Green tea cancer research
Cancercauses and preventionrisk factors and -causing cancer myths and cancer genetics services prevention and cancer is tea? In the united states, united kingdom (uk), and europe, black tea is the most common tea beverage consumed; green tea is the most popular tea in japan and china (2). The polyphenols, a large group of plant chemicals that includes the catechins (4), are thought to be responsible for the health benefits that have traditionally been attributed to tea, especially green tea. The active catechins and their respective concentrations in green tea infusions are listed in the table in concentrations of green tea infusionscatechin in green tea infusioncatechin concentration(mg/l)*catechin concentration(mg/8 fl oz)*epigallocatechin-3-gallate (egcg)117–44225–106epigallocatechin (egc)203–47149–113epicatechin-3-gallate (ecg)17–1504–36epicatechin (ec)25–816–19 *mg = milligram; l = liter; fl oz = fluid ounce. White and green tea contain similar amounts of egcg but different amounts of other polyphenols (7). Study that evaluated 19 different green tea supplements for tea catechin and caffeine content, the product labels varied in their presentation of catechin and caffeine information, and some values reported on product labels were inconsistent with analyzed values (1). Their many biological activities, the predominant polyphenols in green tea―egcg, egc, ecg, and ec―and the theaflavins and thearubigins in black teas have antioxidant activity (12). Furthermore, green teas have been shown to activate detoxification enzymes, such as glutathione s-transferase and quinone reductase, that may help protect against tumor development (16). Although many of the potential beneficial effects of tea have been attributed to the strong antioxidant activity of tea polyphenols, the precise mechanism by which tea might help prevent cancer has not been established (13). In a japanese study, children aged 6 to 16 years consumed a green tea beverage containing 576 mg catechins (experimental group) or 75 mg catechins (control group) for 24 weeks with no adverse effects (19). Green and white teas contain slightly less caffeine, ranging from 24 to 39 mg per 8 fl oz serving and 32 to 37 mg per 8 fl oz serving, respectively (22). Studies have found concentrations of aluminum (which is naturally taken up from soil) in infusions of green and black teas that range from 14 to 27 micrograms per liter (μg/l) to 431 to 2239 μg/l (4). Has long been regarded as an aid to good health, and many believe it can help reduce the risk of cancer. Although tea and/or tea polyphenols have been found in animal studies to inhibit tumorigenesis at different organ sites, including the skin, lung, oral cavity, esophagus, stomach, small intestine, colon, liver, pancreas, and mammary gland (24), the results of human studies—both epidemiologic and clinical studies—have been iologic studiesmore than 50 epidemiologic studies of the association between tea consumption and cancer risk have been published since 2006. The results of these studies have often been inconsistent, but some have linked tea consumption to reduced risks of cancers of the colon, breast, ovary, prostate, and lung (6, 25–57). The inconsistent results may be due to variables such as differences in tea preparation and consumption, the types of tea studied (green, black, or both), the methods of tea production, the bioavailability of tea compounds, genetic variation in how people respond to tea consumption, the concomitant use of tobacco and alcohol, and other lifestyle factors that may influence a person’s risk of developing cancer, such as physical activity or weight al trialsseveral clinical trials have investigated the role of tea and tea polyphenols in cancer prevention (58–66). However, few trials have examined the effects of tea or tea polyphenols on cancer incidence or randomized trials evaluated the effects of tea extracts on premalignant oral lesions (58, 59). One of the trials was a double-blind interventional trial involving 59 people with leukoplakia, which is a putative precursor lesion for oral cancer (58). Furthermore, mucosal cell proliferation decreased in the treatment group, suggesting a possible protective effect of tea on the development of oral cancer. In contrast, in the second trial, 39 people with high-risk premalignant oral lesions were randomly assigned to receive one of three doses of a green tea extract—500 mg per square meter of body surface area (mg/m2), 750 mg/m2, or 1000 mg/m2—or a placebo three times daily for 12 weeks (59). At the end of the trial, no differences in lesion responses or histology were found between the other randomized trials examined the effects of tea on urine levels of 8-hydroxydeoxyguanosine (8-ohdg), a biomarker of oxidative dna damage that may be a predictor of increased cancer risk. Urinary 8-ohdg levels are higher in individuals with lung cancer than in control subjects, and human breast, lung, liver, kidney, brain, stomach, and ovarian tumor tissue has a higher content of 8-ohdg than adjacent nontumor tissue (60). In one trial, 133 adult heavy smokers were randomly assigned to drink 4 cups of one of the following beverages each day for 4 months: decaffeinated green tea, decaffeinated black tea, or water (60). Among those who drank green tea, there was a statistically significant 31 percent decrease in urinary levels of 8-ohdg; in the black tea group, there was no change in urinary 8-ohdg levels (60). In the second trial, 124 individuals at increased risk of liver cancer due to hepatitis b virus infection and aflatoxin exposure took a placebo or 500 mg or 1000 mg of a green tea polyphenol supplement daily (61). The two supplement doses were reported to be equivalent to 2 or 4 cups, respectively, of green tea infusions. Compared with those in the placebo group, individuals who took the green tea supplement at either dose for 3 months had substantially lower urinary 8-ohdg levels (61).
