Study of effectiveness of bezafibrate in the treatment of chronic hepatitis C

PPAR Ligands Induce Antiviral Effects Targeting Perturbed Lipid Metabolism during SARS-CoV-2, HCV, and HCMV Infection

Simple Summary

The current coronavirus disease 2019 pandemic turned the attention of researchers to developing novel strategies to counteract virus infections. Despite several antiviral drugs being commercially available, there is an urgent need to identify novel molecules efficacious against viral infections that act through different mechanisms of action. In this context, our attention is focused on novel compounds acting on nuclear receptors, whose activity could be beneficial in viral infections, including coronavirus, hepatitis C virus, and cytomegalovirus.

Abstract

The manipulation of host metabolisms by viral infections has been demonstrated by several studies, with a marked influence on the synthesis and utilization of glucose, nucleotides, fatty acids, and amino acids. The ability of virus to perturb the metabolic status of the infected organism is directly linked to the outcome of the viral infection. A great deal of research in recent years has been focusing on these metabolic aspects, pointing at modifications induced by virus, and suggesting novel strategies to counteract the perturbed host metabolism. In this review, our attention is turned on PPARs, nuclear receptors controlling multiple metabolic actions, and on the effects played by PPAR ligands during viral infections. The role of PPAR agonists and antagonists during SARS-CoV-2, HCV, and HCMV infections will be analyzed.

The impact of antihyperlipidemic drugs on the viral load of patients with chronic hepatitis C infection: a meta-analysis

Several studies investigating the role of statins and fibrates in chronic hepatitis C virus (HCV) infection offered so far conflicting evidence regarding the antiviral potency of these medications, whereas combination of these drugs with pegylated interferon and ribavirin improved in some trials therapeutic outcome. We conducted a literature search to identify trials that included monoinfected HCV patients, treated with statins or fibrates as monotherapy with the primary end point of our meta-analysis being the quantitative change of HCV-RNA induced by these medications. Logarithmic changes of the viral load (ΔlogVL) and confidence intervals (CIs) were calculated according to the DerSimonian-Laird estimate. Statistical heterogeneity was assessed with the I² statistic. We identified eight observational studies that evaluated the potency of bezafibrate and different statins as monotherapy to induce a significant reduction of HCV-RNA in HCV-monoinfected patients (n = 281). Overall, a significant reduction of viral load with mean 0.19 [log10 IU/mL] (95%-confidence interval, (CI) 0.11-0.28) could be observed when antihyperlipidemic medications were administered. Bezafibrate featured the highest antiviral efficacy (0.45 log10 reduction, 95%-CI, 0.17-0.72) among all medications and fluvastatin (0.20 log10 reduction, 95%-CI, 0.09-0.31) among all statins tested. Based on meta-analysis, fibrates and statins induce a reduction of HCV viral load. We suggest that the addition of statins and fibrates to antiviral regimes, especially in HCV patients with concomitant dyslipidemia, could beside the established reduction of cardiovascular risk increase the potency of antiviral therapy.

Very low-density lipoprotein/lipo-viro particles reverse lipoprotein lipase-mediated inhibition of hepatitis C virus infection via apolipoprotein C-III

OBJECTIVE

Circulating hepatitis C virus (HCV) virions are associated with triglyceride-rich lipoproteins, including very low-density lipoprotein (VLDL) and low-density lipoprotein (LDL), designated as lipo-viro-particles (LVPs). Previous studies showed that lipoprotein lipase (LPL), a key enzyme for hydrolysing the triglyceride in VLDL to finally become LDL, may suppress HCV infection. This investigation considers the regulation of LPL by lipoproteins and LVPs, and their roles in the LPL-mediated anti-HCV function.

DESIGN

The lipoproteins were fractionated from normolipidemic blood samples using iodixanol gradients. Subsequent immunoglobulin-affinity purification from the canonical VLDL and LDL yielded the corresponding VLDL-LVP and LDL-LVP. Apolipoprotein (apo) Cs, LPL activity and HCV infection were quantified.

RESULTS

A higher triglyceride/cholesterol ratio of LDL was found more in HCV-infected donors than in healthy volunteers, and the triglyceride/cholesterol ratio of LDL-LVP was much increased, suggesting that the LPL hydrolysis of triglyceride may be impaired. VLDL, VLDL-LVP, LDL-LVP, but not LDL, suppressed LPL lipolytic activity, which was restored by antibodies that recognised apoC-III/-IV and correlated with the steadily abundant apoC-III/-IV quantities in those particles. In a cell-based system, treatment with VLDL and LVPs reversed the LPL-mediated inhibition of HCV infection in apoC-III/-IV-dependent manners. A multivariate logistic regression revealed that plasma HCV viral loads correlated negatively with LPL lipolytic activity, but positively with the apoC-III content of VLDL. Additionally, apoC-III in VLDL was associated with a higher proportion of HCV-RNA than was IgG.

CONCLUSION

This study reveals that LPL is an anti-HCV factor, and that apoC-III in VLDL and LVPs reduces the LPL-mediated inhibition of HCV infection.

