Salvianolic acid B improves glucolipid metabolism by regulating adipogenic transcription factors in mice with diet-induced obesity

Abstract

Objective: To determine the effect of Salvianolic acid B (Sal B) on glucose and lipid metabolism in mice with high-fat diet (HFD)-induced obesity, and to investigate the underlying mechanisms by measuring the expression levels of key adipogenic transcription factors. Methods: Six-week-old C57BL/6J male mice were fed for 12 weeks with a HFD to induce obesity or a standard diet to serve as normal controls. A mean body weight increase of more than 20% after these 12 weeks was used as the criteria for obesity. HFD-fed obese mice then received a supplement of Sal B (100 mg/kg body weight/day), metformin (75 mg/kg body weight/day) or water (an equivalent volume; served as model controls) by oral gavage for an additional 8 weeks, and the normal controls received water (an equivalent volume) by oral gavage for the same period. Results: Sal B significantly reduced body weight gain (P < .05) without influencing food intake in HFD-fed obese mice relative to model controls. Sal B also reduced the body fat mass of the obese mice relative to model controls in a time-dependent manner (P < .05). Sal B significantly decreased the serum concentrations of low-density lipoprotein cholesterol, total cholesterol, triglyceride and free fatty acids by 25.5%, 20.2%, 20.6% and 13.4%, respectively, and increased the concentration of high-density lipoprotein cholesterol by 50.1% relative to model controls. In addition, Sal B significantly lowered fasting glucose concentrations and improved insulin sensitivity relative to model controls (P < .05). Sal B acted by ameliorating the histopathological changes in both brown and white adipose tissues of obese mice. Moreover, in brown adipose tissue, Sal B up-regulated the mRNA and protein expression of PPARγ and c/EBPα, and the protein expression of PPARα and SREBP-1 (P < .05). In white adipose tissue, Sal B down-regulated the mRNA expression of PPARγ and c/EBPα, and decreased the protein expression of PPARγ and SREBP-1(P < .05). Conclusions: The results suggest that Sal B can reduce body weight gain and regulate glucose and lipid metabolism in mice with diet-induced obesity by regulating adipogenic transcription factors in their adipose tissues.

Keywords

• Salvianolic acid B
• Obesity
• Blood glucose
• Adipose tissue
• Adipogenic transcription factors