Green tea

Chinese Name: Lu cai
Medical Name:
Latin Name: Camellia Sinensis
Origin: Dried leaf

Quotes from Chinese historical sources

VARIORUM OF THE HERBAL CLASSIC OF SHEN-NONG: "Useful in cases of chronic lethargy."

ONE THOUSAND GOLDEN FOOD THERAPIES: "Gives strength to the body and stimulates and delights the mind."

TANG DYNASTY NEWLY REVISED MATERIA MEDICA: "Useful in cases of fistulated ulcer. Diuretic. Relieves phlegm. Relieves chronic thirst. Helps move energy downwards in the body. Breaks down undigested food. Beneficial for the large intestine."

FOOD THERAPY WITH THE MATERIA MEDICA: "Relieves pathogenic heat. Relieves phlegm."

TANG YI MATERIA MEDICA: "Treats wind-stroke.Effective in cases of muddleheadedness, and of chronic lethargy."

AN EXPLANATION OF THE CANON OF MATERIA MEDICA: "Allays fevers.Counters toxins in the body, especially those resulting from alcohol."

COMPENDIUM OF MATERIA MEDICA: "Tea is bitter, cool and yin in nature. In fact, it is the most yin of herbs. Since it moves energy downwards in the body, it is most effective against pathogenic heat. Pathogenic heat is the cause of many diseases. When this heat subsides, the mind, heart and body alike are cleansed. However, each of the five organs has its own type of fire with its own character, either deficient or in excess. When people are young and strong, with healthy stomachs, the fires of their heart, spleen, lung and stomach are easily raised. Such people should drink tea. If they drink tea at a mild temperature, the yin nature of the tea will bring this fire down. If they drink their tea hot, then the fire will rise but quickly dissipate. Tea can also release toxins from food and alcohol from the body. It clears the mind, promotes internal energy and confidence, and dispels lethargy and gloom. This is the great merit of tea."

Western Research

Toxicol Appl Pharmacol. 2006 Nov 29
Tea and cancer prevention: Molecular mechanisms and human relevance.
Yang CS, Lambert JD, Ju J, Lu G, Sang S.
Tea made from the leaves of the plant Camellia sinensis is a popular beverage. The possible cancer-preventive activity of tea and tea polyphenols has been studied extensively. This article briefly reviews studies in animal models, cell lines, and possible relevance of these studies to the prevention of human cancer. The cancer-preventive activity of tea constituents have been demonstrated in many animal models including cancer of the skin, lung, oral cavity, esophagus, stomach, liver, pancreas, small intestine, colon, bladder, prostate, and mammary gland. The major active constituents are polyphenols, of which (-)-epigallocatechin-3-gallate (EGCG) is most abundant, most active, and most studied, and caffeine. The molecular mechanisms of the cancer-preventive action, however, are just beginning to be understood. Studies in cell lines led to the proposal of many mechanisms on the action of EGCG. However, mechanisms based on studies with very high concentrations of EGCG may not be relevant to cancer prevention in vivo. The autooxidation of EGCG in cell culture may also produce activities that do not occur in many internal organs. In contrast to the cancer prevention activity demonstrated in different animal models, no such conclusion can be convincingly drawn from epidemiological studies on tea consumption and human cancers. Even though the human data are inconclusive, tea constituents may still be used for the prevention of cancer at selected organ sites if sufficient concentrations of the agent can be delivered to these organs. Some interesting examples in this area are discussed.

Evid Based Complement Alternat Med. 2006 Jun;3(2):237-47.
Epicatechins Purified from Green Tea (Camellia sinensis) Differentially Suppress Growth of Gender-Dependent Human Cancer Cell Lines.
Ravindranath MH, Saravanan TS, Monteclaro CC, Presser N, Ye X, Selvan SR, Brosman S.
The anticancer potential of catechins derived from green tea is not well understood, in part because catechin-related growth suppression and/or apoptosis appears to vary with the type and stage of malignancy as well as with the type of catechin. This in vitro study examined the biological effects of epicatechin (EC), epigallocatechin (EGC), EC 3-gallate (ECG) and EGC 3-gallate (EGCG) in cell lines from human gender-specific cancers. Cell lines developed from organ-confined (HH870) and metastatic (DU145) prostate cancer, and from moderately (HH450) and poorly differentiated (HH639) epithelial ovarian cancer were grown with or without EC, EGC, ECG or EGCG. When untreated cells reached confluency, viability and doubling time were measured for treated and untreated cells. Whereas EC treatment reduced proliferation of HH639 cells by 50%, EGCG suppressed proliferation of all cell lines by 50%. ECG was even more potent: it inhibited DU145, HH870, HH450 and HH639 cells at concentrations of 24, 27, 29 and 30 microM, whereas EGCG inhibited DU145, HH870, HH450 and HH639 cells at concentrations 89, 45, 62 and 42 microM. When compared with EGCG, ECG more effectively suppresses the growth of prostate cancer and epithelial ovarian cancer cell lines derived from tumors of patients with different stages of disease.

