School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China.
School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China.
J Ethnopharmacol. 2019 Dec 5;245:112103. doi: 10.1016/j.jep.2019.112103. Epub 2019 Jul 20.
Cholestasis is a clinical syndrome caused by toxic bile acid retention that will lead to serious liver diseases. Ursodeoxycholic acid (UDCA) and obeticholic acid (OCA) are the only two FDA-approved drugs for its treatment. Thus, there is a clear need to develop new therapeutic approaches for cholestasis. Here, anti-cholestasis effects of the lignans from a traditional Chinese herbal medicine, Schisandra sphenanthera, were investigated as well as the involved mechanisms.
Adult male C57BL/6J mice were randomly divided into 9 groups including the control group, LCA group, LCA with specific lignan treatment of Schisandrin A (SinA), Schisandrin B (SinB), Schisandrin C (SinC), Schisandrol A (SolA), Schisandrol B (SolB), Schisantherin A (StnA) and Schisantherin B (StnB), respectively. Mice were treated with each drug (qd) for 7 days, while the administration of lithocholic acid (LCA) (bid) was launched from the 4th day. Twelve hours after the last LCA injection, mice were sacrificed and samples were collected. Serum biochemical measurement and histological analysis were conducted. Metabolomics analysis of serum, liver, intestine and feces were performed to study the metabolic profile of bile acids. RT-qPCR and Western blot analysis were conducted to determine the hepatic expression of genes and proteins related to bile acid homeostasis. Dual-luciferase reporter gene assay was performed to investigate the transactivation effect of lignans on human pregnane X receptor (hPXR). RT-qPCR analysis was used to detect induction effects of lignans on hPXR-targeted genes in HepG2 cells.
Lignans including SinA, SinB, SinC, SolA, SolB, StnA, StnB were found to significantly protect against LCA-induced intrahepatic cholestasis, as evidenced by significant decrease in liver necrosis, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) activity. More importantly, serum total bile acids (TBA) and total bilirubin (Tbili) were also significantly reduced. Metabolomics analysis revealed these lignans accelerated the metabolism of bile acids and increased the bile acid efflux from liver into the intestine or feces. Gene analysis revealed these lignans induced the hepatic expressions of PXR-target genes such as Cyp3a11 and Ugt1a1. Luciferase reporter gene assays illustrated that these bioactive lignans can activate hPXR. Additionally, they can all upregulate hPXR-regulate genes such as CYP3A4, UGT1A1 and OATP2.
These results clearly demonstrated the lignans from Schisandra sphenanthera exert hepatoprotective effects against LCA-induced cholestasis by activation of PXR. These lignans may provide an effective approach for the prevention and treatment of cholestatic liver injury.
胆汁淤积是一种由毒性胆汁酸潴留引起的临床综合征，可导致严重的肝脏疾病。熊去氧胆酸（UDCA）和奥贝胆酸（OCA）是仅有的两种经美国食品药品监督管理局批准用于治疗胆汁淤积的药物。因此，显然需要开发新的胆汁淤积治疗方法。在这里，研究了一种传统中药五味子的木脂素对胆汁淤积的抗胆汁淤积作用及其相关机制。
成年雄性 C57BL/6J 小鼠随机分为 9 组，包括对照组、LCA 组、LCA 加五味子甲素（SinA）、五味子乙素（SinB）、五味子丙素（SinC）、五味子醇 A（SolA）、五味子醇 B（SolB）、五味子酯 A（StnA）和五味子酯 B（StnB）的特定木脂素治疗组。小鼠分别用每种药物（qd）处理 7 天，而从第 4 天开始给予胆酸（LCA）（bid）给药。最后一次 LCA 注射后 12 小时，处死小鼠并收集样本。进行血清生化测量和组织学分析。对血清、肝脏、肠道和粪便进行代谢组学分析，以研究胆汁酸的代谢谱。通过 RT-qPCR 和 Western blot 分析确定与胆汁酸稳态相关的肝基因和蛋白质的表达。进行双荧光素酶报告基因检测以研究木脂素对人孕烷 X 受体（hPXR）的转录激活作用。使用 RT-qPCR 分析检测木脂素对 HepG2 细胞中 hPXR 靶向基因的诱导作用。
发现木脂素包括 SinA、SinB、SinC、SolA、SolB、StnA、StnB 可显著预防 LCA 诱导的肝内胆汁淤积，这表现在肝坏死、血清丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）和碱性磷酸酶（ALP）活性显著降低。更重要的是，血清总胆汁酸（TBA）和总胆红素（Tbili）也明显降低。代谢组学分析表明，这些木脂素加速了胆汁酸的代谢，并增加了胆汁酸从肝脏向肠道或粪便的流出。基因分析表明，这些木脂素诱导了 PXR 靶向基因如 Cyp3a11 和 Ugt1a1 的肝表达。荧光素酶报告基因检测表明，这些生物活性木脂素可以激活 hPXR。此外，它们都可以上调 hPXR 调节的基因，如 CYP3A4、UGT1A1 和 OATP2。
这些结果清楚地表明，五味子中的木脂素通过激活 PXR 对 LCA 诱导的胆汁淤积发挥肝保护作用。这些木脂素可能为预防和治疗胆汁淤积性肝损伤提供一种有效方法。