Although these trials indicate that green tea polyphenols from tea or supplements can reduce urinary 8-ohdg levels, it is unclear if reduced 8-ohdg levels are associated with reduced cancer onal trials have investigated whether green tea catechins or green tea extracts alter prostate cancer risk. In a double-blind, placebo-controlled study, 60 men took 200 mg of green tea catechin or a placebo three times daily for 1 year (62). These men had high-grade prostatic intraepithelial neoplasia, which is thought to be a precursor of prostate cancer. After 1 year, fewer prostate cancers were detected in the green tea catechin group (1 cancer in 30 men) compared with the placebo group (9 cancers in 30 men) (62). Two other clinical trials, both uncontrolled studies, investigated the use of green tea extracts to reduce prostate-specific antigen levels in men with prostate cancer and found no evidence of such a reduction (63, 64). Serum pepsinogen is a biomarker of gastric atrophy and an indicator of increased risk for stomach cancer. Yet another trial, a possible role for green tea supplements in treating precancerous lesions of the esophagus was investigated (66). In the trial, 200 chinese participants with such lesions were treated with 5 mg of a decaffeinated green tea extract daily or a placebo. In general, therefore, nci does not make recommendations about specific medical or dietary er, as noted above, the evidence regarding the potential benefits of tea consumption in relation to cancer is inconclusive at that fight ancient times, tea has been used as both beverage and medicine. Both black and green teas contain numerous active ingredients, including polyphenols and flavonoids, which are potent class of flavonoids called catechins has recently become the focus of widespread study for their anti-cancer potential. Tea is the best source of catechins in the human diet, and green tea contains about three times the quantity of catechins found in black laboratory studies, green tea has been shown to slow or completely prevent cancer developent in colon, liver, breast and prostate cells. Other studies involving green tea have shown similar protective effects in tissues of the lung, skin and digestive s that track the diets of human subjects over several years (particularly studies conducted in asia, where green tea consumption is common) have also associated regular usage of green tea with lower risk for bladder, colon, stomach, pancreatic and esophageal ’s second expert report, food, nutrition, physical activity, and the prevention of cancer: a global perspective, was unable to make a recommendation regarding the relationship between tea consumption and cancer risk due to insufficient : very high amounts of green tea components (usually associated with overdosage of green tea supplements) have been shown to interact with drugs that affect blood clotting such as aspirin and change the way the body metabolizes certain researchaicr has funded research on the following topics relating to green tea and the cancer-fighting components it contains. Click each topic to search for relevant aicr-funded research studies performed to and green the full list of aicr’s recommendations for cancer fund cutting-edge research and give people practical tools and information to help them prevent — and survive — an institute for cancer research. Wilson boulevard,Suite 1000, arlington, va the latest cancer research news, tips on how you can reduce your cancer risk, delicious and healthy recipes ‐ and more! 2017 american institute for cancer l cancer l cancer informationtreatment for cancercomplementary and alternative therapiesindividual tea is a drink made from the dried leaves of the asian plant camellia tea is drunk widely across asia. The rates of many cancers are much lower in asia than other parts of the world. Some people believe this is because of the high intake of green may also hear green tea called chinese tea. The substance in green tea that researchers think is most helpful is called epigallocatechin-3-gallate (egcg). Egcg is available as green tea extract which some people take as a supplement in liquid or some people with cancer use green teathere is no real evidence that green tea can help with some people take it because they believe it might:Boost their immune system which might help them fight their cancerimprove health, energy levels and well beingget rid of toxins in the bodygive them some control over their cancer and its treatmenttreat their cancer if no other conventional treatment people think green tea might reduce their risk of getting cancer. There is some evidence from early studies to suggest that having green tea might reduce the risk of some cancers. But at the moment the evidence is not strong enough to know this for recently, black tea has also been promoted as an anti cancer agent. But black tea is made from the fermented leaves of the green tealike most teas on the market, green tea comes as ready made tea bags or leaves that you add to boiling water. Manufacturers often suggest having between 3 and 5 cups a er that most green tea contains caffeine so it will act as a stimulant and keep you awake if you drink it before going to bed. But we don’t know whether removing the caffeine could reduce the possible antioxidant can also buy green tea as capsules. Because green tea is sold as a herbal supplement in most countries, manufacturers don’t have to prove that they are safe or even that they have any health on these supplements usually recommend that you take 3 capsules a day. So our advice is to buy with ch into green tearesearchers have done some research into whether green tea or green tea extract can be helpful in preventing or treating tea and preventing laboratory studies have shown that extracts from green tea can stop cancer cells from growing. Green tea contains substances called polyphenols, and a sub group called catechins, which scientists think give it antioxidant properties.
