Fan Xiaomei, Jiang Yiming, Wang Ying, Tan Huasen, Zeng Hang, Wang Yongtao, Chen Pan, Qu Aijuan, Gonzalez Frank J, Huang Min, Bi Huichang
School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China (X.F., Y.J., Yo.W., H.T., H.Z., Yi. W., M.H., H.B.); The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China (P.C.); and Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland (A.Q., F.J.G).
School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China (X.F., Y.J., Yo.W., H.T., H.Z., Yi. W., M.H., H.B.); The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China (P.C.); and Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland (A.Q., F.J.G)
Drug Metab Dispos. 2014 Dec;42(12):1982-90. doi: 10.1124/dmd.114.059535. Epub 2014 Sep 12.
Schisandra sphenanthera is widely used as a tonic and restorative in many countries to enhance the function of liver and other organs. Wuzhi tablet (WZ) is a preparation of an ethanol extract of Schisandra sphenanthera. Our previous study demonstrated that WZ exerted a protective effect toward acetaminophen (APAP)-induced hepatotoxicity. However, the molecular mechanisms of this protection remain unclear. This study aimed to determine what molecular pathways contributed to the hepatoprotective effects of WZ against APAP toxicity. Administration of WZ 3 days before APAP treatment significantly attenuated APAP hepatotoxicity in a dose-dependent manner and reduced APAP-induced JNK activation. Treatment with WZ resulted in potent inhibition of CYP2E1, CYP3A11, and CYP1A2 activities and then caused significant inhibition of the formation of the oxidized APAP metabolite N-acetyl-p-benzoquinone imine-reduced glutathione. The expression of NRF2 was increased after APAP and/or WZ treatment, whereas KEAP1 levels were decreased. The protein expression of NRF2 target genes including Gclc, Gclm, Ho-1, and Nqo1 was significantly increased by WZ treatment. Furthermore, APAP increased the levels of p53 and its downstream gene p21 to trigger cell cycle arrest and apoptosis, whereas WZ pretreatment could inhibit p53/p21 signaling to induce cell proliferation-associated proteins including cyclin D1, CDK4, PCNA, and ALR to promote hepatocyte proliferation. This study demonstrated that WZ prevented APAP-induced liver injury by inhibition of cytochrome P450-mediated APAP bioactivation, activation of the NRF2-antioxidant response element pathway to induce detoxification and antioxidation, and regulation of the p53, p21, cyclin D1, CDK4, PCNA, and ALR to facilitate liver regeneration after APAP-induced liver injury.
华中五味子在许多国家被广泛用作滋补和恢复剂，以增强肝脏和其他器官的功能。五酯片（WZ）是华中五味子乙醇提取物的制剂。我们之前的研究表明，WZ对乙酰氨基酚（APAP）诱导的肝毒性具有保护作用。然而，这种保护作用的分子机制仍不清楚。本研究旨在确定哪些分子途径促成了WZ对APAP毒性的肝保护作用。在APAP治疗前3天给予WZ以剂量依赖性方式显著减轻了APAP肝毒性，并降低了APAP诱导的JNK激活。WZ处理导致CYP2E1、CYP3A11和CYP1A2活性受到有效抑制，进而显著抑制了氧化型APAP代谢产物N-乙酰对苯醌亚胺-还原型谷胱甘肽的形成。APAP和/或WZ处理后NRF2的表达增加，而KEAP1水平降低。WZ处理显著增加了包括Gclc、Gclm、Ho-1和Nqo1在内的NRF2靶基因的蛋白表达。此外，APAP增加了p53及其下游基因p21的水平以触发细胞周期停滞和凋亡，而WZ预处理可抑制p53/p21信号传导以诱导包括细胞周期蛋白D1、CDK4、PCNA和ALR在内的细胞增殖相关蛋白，从而促进肝细胞增殖。本研究表明，WZ通过抑制细胞色素P450介导的APAP生物活化、激活NRF2-抗氧化反应元件途径以诱导解毒和抗氧化作用，以及调节p53、p21、细胞周期蛋白D1、CDK4、PCNA和ALR来促进APAP诱导的肝损伤后的肝脏再生，从而预防APAP诱导的肝损伤。
