Protective Effects Of Tea Research Articles

Consumption of Green Tea Protects Murine Haematopoiesis from Drug-Induced Myelosuppression

Objectives: Tea is a globally favored beverage. Protective effects of tea are already reported for bacterial infection, several forms of cancer, and against chemotherapeutic agents; however, effects of tea decoctions (as per human consumption) on the lineage differentiation and chemoprotection of the bone marrow haematopoietic stem cells (HSCs) are not widely known. The present work aimed to appraise the possible effect of green and black tea decoctions (prepared as per human consumption) on the lineage differentiation of the HSCs and any protective effect against cellular suppression.
 Methods: Tea decoctions (simulating human consumption, i.e., 2.5 gm. in 100 ml) were prepared with certified organic green and black tea leaves. Cyclophosphamide (80 mg/kg/day; 100 µl/mice) was given as required. BALB/c mice were divided into six groups: Naïve; only cyclophosphamide – treated; groups gavage-fed with only green tea and black tea decoctions; and tea-decoction fed and cyclophosphamide-treated groups. Bone marrow cells were collected, divided, and utilized for further experiments after the experimental period.
 Results: The tea decoctions protected the granulocyte-monocyte progenitors against cyclophosphamide-induced cellular suppression but did not induce HSC proliferation. Further investigation revealed that green tea decoction was more effective in providing myeloprotection by inhibiting the overproduction of reactive oxygen species (ROS), induction of DNA repair enzymes and drug-metabolizing enzymes Cytochrome P450 1a2 (Cyp1a2) and Cyp2b10, and ameliorating the Toll-like receptor 4 (TLR4)-mediated cell-detrimental increase of cytokines.
 Conclusions: Taken together, green tea decoction was effective in protecting cyclophosphamide-induced myelosuppression in murine bone marrow HSCs at human consumption doses.

The tea protection against the reactive oxygen species produced via the photodynamic effect induced by daylight

The combination of light, photosensitizer and molecular oxygen is involved in the photodynamic effect. The life-time of ROS is extremely short and ROS can damage biological systems. The reactive oxygen species (ROS) are also produced upon excitation of the photosensitizer by visible light only. Some drinks and foods have the potential or definite antioxidant capacity to inhibit or terminate the ROS action.Usually, Paramecium caudatum is used to determine the toxic effect; well known is especially the toxicity determination of the photodynamic effect. The aim of this work was to explore if the protective effect of tea against ROS produced by the different types of photosensitizer (methylene blue, eosin, fluorescein, phthalocyanines) upon the excitation by visible light only is also possible to determine on the unicellular organism P. caudatum, and compare the protective effect of the black and green teas against ROS with the protective effect of ascorbic acid and Trolox (a standard for the total antioxidant capacity determination).The teas were able to prolong the P. caudatum life-time; the highest observed protection against the photodynamic ROS production (triggered by methylene blue) was caused by the black and green teas and was identical for both of them. The stronger protective antioxidant properties of the green tea were not observed. The pro-oxidant influence of the used antioxidants was not observed.

Addition of milk prevents vascular protective effects of tea

Addition of milk prevents vascular protective effects of tea

Tea without milk: lifestyle advice based on a small lab study: reply

We thank von Elm and Antes for their comments on our article ‘Addition of milk prevents vascular protective effects of tea’. In the first section of the letter, the authors critically comment on the newspaper coverage of our study, particularly on one-sided and unbalanced reporting in the press. They also note that only a few agencies took the time to give a more complex view and that bad news sells better than good news. We agree with the authors that any one-sided coverage of a story—whatever the topic might …

Milk casein and its benefits on cardiovascular risk

The article by Lorenz et al. on the effects of adding milk on the protective effects of tea is interesting, but results may not translate into clinical benefits. This was a small sample that lacked statistical power and failed to take into account the dietary habits of the participants. Even when milk was not added to tea, participants may have consumed diary …

Addition of milk prevents vascular protective effects of tea: reply

Addition of milk prevents vascular protective effects of tea: reply

The role of tea and tea flavonoids in cardiovascular health

Consumption of green or black tea has been inversely associated with the development and progression of cardiovascular diseases. In this review, the current knowledge about protective effects of tea and tea constituents, particularly flavonoids, on the cardiovascular system is summarized. Underlying mechanisms for the beneficial effects of tea include vasculoprotective, antioxidative, antithrombogenic, anti-inflammatory, and lipid-lowering properties of tea flavonoids. Although promising experimental data on beneficial effects of tea in various cardiovascular diseases are available, results of clinical studies in humans are not uniform. A number of factors are discussed which may contribute to inconsistent data in humans. Overall, tea represents a promising tool for the prevention and treatment of cardiovascular disorders.

Candidate foods in the Asia-Pacific region for cardiovascular protection: Oriental tea.

Chinese tea and the major health effects include: antimicrobial, anti-ultraviolet radiation, anticancer, lowering blood lipid and glucose, and protecting against coronary heart diseases. In contrast to the extensive studies on the protective effects of tea on cancer, fewer studies on the health effects of tea on cardiovascular diseases (CVD) have been published. This paper summarises the research results on the possible protective effects of tea on CVD available in China. The results from animal studies clearly demonstrated that tea pigments are effective in lowering blood lipid levels and preventing plaque formation in the aorta. However, the evidence of tea pigments in protecting ischemia heart disease (IHD) in humans is less convincing. One large well-designed ecological study reported an inverse correlation between tea drinking and IHD mortality; but the inverse correlation disappeared after controlling possible confounding factors. However, the effects in improving blood lipid levels and rheology biomarkers in hyperlipidemia subjects or CVD patients by tea pigments seem promising. However, these studies were not well-designed, controlled randomized clinical trials. This made the assessment difficult and inconclusive.

Green Tea and Its Major Components Ameliorate Immune Dysfunction in Mice Bearing Lewis LungCarcinoma and Treated With the Carcinogen NNK

The protective effects of tea and/or its components on dysfunction of immune functions during tumor growth and carcinogenesis in mice were studied using two experimental models: C57/BL6J mice transplanted with Lewis lung carcinoma (LLC) and Kunming mice treated with a single dose of 4-(methylnitrosamino-)-1-(3-pyridyl)-1-butanone (NNK). In C57/BL6J mice bearing LLC, the weight of the thymus decreased, the proportion of CD4 +-positive T lymphocytes and the ratio of CD4 + to CD8 + decreased, luminol-enhanced chemiluminescence of white blood cells in peripheral blood stimulated by zymosan increased, and plaque-forming cells (PFC) decreased. However, in LLC-bearing mice given green tea as drinking water, all immune functions were improved, along with inhibition of tumor growth. In Kunming mice treated with NNK, during the four weeks of observation, their immunologic indicators, such as phagocytosis of macrophages in the abdominal cavity, luminol-enhanced chemiluminescence of white blood cells, plaque-forming cells, and delayed-type hypersensitivity, increased or decreased to various extents compared with normal controls. However, these changes were significantly prevented in the mice given green tea, mixed tea, or tea polyphenol as drinking water. In conclusion, tea and its components ameliorated immune dysfunction in mice bearing LLC or treated with the carcinogen NNK.