But while these lab results are encouraging, we need evidence from human studies to prove evidence we have at the moment from human studies is overview of studies (a meta analysis) published in 2014 suggested that green tea could reduce the risk of developing mouth cancers. Another meta analysis has suggested that drinking green tea could reduce the risk of lung cancer. The risk of developing cancer of the food pipe also seems to be reduced in women who drink green july 2009, the cochrane library published a review of 51 studies which included more than 1. This review was looking for a link between drinking green tea and having a lower risk of cancer. The cancers included in the review were digestive tract cancers, breast cancer, bladder cancer, prostate cancer and lung cancer, as well as cancer of the mouth. The researchers said that that the research so far is conflicting, which means that green tea remains unproven in preventing cancer. The researchers say it is safe to drink green tea in moderate amounts, of 3 to 5 cups a 2008 the centre for evidence based chinese medicine in china published a review of 43 studies, 4 randomised controlled trials and 1 meta analysis. The trials looked at studies testing whether green tea can reduce the risk of cancer. Some trials seemed to suggest that green tea can reduce the risk of developing cancers of the digestive system but other trials didn' studies have also given conflicting results, for example, a meta analysis published in 2006 suggested that green tea may lower the risk of breast cancer. But an earlier meta analysis couldn't find any significant evidence to support a reduction in the risk of breast has been suggested that green tea may help to prevent prostate cancer. However, a study of almost 20,000 japanese men, published in the british journal of cancer in 2006, found no relationship between green tea and prostate really need more evidence from randomised controlled clinical trials to help us know whether green tea has a role in preventing cancer. At the moment it is impossible to draw any firm conclusions because:Only a small number of studies have been donethere is a lack of randomised controlled clinical trialsthere are differences in lifestyle factors within studies (most studies have been done in east asia)different amounts of tea have been taken within the studiesthere is possible interaction with other treatments or diet supplements used by people in the tea to treat little research has been done into whether green tea or green tea extract can be helpful in treating 2012 an american study looked at giving a green tea extract called polyphenon e to 42 patients with a type of leukaemia called chronic lymphocytic leukaemia. The people in the trial were not taking any other kind of researchers found that the number of leukaemic cells lessened in a third of the participants and their lymph nodes shrank. We need larger trials before we know whether green tea or its extracts can help people with le side effectsgreen tea is generally safe to drink, but can cause sickness and an upset stomach in some tea contains caffeine which is a stimulant. If it is taken in large amounts it can cause:Difficulty sleepingirritabilityanxietypassing urine green tea safelyas green tea is a herbal product it hasn't necessarily been thoroughly tested for interactions with foods, medicines or other supplements. Laboratory study in 2013 showed that the substance in green tea called epigallocatechin-3-gallate (egcg) might increase the actions of some anti cancer drugs. But this substance may also reduce the effect of other research has raised concerns about a possible interaction between green tea and the drug bortezomib (velcade). Do remember that we'd need much more research to find out if green tea has the same effect in humans. But if you are taking velcade, you might want to avoid green tea or the extract egcg, which some people take as a supplement in liquid or capsules. If you have any worries, talk it over with your cancer are no reports of any other harmful effects from using green tea. And if you are taking other drugs, herbs, or supplements, you need to check with your doctor about possible is important to remember that green tea contains caffeine. We recommend that you don't replace your conventional cancer treatment with any type of supplement like green tea. It may be safe to take it alongside your cancer treatment but check with your doctor first to make cam-cancer for more information about green cost of green teagreen tea is sold in health food shops, supermarkets, chemists and over the internet. Prices can vary depending on the amount you buy and where you buy quality or grade of green tea can also vary. For example, one company we looked at online sold 50g of different types of green tea for between £2. And ation about types of cancer generously supported by dangoor education since a clinical our clinical trials database for all cancer trials and studies recruiting in the to other people affected by helpline 0808 800 ons about cancer? Author manuscript; available in pmc 2011 jul hed in final edited form as:cancer metastasis rev.