Mol Nutr Food Res. 2007 Feb;51(2):221-8.
Fatty acids in tea shoots (Camellia sinensis (L.) O. Kuntze) and their effects on the growth of retinal RF/6A endothelial cell lines.
Shen SR, Yu HN, Chen P, Yin JJ, Xiong YK.
College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, P. R. China.
Chemo-protective effects of tea on ocular diseases were recorded in Chinese pharmacopoeia about 2000 years ago by eating tea. In the present study, contents of fatty acids (FAs) in tea shoots were determined by capillary GC; and the growth of RF/6A cells was also investigated by exposure to various representative FAs existing in tea shoots with pathologically relevant concentrations (40-500 muM) by ameliorated MTT assay and flow cytometry. Electron spin resonance (ESR) was used to measure oxygen consumption and investigate the free radical scavenging ability of linoleic acid (LA). Results showed that the most abundant long chain FAs were palmitic, linoleic, and alpha-linolenic acid in tea shoots; some RF/6A cells became suspended in culture medium treated by a high dose of both saturated and unsaturated FAs, but no apoptosis was observed. Moreover, it seemed that those FAs with different structure had various effects on the cell proliferation at their relatively low concentrations, LA expressed antioxidant activity in this study, which might be an important mechanism on the protection of eyes.

J Orthop Res 2003 Jan;21(1):102-9
Epigallocatechin-3-gallate selectively inhibits interleukin-1beta-induced activation of mitogen activated protein kinase subgroup c-Jun N-terminal kinase in human osteoarthritis chondrocytes.
Singh R, Ahmed S, Malemud CJ, Goldberg VM, Haqqi TM.
Department of Medicine, Division of Rheumatic Diseases, Case Western Reserve University, 2109 Adelbert Road, 44106-4946, Cleveland, OH, USA
Green tea (Camellia sinensis) is a widely consumed beverage and we earlier showed that polyphenols present in green tea (GTP) inhibit the development of inflammation and cartilage damage in an animal model of arthritis. In this study we evaluated the role of epigallocatechin-3-gallate (EGCG), a green tea polyphenol which mimics its anti-inflammtory effects, in modulating the IL-1beta-induced activation of MAPK's in human chondrocytes. EGCG may be of potential benefit in inhibiting IL-1beta-induced catabolic effects in OA chondrocytes that are dependent on JNK activity.

Ophthalmic Res 2002 Jul-Aug;34(4):258-63
Green tea (Camellia sinensis) protects against selenite-induced oxidative stress in experimental cataractogenesis.
Gupta SK, Halder N, Srivastava S, Trivedi D, Joshi S, Varma SD.
Department of Pharmacology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India. skgup@hotmail.com
The present study was undertaken to evaluate the anticataract potential of green tea leaf (GTL) extract in the development of lens opacification. The results suggest that green tea possesses significant anticataract potential and acts primarily by preserving the antioxidant defense system. Copyright 2002 S. Karger AG, Basel

J Agric Food Chem 2002 Nov 20;50(24):7182-6
Tea enhances insulin activity.
Anderson RA, Polansky MM.
Nutrient Requirements and Functions Laboratory, Beltsville Human Nutrition Research Center, U.S. Department of Agriculture, Beltsville, Maryland 20705, USA.
Black, green, and oolong teas but not herbal teas were all shown to increase insulin activity. These data demonstrate that tea contains in vitro insulin-enhancing activity and the predominant active ingredient is epigallocatechin gallate.

Wien Med Wochenschr 2002;152(5-6):153-8
Cancer prevention with green tea: reality and wishful thinking [Article in German]
Bertram B, Bartsch H.
Abteilung fur Toxikologie und Krebsrisikofaktoren, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, D-69120 Heidelberg, Deutschland. b.bertram@dkfz.de
The tea polyphenols, in particular (-)-epigallocatechin gallate (EGCG) were found to account for most of the protective effects. Tea polyphenols reactivate processes which are impaired in tumor cells, such as the programmed cell death and the tumorsuppressor gene p53. Finally, tea polyphenols can also block angiogenesis leading to a starvation of the tumor.