6 replies to this topic

[FunkOdyssey]

Anti-Cancer Compound in Green Tea Identified

Thursday March 16, 2006 (0052 PST)

ISLAMABAD: Spanish and British scientists have discovered how green tea helps to prevent certain types of cancer.

Researchers at the University of Murcia in Spain (UMU) and the John Innes Center (JIC) in Norwich, England have shown that a compound called EGCG in green tea prevents cancer cells from growing by binding to a specific enzyme.

"We have shown for the first time that EGCG, which is present in green tea at relatively high concentrations, inhibits the enzyme dihydrofolate reductase (DHFR), which is a recognized, established target for anti-cancer drugs, " says Professor Roger Thorneley, of JIC.

"This is the first time, to our knowledge, a known target for an anti-cancer drug has been identified as being inhibited by EGCG," he added.

Green tea has about five times as much EGCG as regular tea, studies have shown. It decreased rates of certain cancers but scientists were not sure what compounds were involved or how they worked. Nor had they determined how much green tea a person would have to drink to have a beneficial effect, he said.

Thorneley said EGCG is probably just one of a number of anti-cancer mechanisms in green tea.

"We have identified this enzyme in tumour cells that EGCG targets and understand how it stops this enzyme from making DNA. This means we may be able to develop new anti-cancer drugs based on the structure of the EGCG molecule," Thorneley explained.

The scientists decided to look at ECGC after they realized its structure was similar to a cancer drug called methotrexate. "We discovered that EGCG can kill cancer cells in the same way as methotrexate," Dr Jose Neptuno Rodriguez-Lopez, of UMU, a joint author of the research published in the journal Cancer Research.

EGCG binds strongly to DHFR, which is essential in both healthy and cancerous cells. But it does not bind as tightly as methotrexate, so its side effects on healthy cells could be less severe than those of the drug.

Thorneley said EGCG could be a lead compound for new anti-cancer drugs.

The findings could also explain why women who drink large amounts of green tea around the time they conceive and early in their pregnancy may have an increased risk of having a child with spina bifida or other neural tube disorders.

Women are advised to take supplements of folic acid because it protects against spina bifida. But large amounts of green tea could decrease the effectiveness of folic acid.

"This enzyme, (DHFR), is the one folic acid supplements are given for. Folic acid deficiency leads to neural tube development defects," Thorneley added.

I like how they conclude that EGCG has anti-cancer activity similar to anti-cancer drugs, but without the side effects on healthy cells, so now they want to design a drug to mimic EGCG more closely. Of course the idea of just taking EGCG is not mentioned (no money to make there). F*ckers.

[syr_]

It is:

http://lef.org/news/...Section=DISEASE

03-17-06
TOKYO, March 17 Asia Pulse - Japan's Mitsui Norin Co. is stepping up its efforts to develop therapeutic medicines based on catechin derived from tea leaves.

The tea company began collaborative studies with the U.S. National Cancer Institute in 2002 on the development of an oral preparation of highly refined catechin for the treatment and prevention of cancer. Development has gone well, and last year the substance was being used in 11 different clinical studies for applications including treatment of prostate cancer, lung cancer, leukemia, bladder cancer and breast cancer.

To supply all the catechin needed for these trials, Mitsui Norin has invested around 450 million yen (US$3.85 million) to increase its production capacity some 40-fold to 10 tons a year. The company uses a proprietary technology to refine the catechin from tea leaves, with a purity of greater than 90%.

The company has registered its high-purity tea catechin as a pharmaceutical ingredient with the U.S. Food and Drug Administration and hopes to commercialize catechin drugs for the treatment of cancer by around 2010.

In the meantime, a German drug company has applied to the FDA to market a treatment for skin tumors based on catechin supplied by Mitsui Norin. The German firm could gain approval and begin marketing the drug as early as 2007.

As of now, no herbal medicines have been approved as pharmaceutical products by the FDA, so a catechin drug could become the first plant-extract pharmaceutical sold in the U.S.

Edited by syr_, 23 March 2006 - 09:50 PM.

