Lee Kyung Jin, Choi Jae Ho, Khanal Tilak, Hwang Yong Pil, Chung Young Chul, Jeong Hye Gwang
BK21 Project Team, Department of Pharmacy, College of Pharmacy, Research Center for Proteineous Materials, Chosun University, Gwangju, South Korea.
Toxicology. 2008 Jun 3;248(1):18-24. doi: 10.1016/j.tox.2008.03.009. Epub 2008 Mar 20.
This study was designed to investigate the protective effects of the phenethyl ester of caffeic acid (CAPE) against carbon tetrachoride (CCl(4))-induced hepatotoxicities in mice. Pretreatment with CAPE prior to administration of CCl(4) significantly prevented the increases in serum alanine, aspartate aminotransferase and alkaline phosphatase activities, hepatic lipid peroxidation formation, and depletion of glutathione content. In addition, CAPE prevented CCl(4)-induced apoptosis and necrosis, as indicated by liver histopathology and DNA laddering studies. To determine whether the Fas/Fas ligand (FasL) pathway is involved in CCl(4)-induced acute liver injury, Fas and FasL proteins and caspase-3 and -8 activities were tested by western blotting and ELISA. CAPE markedly decreased CCl(4)-induced Fas/FasL protein expression levels and, in turn, attenuated CCl(4)-induced caspase-3 and -8 activities in mouse liver. Moreover, the effect of CAPE on CYP2E1, the major isozyme involved in CCl(4) bioactivation, was investigated. Treatment with CAPE significantly decreased the CYP2E1-dependent hydroxylation of aniline. In addition, CAPE attenuated the CCl(4)-mediated depletion of antioxidant enzyme (catalase, superoxide dismutase and glutathione-S-transferase) activities. These findings suggest that the protective effects of CAPE against CCl(4)-induced acute liver injury may involve its ability to block CYP2El-mediated CCl(4) bioactivation and to protect against Fas/FasL-mediated apoptosis.
本研究旨在探讨咖啡酸苯乙酯（CAPE）对四氯化碳（CCl₄）诱导的小鼠肝毒性的保护作用。在给予CCl₄之前用CAPE预处理可显著预防血清丙氨酸、天冬氨酸转氨酶和碱性磷酸酶活性的升高、肝脂质过氧化的形成以及谷胱甘肽含量的消耗。此外，如肝脏组织病理学和DNA梯状条带研究所示，CAPE可预防CCl₄诱导的细胞凋亡和坏死。为了确定Fas/Fas配体（FasL）途径是否参与CCl₄诱导的急性肝损伤，通过蛋白质印迹法和酶联免疫吸附测定法检测了Fas和FasL蛋白以及半胱天冬酶-3和-8的活性。CAPE显著降低了CCl₄诱导的Fas/FasL蛋白表达水平，进而减弱了CCl₄诱导的小鼠肝脏中半胱天冬酶-3和-8的活性。此外，还研究了CAPE对参与CCl₄生物活化的主要同工酶CYP2E1的影响。用CAPE处理可显著降低CYP2E1依赖的苯胺羟基化作用。此外，CAPE减弱了CCl₄介导的抗氧化酶（过氧化氢酶、超氧化物歧化酶和谷胱甘肽-S-转移酶）活性的消耗。这些发现表明，CAPE对CCl₄诱导的急性肝损伤的保护作用可能涉及其阻断CYP2E1介导的CCl₄生物活化以及防止Fas/FasL介导的细胞凋亡的能力。
