红花黄色素对缺血性脑室周围白质软化新生鼠脑保护作用及机制研究

目的]探讨红花黄色素对缺血性脑室周围白质软化(PVL)新生鼠的脑保护作用及机制。方法]选取健康清洁级新生7日龄大鼠60只,随机分为假手术组、模型组、阳性对照组、红花组各15只。假手术组游离两侧颈总动脉后不结扎直接进行缝合,不给予用药处理;其他组均建造新生鼠PVL模型,阳性对照组造模成功后立即给予重组促红细胞生成素(r EPO)5 000 IU/kg腹腔注射,红花组造模成功后立即给予红花黄色素3 mg/kg腹腔注射,模型组不给予用药处理。48 h后处死大鼠,苏木精-伊红(HE)染色分析脑组织的病理变化,用分光光度法对超氧化物歧化酶(SOD)、过氧化物酶(CAT)、谷胱甘肽过氧化酶(GPx)、丙二醛(MDA)及谷胱甘肽(GSH)的含量进行检测,用免疫组化法检测各组幼鼠脑室周围白质损伤标志物O4、MBP、CX47、nestin表达,用免疫印迹法检测细胞凋亡相关蛋白Bax、Bcl-2、Caspase-9及Caspase3活化片段表达。结果]阳性对照组、红花组脑白质整体损伤程度明显轻于模型组(P0.05);模型组大鼠O4、MBP、CX47阳性细胞数明显低于假手术组,Nestin阳性细胞数明显高于假手术组(均达到P0.05);与模型组比较,阳性对照组、红花组O4、MBP、CX47及Nestin阳性细胞数均明显升高(P0.05);模型组大鼠GPx、SOD、CAT及GSH水平明显低于假手术组,MDA水平明显高于假手术组(均达到P0.05);与模型组比较,阳性对照组、红花组GPx、SOD、CAT及GSH水平均明显升高,MDA水平明显降低(均达到P0.05);与假手术组比较,模型组Bax表达明显升高,Bcl-2表达明显降低,Cleaved Caspase-9及Cleaved Caspase-3激活均明显增加(P0.05);与模型组比较,阳性对照组及红花组Bax表达明显降低,Bcl2表达明显升高,Cleaved Caspase-9及Cleaved Caspase-3激活均明显降低(P0.05)。结论]红花黄色素对新生鼠缺血性脑室周围白质损伤有保护作用,其作用机制不仅与调节抗氧化系统有关,还可能与调节细胞凋亡相关因子有关。

Protective effect of safflower yellow pigment on periventricular leukomalacia of ischemic rats and its mechanism

Objective] To investigate the cerebral protective effect and mechanism of safflower yellow pigment on neonatal mice with periventricular leukomalacia (PVL).Methods] Sixty healthy and clean newborn 7-day old rats were randomly divided into sham operation group, model group, positive control group and safflower groupeach (each 15). In the sham operation group, the common carotid arteries on both sides were dissociated and sutured without ligation, no medication was given. PVL model of newborn mice were built in other groups. The positive control group was given recombinant erythropoietin (rEPO) 5 000 IU/kg intraperitoneal injection immediately after successful modeling. 3 mg/kg safflower yellow pigment was immediately given intraperitoneal injection in the safflower group after successful modeling.The model group was not given medication. After 48 h, rats were sacrificed and the pathological changes of brain tissues were analyzed by HE staining. The contents of SOD, CAT, GPx, MDA and GSH were determined by spectrophotometry and immunohistochemical method was used to detect the expressions of O4, MBP, CX47 and nestin, markers of white matter injury around the ventricle of each group. The expression of Bax, bcl-2, cleaved caspase-9 and cleaved caspase-3 were detected by western blot.Results] Compared with the model group, the level of the whole brain white matter damage in the positive control group and the safflower group was significantly lower than that in the model group (P<0.05). The number of O4, MBP and CX47 positive cells in the model group was significantly lower than that in the sham group, and the number of Nestin positive cells was significantly higher than that in the sham group. (P<0.05). Compared with the model group, O4, MBP, CX47 and Nestin positive cells were significantly increased in the positive control group and the safflower group (P<0.05). GPx, SOD, CAT and GSH levels in the model group were significantly lower than those in the sham group, and MDA levels were significantly higher than those in the sham group (P<0.05). Compared with the model group, GPx, SOD, CAT and GSH levels in the positive control group and safflower group were significantly increased, while MDA levels were significantly decreased (P<0.05). Compared with the sham group, the expression of Bax was significantly increased, the expression of bcl-2 was significantly decreased, and the activation of Cleaved caspase-9 and Cleaved caspase-3 were significantly increased in the model group (P<0.05). Compared with the model group, the expression of Bax was significantly decreased and Bcl2 expression was significantly increased in the positive control group and safflower group, the activation of Cleaved caspase-9 and Cleaved caspase-3 was significantly reduced (P<0.05).Conclusion] Safflower yellow pigment can protect the white matter around the ischemic ventricle in newborn rats. The mechanism is not only related to the regulation of antioxidant system, but also may be related to the regulation of apoptosis related factors.