S10555-010-9236-1pmcid: pmc3142888nihmsid: nihms311687cancer and metastasis: prevention and treatment by green teanaghma khan and hasan mukhtardepartment of dermatology, university of wisconsin, 4385, medical sciences center, 1300 university avenue, madison, wi 53706, usacorresponding mukhtar: @rathkumh author information ► copyright and license information ►copyright notice and disclaimerthe publisher's final edited version of this article is available at cancer metastasis revsee other articles in pmc that cite the published ctmetastasis is the most deadly aspect of cancer and results from several interconnected processes including cell proliferation, angiogenesis, cell adhesion, migration, and invasion into the surrounding tissue. The appearance of metastases in organs distant from the primary tumor is the most destructive feature of cancer. Metastasis remains the principal cause of the deaths of cancer patients despite decades of research aimed at restricting tumor growth. Several in vitro, in vivo, and epidemiological studies have reported that the consumption of green tea may decrease cancer risk. Epigallocatechin-3-gallate, major component of green tea, has been shown to inhibit tumor invasion and angiogenesis which are essential for tumor growth and metastasis. This article summarizes the effect of green tea and its major polyphenolic compounds on cancer and metastasis against most commonly diagnosed cancer ds: cancer, egcg, green tea, metastasis, tumor growth1 introductioncancer is recognized worldwide to be a major health problem. A total of 1,479,350 new cancer cases and 562,340 deaths from cancer were projected to occur in the united states in 2009 [1]. The main reason for such a high mortality from cancer is due to the highly invasive behavior of cancer cells, which usually results in cancer progression and metastasis. Metastasis is the process whereby neoplastic cells spread from a primary site where the primary tumor originated to distant organs and is responsible for the majority of deaths related to cancer. Metastatic cancer cells require properties that allow them not only to adapt to a foreign microenvironment but to subvert it in a way that is conducive to their continued proliferation and e improvements in diagnosis, surgical techniques, patient care, and adjuvant therapies, most deaths from cancer are due to metastasis that is resistant to conventional therapies, direct organ damage by the growing lesions, paraneoplastic syndromes, or from the complications of treatment [5]. The outcome of cancer metastasis depends on multiple interactions between metastatic cells and homeostatic mechanisms that are unique to one or another organ microenvironment. The specific organ microenvironment determines the extent of cancer cell proliferation, angiogenesis, invasion, and survival. Therefore, the therapy of metastasis should be targeted against tumor cells and the host factors that contribute to and support the progressive growth and survival of metastatic cancer , derived from the plant camellia sinensis, is the most globally consumed beverage as green, black, or oolong tea. Million tons of tea leaves are produced throughout the world each year with 20% produced as green tea, which is mainly consumed in asia, some parts of north africa, the united states, and europe [8]. The anti-cancer effects of egcg have been reported to be linked to the modulation of multiple signaling pathways, finally resulting in the downregulation of expression of proteins involved in the invasiveness of cancer cells [11]. In this review article, we discuss the modulation of signaling pathways responsible for invasive behavior and metastasis of different cancer types by green tea [tables 1 and and22]. 1effect of green tea on metastasis of cancer in cell culture systemstable 2effect of green tea on metastasis of cancer in animal models2 green tea and metastasis of skin cancerthe skin cancer incidence is increasing by epidemic proportions. Treatment with a diet containing lysine, proline, arginine, ascorbic acid, and green tea extract to athymic nude mice implanted with human melanoma a2058 cells strongly suppressed tumor growth with inhibition of mmp-9 and vegf secretion [13]. In skh-1 hairless mice, oral administration of green tea polyphenols (gtp) reduced ultraviolet (uv)b-induced tumor incidence, tumor multiplicity, and tumor growth. Uvb-induced skin tumors with and without treatment of egcg and age-matched skin biopsies from skh-1 hairless mice were used to identify potential molecular targets of skin cancer prevention by egcg. Treatment of pca pc-3 cells with traditional botanical supplement-101 (tbs-101), a botanical agent containing standardized botanical extracts of panax ginseng, cranberry, green tea, grape skin, grape seed, ganoderma lucidum, and chamomile resulted in dose-dependent inhibition of cell growth with concomitant induction of apoptosis. Effects of a diet containing lysine, proline, arginine, ascorbic acid, and green tea extract on the growth of tumors induced by implanting human pca pc-3 cells in athymic nude mice and on the expression of mmps, vegf, ki-67, and fibronectin in these tumors, as well as the production of mucin, were investigated. There were increased levels of igf-i, phosphatidylinositol 3′-kinase (pi3k), phosphorylated akt, and extracellular signal-regulated kinase (erk)1/2 with concomitant decrease in igfbp-3 in dorsolateral prostate of tramp mice during the course of cancer progression. Egcg was found to inhibit degradation of gelatin, degradation of type iv collagen in reconstituted basement membrane (matrigel), and activation of mmp-2 but not pro-mmp-9 in a cell-free system in a dose-dependent manner at concentrations lower than the cytotoxic serine-protease inhibitor phenylmethyl sulfonyl fluoride and close to levels measured in the serum following ingestion of green tea [24]. Soy phytochemical concentrate (spc), black tea, and green tea significantly reduced tumorigenicity, while spc and black tea also significantly reduced final tumor weights. Green tea did not reduce final tumor weight, but it elevated serum dihydrotestosterone (dht) concentration. There was inhibition of prostate tumorigenicity, final tumor weight, and metastases to lymph nodes in vivo by combination of spc and black tea while the combination of spc and green tea inhibited final tumor weight and metastasis and significantly reduced serum concentrations of both testosterone and dht in vivo.
