Objective: To examine the effects of chlorogenic acid (CGA) on lipid and glucose metabolism under a high dietary fat burden and to explore the possible role of peroxisome proliferator-activated receptor-alpha (PPAR-alpha) in these effects.
Methods: Twenty male golden hamsters were randomly divided into CGA treatment group (n=10, given peritoneal injection of CGA solution prepared with PBS, 80 mg CGA/kg body weight daily), and control group (n=10, given PBS i.p. at the average volume of the treatment group). Animals in both groups were given 15% high fat diet. Eight weeks after treatment with CGA, the level of biochemical parameters in fasting serum and tissues and the expression of hepatic mRNA and protein PPAR-alpha were determined.
Results: Eight weeks after treatment with CGA, the levels of fasting serum triglyceride (TG), free fatty acid (FFA), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), glucose (FSG), and insulin (FSI) were significantly lower in the GGA treatment group than in the control group. CGA also led to higher activity of hepatic lipase (HL), lower contents of TG and FFA in liver, and lower activity of lipoprotein lipase (LPL) in skeletal muscle. Furthermore, CGA significantly elevated significantly elevated the expression level of mRNA and protein expression in hepatic PPAR-alpha.
Conclusion: CGA can modify lipids and glucose metabolism, which may be attributed to PPAR-alpha facilitated lipid clearance in liver and improved insulin sensitivity.