heart-health

Author: Rachel Johnson and Susan Bryant and Alyson L. Huntley

Author: Baruch Narotzki and Abraham Z. Reznick and Dror Aizenbud and Yishai Levy

Green tea is a leading beverage in the Far East for thousands of years; it is regarded for a long time as a health product. Green tea is important source of polyphenol antioxidants. Polyphenols including epigallocatechin 3 gallate (EGCG) constitute the most interesting components in green tea leaves. Green tea has the potential to protect against various malignant, cardiovascular and metabolic diseases. There is a growing body of evidence pointing a beneficial role of green tea and its polyphenols in oral health. Green tea protects against bacterial induced dental caries. Tea polyphenols possess antiviral properties, believed to help in protection from influenza virus. Additionally, green tea polyphenols can abolish halitosis through modification of odorant sulphur components. Oral cavity oxidative stress and inflammation, consequent to cigarette smoking and cigarettes’ deleterious compounds nicotine and acrolein, may be reduced in the presence of green tea polyphenols. Generally, green tea defends healthy cells from malignant transformation and locally has the ability to induce apoptosis in oral cancer cells. All together, there is an increasing interest in the health benefits of green tea in the field of oral health. Nonetheless, there is still a need for more clinical and biological studies to support guidelines for green tea intake as part of prevention and treatment of specific oral pathologies.

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Author: Markus Brückner and Sabine Westphal and Wolfram Domschke and Torsten Kucharzik and Andreas Lügering

Background and aims: Leukocyte infiltration, up-regulation of proinflammatory cytokines and severe oxidative stress caused by increased amounts of reactive oxygen species are characteristics of inflammatory bowel disease. The catechin (2R,3R)-2-(3,4,5-Trihydroxyphenyl)-3,4-dihydro-1(2H)-benzopyran-3,5,7-triol-3-(3,4,5-trihydroxybenzoate), named epigallocatechin-3-gallate, EGCG, has been demonstrated to exert anti-inflammatory and antioxidative properties, reducing reactive oxygen species in the inflamed tissues. The aim of this study was to evaluate the therapeutic effects of EGCG in a murine model of colitis induced by oral administration of dextran sodium sulfate. Methods: Mice received a daily oral administration of 6.9 mg/kg body weight EGCG or Piper nigrum (L.) alkaloid (2E,4E)-5-(1,3-benzodioxol-5-yl)-1-piperidin-1-ylpenta-2,4-dien-1-one, named piperine (2.9 mg/kg body weight) or the combination of the both — piperine was used in this combination to enhance the bioavailability of EGCG. Results:In vivo data revealed the combination of EGCG and piperine to significantly reduce the loss of body weight, improve the clinical course and increase overall survival in comparison to untreated groups. The attenuated colitis was associated with less histological damages to the colon and reduction of tissue concentrations of malondialdehyde, the final product of lipid peroxidation. Neutrophils accumulation indicator myeloperoxidase was found to be reduced in colon tissue, while antioxidant enzymes like superoxide dismutase and glutathione peroxidase showed an increased activity. In vitro, the treatment with EGCG plus piperine enhanced the expression of SOD as well as GPO and also reduced the production of proinflammatory cytokines. Conclusion: These data support the concept of anti-inflammatory properties of EGCG being generally beneficial in the DSS-model of colitis, an effect that may be mediated by its strong antioxidative potential.

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Author: Xinshan Lu and Yan Zhao and Yanfei Sun and Su Yang and Xingbin Yang

This study was to examine the hepatoprotective effects of polysaccharides from green tea of Huangshan Maofeng (HMTP) against CCl4-induced oxidative damage in mice. HMTP is an acidic heteropolysaccharide with galactose (35.0%, mol.%), arabinose (28.9%) and galacturonic acid (11.3%) being the main monosaccharide components. HMTP (400 and 800 mg/kg·bw) administered orally daily for 14 days before CCl4 administration significantly reduced the impact of CCl4 toxicity on the serum markers of liver damage, alanine aminotransferase, aspartate aminotransferase, total-cholesterol and triglycerides. This method of HMTP administration also markedly restrained hepatic lipid peroxidation formation of malondialdehyde and 15-F2t isoprostanes, and elevated the antioxidant levels of hepatic glutathione and superoxide dismutase. These results together with liver histopathology indicated that HMTP exhibited hepatoprotection against CCl4-induced injury, which was found to be comparable to that of biphenyldicarboxylate. The hepatoprotective effects of HMTP may be due to both the inhibition of lipid peroxidation and the increase of antioxidant activity.

