Obeticholic Acid Protects Against Cholestatic Liver Injury Induced by Lithocholic Acid via Inhibiting Exogenous Cell Apoptosis

Background: Lithocholic acid (LCA) is one kind of endogenous bile acids which is a typical index in primary biliary cholangitis (PBC). It could cause severe cholestatic liver injury in rodents. Obeticholic acid (OCA) is a major treatment for PBC. However, its effect and mechanism in LCA-induced liver injury was still unclear beside of bile acid regulation. This study aims to evaluate the hepatoprotective effect and mechanism of OCA against LCA-induced cholestatic liver injury. Results: LCA-induced upregulations of ALT, AST, ALP and TBA were reduced and the bile acid profiles in serum, liver and bile were improved significantly by OCA. This bile acid regulating effect of OCA was mainly based on increasing the expression of bile acid efflux transporters bile salt export pump (BSEP), multidrug resistant associated protein 2 (MRP2), MRP3 and multi-drug resistance 3 (MDR3) instead of bile acid synthesis inhibition. Furthermore, it was found that OCA reduced the activation and expression of Caspase 8/3 signaling pathway without the change of p-MLKL and BAX in LCA-induced cholestatic model. And the inhibition of Caspase 8/3 signaling pathway depended on the activation of Farnesoid X receptor (FXR) to inhibit Caspase 8 cleavage to form a active complex.Conclusions: This study found OCA improved LCA-induced cholestatic liver injury via FXR-induced exogenous cell apoptosis, which provided a new evidence for the application of OCA to ameliorate PBC in clinical.

Detection and Evaluation of process related impurities in Obeticholic Acid Drug material using HPLC Method

Obeticholic acid (OBE) is being used to treat primary biliary cirrhosis and cholangitis. An HPLC with refractive index detection method for eight process related substances of OBE was developed and verified for use in quality assurance laboratories for regular analysis. The separation and analysis were performed on YMC Triart C18 (3.0 µm particle size, 250 mm × 4.6 mm) column. Mobile phase employed consisted of 0.01N potassium phosphate buffer (3.0 ± 0.05 pH, set with 0.1% orthophosphoric acid) and acetonitrile at 45:55 (v/v) ratio. The method established for determination of eight impurities in OBE was validated and verified in keeping with International Council for Harmonisation guidelines. This method can be used for routine analysis of eight impurities in OBE bulk samples.

Obeticholic Acid Improves Aminotransferases Early during Treatment in Patients with Primary Biliary Cholangitis Not Responding to Ursodeoxycholic Acid: A Study in Clinical Practice

Obeticholic acid (OCA) improves cholestasis and is generally well tolerated in patients with primary biliary cholangitis (PBC) not responding, or intolerant, to ursodeoxycholic acid (UDCA). As PBC is mainly a cholestatic disorder, less attention is paid to aminotransferase behavior in the course of treatment. In this study we evaluated, in clinical practice, the efficacy of OCA treatment on both alkaline phosphatase (ALP) and alanine aminotransferase (ALT) using updated healthy ranges for aminotransferases. Fifteen PBC patients, non-responders to UDCA, were evaluated at baseline and during OCA treatment with serial measurement of cholestasis indexes and ALT, that were also assessed using updated normal ranges (<30 IU/L in males, <19 IU/L in females). Median ALP and ALT decreased from 2.16 to 1.27 × upper limit of normal (p = 0.003) and from 0.93 to 0.78 × upper limit of normal (p = 0.008), respectively, in the course of OCA treatment. At treatment day-15, median ALT decreased by 29.7% and ALP by 8.8%. Bilirubin and albumin were unmodified throughout treatment. Using updated normal ranges, ALT levels were normal in 6.7% of patients at baseline and in 33.3% of patients at 18 months of treatment. OCA treatment improves cholestasis and, also, indexes of hepatocyte necrosis, with a decline in necro-inflammatory activity even predating the improvement in cholestasis. Use of recalibrated healthy ranges for aminotransferases might be a useful tool to assess hepatic histological activity and its improvement with OCA treatment.

Modelling human liver fibrosis in the context of non-alcoholic steatohepatitis using a microphysiological system

Non-alcoholic steatohepatitis (NASH) is a common form of chronic liver disease characterised by lipid accumulation, infiltration of immune cells, hepatocellular ballooning, collagen deposition and liver fibrosis. There is a high unmet need to develop treatments for NASH. We have investigated how liver fibrosis and features of advanced clinical disease can be modelled using an in vitro microphysiological system (MPS). The NASH MPS model comprises a co-culture of primary human liver cells, which were cultured in a variety of conditions including+/− excess sugar, fat, exogenous TGFβ or LPS. The transcriptomic, inflammatory and fibrotic phenotype of the model was characterised and compared using a system biology approach to identify conditions that mimic more advanced clinical disease. The transcriptomic profile of the model was shown to closely correlate with the profile of patient samples and the model displayed a quantifiable fibrotic phenotype. The effects of Obeticholic acid and Elafibranor, were evaluated in the model, as wells as the effects of dietary intervention, with all able to significantly reduce inflammatory and fibrosis markers. Overall, we demonstrate how the MPS NASH model can be used to model different aspects of clinical NASH but importantly demonstrate its ability to model advanced disease with a quantifiable fibrosis phenotype.