Decreasing pro-inflammatory cytokine and reversing the immunosenescence with extracts of Pu-erh tea in senescence accelerated mouse (SAM).

Immunosenescence, the progressive decline of adaptive immunity and chronic inflammation with ageing has been demonstrated to be the main factor responsible for infections, cancer and autoimmune conditions in the elderly. Senescence-accelerated mouse (SAM) was used to study the protective effects of Pu-erh tea in the elderly. The senile-prone sub-strain, SAM-P8 mice were administered individually with ripened or crude Pu-erh tea at 125, 250 or 500mg/kg. The results showed that Pu-erh tea significantly increased the fractions of naïve T lymphocytes, CD8(+)CD28(+) T lymphocytes and NK cells in the peripheral blood, but decreased the levels of IL-6 in aged mice. These data suggested that the Pu-erh tea reversed the immunosenescence by restoring the immune deficiency and decreasing pro-inflammatory cytokine. Thus, long term drinking of Pu-erh tea may be beneficial for the aged population in terms of increasing the body's resistance to infection and cancer.

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.

Simultaneous Distillation Extraction of Some Volatile Flavor Components from Pu-erh Tea Samples-Comparison with Steam Distillation-Liquid/Liquid Extraction and Soxhlet Extraction.

A simutaneous distillation extraction (SDE) combined GC method was constructed for determination of volatile flavor components in Pu-erh tea samples. Dichloromethane and ethyl decylate was employed as organic phase in SDE and internal standard in determination, respectively. Weakly polar DB-5 column was used to separate the volatile flavor components in GC, 10 of the components were quantitatively analyzed, and further confirmed by GC-MS. The recovery covered from 66.4%-109%, and repeatability expressed as RSD was in range of 1.44%-12.6%. SDE was most suitable for the extraction of the anlytes by comparing with steam distillation-liquid/liquid extraction and Soxhlet extraction. Commercially available Pu-erh tea samples, including Pu-erh raw tea and ripe tea, were analyzed by the constructed method. the high-volatile components, such as benzyl alcohol, linalool oxide, and linalool, were greatly rich in Pu-erh raw teas, while the contents of 1,2,3-Trimethoxylbenzene and 1,2,4-Trimethoxylbenzene were much high in Pu-erh ripe teas.