title: Therapeutic properties of green tea against environmental insults.
abstract: Pesticides, smoke, mycotoxins, polychlorinated biphenyls (PCBs), and arsenic are the most common environmental toxins and toxicants to humans. These toxins and toxicants may impact on human health at the molecular (DNA, RNA, or protein), organelle (mitochondria, lysosome, or membranes), cellular (growth inhibition or cell death), tissue, organ, and systemic levels. Formation of reactive radicals, lipid peroxidation, inflammation, genotoxicity, hepatotoxicity, embryotoxicity, neurological alterations, apoptosis, and carcinogenic events are some of the mechanisms mediating the toxic effects of the environmental toxins and toxicants. Green tea, the nonoxidized and nonfermented form of tea that contains several polyphenols, including green tea catechins, exhibits protective effects against these environmental toxins and toxicants in preclinical studies and to a much-limited extent, in clinical trials. The protective effects are collectively mediated by antioxidant, antiinflammatory, antimutagenic, hepatoprotective and neuroprotective, and anticarcinogenic activities. In addition, green tea modulates signaling pathway including NF-κB and ERK pathways, preserves mitochondrial membrane potential, inhibits caspase-3 activity, down-regulates proapoptotic proteins, and induces the phase II detoxifying pathway. The bioavailability and metabolism of green tea and its protective effects against environmental insults induced by pesticides, smoke, mycotoxins, PCBs, and arsenic are reviewed in this paper. Future studies with emphasis on clinical trials should identify biomarkers of green tea intake, examine the mechanisms of action of green tea polyphenols, and investigate potential interactions of green tea with other toxicant-modulating dietary factors.
authors.affiliation: 1966 Services, Irving, TX, USA.
authors.forename: Lixia
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Nutrition, Byrdine F. Lewis School of Nursing and Health Professions, Georgia State University, Atlanta, GA, USA.
authors.forename: Huanbiao
authors.initials: H
authors.lastname: Mo
authors.affiliation: Department of Nutrition, University of Tennessee, Knoxville, TN, USA.
authors.forename: Ling
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, Lubbock, TX, USA.
authors.forename: Weimin
authors.initials: W
authors.lastname: Gao
authors.affiliation: Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, USA.
authors.forename: Shu
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, Lubbock, TX, USA.
authors.forename: Meghan M
authors.initials: MM
authors.lastname: Cromie
authors.affiliation: 1966 Services, Irving, TX, USA.
authors.forename: Chuanwen
authors.initials: C
authors.lastname: Lu
authors.affiliation: Department of Environmental Health Science, University of Georgia, Athens, GA, USA.
authors.forename: Jia-Sheng
authors.initials: JS
authors.lastname: Wang
authors.affiliation: Department of Pathology, Texas Tech University Health Sciences Center, Lubbock, TX, USA. Electronic address: leslie.shen@ttuhsc.edu.
authors.forename: Chwan-Li
authors.initials: CL
authors.lastname: Shen
mesh_terms: D001151:Arsenic / Q000633:toxicity; D001682:Biological Availability; D002392:Catechin / Q000493:pharmacokinetics* / Q000494:pharmacology; D004781:Environmental Exposure / Q000009:adverse effects*; D006801:Humans; D009183:Mycotoxins / Q000633:toxicity*; D009369:Neoplasms / Q000517:prevention & control; D010575:Pesticides / Q000633:toxicity*; D011078:Polychlorinated Biphenyls / Q000633:toxicity; D013662:Tea / Q000737:chemistry
chemical_list: D009183:Mycotoxins; D010575:Pesticides; D013662:Tea; D002392:Catechin; D011078:Polychlorinated Biphenyls; D001151:Arsenic
keywords: Cigarette smoke; Green tea; Heavy metal; Mycotoxin; PCB; Pesticides