State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China.
Institute of Biomedical Engineering, Department of Electrical and Computer Engineering, National Chiao Tung University, Hsinchu, Taiwan.
Med Res Rev. 2017 Jul;37(4):665-701. doi: 10.1002/med.21422. Epub 2016 Dec 22.
Tannins, polyphenols in medicinal plants, have been divided into two groups of hydrolysable and condensed tannins, including gallotannins, ellagitannins, and (-)-epigallocatechin-3-gallate (EGCG). Potent anticancer activities have been observed in tannins (especially EGCG) with multiple mechanisms, such as apoptosis, cell cycle arrest, and inhibition of invasion and metastases. Furthermore, the combinational effects of tannins and anticancer drugs have been demonstrated in this review, including chemoprotective, chemosensitive, and antagonizing effects accompanying with anticancer effect. However, the applications of tannins have been hindered due to their poor liposolubility, low bioavailability, off-taste, and shorter half-life time in human body, such as EGCG, gallic acid, and ellagic acid. To tackle these obstacles, novel drug delivery systems have been employed to deliver tannins with the aim of improving their applications, such as gelatin nanoparticles, micelles, nanogold, liposomes, and so on. In this review, the chemical characteristics, anticancer properties, and drug delivery systems of tannins were discussed with an attempt to provide a systemic reference to promote the development of tannins as anticancer agents.
单宁，药用植物中的多酚，可分为水解单宁和缩合单宁两类，包括没食子单宁、鞣花单宁和（-）-表没食子儿茶素-3-没食子酸酯（EGCG）。单宁（尤其是 EGCG）具有多种作用机制，如细胞凋亡、细胞周期阻滞、抑制侵袭和转移等，表现出了强大的抗癌活性。此外，本综述还证明了单宁与抗癌药物的联合作用，包括化学保护、化学增敏和抗癌作用伴随的拮抗作用。然而，由于单宁类化合物（如 EGCG、没食子酸和鞣花酸）脂溶性差、生物利用度低、口感不佳和在人体内半衰期较短，其应用受到了限制。为了解决这些问题，人们采用了新型药物传递系统来传递单宁类化合物，旨在改善其应用，如明胶纳米粒、胶束、纳米金、脂质体等。本综述讨论了单宁的化学特性、抗癌特性和药物传递系统，以期为促进单宁类化合物作为抗癌药物的发展提供系统的参考。
