Effects of 1-O-hexyl-2,3,5-trimethylhydroquinone on carbon tetrachloride-induced hepatic cirrhosis in rats

BTT-105 ameliorates hepatic fibrosis in non-alcoholic fatty liver animal model

BTT-105 (1-O-hexyl-2,3,5-trimethylhydroquinone), a hydroquinone derivative, is a potent anti-oxidant that was safe and tolerable in phase I clinical trial. This study examined the anti-fibrotic effect of BTT-105 in a mouse model of non-alcoholic fatty liver disease (NAFLD) along with the underlying mechanisms. In vivo, efficacy of BTT-105 evaluated from three kinds of NAFLD models (methionine/choline deficient diet (MCD), high fat diet (HF) and western diet (WD)). Metabolomics and transcriptomics profiling analysis in liver tissues were conducted. In vitro, anti-fibrotic effect of BTT-105 assessed in human hepatic stellated cells (HSCs) and primary mouse HSCs. BTT-105 improved NAFLD activity score in three kinds of NAFLD animal models (MCD, HF, and WD). BTT-105 also decreased levels of hepatic pro-collagen and collagen fibers deposition in liver tissue. Metabolome and transcriptome analysis revealed that BTT-105 decreased lipid metabolites and increased antioxidants in NAFLD mice. In HepG2 cells, BTT-105 enhanced Nrf2-ARE reporter activity in a dose-dependent manner and increased the levels of antioxidant gene expression. BTT-105 showed inhibition of HSCs activation and migration. Gene expression profiling and protein expression showed that BTT-105 increased Nrf2 activation as well as decreased PI3K-Akt pathway in activated HSCs. BTT-105 attenuated ameliorates steatohepatitis and hepatic fibrosis.

1-O-Hexyl-2,3,5-Trimethylhydroquinone Ameliorates the Development of Preeclampsia through Suppression of Oxidative Stress and Endothelial Cell Apoptosis

1-O-Hexyl-2,3,5-trimethylhydroquinone (HTHQ), a potent nuclear factor-E2-related factor 2 (Nrf2) activator, has potent antioxidant activity by scavenging reactive oxygen species (ROS). However, the role of HTHQ on the development of preeclampsia (PE) and the underlying mechanisms have barely been explored. In the present study, PE model was induced by adenovirus-mediated overexpression of soluble fms-like tyrosine kinase 1 (sFlt-1) in pregnant mice. The results showed that HTHQ treatment significantly relieved the high systolic blood pressure (SBP) and proteinuria and increased the fetal weight and fetal weight/placenta weight in preeclamptic mice. Furthermore, we found that HTHQ treatment significantly decreased soluble endoglin (sEng), endothelin-1 (ET-1), and activin A and restored vascular endothelial growth factor (VEGF) in preeclamptic mice. In addition, HTHQ treatment inhibited oxidative stress and endothelial cell apoptosis by increasing the levels of Nrf2 and its downstream haemoxygenase-1 (HO-1) protein. In line with the data in vivo, we discovered that HTHQ treatment attenuated oxidative stress and cell apoptosis in human umbilical vein endothelial cells (HUVECs) following hypoxia and reperfusion (H/R), and the HTHQ-mediated protection was lost after transfected with siNrf2. In conclusion, these results suggested that HTHQ ameliorates the development of preeclampsia through suppression of oxidative stress and endothelial cell apoptosis.

HX-1171, a Novel Nrf2 Activator, Induces NQO1 and HMOX1 Expression

HX-1171 (1-O-hexyl-2,3,5-trimethylhydroquinone) is a novel synthesized vitamin E derivative, which reportedly has positive effects on various diseases and conditions, such as liver fibrosis, hepatic cirrhosis, and cancer. In this study, we analyzed the transcriptional activity induced by HX-1171. Results from reverse transcription polymerase chain reaction and promoter assays reveal that HX-1171 increased the expression of NQO1 and HMOX1, encoding antioxidant-related enzymes, in A549 human lung epithelial cells. The activity of nuclear factor-E2-related factor (Nrf2), a key transcriptional factor for antioxidative enzymes, was examined in HX-1171-treated cells. Confocal microscopy and Western blotting showed that HX-1171 effectively induced the nuclear translocation and transcriptional activity of Nrf2. We conclude that HX-1171, a novel Nrf2 activator, may be a promising therapeutic agent for oxidative stress-induced diseases. J. Cell. Biochem. 118: 3372-3380, 2017. © 2017 Wiley Periodicals, Inc.