Bezafibrate maintenance therapy in patients with advanced chronic hepatitis C

BACKGROUND

Bezafibrate exerts multiple effects on lipid metabolism by activating the peroxisome proliferator-activated receptor-α, which modulates the expression of key genes of lipid transport, lipoprotein metabolism as well as inflammation. The aim of the present study was to assess the efficacy and safety of bezafibrate in patients with advanced chronic hepatitis C.

MATERIALS AND METHODS

A total of 34 patients received oral bezafibrate treatment (400 mg/day) on the basis of a prospective observational open-label study design. Clinical, biochemical and virological data were evaluated during a mean treatment duration of 19 months. In a subpopulation (n=8), cytokine expression analysis was carried out and compared with an hepatitis C virus treatment-naive control group (n=7).

RESULTS

A significant improvement in aspartate aminotransferase (P=0.007), alanine aminotransferase (P<0.0001), alkaline phosphatase (P=0.001), γ-glutamyltranspeptidase levels (P=0.001) and aspartate aminotransferase-to-platelets ratio index Score (P=0.026) could be found at the end of observation. No significant effect on viral load was observed. Bezafibrate treatment for at least 4 months markedly increased interferon-γ expression compared with the treatment-naive patients (4.81 vs. 1.63 arbitrary units; P=0.005), whereas tumour necrosis factor-α and interleukin-6 levels were not significantly influenced.

CONCLUSION

This observational study provides evidence that bezafibrate is effective for patients with advanced chronic hepatitis C by reducing liver enzymes significantly and should be further evaluated as a potentially beneficial maintenance therapy.

Pioglitazone decreases hepatitis C viral load in overweight, treatment naïve, genotype 4 infected-patients: a pilot study

BACKGROUND

Insulin resistance (IR) is induced by chronic hepatitis C virus (HCV) genotypes 1 and 4 infections. It is not known whether drugs that affect IR such as Pioglitazone and Prednisone also affect serum HCV RNA titers independently of PEG-Interferon-α2/ribavirin treatment. The primary aim was to assess whether Pioglitazone by improving IR and/or inflammation decreases HCV viral load independently of standard of care HCV treatment. A secondary aim was to assess whether Prednisone, a drug that induces insulin resistance and stimulates HCV viral entry and replication in replicon culture systems, increases HCV viral load in this population.

METHODOLOGY/PRINCIPAL FINDINGS

We designed a two-arm, parallel Pilot Study of overweight, treatment naïve genotype 4 HCV-infected patients at a public referral Liver Clinic in Giza, Egypt. The subjects received Pioglitazone (30 mg/day for 14 days) or Prednisone (40 mg/day for 4 days) in a randomized fashion, but the two arms can be considered independent pilot studies. Only changes from baseline within each arm were assessed and no contrasts of the interventions were made, as this was not an aim of the study. Among 105 consecutive HCV genotype 4 patients, 39 were enrolled based on the optimal sample size and power analysis according to the CONSORT statement; 20 to the Pioglitazone group and 19 to the Prednisone group. Pioglitazone was effective in decreasing serum HCV RNA at day-14 (n = 10; difference of means = 205,618 IU/ml; 95% CI 26,600 to 384,600; P<0.001). Although Prednisone did increase serum HCV RNA at day-4 (n = 10; change from baseline = -42,786 IU/ml; 95% CI -85,500 to -15,700; P = 0.049), the log(10) HCV RNA titers were statistically not different from baseline day-0.

CONCLUSION/SIGNIFICANCE

This is the first documentation that Pioglitazone decreases the serum HCV RNA titers independently of PEG-Interferon-α2/ribavirin treatment. The novel findings of our Study provide the foundation for basic and clinical investigations on the molecular mechanisms responsible for the Pioglitazone-induced decrease in HCV genotype 4 RNA titers.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01157975.

Liver disease associated with canalicular transport defects: current and future therapies

Bile formation at the canalicular membrane is a delicate process. This is illustrated by inherited liver diseases due to mutations in ATP8B1, ABCB11, ABCB4, ABCC2 and ABCG5/8, all encoding hepatocanalicular transporters. Effective treatment of these canalicular transport defects is a clinical and scientific challenge that is still ongoing. Current evidence indicates that ursodeoxycholic acid (UDCA) can be effective in selected patients with PFIC3 (ABCB4 deficiency), while rifampicin reduces pruritus in patients with PFIC1 (ATP8B1 deficiency) and PFIC2 (ABCB11 deficiency), and might abort cholestatic episodes in BRIC (mild ATP8B1 or ABCB11 deficiency). Cholestyramine is essential in the treatment of sitosterolemia (ABCG5/8 deficiency). Most patients with PFIC1 and PFIC2 will benefit from partial biliary drainage. Nevertheless liver transplantation is needed in a substantial proportion of these patients, as it is in PFIC3 patients. New developments in the treatment of canalicular transport defects by using nuclear receptors as a target, enhancing the expression of the mutated transporter protein by employing chaperones, or by mutation specific therapy show substantial promise. This review will focus on the therapy that is currently available as well as on those developments that are likely to influence clinical practice in the near future.

