Anti-obesity effect of Liupao tea extract by modulating lipid metabolism and oxidative stress in high-fat-diet-induced obese mice.

Liupao tea (LPT) is traditional dark Chinese tea. The effect of LPT extract on high-fat-diet-induced obese mice was investigated systematically. The results showed that LPT extract could reduce body weight and significantly alleviate liver damage and fat accumulation. LPT could also decrease the levels of alanine aminotransferase (ALT), aspartate transaminase (AST), alkaline phosphatase (AKP), total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) and increase the level of high-density lipoprotein cholesterol (HDL-C) in the liver. It also decreased the serum levels of inflammatory cytokines, including tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), interleukin (IL)-1β, and IL-6 and increased the serum levels of anti-inflammatory cytokines, including IL-10 and IL-4. Moreover, LPT improved the levels of total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) and reduced the level of malondialdehyde (MDA) in the liver. Moreover, LPT could upregulate the mRNA and protein expressions of peroxisome proliferator-activated receptor alpha (PPAR-α), lipoprotein lipase (LPL), carnitine palmitoyltransferase 1(CPT1), and cholesterol 7 alpha-hydroxylase (CYP7A1) and downregulate those of PPAR-γ and CCAAT/enhancer-binding protein alpha (C/EBP-α) in the liver. It also increased the mRNA expression of copper/zinc superoxide dismutase (SOD1), manganese superoxide dismutase (SOD2), CAT, gamma-glutamylcysteine synthetase 1 (GSH1), and GSH-Px. The components of LPT extract include catechin, rutin, taxifolin, and astragalin, which possibly have a wide range of biological activities. In conclusion, our work verified that LPT extract possessed an anti-obesity effect and alleviated obesity-related symptoms, including lipid metabolism disorder, chronic low-grade inflammation, and liver damage, by modulating lipid metabolism and oxidative stress.