摘要目的 研究表没食子儿茶素没食子酸酯(EGCG)对高脂饮食(SD)大鼠白色脂肪组织的血管生成作用及其作用机制.方法 24只雄性离乳SD大鼠随机分为正常对照组,高脂饮食组,EGCG干预组,每组8只.正常对照组喂饲基础饲料,高脂饮食组喂饲高脂饲料,EGCG干预组在喂饲高脂饲料的同时以200 mg/ (kg·d)EGCG灌胃.喂养8周末,处死大鼠.观察各组大鼠显微镜下腹腔脂肪组织脂肪细胞大小、血管密度,ELISA法检测大鼠血清血管内皮生长因子(VEGF)浓度,RT-PCR检测脂肪组织VEGF、核因子E2相关因子(Nrf2)及下游抗氧化蛋白血红素加氧酶-1(HO-1)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GPx),炎症因子白介素-6(IL-6)、单核细胞趋化蛋白-1(MCP-1)mRNA的表达水平.结果 高脂饮食组大鼠脂肪细胞大小、单位脂肪细胞血管计数、血清VEGF浓度、脂肪组织VEGF mRNA表达水平均显著高于正常对照组(P均＜0.05).EGCG能显著降低高脂饮食组这些指标(P均＜0.05).EGCG干预组大鼠脂肪组织Nrf2、HO-1、SOD、GPx、CAT mRNA表达均显著高于高脂饮食组及正常对照组(P均＜0.05).EGCG干预组大鼠脂肪组织MCP-1、IL-6 mRNA表达显著低于高脂饮食组(P均＜0.05).结论 EGCG可降低高脂饮食大鼠血清VEGF生成,白色脂肪组织血管密度和VEGF mRNA表达,对白色脂肪组织血管生成具有抑制作用,其作用机制可能与上调Nrf2/HO-1途径提高抗氧化酶SOD、CAT、GPx表达,减少ROS生成和降低炎症反应有关.

abstractsObjective To investigate the effects and mechanism of (-)-epigallocatechin-3-gallate (EGCG) on white adipose tissue angiogenesis in high fat diet rats.Methods Twenty-four male weaning SD rats were randomly divided into normal control group,high fat diet group and EGCG intervention group,8 rats in each group.Normal control group were fed with normal diet,high-fat diet group were fed with high-fat diet,EGCG intervention group were fed with high-fat diet along with intragastric administration of 200 mg/ (kg · d) EGCG.After 8 weeks,the rats were sacrificed.The adipocyte size and vascular density of the abdominal adipose tissue in rats in each group were observed under the microscope.The serum vascular endothelial growth factor (VEGF) concentration was detected by Elisa Kit.RT-PCR was used to detect the expression of VEGF,nuclear factor E2 (Nrf2),heme oxygenase-1 (HO-1),catalase (CAT),SOD,GPx,interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) mRNA.Results The adipocyte size,number of vascular/each adipocyte,serum VEGF concentration and VEGF mRNA expression in adipose tissue of high fat diet group were significantly higher than those of normal control group (all P＜0.05).EGCG can significantly reduce the above indicators of high fat diet group (all P＜0.05).The expression of Nrf2,HO-1,SOD,GPx and CAT mRNA in adipose tissue of EGCG group was significantly higher than those in high fat diet group and normal control group (all P＜0.05).The expression of MCP-1 and IL-6 mRNA in adipose tissue of EGCG group was significantly lower than that in high fat diet group (all P＜0.05).Conclusion EGCG can decrease the production of serum VEGF,vascular density and the expression of VEGF mRNA in white adipose tissue of high fat diet rats,and inhibit the angiogenesis in white adipose tissue possibly due to its up-regulation of Nrf2/HO-1 pathway to increase the expression of antioxidant enzymes (SOD,CAT,GPx),reduce ROS production and decrease the inflammatory response.