Peroxisome proliferator-activated receptors in HCV-related infection

The topic of peroxisome proliferator-activated receptors has been developed in the field of hepatology allowing envisaging therapeutic strategies for the most frequent chronic liver diseases such as chronic infection with hepatitis C virus (HCV). PPARs contribute to wide physiological processes within the liver such as lipid/glucid metabolisms, inflammatory response, cell differentiation, and cell cycle. In vitro experiments and animal studies showed that PPARα discloses anti-inflammatory property, and PPARγ discloses anti-inflammatory, antifibrogenic, and antiproliferative properties in the liver. Experimental and human studies showed impaired PPARs expression and function during HCV infection. The available nonhepatotoxic agonists of PPARs may constitute a progress in the therapeutic management of patients chronically infected with HCV.

[Nuclear receptor PPAR and hepatology: pathophysiological and therapeutical aspects]

In last few years, the topic of nuclear receptor has been developed in the field of hepatology allowing envisaging therapeutic strategies for the most frequent chronic liver diseases. Peroxysome proliferator-activated receptors (PPAR) contribute to wide physiological processes within the liver such as lipid/glucid metabolisms, inflammatory response, cell differenciation and cell cycle. In vitro experiments and animal studies showed that PPARalpha discloses anti-inflammatory property and PPARgamma discloses anti-inflammatory, antifibrogenic and antiproliferative properties in the liver. Main available agonists are fibrates (PPARalpha) used for 20 years in cases of lipid metabolism abnormalities and glitazones (PPARgamma) used since 2000 for type 2 diabetes. In terms of therapy, animal studies and human trials have been conducted in steatopathies. However, clinicians have to be aware of potential specific side effects related to glitazones especially on cardiovascular system.

Inhibition of subgenomic hepatitis C virus RNA in Huh-7 cells: ribavirin induces mutagenesis in HCV RNA

Hepatitis C virus (HCV) infection is a major problem throughout the world. Combination therapy of interferon (IFN) and ribavirin is the best treatment for eradication at present, but the mechanism is not completely understood. We used the HCV replicon system to investigate this mechanism. The effects of six drugs (UDCA, glycyrrhizin, TJ-9, bezafibrate, ribavirin, and alpha-IFN 2b) on HCV subgenomic RNA (genotype 1b, NS5B 415Y) were examined by reverse transcription polymerase chain reaction, cloning and sequencing. The HCV replication was inhibited by alpha-IFN 2b (7.39-13.2% at 10 U/mL, 3.29-6.12% at 100 U/mL, 1.3-4.86% at 1000 U/mL) and by ribavirin (4.36-13.9% at 100 microg/mL), but not by the other drugs at 24-72 h after treatment. Furthermore, the combination treatment was superior to IFN monotherapy and to ribavirin monotherapy at 72 h post-treatment. Sequence analyses of the double-stranded RNA-activated protein kinase (PKR)-binding domain and flanking regions within the HCV NS5A region revealed that the total numbers of substitutions caused by ribavirin (n = 36) or combination treatment (n = 57) were more than those of IFN alone (n = 5) and controls (n = 6). The HCV replicon system is the most efficient system for HCV replication and is an excellent choice for testing anti-HCV drugs and disinfectants. Our results further suggested that the combination of alpha-IFN 2b and ribavirin might induce mutations, and inhibit HCV RNA synthesis in hepatocytes to a greater extent than ribavirin monotherapy.

Inhibition of TNF-alpha-induced RANTES expression in human hepatocyte-derived cells by fibrates, the hypolipidemic drugs

Increased concentrations and activity of plasma cytokines produced by monocytes, macrophages, and hepatocytes in patients with alcoholic liver diseases, correlate with the clinical course of liver diseases and are of prognostic value. Especially, high levels of circulating tumor necrosis factor (TNF)-alpha have been found to correlate with increased mortality in alcoholic hepatitis. Moreover, hepatic RANTES was increased in patients with alcoholic hepatitis. Thus, TNF-alpha-induced RANTES expression may have a critical role in cell-mediated liver injury associated with alcoholic hepatitis. Fibrates are widely used in the treatment of hyperlipidemia and lower triglyceride levels in patients with hyperlipidemia. Recently, several groups reported that bezafibrate, one of fibrates, is effective in primary biliary cirrhosis treatment. Additionally, it is reported that bezafibrate is effective in the treatment not only of primary biliary cirrhosis but also of chronic hepatitis C and tamoxifen-induced non-alcoholic steatohepatitis. We, here, presented that bezafibrate and fenofibrate repressed TNF-alpha-induced protein production and mRNA expression of RANTES in human hepatocyte-derived cells. Luciferase assay showed that bezafibrate and fenofibrate inhibited RANTES gene expression in response to TNF-alpha. Moreover, bezafibrate repressed TNF-alpha-induced DNA-binding activity of NF-kappaB. Thus, fibrates reduced TNF-alpha-induced NF-kappaB activation and RANTES expression, possibly suggesting that fibrates might be inhibitory agents of migration of inflammatory cells by RANTES to the liver in patients with alcoholic liver diseases. In line of these results, it might be possible that fibrates are therapeutic agents in alcoholic liver diseases.