Wang Z Y, Huang M T, Ferraro T, Wong C Q, Lou Y R, Reuhl K, Iatropoulos M, Yang C S, Conney A H
Department of Chemical Biology and Pharmacognosy, College of Pharmacy, Rutgers, State University of New Jersey, Piscataway 08855.
Cancer Res. 1992 Mar 1;52(5):1162-70.
Green tea was prepared by extracting 12.5 g of green tea leaves twice with 500 ml of boiling water, and the extracts were combined. This 1.25% green tea extract (1.25 g of tea leaves/100 ml of water) contained 4.69 mg of green tea extract solids per ml and was similar in composition to some green tea beverages consumed by humans. A 2.5% green tea extract (2.5 g of tea leaves/100 ml of water) was prepared similarly. Treatment of female SKH-1 mice with 180 mJ/cm2 of ultraviolet B light (UVB) once daily for 7 days resulted in red sunburn lesions of the skin. The intensity of red color and area of these lesions were inhibited in a dose-dependent fashion by the administration of 1.25 or 2.5% green tea extract as the sole source of drinking water before and during UVB treatment. Treatment of female SKH-1 mice with 180 mJ/cm2 of UVB once daily for 10 days followed 1 wk later by twice weekly application of 12-O-tetradecanoylphorbol-13-acetate for 25 wk resulted in the development of skin tumors. The formation of skin tumors was inhibited by administration of 1.25% green tea extract as the sole source of drinking water prior to and during the 10 days of UVB treatment and for 1 wk after UVB treatment. In additional experiments, female SKH-1 mice were treated with 200 nmol of 7,12-dimethylbenz(a)anthracene followed 3 wk later by irradiation with 180, 60, or 30 mJ/cm2 of UVB twice weekly for 30 wk. UVB-induced formation of skin tumors and increased spleen size were inhibited by administration of 1.25% green tea extract as the sole source of drinking water prior to and during the 30 wk of UVB treatment. In these experiments, treatment of the animals with the green tea extract not only decreased the number of skin tumors but also decreased substantially the size of the tumors. In additional studies, SKH-1 mice were initiated by topical application of 200 nmol of 7,12-dimethylbenz(a)anthracene followed by twice weekly application of 12-O-tetradecanoylphorbol-13-acetate for 25 wk. Administration of 1.25% green tea extract as the sole source of drinking water during promotion with 12-O-tetradecanoylphorbol-13-acetate reduced the number and incidence of skin tumors.
将12.5克绿茶茶叶用500毫升沸水提取两次，合并提取物，以此制备绿茶提取物。这种1.25%的绿茶提取物（1.25克茶叶/100毫升水）每毫升含有4.69毫克绿茶提取物固体成分，其成分与人类饮用的某些绿茶饮品相似。同样地制备了2.5%的绿茶提取物（2.5克茶叶/100毫升水）。对雌性SKH - 1小鼠每天用180 mJ/cm²的紫外线B（UVB）照射一次，持续7天，会导致皮肤出现晒伤红斑。在UVB照射前及照射期间，以1.25%或2.5%的绿茶提取物作为唯一饮用水来源给药，这些红斑的红色强度和面积受到剂量依赖性抑制。对雌性SKH - 1小鼠每天用180 mJ/cm²的UVB照射一次，持续10天，1周后每周两次涂抹12 - O - 十四烷酰佛波醇 - 13 - 乙酸酯，持续25周，会导致皮肤肿瘤的发生。在UVB照射的10天期间及照射后1周，以1.25%的绿茶提取物作为唯一饮用水来源给药，可抑制皮肤肿瘤的形成。在另外的实验中，给雌性SKH - 1小鼠注射200纳摩尔的7,12 - 二甲基苯并(a)蒽，3周后每周两次用180、60或30 mJ/cm²的UVB照射，持续30周。在UVB照射的30周期间及照射前，以1.25%的绿茶提取物作为唯一饮用水来源给药，可抑制UVB诱导的皮肤肿瘤形成及脾脏增大。在这些实验中，用绿茶提取物处理动物不仅减少了皮肤肿瘤的数量，还显著减小了肿瘤的大小。在另外的研究中，通过局部涂抹200纳摩尔的7,12 - 二甲基苯并(a)蒽启动SKH - 1小鼠，随后每周两次涂抹12 - O - 十四烷酰佛波醇 - 13 - 乙酸酯，持续25周。在以12 - O - 十四烷酰佛波醇 - 13 - 乙酸酯进行促癌过程中，以1.25%的绿茶提取物作为唯一饮用水来源给药，可减少皮肤肿瘤的数量和发生率。
