Green Tea And Thermogenesis

May 28, 2008 by  
Filed under All, Science, Tea

The thermogenic effect of tea is generally attributed to its caffeine content. An article in Alternative Medicine Review reports that green tea extract stimulates brown adipose tissue thermogenesis to an extent which is much greater than can be attributed to its caffeine content alone. Since polyphenols and caffeine inhibit different cellular reactions involving norepinephrine, the authors postulate that the combination of caffeine and polyphenols present in green tea extract “is effective in stimulating thermogenesis by relieving inhibition at different control points. Such a synergistic interaction between polyphenols and caffeine to augment and prolong sympathetic stimulation of thermogenesis could be of value in assisting the management of obesity.”
Green tea and thermogenesis: interactions between catechin-polyphenols, caffeine and sympathetic activity. Read more

Green Tea Anti-Inflammatory

May 28, 2008 by  
Filed under All, Science, Tea

Green tea polyphenols such as EGCG have potent anti-inflammatory properties. Prior research had shown that EGCG inhibits tumor necrosis factor through a mechanism that was thought to have implications for inflammation generally. Epidemiological studies link regular consumption of tea with decreased cancer risk and a reduction in mortality during the 12 month period following a heart attack. “Considerably less is known regarding the mechanisms by which tea confers these health benefits.” The present research demonstrates one important mechanism in the inhibition of interleukin-1 mediated signal transduction. “Given the long safety record of tea consumption, the use of EGCG and related compounds may represent a novel pharmacological strategy for the modulation of inflammation. EGCG and related compounds could potentially be used as a nutritional supplement in patients with inflammatory disease processes. The next steps to further substantiate these assertions are to test the efficacy of green tea derived polyphenols such as EGCG in animal models of inflammation associated organ injury and to further elucidate the mechanisms by which these compounds modulate no inflammatory signal transduction pathways.” Read more

Potent Suppressive Effect Of Green Tea Polyphenols On Tobacco Induced Mutagenicity

May 28, 2008 by  
Filed under All, Science, Tea

Research from India reported in Phytomedicine explored the anti-mutagenic activity of green tea. Using standard mutagenicity assays, a team of research demonstrated that green tea polyphenols could inhibit the mutagenicity of tobacco in a concentration-dependent manner. The polyphenols were also found to inhibit urinary mutagenicity in rats induced by tobacco extract. Thus “green tea has a dual action to bring about a reduction in the mutagenic and carcinogenic potential of tobacco.” Read more

Green and Black Tea Against Prostate Cancer

May 28, 2008 by  
Filed under All, Science, Tea

Green and black tea have shown promise in the chemoprevention of prostate cancer. In this study, the relative prostate bioavailability of theaflavin was 70% higher than that of EGCG. “This is the first human study to show that tea polyphenols and theaflavins are bioavailable in the prostate where they may be active in the prevention of prostate cancer.”
The Journal of Nutrition. July 1, 2006. Aronson, William; Conde, Francisco; Et al; Niu, Yantao; Henning, Susanne M Read more

Green Tea Protects Against Skin Cancer

May 28, 2008 by  
Filed under All, Science, Tea

A study reported in the Journal of Nutrition demonstrated the promise of green tea polyphenols as anticarcinogenic agents to prevent the development of solar ultraviolet radiation induced skin cancer. Oral administration of green tea polyphenols reduced UVB induced tumor incidence by 35%, tumor multiplicity by 63%, and tumor growth by 55%. “GTP’s prevent UVB induced skin carcinogenesis.” Note that in this research, the tea extract was not applied topically (which has also been shown effective) but taken orally. “We found that oral administration of GTP’s resulted in significant protection against photo-carcinogenesis. This degree of prevention was less than that reported for topical application of EGCG. The chemo protective effects we observed were appreciable, however, and directly relevant because green tea is commonly consumed as a beverage. Thus administration of GTP’s as a beverage may serve as a complementary and alternative medicine for the prevention of skin cancer.” Read more

Green Tea Catechin Protect Against Hypoxia

May 28, 2008 by  
Filed under All, Science, Tea

Intermittent hypoxia is a feature of sleep disordered breathing, and impairs spatial learning and oxidative stress. In research conducted at the University of Louisville, Kentucky, oral green tea polyphenols reduced the spatial learning deficits and oxidative stress caused by intermittent hypoxia. “The potential therapeutic role of green tea polyphenols in sleep disordered breathing deserves further exploration.” Read more

