Green tea: nature's defense against malignancies.
ABSTRACT The current practice of introducing phytochemicals to support the immune system or fight against diseases is based on centuries old traditions. Nutritional support is a recent advancement in the domain of diet-based therapies; green tea and its constituents are one of the important components of these strategies to prevent and cure various malignancies. The anti-carcinogenic and anti-mutagenic activities of green tea were highlighted some years ago suggesting that it could reduce the prevalence of cancer and even provide protection. The pharmacological actions of green tea are mainly attributed to polyphenols that includes epigallocatechin-3-gallate (EGCG), epicatechin, epicatechin-3-gallate, epigallocatechin. Green tea and its components effectively mitigate cellular damage arising due to oxidative stress. Green tea is supposed to enhance humoral and cell-mediated immunity, decreasing the risk of certain cancers, and may have certain advantage in treating inflammatory disorders. Much of the cancer chemopreventive properties of green tea are mediated by EGCG that induces apoptosis and promotes cell growth arrest, by altering the expression of cell cycle regulatory proteins, activating killer caspases, and suppressing nuclear factor kappa-B activation. Besides, it regulates and promotes IL-23 dependent DNA repair and stimulates cytotoxic T cells activities in a tumor microenvironment. It also blocks carcinogenesis by modulating the signal transduction pathways involved in cell proliferation, transformation, inflammation and metastasis. The review is intended to highlight the chemistry of green tea, its antioxidant potential, its immunopotentiating properties and mode of action against various cancer cell lines that showed its potential as a chemopreventive agent against colon, skin, lung, prostate, and breast cancer.
SourceAvailable from: Jeong-Heui Choi[Show abstract] [Hide abstract]
ABSTRACT: Consumers are very aware of contaminants that could pose potential health hazards. Most people drink tea as an infusion (adding hot water); however, in some countries, including India, China, and Egypt tea is drunk as a decoction (tea and water are boiled together). An infusion usually brings the soluble ingredients into solution; whereas a decoction brings all soluble and non-soluble constituents together. Therefore, a cup of tea may contain various kinds of contaminants. In this review, we focus on green and black tea, because they are most commonly consumed. Our target was to examine the transfer rate of contaminants (pesticides, environmental pollutants, mycotoxins, microorganisms, toxic heavy metals, radioactive isotopes (radionuclides), and plant growth regulators) from tea to infusion/brewing, factors contributing to the transfer potential and contaminants degradation, and residues in or on the spent leaves. We concluded that most contaminants leaching into tea infusion are not detected or are detected at a level lower than the regulatory limits.However, the traditional practice of over-boiling tea leaves should be discouraged, as there may be a chance for more transfer of contaminants from the tea to the brew.Food Additives and Contaminants - Part A Chemistry, Analysis, Control, Exposure and Risk Assessment 08/2014; 31(11). DOI:10.1080/19440049.2014.958575
[Show abstract] [Hide abstract]
ABSTRACT: Varying consumption trends and poor dietary habits had led to widespread prevalence of various lifestyles related disorders including obesity, diabetes and dyslipidemia. The reliance of communities on processed foods is also detrimental factor in their progression. The concerted efforts are required in order to eliminate these problems. In this project, efforts were directed to prepare nutritious dietetic cookies using Black Cumin Fixed Oil (BCFO). Accordingly, formulations of cookies were modified to reduce the fats, sugar and energy level along with provision of some bioactive molecules from BCFO. The results indicated that reduction in fat and sugar levels provided less calorific value to cookies. However, utilization of BCFO (~4%) resulted in some quality retention even at reduced levels of fats and sugars. Furthermore, reducing the level of shortening and sugars resulted in decreased fat contents (45.61%) as compared to control. Similarly, total sugar levels were decreased by 43.17%. These cumulative factors led to dwindled calorific value by 37.98%. The reduction in fats and sugars led to decreased sensory appraisal from trained taste panel. However, at 40% reduction in fats and sugars were quite acceptable owing to presence of BCFO. It further provided protection against lipid per-oxidation as indicated from peroxide value. In the nutshell, preparation of nutritious and dietetic cookies using BCFO is feasible approach to reduce the calorific value of cookies and such novel products hold potential to reduce the obesity and related disorders.Pakistan Journal of Nutrition 05/2011; 10(5). DOI:10.3923/pjn.2011.451.456
[Show abstract] [Hide abstract]
ABSTRACT: Green tea presents catechins as its major components and it has a potential antioxidant activity. Cyclophosmamide (CP) is an antineoplastic and immunosuppressive agent, known to reduce fertility. In the present study, we evaluated the effect of green tea infusion on cyclophosphamideinduced damage in male mice reproductive system. Mice received green tea infusion (250 mg/kg) or vehicle by gavage for 14 days. Saline or CP were injected intraperitoneally at a single dose (100 mg/kg) at the 14th day. Animals were euthanized 24 h after CP administration and testes and epididymis were removed for biochemical analysis and sperm evaluation. Catechins concentration in green tea infusion was evaluated by HPLC. CP increased lipid peroxidation, DNA damage and superoxide dismutase activity whereas sperm concentration, glutathione peroxidase (GPx), glutathione S-transferase (GST) and 17 β–hydroxysteroid (17 β-HSD) dehydrogenase activities were reduced in both tissues tested. Catalase activity and protein carbonyl levels were changed only in testes, after CP administration. Green tea pre-treatment reduced significantly lipid peroxidation, protein carbonylation, DNA damage and restored GPx and GST activity in testes. In epididymis, therapy significantly increased sperm concentration and restored GPx and 17 β-HSD activity. Green tea improves CP-induced damage on reproductive system, probably due to their high catechins content.Toxicology Reports 12/2014; 180.