Hepatoprotective properties of kombucha tea against TBHP-induced oxidative stress via suppression of mitochondria dependent apoptosis.
This popular drink is now being sold in most stores when just a few years ago it could only be found in health food stores. This article indicates kombucha is beneficial against liver disease.
Kombucha, a fermented tea (KT) is claimed to possess many beneficial properties. Recent studies have suggested that KT prevents paracetamol and carbon tetrachloride-induced hepatotoxicity. We investigated the beneficial role of KT was against tertiary butyl hydroperoxide (TBHP) induced cytotoxicity and cell death in murine hepatocytes. TBHP is a well known reactive oxygen species (ROS) inducer, and it induces oxidative stress in organ pathophysiology. In our experiments, TBHP caused a reduction in cell viability, enhanced the membrane leakage and disturbed the intra-cellular antioxidant machineries while simultaneous treatment of the cells with KT and this ROS inducer maintained membrane integrity and prevented the alterations in the cellular antioxidant status. These findings led us to explore the detailed molecular mechanisms involved in the protective effect of KT. TBHP introduced apoptosis as the primary phenomena of cell death as evidenced by flow cytometric analyses. In addition, ROS generation, changes in the mitochondrial membrane potential, cytochrome c release, activation of caspases (3 and 9) and Apaf-1 were detected confirming involvement of mitochondrial pathway in this pathophysiology. Simultaneous treatment of KT with TBHP, on the other hand, protected the cells against oxidative injury and maintained their normal physiology. In conclusion, KT was found to modulate the oxidative stress induced apoptosis in murine hepatocytes probably due to its antioxidant activity and functioning via mitochondria dependent pathways and could be beneficial against liver diseases, where oxidative stress is known to play a crucial role.Pathophysiology. 2011 Jun;18(3):221-34. Epub 2011 Mar 8.
Observational studies on tea consumption and prostate cancer (PCa) risk
are still inconsistent. The authors conducted a meta-analysis to
investigate the association between green tea and black tea consumption
with PCa risk. Thirteen studies providing data on green tea or black tea
consumption were identified by searching PubMed and ISI Web of Science
databases and secondary referencing qualified for inclusion. A
random-effects model was used to calculate the summary odds ratios (OR)
and their corresponding 95% confidence intervals (CIs). For green tea,
the summary OR of PCa indicated a borderline significant association in
Asian populations for highest green tea consumption vs. non/lowest (OR =
0.62; 95% CI: 0.38-1.01); and the pooled estimate reached statistically
significant level for case-control studies (OR = 0.43; 95% CI:
0.25-0.73), but not for prospective cohort studies (OR = 1.00; 95% CI:
0.66-1.53). For black tea, no statistically significant association was
observed for the highest vs. non/lowest black tea consumption (OR =
0.99; 95% CI: 0.82-1.20). In conclusion, this meta-analysis supported
that green tea but not black tea may have a protective effect on PCa,
especially in Asian populations. Further research regarding green tea
consumption across different regions apart from Asia is needed.
From time to time, many people experience difficulty falling asleep. The best way to manage your sleep cycle is to have a bedtime routine and stick to the routine every night. But when your routine does not work nor does the warm glass of milk there are herbal allies which can help. Passion Flower is one of these herbs. Next time try a nice cup of tea with Passion Flower in the ingredients.
Extracts and fluid extracts from the aerial parts from Passiflora incarnata L. are widely used as components of herbal sedatives. Many pharmacological investigations confirm the sedative effects of Passiflorae herba. From some of the studies also anxiolytic effects can be deduced. As Passionflower is mainly used in combinations, clinical studies of the single drug are not available. Based on pharmacological data, the experiences of traditional use and the use in combinations Passiflora extracts are an important factor in the phytotherapy of tenseness, restlessness and irritability with difficulty in falling asleep.
Wien Med Wochenschr. 2002;152(15-16):404-6.
Tiger Woods says his experience with the “calming” alkaloid l-theanine in the form of Gatorade Tiger Focus, “is taking me someplace I never imagined.” An article in The Gazette, May 24, 2009 details some of the research on theanine and the “tea paradox” of how a caffeinated beverage can be described as “calming.”
A relaxed, awake state is associated with Alpha waves, and an awake and excited brain will emit high frequency Beta waves. Caffeine can be shown to suppress theta and alpha waves, while promoting the beta waves that are linked with stress and anxiety. So, what does theanine do?
A number of studies have confirmed that within 30 minutes of ingesting theanine, there is a measurable enhancement of alpha wave activity, implying an alert but relaxed state.