Equivalent to six cups of green tea per day, significantly inhibited pca development and increased survival in male tramp mice. There was also significant apoptosis of pca cells resulting in the reduced dissemination of cancer cells, thereby causing inhibition of pca development, progression, and metastasis of pca to distant organ sites by gtp consumption [26]. Green tea and metastasis of breast cancermetastasis of breast cancer is the major reason for the high mortality of breast cancer patients and is directly linked to the invasive behavior of breast cancer cells. Cancer metastasis consists of several interdependent processes including cancer cell adhesion, cancer cell migration, and invasion of cancer cells. It was concluded that egc and egcg could play important role against the promotion of metastasis of breast cancer cells [28]. Gtp has been reported to inhibit cell growth and invasive behavior of human breast cancer mda-mb-231 cells. It also caused inhibition of constitutively active transcription factors ap-1 and nf-κb, which further suppressed secretion of upa from breast cancer cells. Upa, upa-receptor, vitronectin, and integrin receptor by inhibiting the invasive behavior of breast cancer cells [30]. The association between consumption of green tea prior to clinical cancer onset and various clinical parameters assessed at surgery among 472 patients with stage i, ii, and iii breast cancer were examined. There was decrease in the numbers of auxiliary lymph node metastases among premenopausal patients with stage i and ii breast cancer and increased expression of progesterone receptor and estrogen receptor among postmenopausal patients on increased consumption of green tea. In a 7-year follow-up of stage i and ii breast cancer patients, increased consumption of green tea was correlated with decreased recurrence of stage i and ii breast cancer. This showed that increased consumption of green tea prior to clinical cancer onset was significantly associated with improved prognosis of stage i and ii breast cancer, and this association may be related to a modifying effect of green tea on the clinical characteristics of the cancer [32]. Green tea and metastasis of lung cancerlung cancer is the most common cancer in the world and represents a major public health problem. The preventive effect of green tea catechins intake on lung tumor metastasis was examined in senescence-accelerated mice prone (samp) 10. Green tea catechins intake increased natural killer cell activity, which is an indicator of immune surveillance potential and was reduced in control group mice with age. Mice were given intravenous injection of the melanoma cells and the early accumulation of lung-metastatic k1735m2 melanoma cells and the subsequent experimental lung metastasis was investigated after treatment with green tea catechins. The accumulation at 6 and 24 h after injection of melanoma cells and the number of lung-metastatic colonies were significantly reduced in mice treated with green tea catechins as compared to mice in control group suggesting that green tea catechin intake prevented the experimental tumor metastasis in aged samp10 mice via inhibition of the reduction in immune surveillance potential with age [33]. The effect of cytokines, mitogens, and inhibitors on mmp-2 and -9 expressions in human lung cancer a549 cells malignant melanoma msto-211h cells was investigated. Effects of a nutrient mixture consisting of ascorbic acid, lysine, proline, arginine, and green tea extract were investigated on lung metastasis by b16f0 melanoma cells in c57bl/6 female mice. This nutrient mixture supplementation to athymic nude mice implanted with human lung cancer a549 cells suppressed the tumor growth without adverse effects. In a spontaneous metastasis system, the administration of green tea infusion reduced the number of lung colonies of mouse lewis lung carcinoma cells which was attributed to the inhibitory effects of the green tea infusion and its constituent catechins on the penetration of the cells through the basement membrane [40]. Green tea and metastasis of liver cancerhepatocellular carcinoma is a growing health problem worldwide and only few promising treatment options are available at present, stressing the urgent need for novel therapeutic approaches. The effect of a nutrient mixture containing lysine, proline, arginine, ascorbic acid, and green tea extract on tumor growth and hepatic metastasis were investigated in athymic nude male mice inoculated with 10(6) b16fo melanoma cells. It was concluded in the study that the combination of egcg and ascorbic acid strongly suppressed the proliferation and metastasis of liver cancer cells, possibly with a mechanism associated with the scavenging of reactive oxygen species [43]. Green tea and metastasis of colon cancercolorectal cancer is the second most deadly cancer in the united states. Human colon cancer cell lines hct116 and ht29 were used to examine the relationships between met activation, egcg treatment, and generation of h2o2. Diet of nutrient mixture containing amino acids, ascorbic acid, and green tea extract inhibited growth and reduced the size of tumors in nude mice implanted with human colon hct 116 cells.