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Author: Matthew P.G. Barnett and Janine M. Cooney and Yvonne E.M. Dommels and Katia Nones and Diane T. Brewster and Zaneta Park and Christine A. Butts and Warren C. McNabb and William A. Laing and Nicole C. Roy

Animal models are an important tool to understand the complex pathogenesis of inflammatory bowel diseases (IBDs). This study tested the anti-inflammatory potential of a green tea extract rich in polyphenols (GrTP) in the colon of the multidrug resistance targeted mutation (Mdr1a−/−) mouse model of IBD. Insights into mechanisms responsible for this reduction in inflammation were gained using transcriptome and proteome analyses. Mice were randomly assigned to an AIN-76A (control) or GrTP-enriched diet. At 21 or 24 weeks of age, a colonic histological injury score was determined for each mouse, colon mRNA transcript levels were assessed using microarrays, and colon protein expression was measured using two-dimensional gel electrophoresis and liquid chromatography–mass spectrometry protein identification. Mean colonic histological injury score of GrTP-fed Mdr1a−/− mice was significantly lower compared to those fed the control diet. Microarray and proteomics analyses showed reduced abundance of transcripts and proteins associated with immune and inflammatory response and fibrinogenesis pathways, and increased abundance of those associated with xenobiotic metabolism pathways in response to GrTP, suggesting that its anti-inflammatory activity is mediated by multiple molecular pathways. Peroxisome proliferator-activated receptor-α and signal transducer and activator of transcription 1 appear to be two key molecules which regulate these effects. These results support the view that dietary intake of polyphenols derived from green tea can ameliorate intestinal inflammation in the colon of a mouse model of IBD, and are in agreement with studies suggesting that consumption of green tea may reduce IBD symptoms and therefore play a part in an overall IBD treatment regimen.

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Author: Karl Fraser and Geoff A. Lane and Don E. Otter and Yacine Hemar and Siew-Young Quek and Scott J. Harrison and Susanne Rasmussen

Tea is an infusion made from the dried leaves of Camellia sinensis L. and is the second most consumed beverage in the world. It has been shown that factors such as fermentation methods, cultivar, geographical origin and season can affect the biochemical composition of tea. In this study, the biochemical composition of green, oolong and black commercial tea samples from around the world was studied using a non-targeted method utilising reversed phase ultra high pressure liquid chromatography (UHPLC) and high resolution mass spectrometry. Principal component analysis of green, oolong and black tea extracts clearly showed that fermented tea can be resolved from non-fermented tea. When the non-targeted data were combined with the supervised multivariate technique, partial least squares discriminant analysis, the method was able to clearly distinguish ‘country of origin’ within green tea and to a lesser extent within a black tea sample set, plus provide indicative marker ions for the country of origin. Many of the significant components detected in this study are unknowns, emphasising the importance of un-biased non-targeted analytical techniques. This study highlights the potential efficacy of non-targeted UHPLC–mass spectrometry when combined with multivariate statistics to differentiate fermented from non-fermented tea and provide potential indicators of provenance of tea samples for further examination.

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Author: Aditi Jain and Chanchal Manghani and Shrey Kohli and Darshika Nigam and Vibha Rani

Tea is one of the most popularly consumed beverage. Depending on the manufacturing process, different varieties of tea can be produced. The antioxidative and antimutagenic potential of tea in cardiovascular diseases, cancer and obesity have long been studied. These therapeutic and nutritional benefits of tea can be attributed to the presence of flavanoids. However, these flavanoids also have certain detrimental effects on human health when their consumption exceeds certain limits. The toxicity of these flavanoids can be attributed to the formation of reactive oxygen species in the body which causes damage to the DNA, lipid membranes etc. The aim of this review is to summarize briefly, the less studied evidences of various forms of toxicity associated with tea and its harmful effects on human health.

