced brain histopathological damage,increased expression of UCP2 and SIRT3,decreased expression of caspase-3(P<0.01),increased serum SOD activity and decreased MDA concentration(P<0.01);compared with the EGb761 group,rats in the EGb761+Genipin group had increased neurological deficit scores(P<0.05),decreased body weight after reperfusion(P<0.05),more severe brain histopathological damage,decreased UCP2 and SIRT3 expression,increased caspase 3 expression(P<0.05),serum SOD activity decreased and MDA concentration increased(P<0.01).Conclusion:ECb761 may ameliorate CIRI injury in rats by regulating the UCP2/SIRT3 pathway.