Caffeic acid prevents acetaminophen-induced liver injury by activating the Keapl-Nrf2 antioxidative defense system
Caffeic acid prevents acetaminophen-induced liver injury by activating the Keapl-Nrf2 antioxidative defense system
复制标题
DOI：
10.1016/j.freeradbiomed.2015.12.024
复制
发表时间：
2016-02-01
影响因子：
7.4
通讯作者：
Ji, Lili
中科院分区：
文献类型：
--
作者：
Pang, Chun;Zheng, Zhiyong;Ji, Lili
对乙酰氨基酚(APAP)过量所致急性肝功能衰竭是药物性肝损伤(DILI)的主要原因。咖啡酸(CA)是一种从多种天然产物中提取的酚类化合物。本研究旨在探讨CA对APAP所致肝损伤的保护作用机制。血清丙氨酸/天冬氨酸氨基转移酶(ALT/AST)、肝脏髓过氧化物酶(MPO)活性、肝脏谷胱甘肽(GSH)和活性氧(ROS)水平的测定结果表明，CA对APAP诱导的肝损伤具有保护作用。肝组织学观察为CA的保护作用提供了进一步的证据。CA能逆转APAP诱导的人正常肝L-02细胞和人肝癌细胞株HepG2细胞活力的下降。CA还能降低APAP引起的肝细胞内ROS水平的升高。荧光素酶活性测定和Western-印迹分析结果表明，在APAP存在的情况下，CA可增强核因子红系2相关因子2(NRF2)的转录活性。Nrf2 siRNA可降低CA对APAP肝毒性的保护作用。CA还能逆转APAP引起的血红素加氧酶1(HO-1)和NAD(P)H：苯醌氧化还原酶L(NQO1)基因和蛋白表达的下降。此外，HO-1抑制剂锌原卟啉(ZnPP)和NQO1抑制剂达莫托(Dim)可降低CA对APAP所致肝损伤的保护作用。CA还可降低海带样ECH相关蛋白-1(KEAPL)的表达。分子对接表明CA可能与Keap1蛋白中的Nrf2结合部位相互作用。在体外，CA对细胞色素P450(CYP)3A4和细胞色素P2E1酶活性影响不大。综上所述，我们证明CA通过减少Keap1的表达，抑制Keap1与Nrf2的结合，从而激活Nrf2，增加包括HO-1和NQO1在内的抗氧化信号的表达，从而预防APAP诱导的肝毒性。(C)2015 Elsevier Inc.保留所有权利。
Acute liver failure induced by acetaminophen (APAP) overdose is the main cause of drug-induced liver injury (DILI). Caffeic acid (CA) is a phenolic compound from many natural products. This study aims to investigate the protective mechanism of CA in APAP-induced liver injury. The results of serum alanine/ aspartate aminotransferases (ALT/AST), liver myeloperoxidase (MPO) activity, liver glutathione (GSH) and reactive oxygen species (ROS) levels demonstrated the protection of CA against APAP-induced liver injury. Liver histological observation provided further evidences of CA-induced protection. CA was found to reverse the APAP-induced decreased cell viability in human normal liver L-02 cells and HepG2 cells. CA also reduced the increased cellular ROS level induced by APAP in hepatocytes. The results of luciferase assay and Western-blot analysis showed that CA increased the transcriptional activation of nuclear factor erythroid 2-related factor 2 (Nrf2) in the presence of APAP. Nrf2 siRNA reduced the protection of CA against APAP-induced hepatotoxicity. CA also reversed the APAP-induced decreased mRNA and protein expression of heme oxygenase 1 (HO-1) and NAD(P)H: quinone oxidoreductase l(NQO1). In addition, HO-1 inhibitor zinc protoporphyrin (ZnPP) and NQO1 inhibitor diminutol (Dim) reduced the protection of CA against APAP-induced hepatotoxicity. CA also decreased the expression of kelch-like ECH-associated protein-1(Keapl). Molecular docking indicated the potential interacting of CA with Nrf2 binding site in the Keapl protein. CA had little effect on the enzymatic activity of cytochrome P450 (CYP) 3A4 and CYP2E1 in vitro. In conclusion, we demonstrated that CA prevented APAP-induced hepatotoxicity by decreasing Keapl expression, inhibiting binding of Keapl to Nrf2, and thus activating Nrf2 and leading to increased expression of antioxidative signals including HO-1 and NQO1. (C) 2015 Elsevier Inc. All rights reserved.