The analysis of eligible studies showed that the administration of green tea beverages or extracts resulted in significant reductions in serum TC and LDL-cholesterol concentrations, but no effect on HDL cholesterol was observed.

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Background:Green tea has been shown to improve cholesterol metabolism in animal studies, but the molecular mechanisms underlying this function have not been fully understood. Long non-coding RNAs (lncRNAs) have recently emerged as a major class of regulatory molecules involved in a broad range of biological processes and complex diseases. Our aim was to identify important lncRNAs that might play an important role in contributing to the benefits of epigallocatechin-3-gallate (EGCG) on cholesterol metabolism.Methods:Microarrays was used to reveal the lncRNA and mRNA profiles in green tea polyphenol(-)-epigallocatechin gallate in cultured human liver (HepG2) hepatocytes treated with EGCG and bioinformatic analyses of the predicted target genes were performed to identify lncRNA-mRNA targeting relationships. RNA interference was used to investigate the role of lncRNAs in cholesterol metabolism.Results:The expression levels of 15 genes related to cholesterol metabolism and 285 lncRNAs were changed by EGCG treatment. Bioinformatic analysis found five matched lncRNA-mRNA pairs for five differentially expressed lncRNAs and four differentially expressed mRNA. In particular, the lncRNA AT102202 and its potential targets mRNA-3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) were identified. Using a real-time polymerase chain reaction technique, we confirmed that EGCG down-regulated mRNA expression level of the HMGCR and up-regulated expression of AT102202. After AT102202 knockdown in HepG2, we observed that the level of HMGCR expression was significantly increased relative to the scrambled small interfering RNA control (P < 0.05).Conclusions:Our results indicated that EGCG improved cholesterol metabolism and meanwhile changed the lncRNAs expression profile in HepG2 cells. LncRNAs may play an important role in the cholesterol metabolism.

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The effect of tea intake on blood pressure (BP) is controversial. We performed a meta-analysis of randomised controlled trials to determine the changes in systolic and diastolic BP due to the intake of black and green tea. A systematic search was conducted in MEDLINE, EMBASE and the Cochrane Controlled Trials Register up to May 2014. The weighted mean difference was calculated for net changes in systolic and diastolic BP using fixed-effects or random-effects models. Previously defined subgroup analyses were performed to explore the influence of study characteristics. A total of twenty-five eligible studies with 1476 subjects were selected. The acute intake of tea had no effects on systolic and diastolic BP. However, after long-term tea intake, the pooled mean systolic and diastolic BP were lower by 21·8 (95 % CI 2 2·4, 21·1) and 21·4 (95 % CI 22·2, 2 0·6) mmHg, respectively. When stratified by type of tea, green tea significantly reduced systolic BP by 2·1 (95 % CI 22·9, 2 1·2) mmHg and decreased diastolic BP by 1·7 (95 % CI 22·9, 2 0·5) mmHg, and black tea showed a reduction in systolic BP of 1·4 (95 % CI 22·4, 20·4) mmHg and a decrease in diastolic BP of 1·1 (95 % CI 21·9, 20·2) mmHg. The subgroup analyses showed that the BP-lowering effect was apparent in subjects who consumed tea more than 12 weeks (systolic BP 22·6 (95 % CI 23·5, 21·7) mmHg and diastolic BP 22·2 (95 % CI 2 3·0, 21·3) mmHg, both P,0·001). The present findings suggest that long-term ($12 weeks) ingestion of tea could result in a significant reduction in systolic and diastolic BP.

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There is currently limited data on which drug should be used to improve blood pressure (BP) control in patients with resistant hypertension (RH). We performed a systematic review and meta-analysis of published studies evaluating the anti-hypertensive benefit of aldosterone antagonists (AA) as an add-on therapy in patients with RH. A systematic literature search for eligible studies was conducted until June 2014, using literature databases and hand search. Studies were stratified according to controlled vs uncontrolled design and analyzed using random-effect models. We identified 13 eligible studies involving a total of 2640 patients, consisting of 3 randomized controlled trials, and 10 observational studies without a control group. In controlled studies, there was a reduction in mean systolic and diastolic BP of -16.5 (95% confidence interval (CI), -30.0 to -3.0) and -4.1 (95% CI, -7.8 to -0.32) mm Hg, respectively, compared with control. In uncontrolled studies, there was a reduction in mean systolic and diastolic BP of -19.7 (95% CI, -23.2 to -16.2) and -9.1 (95% CI, -10.3 to -7.8) mm Hg, respectively, compared with pre-AA therapy. Subgroup analysis showed that the systolic BP change was more pronounced in patients with baseline systolic BP >150 mm Hg (weighted mean difference (WMD), -23.1 mm Hg) than in patients with ⩽150 mm Hg (WMD, -15.4 mm Hg) (between groups P<0.001), suggesting that the baseline systolic BP was a predictor of the BP response to AA treatment. Furthermore, AA demonstrated a mild increase in serum potassium and creatinine (for both, P<0.001). The findings suggest that AA as an add-on therapy was effective for lowering systolic and diastolic BP in patients with RH.

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