Egcg treatment increased both intracellular and extracellular pro-mmp-7 protein levels in dose- and time-dependent manner ht-29 human colorectal cancer cells with a significant upregulation of its mrna expression. Green tea and metastasis of pancreatic cancerit is difficult to detect pancreatic cancer in the early stage despite the development of more sophisticated diagnostic techniques and surgical resection provides the only option. There was reduction in ki-67, pcna, von willebrand factor, vegf, cd31, vegfr-2, erk1/2, jnk1/2, p38, mmp-2, mmp-7, mmp-9, and mmp-12 and induction of apoptosis, caspase-3 activity, and p21/waf1 in tumors of athymic nude mice implanted with human pancreatic cancer aspc-1 cells suggesting that egcg inhibited pancreatic cancer growth, invasion, metastasis, and angiogenesis [49]. In pancreatic cancer cell line mia paca-2, nutrient mixture containing green tea exhibited a dose-dependent antiproliferative effect, decreased expression of mmp-9, and inhibition of invasion through matrigel [50]. Hamsters, the inhibitory effect of green tea extract on the process of pancreatic carcinogenesis induced by n-nitrosobis-(2-oxypropyl)amine and on tumor promotion after transplantation of n-nitrosobis-(2-hydroxypropyl)amine (bhp)-induced pancreatic cancer were investigated. In the control group, seven of the 13 hamsters were found to have pancreatic tumors, while six of the 18 hamsters had pancreatic tumors in the green tea extract group. Hamster with pancreatic cancer incidence of 54% compared with the green tea extract group which had average number of tumors of 0. The number of pancreatic cancers, including invasive carcinoma, carcinoma in situ, and incidence of atypical ductal hyperplasia, which is thought to be an early pancreatic cancer, was significantly lower in the green tea extract group than in the control group. In a different experiment, 1 mm3 pieces of bhp-induced pancreatic cancer were transplanted into the back of hamsters and were given tap water and green tea extract. Till 11 weeks after transplantation, tumor growth was similar in both groups, but inhibition of tumor growth became evident after 11 weeks in the green tea extract treated group. The average tumor volume in the green tea extract group was significantly lower than that in the control group at 13 weeks demonstrating that green tea extract had an inhibitory effect on the process of pancreatic carcinogenesis and on tumor promotion of transplanted pancreatic cancer in hamsters [51]. Green tea and metastasis of miscellaneous cancersthe effects of egcg on the methylation status of the reversion-inducing cysteine-rich protein with kazal motifs (reck) gene and cancer invasion in oral squamous cell carcinoma cell lines were investigated. Egcg treatment of oral cancer cells partially reversed the hypermethylation status of the reck gene and significantly enhanced the expression level of reck mrna with inhibition of mmp-2 and mmp-9 levels. Egcg also suppressed cancer cell-invasive ability by decreasing the number of invasive foci as well as invasion depth in 3d collagen invasion model [52]. In precancerous normal tissues among esophageal squamous cell carcinoma patients, while no hypermethylation was found in normal esophageal tissues from healthy adult subjects. In patients with lymph node metastasis, the methylation rate of mgmt gene in cancer tissues was significantly higher than in those without lymph node metastasis. Of the metastasis-associated 67-kda laminin receptor (lr) confers egcg responsiveness to cancer cells at physiologically relevant concentrations [55]. The effects of green tea extract on cell viability, cell proliferation, cell cycle dynamics, vegf, and expression of vegf receptors fms-like tyrosine kinase (flt)-1 and fetal liver kinase (flk)-1/kinase insert domain containing receptor (kdr) were studied in vitro using huvecs. Treatment of cells with green tea extract did not affect cell viability but significantly reduced cell proliferation dose-dependently and caused a dose-dependent accumulation of cells in the g1 phase. There was also decrease in the expression of flt-1 and flk-1/kdr/in huvecs on treatment with green tea extract suggesting that it affects tumor angiogenesis and metastasis through reduction in the expression of vegf receptors [59]. Egcg treatment also caused inhibition of the phosphorylation of erk1/2 and p38 mapk activity showing that suppression of erk phosphorylation by egcg was involved in the inhibition of mmp-2 and mmp-9 mrnas, leading to the reduction of their enzyme activities in the cancer cells [60]. Conclusions and perspectivesthe possible cancer-preventive activity of green tea constituents has been studied extensively and the amount of experimental evidence documenting the properties of green tea, which affects multiple signaling pathways (fig. Metastasis is responsible for most deaths due to cancer and therefore, therapeutic strategies to prevent development of metastases have potential to impact on cancer mortality. Significant improvements in early detection of cancer and development of effective novel therapeutic strategies targeting metastasis will help improve patient outcome. A better approach for the treatment of cancer seems to be the development of strategies to treat tumor cells and to modulate the host microenvironment. For better understanding of the interaction of green tea, employment of more specific and sensitive methods with more representative models of metastasis in conjunction with the development of good predictive biomarkers are required. Well-designed clinical and intervention trials will give the clear picture about the protective effects of green tea against metastasis of .