Single and multiple dose pharmacokinetics and tolerability of HX-1171, a novel antioxidant, in healthy volunteers

BACKGROUND

HX-1171 (1-O-hexyl-2,3,5-trimethylhydroquinone) is a promising antioxidant with therapeutic potential for hepatic fibrosis. The aim of this study was to investigate the tolerability and pharmacokinetics of HX-1171 in healthy volunteers.

METHODS

A randomized, single-blind, placebo-controlled, dose escalation study was conducted in 83 subjects. In the single ascending dose study, 20, 40, 80, 160, 300, 600, 1,200, 1,500 or 2,000 mg of HX-1171 was administered to 67 subjects. In the multiple ascending dose study, 500 or 1,000 mg was administered to 16 subjects for 14 days. The plasma and urine concentrations of HX-1171 were determined by using a validated liquid chromatography-mass spectrometry method. Pharmacokinetic parameters were obtained by non-compartmental analysis. Tolerability was assessed based on physical examinations, vital signs, clinical laboratory tests, and electrocardiograms.

RESULTS

Adverse events reported in the study were all mild in intensity and resolved without any sequelae. HX-1171 was rapidly and minimally absorbed with a median time at maximal concentration of 0.63-1.50 hours and slowly eliminated with a terminal half-life of 21.12-40.96 hours. Accumulation index ranged from 2.0 to 2.2 after repeated dosing for 14 days. For both the single and multiple doses administrations, urinary concentrations indicated that less than 0.01% of the HX-1171 administered was excreted in urine.

CONCLUSION

HX-1171 was well tolerated and minimally absorbed in healthy volunteers. The pharmacokinetic profile of HX-1171 was consistent with once-a-day dosing.

Emerging drugs for non-alcoholic steatohepatitis

INTRODUCTION

The prevalence of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) is increasing along with the worldwide epidemic of obesity and their strong association with metabolic syndrome. Currently existing pharmacological therapies include anti-oxidants, insulin-sensitizing agents, lipid-lowering drugs and cytoprotective agents, but there is a lack of consensus regarding the most effective and appropriate pharmacologic therapies for NASH. Clinical trials examining new therapeutic drugs for NASH that act via various mechanisms are being performed in several countries, and these drugs may strongly influence current NASH treatment.

AREAS COVERED

This article provides a review of recent data on the safety and efficacy of existing and emerging agents for the treatment of NASH.

EXPERT OPINION

Ideally, treatment for NASH should not only improve liver disease, but also reduce the risks of adverse cardiovascular outcomes and the development of diabetes and cancers. However, this goal is likely to be too high in the context of clinical trials designed to obtain approval for the treatment of liver disease. The only way to achieve the goal is to accumulate the results of these relatively short-term clinical trials.

Enhanced expression of WD repeat-containing protein 35 (WDR35) stimulated by domoic acid in rat hippocampus: involvement of reactive oxygen species generation and p38 mitogen-activated protein kinase activation

Background

Domoic acid (DA) is an excitatory amino acid analogue of kainic acid (KA) that acts via activation of glutamate receptors to elicit a rapid and potent excitotoxic response, resulting in neuronal cell death. Recently, DA was shown to elicit reactive oxygen species (ROS) production and induce apoptosis accompanied by activation of p38 mitogen-activated protein kinase (MAPK) in vitro. We have reported that WDR35, a WD-repeat protein, may mediate apoptosis in several animal models. In the present study, we administered DA to rats intraperitoneally, then used liquid chromatography/ion trap tandem mass spectrometry (LC-MS/MS) to identify and quantify DA in the brains of the rats and performed histological examinations of the hippocampus. We further investigated the potential involvement of glutamate receptors, ROS, p38 MAPK, and WDR35 in DA-induced toxicity in vivo.

