Department of Forestry, National Chung Hsing University, Kou Kung Road, Taichung 402, Taiwan.
J Ethnopharmacol. 2011 Jun 14;136(1):168-77. doi: 10.1016/j.jep.2011.04.030. Epub 2011 Apr 20.
In recent years, the medicinal mushroom Antrodia cinnamomea, known as "niu-chang chih" has received much attention with regard to its possible health benefits; especially its hepatoprotective effects against various drugs, toxins, and alcohol induced liver diseases. However, the molecular mechanism underlying this protective effect of Antrodia cinnamomea and its active compound antroquinonol was poorly understood. In the present study we evaluated to understand the hepatoprotective efficacy of antroquinonol and ethanolic extracts of mycelia of Antrodia cinnamomea (EMAC) in vitro and in vivo.
The protective mechanism of antroquinonol and EMAC against ethanol-induced oxidative stress was investigated in cultured human hepatoma HepG2 cells and ICR mice model, respectively. HepG2 cells were pretreated with antroquinonol (1-20μM) and oxidative stress was induced by ethanol (100mM). Meanwhile, male ICR mice were pretreated with EMAC for 10 days and hepatotoxicity was generated by the addition of ethanol (5g/kg). Hepatic enzymes, cytokines and chemokines were determined using commercially available assay kits. Western blotting and real-time PCR were subjected to analyze HO-1 and Nr-2 expression. EMSA was performed to monitor Nrf-2 ARE binding activity. Possible changes in hepatic lesion were observed using histopathological analysis.
Antroquinonol pretreatment significantly inhibited ethanol-induced AST, ALT, ROS, NO, MDA production and GSH depletion in HepG2 cells. Western blot and RT-PCR analysis showed that antroquinonol enhanced Nrf-2 activation and its downstream antioxidant gene HO-1 via MAPK pathway. This mechanism was then confirmed in vivo in an acute ethanol intoxicated mouse model: serum ALT and AST production, hepatocellular lipid peroxidation and GSH depletion was prevented by EMAC in a dose-dependent manner. EMAC significantly enhanced HO-1 and Nrf-2 activation via MAPKs consistent with in vitro studies. Ethanol-induced hepatic swelling and hydropic degeneration of hepatocytes was significantly inhibited by EMAC in a dose-dependent manner.
These results provide a scientific basis for the hepatoprotective effects of Antrodia cinnamomea. Data also imply that antroquinonol, a potent bioactive compound may be responsible for the hepatoprotective activity of Antrodia cinnamomea. Moreover, the present study highly supported our traditional knowledge that Antrodia cinnamomea as a potential candidate for the treatment of alcoholic liver diseases.
近年来，药用真菌牛樟芝因其可能具有的健康益处而备受关注；特别是其对各种药物、毒素和酒精性肝损伤的保肝作用。然而，牛樟芝及其活性化合物antroquinonol 发挥这种保护作用的分子机制尚不清楚。本研究旨在评估 antroquinonol 和牛樟芝菌丝体乙醇提取物（EMAC）在体外和体内的保肝作用。
分别在培养的人肝癌 HepG2 细胞和 ICR 小鼠模型中研究 antroquinonol 和 EMAC 对乙醇诱导的氧化应激的保护机制。用乙醇（100mM）诱导 HepG2 细胞产生氧化应激，用 1-20μM 的 antroquinonol 预处理 HepG2 细胞。同时，用 EMAC 预处理雄性 ICR 小鼠 10 天，然后加入乙醇（5g/kg）生成肝毒性。用商业试剂盒测定肝酶、细胞因子和趋化因子。用 Western blot 和实时 PCR 分析 HO-1 和 Nr-2 表达。EMSA 用于监测 Nrf-2 ARE 结合活性。通过组织病理学分析观察肝损伤的可能变化。
antroquinonol 预处理可显著抑制 HepG2 细胞中乙醇诱导的 AST、ALT、ROS、NO、MDA 产生和 GSH 耗竭。Western blot 和 RT-PCR 分析表明，antroquinonol 通过 MAPK 通路增强 Nrf-2 激活及其下游抗氧化基因 HO-1。在急性乙醇中毒小鼠模型中，这一机制得到了进一步证实：EMAC 可剂量依赖性地防止血清 ALT 和 AST 生成、肝细胞脂质过氧化和 GSH 耗竭。EMAC 显著增强 MAPKs 中的 HO-1 和 Nrf-2 激活，与体外研究一致。EMAC 可剂量依赖性地显著抑制乙醇诱导的肝肿胀和肝细胞水样变性。
这些结果为牛樟芝的保肝作用提供了科学依据。数据还表明，antroquinonol 作为一种有效的生物活性化合物，可能是牛樟芝保肝作用的原因。此外，本研究高度支持我们的传统知识，即牛樟芝是治疗酒精性肝病的潜在候选药物。
