Green Tea: Health Articles
Database - Green tea research has shown it has an effect on variety of health conditions. The ability to lower blood sugar, chelate iron and control the production of nitric oxide are all especially
important. This ancient beverage seems custom-made to protect health and delay aging. To find how green tea benefits different organs and conditions click a specific topic from our article database below:
Cup Of Green Tea To Keep The Bacteria Away
ScienceDaily (Jan. 16, 2007) — Beneficial effects of green tea have been known for millenia, particularly in Asian cultures. An ancient Chinese proverb says: "Better to be deprived of food for three days, than tea for one". A cup of green tea contains up to 200 mg of catechins, whose biological activity has been mainly attributed to its antioxidant activity. Efficiency of green tea extract in oral hygiene has been known for centuries and this gave researchers a clue that antibacterial activity might be involved. Now researchers from the National institute of Chemistry in Ljubljana, Slovenia discovered that the main ingredients of green tea are able to perform other tricks. They found out that green tea catechins inhibit essential bacterial enzyme DNA gyrase, which is the target of several existing clinically used drugs. By the use of NMR spectroscopy, researchers from Slovenia have now pinpointed the ATP-binding site of DNA gyrase as target of EGCG, the most abundant catechin from the green tea extract. Up to now several compounds targeted against the ATP-binding site of bacteria gyrase have been known but couldn't be used as drugs due to their side effects on mammalian cells. Lead researcher Roman Jerala, the head of the Laboratory of Biotechnology at NIC explains: "We can anticipate to avoid the problem of toxicity using the compounds based on the green tea catechins, which have centuries of established safety record in the human diet." This finding may be used to develop even more potent antibacterial compounds. Results were recently published in the Journal of Medicinal Chemistry.
Anti-Bacterial Properties of Green Tea
A particularly exciting discovery related to the antibacterial properties of green tea polyphenols has been the finding that these compounds inhibit the growth and adherence of oral bacteria. Green tea extract has been found to strongly inhibit periodontal-causing bacterium, Porphyromonas, and decay-causing bacteria such as Streptococcus salivarius and Streptococcus mutans. A Chinese study showed that Streptococcus mutans could be inhibited completely by sufficient contact with green tea polyphenols. Using green tea as a mouth rinse resulted in less plaque and periodontal disease. Black tea has also been found effective. One possible mechanism of the action of tea in preventing dental decay is its ability to inhibit the enzyme amylase present in the saliva. Thus, less starch gets converted in the mouth into bacteria-feeding simple sugars such as glucose and maltose. Bacterial amylase is likewise inhibited, making less nutrition available to the decay-causing organisms. Green tea catechins also help destroy harmful intestinal bacteria. When tube-fed patients received 300 mg of tea catechins a day, the putrefactive products in their gastrointestinal tract decreased, and organic acids increased, lowering the pH. The greater acidity is highly beneficial, since it makes the environment inhospitable to harmful bacteria, while beneficial lactic acid bacteria can thrive. Indeed, the bactericidal activity of green tea does not affect lactic acid bacteria. Decreased levels of putrefactive products and improved intestinal flora lead to better digestion, better immune function, and lower risk of colorectal cancer.
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