Modulation of Oxidative Damage by Tea Polyphenols

茶多酚调节氧化损伤

• 批准号: 6524836
• 负责人: JIA-SHENG WANG
• 金额: $ 7.3万
• 依托单位: TEXAS TECH UNIVERSITY HEALTH SCIS CENTER
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-30 至 2003-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6524836
• 关键词: aflatoxins; alternative medicine; antioxidants; benzopyrans; biotransformation; cancer risk; chemical structure function; chemoprevention; clinical research; electrospray ionization mass spectrometry; guanosine triphosphate; hepatitis virus; high performance liquid chromatography; human middle age (35-64); human therapy evaluation; human tissue; liver neoplasms; longitudinal human study; nutrition related tag; oxidative stress; plant extracts; tea; ultraviolet spectrometry; urinalysis; virus diseases; virus related neoplasm /cancer

DESCRIPTION (provided by applicant) The primary objective of this research project is to study the modulating effects of green tea polyphenols on reducing hepatocarcinogen-induced oxidative damages in high-risk human populations. Oxidative damage induced by reactive oxygen species in vivo plays important roles in human hepatocarcinogenesis primarily caused by chronic infection of hepatitis B/C viruses and exposure to dietary aflatoxins. The level of 8-hydroxy-2'- deoxyguanosine, a biomarker for oxidative DNA damage, increases in hepatitis B virus surface antigen positive and aflatoxin-exposed humans and in aflatoxin- treated animals. Dietary antioxidants are important components of cancer modulating agents, which have been proven to effectively target carcinogen biomarkers, including oxidative damages, in high-risk human populations. Among various identified dietary associated antioxidants, green tea and its polyphenols have been shown to be safe and highly effective in inhibition of a variety of carcinogen-induced oxidative damages, mutagenesis, and tumorigenesis in in vitro bioassays and in vivo animal models. The general hypothesis underlying this proposal is that green tea polyphenols have a protective effect against oxidative stress or damage induced by aflatoxin and hepatitis B/C viruses through the mechanisms of modulating aflatoxin metabolism and oxidated DNA damage. The specific aims include: (1) to determine antioxidative role of green tea polyphenols in inhibition of the level of 8-hydroxy-2'-deoxyguanosine in urine samples collected from an intervention study of 120 participants who are double positive for hepatitis B virus surface antigen and aflatoxin-albumin adducts, and (2) to determine the modulating effect of green tea polyphenols on excretion of carcinogen detoxifying product, aflatoxin Bl-mercapturic acid in urine samples collected from the study participants. The results of this proposed study will help to understand the mechanisms of antioxidative role of tea polyphenols in modulating human hepatocarcinogenesis caused by hepatitis B/C viruses and aflatoxins.

描述（由申请人提供） 该研究项目的主要目的是研究调节 绿茶多酚对降低肝癌的作用 高危人群的氧化损伤。 氧化损伤引起 体内活性氧对人体起着重要作用 主要由乙型/丙型肝炎慢性感染引起的肝癌 病毒和接触膳食黄曲霉毒素。 8-羟基-2'-水平 脱氧鸟苷（DNA 氧化损伤的生物标志物）会增加乙型肝炎的发生 病毒表面抗原阳性和黄曲霉毒素暴露人群以及黄曲霉毒素- 治疗的动物。 膳食抗氧化剂是癌症的重要组成部分 调节剂，已被证明可以有效针对致癌物质 高危人群中的生物标志物，包括氧化损伤。 在各种已确定的与膳食相关的抗氧化剂中，绿茶及其 多酚已被证明安全且高效地抑制 多种致癌物引起的氧化损伤、突变和 体外生物测定和体内动物模型中的肿瘤发生。 将军 该提议的假设是绿茶多酚具有 对黄曲霉毒素引起的氧化应激或损伤的保护作用 乙型/丙型肝炎病毒通过调节黄曲霉毒素的机制 代谢和氧化 DNA 损伤。 具体目标包括：（1） 确定绿茶多酚在抑制中的抗氧化作用 尿液样本中 8-羟基-2'-脱氧鸟苷的水平 120 名乙型肝炎双阳性参与者的干预研究 病毒表面抗原和黄曲霉毒素-白蛋白加合物，以及(2)确定 绿茶多酚对致癌物质排泄的调节作用 解毒产品，收集尿样中的黄曲霉毒素Bl-硫醇酸 来自研究参与者。 这项拟议研究的结果将有助于 了解茶多酚的抗氧化作用机制 调节乙型/丙型肝炎病毒引起的人类肝癌发生 黄曲霉毒素。