Next to water, tea is the most ancient and widely consumed beverage in the world. Epidemiological studies have suggested a cancer protective effect, but the results obtained so far are not conclusive. In the current study, mechanisms of the apoptogenic effect of black tea extract were delineated. Black tea administration to Ehrlich's ascites carcinoma (EAC)-bearing Swiss albino mice caused a si...

The relative efficacy of infusion of black tea leaf, Camellia sinensis (Linn.) O. Kuntze, (Theaceae), and iron as freshly prepared aqueous solution of ferrous sulphate in reducing the cytotoxic effects of arsenic, was tested in bone marrow cells of laboratory bred Swiss albino mice. Ferrous sulphate and tea given alone did not induce chromosomal breakage to any appreciable extent. Tea decreased...

The objective of this study was to investigate in a crossover study conducted in human volunteers whether black tea intake modulates the metabolism of heterocyclic amines, consumed in the form of well-cooked beefburgers, as exemplified by the excretion of mutagens in the urine. Mutagens were extracted from urine with blue rayon, and mutagenic activity was determined in the Ames test, in the pre...

The present study was undertaken to investigate the effect of aqueous tea extracts on lipid peroxidation and α and γ tocopherols concentration in the oxidative damage of human red blood cells (RBC). RBC was taken as the model for study of the oxidative damage was induced by cumene hydroperoxide (cumOOH). The antioxidative property of leaf green tea, leaf and granulate of black tea and white tea...

There is increasing evidence from observational studies that breast cancer risk is inversely associated with soy and green tea consumption. We investigated the effects of these two dietary agents on mammographic density, a well-established biomarker for breast cancer risk, in a cross-sectional analysis of mammograms and validated food frequency questionnaires from 3,315 Chinese women in Singapo...

BACKGROUND Epidemiological studies suggest that tea consumption decreases cardiovascular risk, but the mechanisms of benefit remain undefined. Endothelial dysfunction has been associated with coronary artery disease and increased oxidative stress. Some antioxidants have been shown to reverse endothelial dysfunction, and tea contains antioxidant flavonoids. Methods and Results-- To test the hypo...

The variation in the composition of fresh tea leaves with season and shoot maturity, and to the applicability of cold storage (4C and 90% relative humidity [RH]) for the purpose of withering of tea leaves were studied. The results showed that the levels of polyphenol oxidase (PPO) activity and the polyphenolic content changed significantly with plucking season and shoot maturity. No significant...

The association between black tea consumption and iron status was investigated in a sample of African adults participating in the cross-sectional THUSA (Transition and Health during Urbanization of South Africans) study in the North West Province, South Africa. Data were analysed from 1605 apparently healthy adults aged 15-65 years by demographic and FFQ, anthropometric measurements and biochem...

Green tea catechins, including (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC) and (-)-epigallocatechin gallate (EGCG), are oxidized and dimerized during the manufacture of black tea and oolong tea to form orange-red pigments, theaflavins (TF), a mixture of theaflavin (TF1), theaflavin-3-gallate (TF2A), theaflavin-3'-gallate (TF2B) and theaflavin-3,3'-digallate (...