关键词: 丙酸, 丁酸, 肥胖, 小鼠, 脂肪代谢

Abstract: Objective To investigate the effect of exogenous short-chain fatty acids (SCFAs) on fat metabolism in high-fat-diet induced obese mice. Methods Totally 40 male C57BL/6J mice aged three to four weeks were divided into four groups, and were fed with the normal-fat diet,high-fat diet,high-fat diet with propionate or butyrate for 4 months, respectively.At the end of the experiments, the blood, epididymal and subscapular fat and the liver were collected.Plasma triglyceride (TG) and total cholesterol (TCH) were measured, and hepatic and adipose tissue morphology were examined.Meanwhile, the mRNA expressions of fat metabolism associated genes were assayed by RT-PCR, including the adipose triglyceride lipase (atgl), hormone-sensitive lipase (hsl), acyl CoA:diacylgycerol acyltransferase 2 (dgat2), carnitine palmitoyltransferase (cpt) and uncoupling protein-1 (ucp1). Results Compared with the normal diet group, the body weight, plasma concentrations of TG and TCH, and fat accumulation in the liver significantly increased in the high-fat diet group (P<0.05). Supplementation of propionate or butyrate to the high-fat diet inhibited the increase in body weight and lipid droplet accumulation in the liver, and reduced plasma TG and TCH levels (P<0.05).The RT-PCR analysis showed that the mRNA expressions of atgl, hsl, and cpt1c in both the epididymal fat and liver in high-fat diet group significantly decreased compared with the normal diet group, while the dgat2 expression significantly increased (P<0.05). Supplementation of propionate or butyrate to the high-fat diet increased the mRNA expressions of atgl, hsl, and cpt1c, and reduced the dgat2 expression in the epididymal fat and liver (P<0.05).However, the expression of these genes in the subscapular fat was not affected by dietary propionate or butyrate supplementation (P>0.05). Conclusion Dietary supplementation of propionate and butyrate might inhibit the body weight gain in high-fat-diet induced obese mice by promoting TG lipolysis and oxidation.

Key words: propionate, butyrate, obesity, mouse, fat metabolism