1modulation of signaling pathways and cascade of metastasis by green teaacknowledgmentsthe original work from the author’s (hm) laboratory outlined in this review was supported by united states public health service grants ro1 ca 78809, ro1 ca 101039, ro1 ca 120451, and p50 nces1. In vivo and in vitro antitumor effect of ascorbic acid, lysine, proline and green tea extract on human melanoma cell line a2058. Orally administered green tea polyphenols prevent ultraviolet radiation-induced skin cancer in mice through activation of cytotoxic t cells and inhibition of angiogenesis in tumors. The effect of a novel botanical agent tbs-101 on invasive prostate cancer in animal models. Green tea polyphenol egcg sensitizes human prostate carcinoma lncap cells to trail-mediated apoptosis and synergistically inhibits biomarkers associated with angiogenesis and metastasis. In vivo antitumor effect of ascorbic acid, lysine, proline and green tea extract on human prostate cancer pc-3 xenografts in nude mice: evaluation of tumor growth and immunohistochemistry. Prognostic significance of metastasis-associated protein s100a4 (mts1) in prostate cancer progression and chemoprevention regimens in an autochthonous mouse model. Oral consumption of green tea polyphenols inhibits insulin-like growth factor-i-induced signaling in an autochthonous mouse model of prostate cancer. Prostate carcinoma and green tea: psa-triggered basement membrane degradation and mmp-2 activation are inhibited by (−)epigallocatechin-3-gallate. Multifunctional effect of epigallocatechin-3-gallate (egcg) in downregulation of gelatinase-a (mmp-2) in human breast cancer cell line mcf-7. Green tea polyphenols modulate secretion of urokinase plasminogen activator (upa) and inhibit invasive behavior of breast cancer cells. Growth inhibitory and antimetastatic effect of green tea polyphenols on metastasis-specific mouse mammary carcinoma 4t1 cells in vitro and in vivo systems. Modulation of mmp-2 and mmp-9 by cytokines, mitogens and inhibitors in lung cancer and malignant mesothelioma cell lines. Inhibition of pulmonary metastasis of melanoma b16fo cells in c57bl/6 mice by a nutrient mixture consisting of ascorbic acid, lysine, proline, arginine, and green tea extract. In vivo and in vitro antitumor effect of a unique nutrient mixture on lung cancer cell line a-549. Inhibition of collagenases from mouse lung carcinoma cells by green tea catechins and black tea theaflavins. Inhibitory effects of green tea infusion on in vitro invasion and in vivo metastasis of mouse lung carcinoma cells. Inhibition of liver cancer cell proliferation and migration by a combination of (−)-epigallocatechin-3-gallate and ascorbic acid. Suppression of met activation in human colon cancer cells treated with (−)-epigallocatechin-3-gallate: minor role of hydrogen peroxide. A green tea component suppresses posttranslational expression of basic fibroblast growth factor in colorectal cancer. In vivo antitumor effect of ascorbic acid, lysine, proline and green tea extract on human colon cancer cell hct 116 xenografts in nude mice: evaluation of tumor growth and immunohistochemistry. Epigallocatechin-3-gallate promotes pro-matrix metalloproteinase-7 production via activation of the jnk1/2 pathway in ht-29 human colorectal cancer cells. Antitumor effect of a combination of lysine, proline, arginine, ascorbic acid, and green tea extract on pancreatic cancer cell line mia paca-2. Inhibitory effect of green tea extract on the process of pancreatic carcinogenesis induced by n-nitrosobis-(2-oxypropyl)amine (bop) and on tumor promotion after transplantation of n-nitrosobis-(2-hydroxypropyl) amine (bhp)-induced pancreatic cancer in syrian hamsters. Effects of green tea polyphenol on methylation status of reck gene and cancer cell invasion in oral squamous cell carcinoma cells. Green tea catechin inhibits ephrin-a1-mediated cell migration and angiogenesis of human umbilical vein endothelial cells. Green tea extract inhibits angiogenesis of human umbilical vein endothelial cells through reduction of expression of vegf receptors.
Article | pubreader | epub (beta) | pdf (387k) | links skip to primary navigation skip to content skip to primary sidebar skip to footer main navigation ttac » nutrition » food & drink » 3 anti-cancer health benefits of green tea share5. You are probably already aware, the many health benefits of green tea − once just a popular beverage in china and japan − has led to its popularity, growing by leaps and bounds among health-conscious people all over the world. Specifically, egcg and other green tea antioxidants have been found to stop cancer cells from growing, kill cancer cells, and prevent the formation and growth of new blood vessels in tea antioxidants green tea leaves contain so-called ‘bioactive’ compounds, including green tea antioxidants, which act on our body in multiple beneficial ways. Specifically, green tea polyphenols known as catechins are believed to be responsible for many of the health benefits of green locatechin-3-gallate (egcg) is the most abundant catechin in green tea and accounts for 50-75% of its total catechin content. Egcg is also the most effective green tea antioxidant as far as its health benefits are concerned – and it has been tested extensively over the past few years to better understand its potential cancer-fighting results of these studies clearly show that egcg and other green tea antioxidants are toxic to cancer cells in laboratory experiments and indicate why health experts are so optimistic about their use in cancer therapies in the near stops cancer cells from growingcancer cells are formed when our body’s cells break free of the normal cycle of growth and death and begin to grow uncontrollably, giving rise to harmful, even life-threatening tumors in different parts of the body. Egcg and other green tea antioxidants act in very specific ways to prevent cancer cells from growing – and are very likely responsible for at least some of the anticancer health benefits of green antioxidants have been shown to prevent cancer cells from growing in multiple ways:they lower cellular levels of a protein known as cyclin d1 that is needed by cancer cells to grow properly. Egcg also blocks enzymes that help to maintain cancer cells in the so-called ‘cell cycle’, which allows them to keep growing. Because of these actions, egcg forces cancer cells to go into ‘growth arrest’ – meaning they stop growing, usually also increases the levels of other important cellular proteins that make it very difficult