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Green Tea

Camellia sinensis is the species of plant whose leaves and leaf buds are used to produce green tea. It belongs to genus Camellia a genus of flowering plants, and family Theaceae. Camellia sinensis is native to mainland China, South and Southeast Asia, but it is today cultivated across the world in tropical and subtropical regions. It is an evergreen shrub or small tree that is usually trimmed to below two meters when cultivated for its leaves. The leaves are 4–15 cm long and 2–5 cm broad. The young, light green leaves are preferably harvested for tea production.

Listing Details

Botanical Names
Camellia sinensis
Indian Names
Green Tea
Chemical Constituents
Main chemical components present in green tea are caffeine, and catechins. Dried tea extract contains 30% to 40% of catechins. The four main catechins are epicatechin, epicatechin-3-gallate, epigallocatechin, and epigallocatechin-3-gallate (EGCG). Other compounds present in green tea are malic acid, oxalic acid, theophylline, theobromine, xanthine, inositol, kaempferol and quercetin. The presence of polyphenols and methylxanthines are the basic characteristic of the green tea chemical composition. They amount up to 17 to 30 % of the dry leaf weight. The compounds responsible for the flavor and aroma of tea are about 0.01-0.02% of the dry leaf weight. They consist of heterogeneous group of substances like alcohols, monoterpenic aldehydes and also free amino acids. The largest and most important chemical compound is polyphenols. This is because they contain flavonoids an important class of antioxidants. Dried leaves can contain 7% to 14% of other flavonoids compounds. It also contains other antioxidants, such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and resveratol (1). Green tea contains several B vitamins and C vitamin. Other green tea ingredients include 6% to 8% of minerals such as aluminium, fluoride and manganese. Green tea also contains organic acids such as gallic and quinic acids, and 10% to 15% of carbohydrate and small amount of volatiles (2).
Pesticide Limits
A limit for pesticide is one of the major issues in standardization of medicinal plants and products in view of the worldwide widespread use of pesticides in cultivated plants. The presence of pesticides in extracts increase the health risk by many folds. The pesticides can be extremely irritant on skin as well as in the internal organs, it is essential to monitor its concentration as a part of GMP. Various analytical methods for the quantitative determination of pesticides by gas chromatography coupled with mass-spectrophotometer are in use. Konark Research Foundation (KRF), a NABL certified lab is well equipped with the latest technology and instruments and monitors the pesticide limit as part of its GMP.
Chromatographic Profile
From the pharmacopoeia perspective, a better quality control of raw material can be achieved by specifying quantitative test procedure for the determination of the range or a minimum content of the active ingredient or marker substances. A chromatographic finger profile represents qualitative/ quantitative determination of various components present in a complex plant extract, irrespective whether or not their exact identity is known. Thin layer chromatographic technique is the simplest and least expensive method that provides plenty of information on the composition of raw herbs and its preparation. For quantitative analysis of active ingredients or marker substances with simultaneous separation and detection High Pressure liquid chromatography is the best technique. We use the latest model of HPLC for all its analysis.
Limits of Impurities
A test requirement for foreign organic matter would ensure the extent of contamination of extraneous matters such as filth and other parts of botanicals not covered by the definition of the herbal drug. Since sand and soil are predictable contaminants of botanicals, test requirements for ‘total ash’, water soluble ash’, ‘acid soluble ash’, residue on ignition and sulphated ash would be expected to limit such contaminants. Test requirement for heavy metals in botanical raw material are probably more relevant for parts of plants growing under ground than for the aerial parts of the plant. The presence of high levels of minerals interacts with the final product there by affecting its keeping quality.
Microbial Limits
If the raw herbs are to be used directly without boiling in water prior to consumption, restrictive limits on microbial contaminants are required for pathogens such as Salmonella sp. Enterobacter and E. coli which are causative agent for various gastrointestinal diseases. A lower level of yeasts and molds and a limit on total aerobes are considered appropriate in plant material for topical use. The presence of aflatoxins detected by chemical means is generally independent of the number of viable molds that are detected using microbiological methods. Aflatoxins in microgram quantity are capable of giving serious hypersensitivity reactions which can be extremely harmful to human health.