[lunarsolarpower]

As of now, no herbal medicines have been approved as pharmaceutical products by the FDA, so a catechin drug could become the first plant-extract pharmaceutical sold in the U.S.

What about Taxol? Or is that synthesized too?

[bgwowk]

As of now, no herbal medicines have been approved as pharmaceutical products by the FDA, so a catechin drug could become the first plant-extract pharmaceutical sold in the U.S.

That's ridiculous. Before the days of synthetic organic chemistry, many (most?) medicines were from plants. Even the original form of aspirin, salicylic acid, was from a plant.

---BrianW

[syr_]

To be clear that affirmation was on the press relase: its not mine

[simple]

Oh, please read on,

[quote]About tea, it is a good source of Manganese and Potassium, there has been studies, that tea contains a very strong antioxidant, Epigallocatechin, and flavonoids that helps increase bone mass density, also, tea contains polyphenols, which supress oxidation of low density lipoproteins, wich is an step involved in the pathogenesis of Artherosclerosis.

Green Tea compounds helps protect damage to DNAS caused by tobacco, it is also antinflamatory
on the other hand, tea contains high amounts of Fluoride, wich it has been demonstrated that its accumulation causes osteosarcoma and uterine cancer, among other maladies

While there can be no doubt as to the beneficial effects of individual antioxidants found in green tea, the same cannot be said about green tea as a beverage. The studies that you mention concentrate on epigallocatechin gallate (EGCG) wich with other polyphenols are constituents of tea - especially of green tea, but , however, no studies exist investigating the effects of fluorides on these anti-oxidants and there lies the reason why they are trying to separate EGCG from green teas

Existing studies involving other antioxidants and fluoride compounds give evidence that fluorides can adversely affect the action of antioxidants. Isolated antioxidants may slow down the development of some forms of cancer in experimental studies, but their effect may be annihilated in their complex natural environment (as a sum of the action of all the substances present).

Available data seem undecided in their conclusions as to the inhibition of carcinogenesis in experimental animals by tea or tea compounds. It is suggested "at most a modest benefit, since there is considerable international variation in tea consumption but generally small differences in cancer rates...More relevant case-control and cohort studies show mixed results."

Other epidemiological and human studies have also shown varying results. In a review by Dr.Bushman thirty-one human studies and four reviews were examined. Among five studies reporting on colon cancer, three found an inverse association and one reported a positive association.

For rectal cancer, only one of four studies reported an inverse association; increased risks were seen in two of the studies. An inverse association was suggested for urinary bladder cancer in two of two studies.

While lung cancer studies have shown an inverse effect with Okinawan tea, a tentatively increased risk was shown in another study, clearly indicating that more research into this matter is needed. In a recent study on Finnish men, published in 1998 by Terryl Hartman and others, again a positive correlation between colon cancer and tea intake was found. Colon cancer occurrence increased with higher intake.
Many available green tea/cancer studies last only a few months, and do not take into account the cumulative effects of fluoride, which is a known cancer promoter, and has the ability to transform healthy cells into cancerous ones. For any conclusive evidence to be obtained this must be considered, for long time fluoride ingestion has been shown to _cause_ cancer, especially osteosarcomas and uterine cancer.

Dean Burk, for many decades Chief Chemist at the National Cancer Institute, testified at congressional hearings in 1981 stating that over 40,000 cancer deaths in that year were attributable to fluoridation . He has said that no chemical causes as much cancer, and faster, than fluorides. Public health officials are quick to say that this data is not verified, which is entirely untrue, for international research as well as congressional hearings and court proceedings HAVE verified this information. Dental fluorosis (mottled teeth) is the first visible sign of fluoride poisoning.

[buck1s]

Does anyone know if there's more fluoride in a municipality's tap water than a similar size cup of tea made with unfluoridated water? I'm a big tea drinker and I'd like to get to the bottom of this issue. I currently drink well water at home so I'm not worried about extra fluoride in my part of the country. Some areas of the U.S. have a lot of fluoride in their ground water normally, though.

I guess it all comes back to what I have to remind myself of frequently: moderation, moderation, and fuggedaboutit