Prevention of photocarcinogenesis by topical administration of pure epigallocatechin gallate isolated from green tea
Prevention of photocarcinogenesis by topical administration of pure epigallocatechin gallate isolated from green tea
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DOI：
10.1080/01635589609514488
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发表时间：
1996-01-01
影响因子：
2.9
通讯作者：
Alberts, DS
中科院分区：
文献类型：
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作者：
Gensler, HL;Timmermann, BN;Alberts, DS
从绿色茶中分离的多酚类抗氧化剂纯化的表没食子儿茶素没食子酸酯（EGCG）的局部应用可抑制BALB/cAnNHsd小鼠的光致癌作用，且无可见毒性。在紫外线（UV）处理开始之前和整个实验期间，用200 μ l丙酮中的0、10或50 mg EGCG每周处理三次，持续三周。紫外线辐射包括每周5次30分钟的暴露于6个FS 40 Westinghouse日光灯组中，持续25周。在光致癌研究中，小鼠接受的总剂量约为2.1 × 10（6）J/m（2）。在第一次紫外线治疗后28周，紫外线照射小鼠的皮肤癌发病率为96%; 10或50 mg的EGCG将这一发病率分别降低至62%和39%。紫外线诱导的免疫抑制，评估的UVB照射小鼠无法拒绝同源抗原肿瘤，不受局部表没食子儿茶素没食子酸酯。每升饮用水口服0、100或500 mg纯EGCG（分别约为0、0.56或2.8 mg/天）不会降低UV诱导的皮肤肿瘤发病率、原发性肿瘤生长率或无法排斥抗原性肿瘤。因此，诱导皮肤肿瘤的紫外线辐射显着减少局部，但不是通过口服，通过一种机制，从抑制光免疫抑制不同的纯化的EGCG管理。
Topical application of purified (-)-epigallocatechin-3-gallate (EGCG), a polyphenolic antioxidant isolated from green tea, inhibited photocarcinogenesis in BALB/cAnNHsd mice with no visible toxicity. Mice were treated with 0, 10, or 50 mg of EGCG in 200 mu l of acetone three times weekly for three weeks before ultraviolet (UV) treatments began and throughout the experiment. UV radiation consisted of five 30-minute exposures per week to banks of six FS40 Westinghouse sunlamps for 25 weeks. In the photocarcinogenesis study, mice received a total dose of approximately 2.1 x 10(6) J/m(2). Skin cancer incidence in UV-irradiated mice was 96% at 28 weeks after the first UV treatment; EGCG at 10 or 50 mg reduced this incidence to 62% and 39%, respectively. UV-induced immunosuppression, assessed by the inability of UVB-irradiated mice to reject a syngeneic antigenic tumor, was not influenced by topical EGCG. Oral administration of 0, 100, or 500 mg of pure EGCG per liter of drinking water (approximately 0, 0.56, or 2.8 mg/day, respectively) did not decrease UV-induced skin tumor incidence, rate of primary tumor growth, or inability to reject antigenic tumors. Thus induction of skin tumors by UV radiation was significantly reduced by topical, but not by oral, administration of purified EGCG through a mechanism distinct from inhibition of photoimmunosuppression.