Zwolak Iwona
Centre for Interdisciplinary Research, Laboratory of Oxidative Stress, The John Paul II Catholic University of Lublin, Konstantynów Ave. 1J, 20-708 Lublin, Poland.
Int J Mol Sci. 2021 Apr 14;22(8):4027. doi: 10.3390/ijms22084027.
In this review, we highlight the effects of epigallocatechin gallate (EGCG) against toxicities induced by heavy metals (HMs). This most active green tea polyphenol was demonstrated to reduce HM toxicity in such cells and tissues as testis, liver, kidney, and neural cells. Several protective mechanisms that seem to play a pivotal role in EGCG-induced effects, including reactive oxygen species scavenging, HM chelation, activation of nuclear factor erythroid 2-related factor 2 (Nrf2), anti-inflammatory effects, and protection of mitochondria, are described. However, some studies, especially in vitro experiments, reported potentiation of harmful HM actions in the presence of EGCG. The adverse impact of EGCG on HM toxicity may be explained by such events as autooxidation of EGCG, EGCG-mediated iron (Fe) reduction, depletion of intracellular glutathione (GSH) levels, and disruption of mitochondrial functions. Furthermore, challenges hampering the potential EGCG application related to its low bioavailability and proper dosing are also discussed. Overall, in this review, we point out insights into mechanisms that might account for both the beneficial and adverse effects of EGCG in HM poisoning, which may have a bearing on the design of new therapeutics for HM intoxication therapy.
在本综述中，我们重点介绍了表没食子儿茶素没食子酸酯（EGCG）对重金属（HMs）诱导的毒性的影响。这种最具活性的绿茶多酚已被证明可降低睾丸、肝脏、肾脏和神经细胞等细胞和组织中的重金属毒性。文中描述了几种在EGCG诱导的效应中似乎起关键作用的保护机制，包括清除活性氧、螯合重金属、激活核因子红细胞2相关因子2（Nrf2）、抗炎作用以及保护线粒体。然而，一些研究，尤其是体外实验，报道了在EGCG存在的情况下有害重金属作用的增强。EGCG对重金属毒性的不利影响可能由EGCG的自氧化、EGCG介导的铁（Fe）还原、细胞内谷胱甘肽（GSH）水平的消耗以及线粒体功能的破坏等事件来解释。此外，还讨论了阻碍EGCG潜在应用的挑战，这些挑战涉及其低生物利用度和合适的剂量。总体而言，在本综述中，我们指出了对EGCG在重金属中毒中有益和不利影响的潜在机制的见解，这可能与设计新的重金属中毒治疗方法有关。
