Pu-erh tea, green tea, and black tea suppresses hyperlipidemia, hyperleptinemia and fatty acid synthase through activating AMPK in rats fed a high-fructose diet.
ABSTRACT Although green tea extract has been reported to suppress hyperlipidemia, it is unclear how tea extracts prepared from green, oolong, black and pu-erh teas modulate fatty acid synthase expression in rats fed on a high-fructose diet. In this animal study, we evaluated the hypolipidemic and hypoleptinemia effect of these four different tea leaves fed to male Wistar rats for 12 weeks. The results showed that a fructose-rich diet significantly elevated serum triacylglycerols, cholesterol, insulin, and leptin concentrations, as compared with those in the control group. Interestingly, consuming tea leaves for 12 weeks almost normalized the serum triacylglycerols concentrations. Again, rats fed with fructose/green tea and fructose/pu-erh tea showed the greatest reduction in serum TG, cholesterol, insulin and leptin levels. In contrast, serum cholesterol and insulin concentrations of the fructose/oolong tea-fed rats did not normalize. The relative epididymal adipose tissue weight was lower in all rats supplemented with tea leaves than those fed with fructose alone. There was molecular evidence of improved lipid homeostasis according to fatty acid synthase (FAS) protein expression. Furthermore, supplementation of green, black, and pu-erh tea leaves significantly decreased hepatic FAS mRNA and protein levels, and increased AMPK phosphorylation, compared with those of rats fed with fructose only. These findings suggest that the intake of green, black, and pu-erh tea leaves ameliorated the fructose-induced hyperlipidemia and hyperleptinemia state in part through the suppression of FAS protein levels and increased AMPK phosphorylation.
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ABSTRACT: Experimental studies have suggested that tea consumption could lower the risk of dyslipidaemia. However, epidemiological evidence is limited, especially in southern China, where oolong tea is the most widely consumed beverage. We conducted a population-based case-control study to evaluate the association between consumption of tea, especially oolong tea, and risk of dyslipidaemia in Shantou, southern China, from 2010 to 2011. Information on tea consumption, lifestyle characteristics and food consumption frequency of 1651 patients with newly diagnosed dyslipidaemia and 1390 controls was obtained using a semi-quantitative questionnaire. Anthropometric variables and serum biochemical indices were determined. Drinking more than 600 ml (2 paos) of green, oolong or black tea daily was found to be associated with the lowest odds of dyslipidaemia risk (P< 0·001) when compared with non-consumption, but only oolong tea consumption was found to be associated with low HDL-cholesterol levels. A dose-response relationship between duration of tea consumption and risk of dyslipidaemia (OR 0·10, 95 % CI 0·06, 0·16), as well as that between amount of dried tea leaves brewed and risk of dyslipidaemia (OR 0·34, 95 % CI 0·24, 0·48), was found. Moreover, consumption of oolong tea for the longest duration was found to be associated with 3·22, 11·99 and 6·69 % lower blood total cholesterol, TAG and LDL-cholesterol levels, respectively. In conclusion, the present study indicates that long-term oolong tea consumption may be associated with a lower risk of dyslipidaemia in the population of Shantou in southern China.The British journal of nutrition 11/2013; · 3.45 Impact Factor
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ABSTRACT: Influenza poses a particular risk of severe outcomes in the elderly, the very young and those with underlying diseases. Tea polyphenols are the natural phenolic compounds in teas, and principally consist of catechins, proanthocyanidins, flavonols, and theaflavins, which antiviral activities have been reported recently. This study is to gain a further insight into potential of various tea polyphenols for inhibiting influenza virus infection. Five tea polyphenols exhibited inhibitory activity against influenza A virus in the trend of theaflavin>procyanidin B-2>procyanidin B-2 digallate>(-)-epigallocatechin(EGC)>(-)-epigallocatechingallate(EGCG) with IC50 values in the range of 16.2-56.5μg/ml. Six of the tested compounds showed anti-influenza B virus activity in the order of kaempferol>EGCG>procyanidin B-2>(-)-EGC~methylated EGC>theaflavin with IC50 values in the range of 9.0-49.7μg/ml. Based on these results, the structure-activity relationship (SAR) was explained as follows. First, the dimeric molecules, such as theaflavin and procyanidin B-2, generally displayed more potent antiviral activity against both influenza A and B viruses than the catechin monomers. Second, the kaempferol for inhibition of influenza B virus indicated that the more planar flavonol structure with only one C-4' phenolic hydroxyl group in the B ring is necessary for the anti-influenza B virus activity. A similar SAR can be drawn from the assays of another enveloped RNA virus, such as respiratory syncytial virus. These results are expected to provide guides for rational design of antiviral drugs based on polyphenols.Fitoterapia 12/2013; · 2.23 Impact Factor
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ABSTRACT: Puerh tea has been proposed to promote weight loss and favorably modify glucose, insulin and blood lipids. This study tested the effect of daily Puerh tea consumption for 3 months on weight and body mass index (BMI), and select metabolic parameters. The effect of daily Puerh tea intake on weight, BMI and changes in glucose, HbA1c and lipids was evaluated in patients with metabolic syndrome. The patients (N = 70) were randomized into two groups: those taking Puerh tea extract capsule (333 mg Puerh tea extract) three times a day and those taking a placebo tea for 3 months. There was a decrease in body weight of 1.3 kg in the Puerh tea group (p = 0.077) versus 0.23 kg in the placebo arm (p = 0.186). There was also a slight decrease in BMI 0.47 kg/m(2) in the Puerh tea group (p = 0.076) versus 0.09 kg/m(2) in the placebo arm (p = 0.185), suggesting a trend of weight change, but without statistical significance. Subgroup analysis of the male patients demonstrated statistically significant improvements in body weight reduction (p = 0.004) and BMI (p = 0.004). However, the change in other metabolic parameters (cholesterol or triglyceride) or HbA1c was not statistically significant. Intake of Puerh tea for 3 months was associated with a slight reduction in body weight and BMI, especially in the male patients. Therefore, daily Puerh tea consumption may be an alternative choice to modify body weight. Copyright © 2014 John Wiley & Sons, Ltd.Phytotherapy Research 01/2014; · 2.07 Impact Factor