Lauric Triglyceride Ameliorates High-Fat-Diet-Induced Obesity in Rats by Reducing Lipogenesis and Increasing Lipolysis and β-Oxidation

Abstract

Medium-chain triglycerides (MCTs) are found in limited foods. In these medium-chain oil resources, the abundance of lauric acid (LA) is the highest among medium-chain fatty acids (MCFAs), and its effects on lipid metabolism in obese rats have not been well-studied. This study aimed to determine the anti-obesity effects and mechanisms of lauric triglyceride (LT) in Sprague Dawley (SD) rats. LA and glycerin were used to synthesize LT, then LT was used to treat obese rats for 12 weeks. The results showed that LT significantly reduced the body weight, body mass index, and Lee's index in obese rats. The mRNA expression levels of the anorexic neuropeptide POMC in the hypothalamus between the LT group and the other groups were not different, while the gene expression levels of the orexigenic neuropeptides NPY and AGRP decreased significantly in the LT group. Except serum cholesterol, LT improved the serum triglyceride metabolism in the obese rats and reduced adipocyte and hepatic lipid deposition. Moreover, LT inhibited the expression of lipogenesis-related genes and proteins (SREBP-1c, ACC1, and FASN) and increased the expression of lipolysis (ATGL, HSL, and LPL) and β-oxidation (PPARα, CPT-1a, and PCG-1α) related genes and proteins in the white fat and liver. Furthermore, LT increased the mRNA expression of mitochondrial-biosynthesis-related genes (SIRT1, NRF1, and TFAM) in the liver. The results indicated that LT ameliorates diet-induced obesity in rats.

C‐section birth increases offspring obesity risk dependent on maternal diet and obesity status in rats

“…Dyslipidemia typically seen in obesity includes hepatic overproduction of very low‐density lipoproteins and increased free fatty acid delivery (18). In order to assess the effects of CS on liver function, we analyzed genes related to lipogenesis (sterol regulatory element binding protein 1 [SREBP‐1c], SREBP‐2, acetyl‐coenzyme A carboxylase [ACC], and fatty acid synthase [FAS]), triacylglycerol storage in adipocytes (peroxisome proliferator‐activated receptor γ [PPARγ]), and lipolysis (lipoprotein lipase [LPL] (19,20). We found no significant differences in mRNA levels of FAS or ACC in the liver (Figure 5A).…”

“…Dyslipidemia typically seen in obesity includes hepatic overproduction of very low-density lipoproteins and increased free fatty acid delivery (18). In order to assess the effects of CS on liver function, (19,20). We found no significant differences in mRNA levels of FAS or ACC in the liver (Figure 5A).…”

High Dietary Intervention of Lauric Triglyceride Might be Harmful to Its Improvement of Cholesterol Metabolism in Obese Rats

“…These were in line with our previous research, showing that as the expression of CYP8B1 protein in the LT group decreased, the expression levels of lipogenesis-related genes and proteins also decreased. 20 LXR is another key regulator of cholesterol homeostasis. It has been reported that the activation of LXR increased the expression of ABCG5 and ABCG8, 51 and it also reduced the small intestinal uptake of sterols.…”

“…Lauric triglyceride was synthesized in our laboratory (the yield of LT is 90%, and the purity after purification is ≥99%, Figure S1). 20 The details of 39 bile acid (BA) standards are shown in Table S1.…”

“…In our previous study, we unexpectedly found that the levels of TC and LDL-c were increased by long-term intervention with LT at a high dose in obese rats. 20 In addition, it was reported that the levels of LDL-c, high-density lipoprotein cholesterol (HDL-c), and TC were increased after the intake of coconut oil when compared with that of other vegetable oils. 21 The study aimed to investigate the mechanism by which LT intervention increases blood TC and LDL-c levels in obese rats, and the effects and mechanism of LT on cholesterol metabolism were also investigated.…”