And while clinical studies to date don’t show an improvement in memory or mental function in humans, rodent studies show some promise. The dose of theanine in the Gatorade product, 25 mg per serving, is below the levels used in studies, but tea itself does fall within the range of use that affects alpha brain waves.
Green Tea is one of the most extensively, and successfully, researched herbs in the world today. It was first noticed several decades ago, that people involved in presenting the green tea ceremonies had remarkably low incidence of cancer. Hundreds of studies later, we now know that green tea, and in fact all tea (Camellia sinensis) as a wide range of beneficial properties for reducing risks of cancer, heart disease and liver disease, plus antioxidant properties, benefits for the skin and much more. We hear present some of the recent research on tea and its antioxidant polyphenols.
For all the latest news on tea, click Tea under Categories to the right.
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 Read more
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. Read more
The incidence of late onset breast cancer has been increasing dramatically in the United States. Since genetic factors are believed to result primarily in early onset cases, accumulation of environmental toxins has been proposed as one factor in the increased incidence. Research reported in the Journal of Nutrition demonstrates that EGCG can protect mice against carcinogen induced breast tumors. The green tea polyphenol significantly decreased mammary tumor burden and invasiveness and significantly increased latency to the first tumor. The authors suggest “the ability of EGCG and other tea polyphenols to inhibit carcinogenesis make EGCG a good template for deriving small molecule drugs. Modifications and structure may improve the pharmacokinetics and effectiveness. As a readily available dietary substance, it holds promise for prevention of early-stage cancer.” FULL ARTICLE –> Read more
Recent research published in the American Journal of Physiology Endocrinology And Metabolism describes wide-ranging cardiovascular protective functions of a green tea polyphenol, EGCG. EGCG improved endothelial function and insulin sensitivity, reduced blood pressure and protected against myocardial ischemia and reperfusion injury. The addition of improvements in insulin sensitivity to the cardiovascular benefits indicates the benefit of green tea polyphenols against metabolic syndrome with hypertension, insulin resistance and overweight.
Am J Physiol Endocrinol Metab, 2007 Jan 16; [Epub ahead of print]Potenza MA, Marasciulo FL, Tarquinio M, et al.
Epigallocatechin gallate (EGCG), a bioactive polyphenol in green tea, may augment metabolic and vascular actions of insulin. We investigated effects of EGCG treatment to simultaneously improve cardiovascular and metabolic function in SHR rats (model of metabolic syndrome with hypertension, insulin resistance, and overweight). In acute studies, EGCG (1-100 microM) elicited dose-dependent vasodilation in mesenteric vascular beds (MVB) from SHR ex vivo, inhibitable by L-NAME (NOS antagonist) or wortmannin (PI 3-kinase inhibitor). In chronic studies, 9-wk old SHR were treated by gavage for 3 weeks with EGCG (200 mg/kg/d), enalapril (30 mg/kg/d), or vehicle. A separate group of SHR receiving L-NAME (80 mg/L in drinking water) was treated for 3 weeks with either EGCG or vehicle. Vasodilator actions of insulin were significantly improved in MVB from EGCG- or enalapril-treated SHR (compared with vehicle-SHR). Both EGCG and enalapril therapy significantly lowered systolic blood pressure (SBP) in SHR. EGCG therapy of SHR significantly reduced infarct size and improved cardiac function in Langendorff-perfused hearts exposed to ischemia/reperfusion injury (I/R). In SHR given L-NAME, effects of EGCG on SBP and I/R were not observed. Both enalapril and EGCG treatment of SHR improved insulin sensitivity and raised plasma adiponectin. We conclude that acute actions of EGCG to stimulate production of NO from endothelium using PI 3-kinase dependent pathways may explain, in part, beneficial effects of EGCG therapy to simultaneously improve metabolic and cardiovascular pathophysiology in SHR. These findings may be relevant to understanding potential benefits of green tea consumption in patients with metabolic syndrome.
The green tea flavonoid EGCG has potential therapeutic value for
treatment to for HIV-1 infection EGCG binds to the CD4 molecule on
T-cells according to research conducted in 2006. “We have
demonstrated clear evidence of high affinity binding of EGCG to the CD4
molecule. EGCG has potential use as an adjunctive treatment in HIV-1
J Allergy Cli, Immunol Williamson ME McCormick TG, Nance CL, Shearer WT. 2006;118:1369-1374.
Epigallocatechin gallate, the main polyphenol in green tea, binds to
the T-cell receptor, CD4: potential for HIV-1 therapy.(Recent
BACKGROUND: The green tea flavonoid, epigallocatechin gallate (EGCG),
has been proposed to have an anti-HIV-1 effect by preventing the
binding of HIV-1 glycoprotein (gp) 120 to the CD4 molecule on T cells.