Black And Green Tea Polyphenols For Blood Pressure

May 28, 2008 by  
Filed under All, Science, Tea

Research in stroke-prone spontaneously hypertensive rats demonstrated benefits from both black and green tea polyphenols. Oxidative stress is reportedly involved not only in cardiovascular disease but also in hypertension. Using continuous monitoring of blood pressure, both green tea polyphenols and black tea polyphenols significantly reduced both systolic and diastolic blood pressure compared with controls. “These data demonstrate that both black and green tea polyphenols attenuate blood pressure increases through their antioxidant properties. Furthermore, because the amounts of polyphenols used in this experiment correspond to those in 1 liter of tea, the regular consumption of black and green tea may also provide some protection against hypertension in humans.” Read more

Green Tea Polyphenol Administration Partly Ameliorates Chemotherapy-Induced Side Effects in the Small Intestine of Mice

May 27, 2008 by  
Filed under All, Science, Tea

The chemotherapy agent irinotecan is highly effective against several types of cancer, but its use is limited due to severe intestinal toxicity. Green tea polyphenols (1 g per liter) used for seven days before and three days after treatment reduced the toxicity. “Green tea polyphenols supplied orally protected against oxidation in our experimental model and could be one approach to reducing the risk of chemotherapy induced side effects in a clinical setting.”

Read more

Green Tea Catechin Polyphenols Attenuate Behavioral and Oxidative Responses to Intermittent Hypoxia

May 25, 2008 by  
Filed under Tea

Rationale: The intermittent hypoxia (IH) that characterizes sleep disordered breathing impairs spatial learning and increases NADPH oxidase activity and oxidative stress in rodents. We hypothesized that green tea catechin polyphenols (GTPs) may attenuate IHinduced neurobehavioral deficits by reducing IH-induced NADPH oxidase expression, lipid peroxidation, and inflammation.

Conclusions: Oral GTP attenuates IH-induced spatial learning deficits and mitigates IH-induced oxidative stress through multiple beneficial effects on oxidant pathways. Because oxidative processes underlie neurocognitive deficits associated with IH, the potential therapeutic role of GTP in sleep-disordered breathing deserves further exploration.

Green Tea Polyphenol Administration Partly Ameliorates Chemotherapy-Induced Side Effects in the Small Intestine of Mice

May 25, 2008 by  
Filed under Science

Abstract

The chemotherapeutic agent irinotecan (IT) is highly effective
against several types of cancer, although its use is limited due to
severe intestinal toxicity. The aim of this study was to evaluate
inflammatory and oxidative stress-related processes contributing to
small intestinal mucosa damage and to determine the extent to which
green tea polyphenols could ameliorate the detrimental effects induced
by IT. In Expt. 1, mice were challenged intraperitoneally with IT or
saline on 2 consecutive days. For time kinetic measurements, the
IT-treated mice were killed at 3, 24, 48, 72, and 96 h after the 2nd
dose of IT. Three hours after IT administration, the ileum glutathione
concentration dropped significantly. Lipid peroxidation and
inflammation, as measured by macrophage inflammatory protein-2 content,
myeloperoxidase activity, and nuclear factor-κB translocation,
were highest between 24 and 48 h after IT treatment. In Expt. 2, green
tea polyphenols (1 g/L) were supplied via drinking water for 7 d before
and 3 d after treatment with IT. Green tea polyphenols significantly
affected the glutathione:glutathione disulfide ratio but not lipid
peroxidation, macrophage inflammatory protein-2 levels, myeloperoxidase
activity, or nuclear factor-κB activation. Our study reveals that
IT administration is associated with oxidative stress and inflammation,
both occurring simultaneously to IT-induced mucosal damage. The
antioxidative defense is affected soon after IT administration. Green
tea polyphenols supplied orally protected against oxidation in our
experimental model and could be one approach to reducing the risk of
IT-induced side effects in the clinical setting. J. Nutr. 137: 634-640,
2007.

« Previous PageNext Page »