Article

Green tea: nature's defense against malignancies.

National Institute of Food Science and Technology, University of Agriculture, Faisalabad.
Critical reviews in food science and nutrition (Impact Factor: 5.55). 06/2009; 49(5):463-73. DOI: 10.1080/10408390802145310
Source: PubMed

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.

0 Followers
 · 
158 Views
  • Source
    [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. DOI:10.1016/j.toxrep.2014.12.016
  • Source
    [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: The objectives of the present study were to first covalently modify different bovine milk proteins (α-lactalbumin, β-lactoglobulin, lactoferrin and sodium caseinate) using (−)-epigallocatechin-3-gallate (EGCG), then compare structural and functional properties between covalent and non-covalent protein–EGCG complexes and finally test the complexes with greater antioxidant potential in stabilizing a model β-carotene emulsion. Covalent modification of milk proteins with EGCG was testified by a reduction of free amino groups and free sulfhydryl groups as well as matrix-assisted laser desorption/ionization time-of-flight mass spectra (MALDI-TOF-MS). Furthermore, the proposed schematic formation pathway showed that milk proteins formed covalent complexes with EGCG dimers. Then structural and functional properties of covalent and non-covalent protein–EGCG complexes were analyzed. Covalent protein–EGCG complexes had higher denaturation temperatures than non-covalent ones. Besides, covalent protein–EGCG complexes exhibited much stronger antioxidant activity than the same amount of non-covalent ones. A comparison of interfacial concentration fraction of protein and EGCG in emulsions revealed that covalent protein–EGCG complexes exhibited better interfacial adsorption behavior and greater antioxidant potential than non-covalent ones in emulsion systems. Thus, research was then focused on testing covalent protein–EGCG complexes in a model β-carotene emulsion. Covalent protein–EGCG complexes significantly enhanced chemical stability of β-carotene in emulsions against heat treatment and ultraviolet (UV) light exposure. Given both physical and chemical stability of emulsions, the overall ability of covalent protein–EGCG complexes in stabilizing a model β-carotene emulsion followed the order: sodium caseinate > β-lactoglobulin > lactoferrin > α-lactalbumin.
    Food Hydrocolloids 03/2015; 45. DOI:10.1016/j.foodhyd.2014.12.008 · 4.28 Impact Factor