for cancer cells to kills cancer cellsin a very promising development, egcg has been shown to kill many different types of cancer cells in laboratory conditions. One way in which egcg does this is by triggering the activity of so-called ‘pro-death’ proteins, causing cancer cells to commit ‘suicide. In one study, treating breast cancer cells with egcg led to so many of them dying that the study researchers were able to measure a significant reduction in tumor size. In other words, not only do egcg and other green tea antioxidants stop cancer cells from growing – they also actively kill prevents formation and growth of new blood vessels in tumorswhen new blood vessels begin to form and grow in a tumor, it is known as angiogenesis. Angiogenesis allows cancer cells to grow faster and spread to other areas of the body by providing them with much-needed nutrients and oxygen. By doing so, egcg prevents cancer cells from growing rapidly and spreading from one location to another and invading other parts of the one study, tumors treated with a potent extract of green tea leaves that contains concentrated tea polyphenols (including egcg) had significantly fewer blood vessels and were noticeably smaller in is green tea a proven cancer fighter? S clear that egcg and other green tea antioxidants can stop cancer cells from growing, even directly kill them. They also seem to be able to prevent new blood vessels from forming within tumors that help cancer cells to grow rapidly and spread to other parts of the body. Egcg does this by interfering specifically with multiple biological mechanisms in cancer cells – and it appears to do so without affecting normal experts believe that these actions of egcg and other green tea antioxidants are to a large extent responsible for the potential anticancer health benefits of green r, it must be remembered that so far the evidence for egcg’s anticancer abilities comes mainly from laboratory studies. Because of these promising results, many human clinical trials have been carried out (and are still being carried out) to find out whether egcg and green tea extract supplements can indeed protect us from developing the results of these studies have not been as clear-cut as health experts would have liked, all the available evidence suggests that daily consumption of two to three cups of green tea can help to lower your overall cancer risk without any serious side r, if you’re on prescription medications or are sensitive to caffeine, you may want to speak to your physician before adding green tea to your daily diet. And if you do experience any uncomfortable symptoms (such as nervousness, confusion, sleep issues, irritability), be sure to discontinue green tea immediately and consult your physician right ’s also important to know that although many commercial iced and ready-to-drink versions of green tea are also quite popular nowadays, they may not have the same healthful levels of green tea antioxidants that you’ll get from a freshly brewed cup using real green tea leaves. The lower the amounts of tea leaves and buds, the lesser the antioxidant content, minimizing the health benefits of green only that, adding other liquids like juices or water further dilutes the levels of green tea antioxidants and weakens their health benefits. Decaffeinated green tea also has significantly lower levels of green tea antioxidant concentrations of green tea – and the health benefits you get from it – depend on the type and quality of green tea you use, how much you use, how long you brew it for, and the temperature of to brew the perfect cup of fresh green teathe perfect cup of green tea is flavorful, not too bitter, weak or watery – in other words, it’s just right! S how you can simply and easily prepare this healthful beverage for yourself and your loved ones at home:use 2 grams (roughly one teaspoon) of loose green tea leaves for every 6 ounces of water. Depending on the particular variety of green tea, it should be allowed to steep for 1-3 minutes. Whole green tea leaves can often be steeped 2-3 times, producing new flavors with each that you know how easy it is… why not go ahead and make yourself a cup (or two) and enjoy the anticancer health benefits of green tea right now? Summarytea is the most popular beverage after water and has evolved to become part of the daily diet of nearly two-thirds of the world’s popularity of green tea has been growing by leaps and bounds among health-conscious people because of green tea’s ability to fight is the most effective green tea antioxidant. It has been tested extensively over the past few years and studies clearly show that egcg and other green tea antioxidants are toxic to cancer cells in laboratory e of these promising results, many human clinical trials have been carried out (and are still being carried out) to find out whether egcg and green tea extract supplements can protect us from developing available evidence suggests that daily consumption of 2-3 cups of green tea can help to lower your overall cancer risk without any serious side health benefits you get from green tea depend on the type and quality of green tea you use, how much you use, how long you brew it for, and the temperature of brewing. Sources and referencessuppression of cell proliferation and gene expression by combinatorial synergy of egcg, resveratrol and gamma-tocotrienol in estrogen receptor-positive mcf-7 breast cancer in hydrate suppresses mcf-7 proliferation through tp53/caspase-mediated tea catechin, epigallocatechin-3-gallate (egcg): mechanisms, perspectives and clinical locatechin-3-gallate (egcg) inhibits cell proliferation and migratory behaviour of triple negative breast cancer tea inhibits vascular endothelial growth factor (vegf) induction in human breast cancer to brew green tea. If you liked this article, get more articles and it by simply subscribing now for free: if cancer scares you, do not miss this...
So if it scares you, that’s r… whether you’re trying to avoid cancer or beat it if you’ve got it, there is one very powerful antidote to the fear, and to the disease itself: “the truth about cancer: a global quest” you’ll discover the most powerful ways to prevent, treat, heal from, and beat the disease. Therefore, this information is not intended as medical advice, a sharing of knowledge and information based on research and publishing encourages you to make your own health care decisions based on nt and research in partnership with a qualified healthcare statements have not been evaluated by the food and stration.
