Carlson Jennifer R, Bauer Brent A, Vincent Ann, Limburg Paul J, Wilson Ted
Department of Biology, Winona State University, Winona, MN 55987, USA.
Mayo Clin Proc. 2007 Jun;82(6):725-32. doi: 10.4065/82.6.725.
Green tea is an extremely popular beverage worldwide. Derivatives of green tea, particularly (-)-epigallocatechin-3-gallate (EGCG), have been proposed to have anticarcinogenic properties based on preclinical, observational, and clinical trial data. To summarize, clarify, and extend current knowledge, we conducted a comprehensive search of the PubMed database and other secondary data sources, as appropriate, regarding the chemopreventive potential of EGCG. Apparently, EGCG functions as an antioxidant, preventing oxidative damage in healthy cells, but also as an antiangiogenic agent, preventing tumors from developing a blood supply needed to grow larger. Furthermore, EGCG may stimulate apoptosis in cancerous cells by negatively regulating the cell cycle to prevent continued division. Finally, EGCG exhibits antibacterial activity, which may be implicated in the prevention of gastric cancer. Although in vitro research of the anticarcinogenic properties of EGCG seems promising, many diverse and unknown factors may influence its in vivo activity in animal and human models. Some epidemiological studies suggest that green tea compounds could protect against cancer, but existing data are inconsistent, and limitations in study design hinder full interpretation and generalizability of the published observational findings. Several clinical trials with green tea derivatives are ongoing, and further research should help to clarify the clinical potential of EGCG for chemoprevention and/or chemotherapy applications.
绿茶是全球极受欢迎的饮品。基于临床前、观察性和临床试验数据，绿茶的衍生物，尤其是（-）-表没食子儿茶素-3-没食子酸酯（EGCG），被认为具有抗癌特性。为了总结、阐明并扩展现有知识，我们对PubMed数据库及其他适当的二级数据源进行了全面检索，以了解EGCG的化学预防潜力。显然，EGCG既作为抗氧化剂发挥作用，防止健康细胞受到氧化损伤，又作为抗血管生成剂，阻止肿瘤形成生长所需的血液供应。此外，EGCG可能通过负向调节细胞周期来刺激癌细胞凋亡，以防止其持续分裂。最后，EGCG具有抗菌活性，这可能与预防胃癌有关。尽管关于EGCG抗癌特性的体外研究似乎前景乐观，但许多不同且未知的因素可能会影响其在动物和人类模型中的体内活性。一些流行病学研究表明，绿茶成分可能预防癌症，但现有数据并不一致，研究设计的局限性阻碍了对已发表观察结果的全面解读和推广。几项关于绿茶衍生物的临床试验正在进行中，进一步的研究应有助于阐明EGCG在化学预防和/或化疗应用方面的临床潜力。
