葡萄籽多酚降血脂及抗动脉粥样硬化的作用及机制

Study on Hypolipidemic and Anti-atherosclerosis Effects and Mechanisms of Grapeseed Polyphenols

目的研究葡萄籽多酚提取物(GSP)降血脂和抗动脉粥样硬化(As)的作用及机制。方法 7-8周龄雄性低密度脂蛋白受体敲除(LDLR-/-)小鼠32只,随机分为4组,每组8只。其中一组喂饲普通饲料并予以生理盐水(正常对照组),其它三组喂饲高脂饲料(含0.5%胆固醇和20%猪油),并分别予以生理盐水(高脂模型组)、5mg/(kg·d)依折麦布(阳性药物组)和750 mg/(kg·d)葡萄籽多酚,依折麦布和葡萄籽多酚用生理盐水配制成溶液后给予。12周时取血检测小鼠血浆中总胆固醇(TC)和甘油三酯(TG)水平,研究GSP对小鼠血脂的影响;小鼠主动脉全长及流出道取材,油红O及苏木精-伊红(HE)染色,对其斑块面积及斑块负荷进行定量,研究GSP对AS病变程度的影响;对主动脉根部进行Mac-2免疫组化染色,观察巨噬细胞对斑块的浸润情况;实时定量PCR检测肝脏组织中与脂质合成、氧化等脂代谢相关基因的mRNA表达。结果与高脂模型组相比,GSP能显著降低小鼠血浆TC和TG水平;减少AS斑块的形成及斑块中巨噬细胞的浸润;上调肝脏中LDLR相关蛋白1(LRP1)和线粒体胆固醇27-羟化酶(CYP27A1)的表达。结论 GSP具有降低小鼠血脂水平和改善As的作用,GSP降脂可能与通过胆固醇代谢中的替代途径和中性合成途径增加胆固醇转化成胆汁酸、促进脂质的转运有关;其抗As的机制可能与降低血浆中TC和TG水平、减少泡沫细胞的形成有关。

Aim To study hypolipidemic and anti-atherosclerosis effects and mechanisms of grape-seed polyphenols( GSP) in LDLR-/-mice. Methods 7 ~ 8 weeks male LDLR-/-mice( n = 32) were randomly divided into 4groups with 8 mice in each group. One group was orally administrated with saline and fed with chow diet( normal control). The other three groups were fed with a high fat diet containing 0. 5% cholesterol and 20% lard and orally administrated with saline( hyperlipidemia control),5 mg /( kg · d) ezetimibe( positive drug control),and 750 mg /( kg · d)GSP,respectively. Ezetimibe and GSP were dissolved in saline for administration. After a 12-week regimen,blood samples of the mice were collected by retro-orbital blood drawing for determining plasma TC and TG levels. All mice were then sacrificed and mouse aortas were isolated and dissected under microscope,and atherosclerotic lesions on aortic walls were stained by oil red O. Mouse aortic roots were frozenly sectioned for HE and oil red O staining,and Mac-2 immunohistochemistry staining as well. Besides,gene expression in mouse livers,related to lipid synthesis,oxidation,and metabolism,were measured by RT-PCR. Results Compared to saline treated hyperlipidemia control group,treating mice with GSP significantly decreased their TC and TG levels,significantly reduced atherosclerosis lesion area in mouse aortas and aortic roots,decreased macrophage infiltration in plaques,and up-regulated gene expression of LRP1 and CYP27A1 in mouse livers. Conclusions GSP has hypolipidemic effects and ameliorates atherosclerosis in LDLR-/-mice. The hypolipidemic mechanisms of GSP may relate to regulation of alternative and neutral synthetic pathways of cholesterol metabolism,which results in an increase of cholesterol transference into bile acid,and improvement of lipid metabolism. The anti-atherosclerosis effects of GSP can be concluded to decrease of plasma TC and TG levels and reduction of foam cell formation.