OBJECTIVE: To demonstrate that EGCG binds to the CD4 molecule at the
gpl20 attachment site and inhibits gp120 binding at physiologically
relevant levels, thus establishing EGCG as a potential therapeutic
treatment for HIV-1 infection. METHODS: Nuclear magnetic resonance
spectroscopy was used to examine the binding of EGCG and control,
(-)-catechin, to CD4-IgG2 (PRO 542). Gp120 binding to human CD4+ T
cells was analyzed by flow cytometry. RESULTS: Addition of CD4 to EGCG
produced a linear decrease in nuclear magnetic resonance signal
intensity from EGCG but not from the control, (-)-catechin. In
saturation transfer difference experiments, addition of 5.8 micromol/L
CD4 to 310 micromol/L EGCG produced strong saturation at the aromatic
rings of EGCG, but identical concentrations of (-)-catechin produced
much smaller effects, implying EGCG/CD4 binding strong enough to reduce
gp120/ CD4 binding substantially. Molecular modeling studies suggested
a binding site for EGCG in the D1 domain of CD4, the pocket that binds
gpl20. Physiologically relevant concentrations of EGCG (0.2 micromol/L)
inhibited binding of gp120 to isolated human CD4+ T cells. CONCLUSION:
We have demonstrated clear evidence of high-affinity binding of EGCG to
the CD4 molecule with a Kd of approximately 10 nmol/L and inhibition
ofgpl20 binding to human CD4+ T cells. CLINICAL IMPLICATIONS:
Epigallocatechin gallate has potential use as adjunctive therapy in
Green tea is the fourth most commonly used dietary supplement in the
United States. After the publication of adverse event case reports
involving green tea products and potential liver toxicity, the US
Pharmacopeia reviewed safety information for green tea products. 216
case reports on green tea products were analyzed including 34 reports
concerning liver damage. 27 reports pertaining to liver damage were
categorized as possible causality and seven as probable causality.
Pharmacokinetic and animal toxicological studies indicate that
consumption of green tea concentrated extracts on an empty stomach is
more likely to lead to adverse effects than consumption in the fed
state. USP concluded “when dietary supplement products containing
green tea extracts are used in formulated appropriately the Committee
is unaware of significant safety issues that would prohibit monograph
development, provided that caution statement is included in the
Safety of Green Tea Extracts : A Systematic Review by the US Pharmacopeia.
Drug Saf. 2008;31(6):469-84.. Sarma DN, Barrett ML, Chavez ML, Gardiner
P, Ko R, Mahady GB, Marles RJ, Pellicore LS, Giancaspro GI, Low Dog T.
Green tea [Camellia sinensis (L.) Kuntze] is the fourth most
commonly used dietary supplement in the US. Recently, regulatory
agencies in France and Spain suspended market authorization of a
weight-loss product containing green tea extract because of
hepatotoxicity concerns. This was followed by publication of adverse
event case reports involving green tea products. In response, the US
Pharmacopeia (USP) Dietary Supplement Information Expert Committee (DSI
EC) systematically reviewed the safety information for green tea
products in order to re-evaluate the current safety class to which
these products are assigned. DSI EC searched PubMed (January 1966-June
2007) and EMBASE (January 1988-June 2007) for clinical case reports and
animal pharmacological or toxicological information. Reports were also
obtained from a diverse range of other sources, including published
reviews, the US FDA MedWatch programme, USP’s MEDMARX((R))
adverse event reporting system, the Australian Therapeutic Goods
Administration, the UK Medicines and Healthcare products Regulatory
Agency, and Health Canada’s Canadian Adverse Drug Reaction
Monitoring Program. Case reports pertaining to liver damage were
evaluated according to the Naranjo causality algorithm scale. In
addition, the Committee analysed information concerning historical use,
regulatory status, and current extent of use of green tea products. A
total of 216 case reports on green tea products were analysed,
including 34 reports concerning liver damage. Twenty-seven reports
pertaining to liver damage were categorized as possible causality and
seven as probable causality. Clinical pharmacokinetic and animal
toxicological information indicated that consumption of green tea
concentrated extracts on an empty stomach is more likely to lead to
adverse effects than consumption in the fed state. Based on this safety
review, the DSI EC determined that when dietary supplement products
containing green tea extracts are used and formulated appropriately the
Committee is unaware of significant safety issues that would prohibit
monograph development, provided a caution statement is included in the
labelling section. Following this decision, USP’s DSI ECs may
develop monographs for green tea extracts, and USP may offer its
verification programmes related to that dietary ingredient.