Green tea contains different bioactive compounds which imparts it many beneficial properties. It is anticancer, antidiabetic, anticholesterol and antibacterial in action (3). Camellia sinensis infusions are useful for treating health conditions such as tumors, abscesses, bladder ailments, and lethargy. Green tea has been claimed to be helpful for atherosclerosis, LDL cholesterol, cancer, inflammatory bowel disease, diabetes, liver disease, and neurodegenerative diseases (4). It acts as an effective antioxidant because of its free radical-scavenging and metal-chelating ability. Due to this, it is active against inflammation, clastogenesis, and several types of cancer. Green tea reduces DNA damage and mutagenesis caused due to oxidative stress or the presence of pro-mutagens through antioxidant function, blocking activation pathways of mutagens, suppressing transcription of enzymes involved etc. Inhibition of low-density lipoprotein (LDL) peroxidation, suppression of fatty acid synthase etc., suggest that green tea may have a role in preventing cardiovascular diseases (5). Besides, green tea has beneficial effects on the gastrointestinal tract; it affects motility, absorption, microflora etc (6). By influencing the hormonal balance and antioxidant function green tea improves bone mineral density. Epigallocatechin gallate, which is the main component of tea polyphenols, showed strong activity against pathogenic bacteria (7).
Health Benefits
Green tea possesses antibacterial, antiseptic, antioxidant and detoxifying properties. It is helpful in curing arthritis and asthma as it is a rich source of antioxidants. It enhances the liver functioning and immune system. It is helpful in mental disorders, skin disorders and cardiovascular diseases. It lowers inflammation in coronary artery diseases (8). It prevents ultra-violet induced oxidative effect and suppression of immune system. It reduces platelet aggregation and lowers cholesterol. It reduces the risk of heart diseases and heart attacks by reducing the risk of trombosis. Drinking green tea inhibits the growth of certain cancer cells, reduces the level of cholesterol in blood, and improves the ratio of good cholesterol to bad cholesterol. It is used to treat rheumatoid arthritis and cardiovascular diseases. It is used to treat impaired immune function. It is a great source of antioxidants which are very beneficial to the human body (9).
Application in Cosmetics
There have been a number of encouraging studies of skin benefits of green tea. Animal studies showed protection from skin cancer. Green tea appears to exert sun damage protection by quenching free radicals and reducing inflammation rather than by blocking UV rays. Therefore, green tea may synergistically enhance sun protection when used in addition to a sunscreen. Green tea possess many beneficial activities such as antimicrobial, astringent, emollient, oral care, skin conditioning, and skin protecting, tonic, and UV absorber. Green tea contains many chemical constituents. One of the polyphenols in green tea is epigallocatechin galate (EGCC) is thought to be 200 times more powerful than vitamin E for neutralizing free radicals (10). when applied on skin, Epigallocatechin promotes synthesis of collagen, which is the constituent of cartilage, capillary vessel and muscle, and destroys chemical substances generated by UV light, thereby preventing skin damage, as well as preventing skin aging, preserving healthy skin, and having superior whitening effects. Green tea combats the effects of pollution, sunlight and smoking, helps skin from wrinkling and aging (11).
Research References
1. Graham HN. Green tea composition, consumption, and polyphenol chemistry. Prev Med 1992;21:334-350. 2. Alschuler L. Green Tea: Healing tonic. Am J Natur Med 1998;5:28-31. 3. Mamoru I., Kouichi S., Takashi K., Sumio H., Takeshi M., and Masaki S. Tea catechins and related polyphenols as anti-cancer agents. 2000 13(1-4): 81–85 4. Sabu M.C., Smitha K. and Ramadasan Kuttan Anti-diabetic activity of green tea polyphenols and their role in reducing oxidative stress in experimental diabetes. Journal of Ethnopharmacology 2002 83 (1-2):109-116 5. Jochmann N, Baumann G, Stangl V. Green tea and cardiovascular disease: from molecular targets towards human health. Curr Opin Clin Nutr Metab Care. 2008 11(6):758-65. 6. Stangl V., Lorenz M., and Stangl K. The role of tea and tea flavonoids in cardiovascular health. Mol Nutr Food Res. 2006 50(2):218-28. 7. Goto K, Kanaya S, Nishikawa T, et al. Green tea catechins improve gut flora. Ann Long-Term Care 1998;6:1-7. 8. Senji S., Lekh R. J., and Makoto T. Antimicrobial effects of green tea polyphenols on thermophilic spore-forming bacteria. Journal of Bioscience and Bioengineering 2000 90 (1): 81-85 9. Serafini M, Ghiselli A, Ferro-Luzzi A. In vivo antioxidant effect of green and black tea in man. Eur J Clin Nutr 1996;50:28-32. 10. Katiyar SK, Matsui MS, Elmets CA, Mukhtar H. Polyphenolic antioxidant (-)-epigallocatechin-3-gallate from green tea reduces UVB-induced inflammatory responses and infiltration of leukocytes in human skin. Photochem Photobiol 1999;69:148-153. 11. Zhao JF, Zhang YJ, Jin XH, et al. Green tea protects against psoralen plus ultraviolet A-induced photochemical damage to skin. J Invest Dermatol 1999;113:1070-1075.