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Author: Shahab Nootash and Najmeh Sheikhzadeh and Behzad Baradaran and Ali Khani Oushani and Mohammad Reza Maleki Moghadam and Katayoon Nofouzi and Amir Monfaredan and Leili Aghebati and Fatemeh Zare and Sadigheh Shabanzadeh

Present study elucidates the efficacy of green tea (Camellia sinensis) on growth performance, immune and antioxidant systems and cytokine gene expression in rainbow trout tissues. Green tea was supplemented at 20, 100, and 500 mg kg−1 diet and fed to fish (average weight: 23.5 g) for 35 days. No remarkable changes in growth performance were observed among all test groups. Lower lipid peroxidation product and higher superoxide dismutase activity were noted in fish received the medium dose of green tea. Significant increase in serum bactericidal activity and total protein were recorded in all treatment groups. All doses of green tea up-regulated Interleukin-1β transcription in the spleen, while Interleukin-1β mRNA level decreased significantly in the kidney of low dose of green tea. Interleukin-6 mRNA level was up-regulated in the spleen of high dose of green tea and liver of middle and high doses of green tea. High dose and medium dose of green tea up-regulated the interleukin-8 transcription in the kidney and liver, respectively. Meanwhile, green tea inhibited the production of interleukin-10 in all treatment groups compared with control group. Medium dose of green tea up-regulated tumor necrosis factor-α transcription in all fish tissues, while high dose and low dose of green tea enhanced tumor necrosis factor-α mRNA levels in the kidney and spleen, respectively. Present study suggests that green tea especially at 100 mg kg−1 feed may effectively enhance the antioxidant system and immune system in rainbow trout.

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Author: Ugo Vertolli and Paul A. Davis and Lucia Dal Maso and Giuseppe Maiolino and Agostino Naso and Mario Plebani and Lorenzo A. Calò

Cardiovascular disease (CVD) remains the most common cause for excess morbidity and mortality in patients with chronic kidney disease (CKD) and end stage renal disease (ESRD) under chronic dialysis. ESRD patients have increased oxidative stress and endothelial dysfunction alongside increased levels of inflammation related proteins, which has prompted the exploration of anti-inflammatory and antioxidant treatments to improve outcomes. As green tea is increasingly well recognized for its antioxidant properties, we probed the effect of consumption of 1 capsule daily of green tea as a commercially available, decaffeinated green tea capsule (1 g, catechin content 68 mg) for 6 months on fibrinogen and inflammation in dialysis patients. Chronic hemodialysis patients (N = 25) were recruited and fibrinogen, FDP-D-dimer, high sensitivity (hs) CRP and the mononuclear cell protein expression of p22phox, were assessed before, i.e. baseline and after 6 months of ingestion of 1 green tea capsule per day. After 6 months of daily green tea capsule ingestion, dialysis patients showed reduced protein expression of p22phox (p < 0.0001), reduced hsCPR (p = 0.032) and fibrinogen (p = 0.022) levels and increased FDP-D-dimer (p = 0.0019) compared to their values at baseline. These results document lower oxidative stress and inflammation with green tea capsule ingestion and suggest a likely positive impact of green tea treatment on the atherosclerotic process of ESRD patients under dialysis.

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Author: Wenping Tang and Shiming Li and Yue Liu and Mou-Tuan Huang and Chi-Tang Ho

Tea is one of the most popular beverages worldwide. The variety of tea and tea extracts in the market has different polyphenol profiles, which are the bioactive chemical entities. In searching for efficacious molecules from tea against hyperglycaemia, we performed a direct comparison between green tea extracts (GTE) and black tea extracts (BTE), which have been chemically well-characterized by HPLC, in a type 2 diabetic mouse model combining low dose streptozotocin (STZ) with high fat (HF) diet. The results revealed that both GTE and BTE in drinking water substantially lowered blood glucose levels and ameliorated glucose intolerance, but GTE was more effective in anti-hyperglycaemic activity and in lowering body weight gain. GTE was also more effective than BTE in reversing histological deterioration of liver in the diabetic mice. Serum insulin levels significantly increased in BTE group but not in GTE group, suggesting that they might exert their hypoglycaemic effects through different pathways. We explored the possible mechanisms by homeostatic model assessment (HOMA), and results showed that the predominant mechanism for the anti-diabetic effect of GTE was through insulin resistance, while for BTE it was through insulin secretion.

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