lignans and Cholestasis

Previously, we demonstrated that Schisandrol B (SolB) protected against lithocholic acid (LCA)-induced cholestatic liver injury (CLI) through pregnane X receptor (PXR). Additionally, growing evidence has revealed that pyroptosis is involved in CLI. Whether the hepatoprotective effect of SolB driven by PXR activation is related to pyroptosis in CLI remains unclear. First, the hepatoprotective effect of SolB was confirmed, as evidenced by the decreased mortality, morphological and histopathological changes, and biochemical parameters. The upregulated serum lactic dehydrogenase (LDH) level, increased number of TUNEL-positive cells, and formation of hepatocyte membrane pores induced by LCA were significantly alleviated after SolB pretreatment, indicating that SolB attenuated LCA-induced hepatocyte damage. Further analysis revealed that both NOD-like receptor protein 3 (NLRP3) inflammasome-induced canonical pyroptosis and apoptosis protease activating factor-1 (Apaf-1) pyroptosome-induced noncanonical pyroptosis were significantly inhibited after SolB pretreatment, as illustrated by the decreased expression levels of NLRP3, ASC, caspase-1, and GSDMD and the levels of Apaf-1, caspase-11 p20, caspase-3 p20, and GSDME. Furthermore, the activation of the NF-κB and FoxO1 signaling pathways was inhibited after SolB pretreatment. In addition, the activation of PXR via SolB was proven by luciferase reporter gene assays and the upregulation of PXR targets. The results illustrated that SolB could significantly inhibit NLRP3 inflammasome-induced canonical pyroptosis through the PXR/NF-κB/NLRP3 axis and inhibit Apaf-1 pyroptosome-induced noncanonical pyroptosis through the PXR/FoxO1/Apaf-1 axis. Collectively, this study revealed that SolB protected against CLI by inhibiting pyroptosis through PXR, providing new insights for understanding the molecular mechanism of SolB as a promising anti-cholestatic agent.

Topics: Caspase 3; Cholestasis; Cyclooctanes; Dioxoles; Humans; Inflammasomes; Lignans; Lithocholic Acid; Liver; Luciferases; NF-kappa B; NLR Family, Pyrin Domain-Containing 3 Protein; Oxidoreductases; Pregnane X Receptor; Pyroptosis

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.

Topics: Animals; Bile Acids and Salts; Chemical and Drug Induced Liver Injury; Cholestasis; Feces; HEK293 Cells; Hep G2 Cells; Humans; Intestinal Mucosa; Lignans; Lithocholic Acid; Liver; Male; Mice, Inbred C57BL; Pregnane X Receptor; Protective Agents; Schisandra

Currently, ursodeoxycholic acid and obeticholic acid are the only two FDA-approved drugs for cholestatic liver diseases. Thus, new therapeutic approaches need to be developed. Here we have evaluated the anti-cholestasis effects of Schisandrol B (SolB), a bioactive compound isolated from Schisandra sphenanthera.. Hepatoprotective effect of SolB against intrahepatic cholestasis, induced by lithocholic acid (LCA), was evaluated in mice. Metabolomic analysis and gene analysis were used to assess involvement of pregnane X receptor (PXR). Molecular docking, cell-based reporter gene analysis and knockout mice were used to demonstrate the critical role of the PXR pathway in the anti-cholestasis effects of SolB.. SolB protected against LCA-induced intrahepatic cholestasis. Furthermore, therapeutic treatment with SolB decreased mortality in cholestatic mice. Metabolomics and gene analysis showed that SolB accelerated metabolism of bile acids, promoted bile acid efflux into the intestine, and induced hepatic expression of the PXR-target genes Cyp3a11, Ugt1a1, and Oatp2, which are involved in bile acid homeostasis. Mechanistic studies showed that SolB activated human PXR and up-regulated PXR target genes in human cell lines. Additionally, SolB did not protect Pxr-null mice from liver injury induced by intrahepatic cholestasis, thus providing genetic evidence that the effect of SolB was PXR-dependent.. These findings provide direct evidence for the hepatoprotective effects of SolB against cholestasis by activating PXR. Therefore, SolB may provide a new and effective approach to the prevention and treatment of cholestatic liver diseases.

Topics: Animals; Cholestasis; Cyclooctanes; Dioxoles; Lignans; Lithocholic Acid; Liver; Male; Mice; Mice, Inbred C57BL; Pregnane X Receptor; Receptors, Steroid; Signal Transduction

We previously reported that the ethanol extract of Schisandra sphenanthera [Wuzhi (WZ) tablet] significantly protects against acetaminophen-induced hepatoxicity. However, whether WZ exerts a protective effect against cholestasis remains unclear. In this study, the protective effect of WZ on lithocholic acid (LCA)-induced intrahepatic cholestasis in mice was characterized and the involved mechanisms were investigated. WZ pretreatment (350 mg/kg) with LCA significantly reversed liver necrosis and decreased serum alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase activity. More importantly, serum total bile acids and total bilirubin were also remarkably reduced. Quantitative reverse-transcription polymerase chain reaction and Western blot analysis showed that hepatic expression of pregnane X receptor (PXR) target genes such as CYP3A11 and UDP-glucuronosyltransferase (UGT) 1A1 were significantly increased by WZ treatment. Luciferase assays performed in LS174T cells illustrated that WZ extract and its six bioactive lignans could all activate human PXR. In addition, WZ treatment significantly promoted liver regeneration via inhibition of p53/p21 to induce cell proliferation-associated proteins such as cyclin D1 and proliferating cell nuclear antigen. In conclusion, WZ has a protective effect against LCA-induced intrahepatic cholestasis, partially owing to activation of the PXR pathway and promotion of liver regeneration.

Topics: Acetaminophen; Animals; Chemical and Drug Induced Liver Injury; Cholestasis; Cytochrome P-450 CYP3A; Drugs, Chinese Herbal; Glucuronosyltransferase; Lignans; Lithocholic Acid; Liver; Liver Regeneration; Male; Mice; Mice, Inbred C57BL; Plant Extracts; Pregnane X Receptor; Protective Agents; Receptors, Steroid; Schisandra; Signal Transduction