Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary.
Nutr Res. 2011 Oct;31(10):731-40. doi: 10.1016/j.nutres.2011.09.008.
Regular green tea consumption has been shown to reduce the risk of cancer and diabetes mellitus. These effects are attributed to tea flavan-3-ols, especially to epigallocatechin gallate; however, the molecular targets and mechanisms of action are still subject of extensive research. The special roles of the endoplasmic reticulum (ER) in biotransformation, protein synthesis, calcium homeostasis, and glucose production make this organelle a potential target of the antitumor and antidiabetic effects of tea flavan-3-ols. The purpose of this review is to present evidence for the biologic actions of tea flavan-3-ols on specific ER targets associated with normal function and disease. Reactivation of chemical carcinogens can be reduced by tea flavan-3-ols through inhibition of glucuronide transport across the ER membrane. Catechins modulate Ca(2+) release from the ER lumen and interfere with glycoprotein maturation, which can lead to decreased viability and increased drug sensitivity of tumor cells. Epigallocatechin gallate inhibits glucose transport across the ER membrane, which can underlie the reduction of hepatic glucose production by tea flavan-3-ols. These mechanisms likely contribute to the chemopreventive and glucose-lowering effects of tea catechins. Investigating the effects of flavan-3-ols on ER functions is a promising field of medical and biochemical research to understand disease and improve health.
经常饮用绿茶已被证明可以降低癌症和糖尿病的风险。这些效果归因于茶类黄酮-3-醇，尤其是表没食子儿茶素没食子酸酯；然而，其分子靶点和作用机制仍在广泛研究中。内质网（ER）在生物转化、蛋白质合成、钙稳态和葡萄糖产生中的特殊作用使该细胞器成为茶类黄酮-3-醇抗肿瘤和抗糖尿病作用的潜在靶点。本综述的目的是提出茶类黄酮-3-醇对与正常功能和疾病相关的特定内质网靶标具有生物学作用的证据。茶类黄酮-3-醇可通过抑制葡萄糖醛酸穿过内质网膜的转运来减少化学致癌物的再激活。儿茶素调节内质网腔中 Ca(2+)的释放，并干扰糖蛋白成熟，这可能导致肿瘤细胞活力降低和药物敏感性增加。表没食子儿茶素没食子酸酯抑制葡萄糖穿过内质网膜的转运，这可能是茶类黄酮-3-醇降低肝葡萄糖产生的基础。这些机制可能有助于茶儿茶素的化学预防和降血糖作用。研究茶类黄酮-3-醇对内质网功能的影响是医学和生化研究的一个有前途的领域，有助于了解疾病并改善健康。
