Jeong Hyesoo, Kim Soolin, Lee Jimin, Park Jin Young, Zhou Wenmei, Liu Xiyuan, Kim So Dam, Song Yun Seon, Jang Chang-Young, Oh Sei-Ryang, Choi Sangho, Chang Minsun
Graduate School of Biological Sciences, Sookmyung Women's University, 100, Chungparo 47-gil, Seoul, 140-742, Korea.
Department of Biological Sciences, College of Science, Sookmyung Women's University, 100, Chungparo 47-gil, Seoul, 140-742, Korea.
Phytother Res. 2017 Jan;31(1):140-151. doi: 10.1002/ptr.5742. Epub 2016 Nov 7.
Larrea nitida Cav. (LNC), which belongs to the family Zygophyllaceae, is widely indigenous and used in South America to treat various pathological conditions. It contains the antioxidant and antiinflammatory but toxic nordihydroguaiaretic acid (NDGA) as well as O-methylated metabolite of NDGA (MNDGA) as bioactive compounds. The hepatic metabolism-based toxicological potential of extracts of LNC (LNE), NDGA, and MNDGA has not previously been reported. The present study aimed to characterize the phase I and phase II hepatic metabolism and reactive intermediates of LNE, NDGA, and MNDGA and their effects on the major drug-metabolizing enzymes in vitro and ex vivo. A methanol extract of LNC collected from Chile as well as NDGA and MNDGA isolated from LNE were subjected to metabolic stability assays in liver microsomes in the presence of the cofactors reduced nicotinamide dinucleotide phosphate (NADPH) and/or uridine 5'-diphosphoglucuronic acid (UDPGA). Cytochrome P450 (CYP) inhibition assays were performed using CYP isozyme-specific model substrates to examine the inhibitory activities of LNE, NDGA, and MNDGA, which were expressed as % inhibition and IC values. Ex vivo CYP induction potential was investigated in the liver microsomes prepared from the rats intraperitoneally administered with LNE. Glutathione (GSH) adduct formation was monitored by LC-MS analysis of the microsomal incubation samples with either NDGA or MNDGA and an excess of GSH to determine the formation of electrophilic reactive intermediates. Both NDGA and MNDGA were stable to NADPH-dependent phase I metabolism, but labile to glucuronide conjugation. LNE, NDGA, and MNDGA showed significant inhibitory effects on CYP1A2, 2C9, 2D6, and/or 3A4, with IC values in the micromolar range. LNE was found to be a CYP1A2 inducer in ex vivo rat experiments, and mono- and di-GSH adducts of both NDGA and MNDGA were identified by LC-MS analysis. Our study suggests that hepatic clearance is the major elimination route for the lignans NDGA and MNDGA present in LNE. These lignans may possess the ability to modify biomacromolecules via producing reactive intermediates. In addition, LNE, NDGA, and MNDGA are found to be inhibitors for various CYP isozymes such as CYP2C9 and 3A4. Thus, the consumption of LNC as an herbal preparation or NDGA may cause metabolism-driven herb-drug interactions. Copyright © 2016 John Wiley & Sons, Ltd.
亮叶拉瑞阿（Larrea nitida Cav.，LNC）属于蒺藜科，在南美洲广泛分布且当地居民常用其治疗多种病症。它含有抗氧化、抗炎但有毒的去甲二氢愈创木酸（NDGA）以及NDGA的O - 甲基化代谢产物（MNDGA）作为生物活性化合物。此前尚未报道过LNC提取物（LNE）、NDGA和MNDGA基于肝脏代谢的毒理学潜力。本研究旨在表征LNE、NDGA和MNDGA的I相和II相肝脏代谢及反应性中间体，以及它们在体外和体内对主要药物代谢酶的影响。从智利采集的LNC甲醇提取物以及从LNE中分离出的NDGA和MNDGA，在存在辅因子还原型烟酰胺腺嘌呤二核苷酸磷酸（NADPH）和/或尿苷5'-二磷酸葡萄糖醛酸（UDPGA）的情况下，于肝微粒体中进行代谢稳定性测定。使用细胞色素P450（CYP）同工酶特异性模型底物进行CYP抑制试验，以检测LNE、NDGA和MNDGA的抑制活性，结果以抑制率（%）和IC值表示。在给大鼠腹腔注射LNE后制备的肝微粒体中研究体内CYP诱导潜力。通过对用NDGA或MNDGA与过量谷胱甘肽（GSH）孵育的微粒体样品进行液相色谱 - 质谱（LC - MS）分析，监测GSH加合物的形成，以确定亲电反应性中间体的形成。NDGA和MNDGA对依赖NADPH的I相代谢均稳定，但对葡萄糖醛酸结合不稳定。LNE、NDGA和MNDGA对CYP1A2、2C9、2D6和/或3A4显示出显著抑制作用，IC值在微摩尔范围内。在体内大鼠实验中发现LNE是CYP1A2诱导剂，并且通过LC - MS分析鉴定出了NDGA和MNDGA的单 - 和双 - GSH加合物。我们的研究表明，肝脏清除是LNE中存在的木脂素NDGA和MNDGA的主要消除途径。这些木脂素可能具有通过产生活性中间体来修饰生物大分子的能力。此外，发现LNE、NDGA和MNDGA是多种CYP同工酶如CYP2C9和3A4的抑制剂。因此，将LNC作为草药制剂或NDGA食用可能会导致代谢驱动的草药 - 药物相互作用。版权所有© 2016 John Wiley & Sons, Ltd.
