Pu-erh tea aqueous extracts lower atherosclerotic risk factors in a rat hyperlipidemia model

Pu-erh tea is believed to possess many beneficial health effects since it is a natural source of cardioprotective lipid lowering and antioxidant compounds, although, the major constituents putatively responsible for these beneficial effects remain unknown. In this study, we examined the effects of two commonly consumed forms of Pu-erh tea, fermented and unfermented, on weight gain, serum levels of lipids and lipoprotein, lipid oxidation, and blood antioxidant enzymes in a rat hyperlipidemia model. Hyperlipidemic rats were treated with water extracts of either 0.5, 1.5 or 3.0 mg/kg fermented or unfermented Pu-erh tea. Serum low density lipoprotein-cholesterol (LDL-C) and triglyceride levels were significantly lowered by tea extract compared to the control group. (p < 0.05) and in most cases were indistinguishable from rats fed normal chow, basal diet. Conversely, levels of high density lipoprotein-cholesterol (HDL-C) were elevated in the groups given daily doses of tea extract (p < 0.05). Compared to the hyperlipidemic control group, activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in serum were significantly elevated in Pu-erh tea-treated groups while levels of malondiadehyde (a byproduct of lipid peroxidation) decreased in the same groups. These effects were most pronounced in the groups treated with the highest dose of fermented Pu-erh tea extract. Our results suggest that Pu-erh tea exerts strong antioxidative and lipid-lowering effects and therefore can be used to reduce the risk of cardiovascular disorders. (C) 2009 Elsevier Inc. All rights reserved.