猕猴桃皮多酚对高脂膳食大鼠脂代谢紊乱的调节作用

Kiwifruit Peel Polyphenols Regulate Lipid Metabolism Disorders Induced by a High Fat Diet in Rats

目的:探讨猕猴桃皮多酚(kiwifruit peel polyphenols,KP)对高脂膳食大鼠脂代谢的影响及其机制。方法:将雄性SD大鼠随机分为正常对照组(NC组)、高脂膳食组(HF组)以及猕猴桃皮多酚低(LKP)、中(MKP)、高(HKP)剂量干预组。连续灌胃9周后,宰杀大鼠,测定肝指数、脂肪指数,肠系膜脂肪、腹部脂肪、睾肾周脂肪质量,血清中的甘油三酯(triglyceride,TG)、总胆固醇(total cholesterol,TC)、高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL-C)、低密度脂蛋白胆固醇(low-density lipoprotein cholesterol,LDL-C)、游离脂肪酸(free fatty acids,FFA)浓度以及肝脏脂代谢相关基因脂肪酸合成酶(fatty acid synthase,FAS)、乙酰辅酶A羧化酶(acetyl CoA-carboxylase,ACC)、肉碱棕榈酰转移酶1(carnitine palmityl transferase 1,CPT-1)和过氧化物酶体增殖物激活受体α(peroxisome proliferator activated receptorα,PPAR-α)mRNA表达水平。结果:与HF组相比,干预组的肝指数以及MKP、HKP组脂肪指数显著降低(P<0.05);MKP、HKP肠系膜脂肪、睾肾周脂肪质量较HF组显著下降(P<0.05),腹部脂肪各组间无显著性差异;干预组血清TG、LDL-C浓度显著下降(P<0.05);MKP、HKP组的TC、FFA浓度显著下降、HDL-C浓度显著上升(P<0.05);脂肪合成相关基因(ACC、FAS)表达显著下调(P<0.05);脂肪分解相关基因CPT-1以及MKP、HKP组PPAR-α表达显著上调(P<0.05)。结论:猕猴桃皮多酚能够缓解高脂膳食导致的脂代谢紊乱,其作用机制与抑制肝脏脂肪酸的合成,以及促进脂肪酸的氧化分解有关。

Objective:To investigate the effect of kiwifruit peel polyphenols on lipid metabolism in rats fed on high fat diet and its underlying mechanism.Methods:Male SD rats were randomly divided into five groups:normal control(NC),high fat diet(HF),and low-dose(LKP),middle-dose(MKP),and high-dose kiwifruit polyphenols(HKP)groups.At the end of the 9-week feeding period,all rats were sacrificed.The liver index,fat index,mesenteric fat mass,abdominal fat mass,and epididymal and perirenal fat pad mass,and serum total cholesterol(TC),triglyceride(TG),low-density lipoprotein(LDL),high-density lipoprotein(HDL)and free fatty acids(FFA)were examined.The mRNA expression of fatty acid synthase(FAS),acetyl CoA-carboxylase(ACC),carnitine palmityl transferase 1(CPT-1)and peroxisome proliferator activated receptorα(PPAR-α)genes in liver were assayed.Results:Compared with the HF group,the liver index in all intervention groups and the fat index in the MKP and HKP groups were significantly decreased(P<0.05).The masses of mesenteric fat and epididymal and perirenal fat pads in the MKP and HKP groups were significantly lower than those in the HF group(P<0.05)while there was no significant difference in abdominal fat mass.Serum TG and LDL-C were significantly decreased in each intervention group(P<0.05).In the MKP and HKP groups,TC and FFA were decreased significantly whereas HDL-C was increased significantly(P<0.05).The expression of fat synthesis-related genes(ACC and FAS)was significantly down-regulated(P<0.05),while the expression of fat decomposition-related gene(CPT-1)was significantly upregulated in all intervention groups(P<0.05).Moreover,the expression of PPAR-αin the MKP and HKP groups was also significantly upregulated(P<0.05).Conclusion:Kiwifruit peel polyphenols can alleviate lipid metabolism disorder caused by high fat diet.The underlying mechanism is related to the inhibition of fatty acid synthesis in the liver and the promotion of oxidative decomposition of fatty acids.