Department of Urology & Nutrition, Case Western Reserve University, Cleveland, OH 44106, USA.
Curr Pharm Biotechnol. 2012 Jan;13(1):191-9. doi: 10.2174/138920112798868584.
Tea is the second most consumed beverage in the world reported to have multiple health benefits. Preventive and therapeutic benefits of tea polyphenols include enhanced general well being and anti-neoplastic effects. The pharmacologic action of tea is often attributed to various catechins present therein. Experiments conducted in cancer cell lines and animal models demonstrate that tea polyphenols protect against cellular damage caused by oxidative stress and altered immunity. Tea polyphenols modify various metabolic and signaling pathways in the regulation of proliferation, apoptosis, angiogenesis, and metastasis and therefore restrict clonal expansion of cancer cells. Tea polyphenols have been shown to reactivate tumor suppressors, block the unlimited replicative potential of cancer cells, and physically bind to nucleic acids involved in epigenetic alterations of gene regulation. Remarkable interest in green tea as a potential chemopreventive agent has been generated since recent epigenetic data showed that tea polyphenols have the potential to reverse epigenetic modifications which might otherwise be carcinogenic. Like green tea, black tea may also possess chemopreventive and chemotherapeutic potential; however, there is still not enough evidence available to make any conclusive statements. Here we present a brief description of tea polyphenols and discuss the findings of various in vitro and in vivo studies of the anticancer effects of tea polyphenols. Detailed discussion of various studies related to epigenetic changes caused by tea polyphenols leading to prevention of oncogenesis or cancer progression is included. Finally, we discuss on the scope and development of tea polyphenols in cancer prevention and therapy.
茶是世界上第二大消费饮料，据报道具有多种健康益处。茶多酚具有预防和治疗作用，包括增强整体健康和抗肿瘤作用。茶的药理作用通常归因于其中存在的各种儿茶素。在癌细胞系和动物模型中进行的实验表明，茶多酚可防止氧化应激和免疫改变引起的细胞损伤。茶多酚可调节增殖、凋亡、血管生成和转移等各种代谢和信号通路，从而限制癌细胞的克隆扩张。茶多酚已被证明可以重新激活肿瘤抑制因子，阻止癌细胞的无限复制潜力，并与涉及基因调控表观遗传改变的核酸物理结合。由于最近的表观遗传数据表明，茶多酚具有逆转可能致癌的表观遗传修饰的潜力，因此对绿茶作为潜在化学预防剂的兴趣显著增加。与绿茶一样，红茶也可能具有化学预防和化疗潜力；然而，目前还没有足够的证据来做出任何结论性的陈述。在这里，我们简要描述了茶多酚，并讨论了茶多酚抗癌作用的各种体外和体内研究结果。详细讨论了与茶多酚引起的表观遗传变化相关的各种研究，这些变化可预防肿瘤发生或癌症进展。最后，我们讨论了茶多酚在癌症预防和治疗中的范围和发展。