Results

Our results showed that intraperitoneally administered DA was present in the brain and induced neurodegenerative changes including apoptosis in the CA1 region of the hippocampus. DA also increased the expression of WDR35 mRNA and protein in a dose- and time-dependent manner in the hippocampus. In experiments using glutamate receptor antagonists, the AMPA/KA receptor antagonist NBQX significantly attenuated the DA-induced increase in WDR35 protein expression, but the NMDA receptor antagonist MK-801 did not. In addition, the radical scavenger edaravone significantly attenuated the DA-induced increase in WDR35 protein expression. Furthermore, NBQX and edaravone significantly attenuated the DA-induced increase in p38 MAPK phosphorylation.

Conclusion

In summary, our results indicated that DA activated AMPA/KA receptors and induced ROS production and p38 MAPK phosphorylation, resulting in an increase in the expression of WDR35 in vivo.

Lipid-lowering agents in nonalcoholic fatty liver disease and steatohepatitis: human studies

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease which refers to the presence of hepatic steatosis without significant intake of alcohol. NAFLD is an asymptomatic disease that can progress to nonalcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and hepatocellular carcinoma. NAFLD is currently the most common cause of incidental abnormal liver tests and elevated serum liver enzyme activities in the developed world. Obesity, diabetes, and other components of the metabolic syndrome are frequently associated with the NAFLD. The treatment of NAFLD focuses on life-style modifications. Statins, fibrates, and other lipid-lowering agents have been proposed as effective lipid-lowering treatments in patients with NAFLD/NASH. However, clinicians are concerned that hyperlipidemic patients with NAFLD/NASH who are treated with statins could develop transaminitis. We assessed the efficacy and safety of lipid-lowering agents for NAFLD/NASH by reviewing reports of human studies including pilot, prospective, preliminary, and post hoc analysis studies on online databases during the period of 1980 to December 2012. The results of studies provide compelling evidence that lipid-lowering agents are safe and efficacious in patients with NAFLD/NASH and that some of these agents can induce a reduction in the extent of the hepatic steatosis. Well-designed randomized controlled studies of adequate size and duration with histological endpoints are needed in order to establish a suitable lipid-lowering treatment for hyperlipidemic patients with NAFLD/NASH, and for nonhyperlipidemic patients with NAFLD/NASH with a high risk for cardiovascular disease.

Statin-based treatment for cardiovascular risk and non-alcoholic fatty liver disease. Killing two birds with one stone?

Cardiovascular disease (CVD) and non-alcoholic fatty liver disease (NAFLD) share common risk factors and may have a parallel course. Statin treatment alone or in combination with other drugs has a substantially beneficial effect on CVD morbidity and mortality. The question was if these regimens were harmful for the liver. Mounting data suggest that statin monotherapy or statin-based treatments are safe in patients with NAFLD and can improve liver tests and liver ultrasonographic evidence of NAFLD. Recent data suggest that statin-based therapies are beneficial to the liver and at the same time reduce CVD morbidity and mortality in patients with NAFLD more than in subjects without it. These findings suggest that with statins we are able to get two birds with one stone.

Organelle dysfunction in hepatitis C virus-associated steatosis: anything to learn from nonalcoholic steatohepatitis?

Nonalcoholic fatty liver disease (NAFLD) spans a pathological spectrum from nonalcoholic steatosis to steatohepatitis. The pathophysiology of this disorder is complex, but includes insulin resistance and disrupted lipid and carbohydrate homeostasis, which at a subcellular level results in oxidative stress, free fatty acid-mediated lipotoxicity, defects in mitochondrial function, endoplasmic reticulum stress and cytokine-mediated toxicity. In chronic hepatitis C (CHC), systemic metabolic derangements similar to NAFLD may be operative, but in addition, virus-specific factors contribute to steatosis. The mechanisms for steatosis in CHC appear to share common pathways with those observed in NAFLD. This article outlines our current understanding of the subcellular mechanisms of steatosis in NAFLD and CHC, including their similarities and differences.

Enhanced expression of naofen in kidney of streptozotocin-induced diabetic rats: possible correlation to apoptosis of tubular epithelial cells

BACKGROUND

Hyperglycemia/high glucose may induce apoptosis in diabetic kidney, but the mechanism is not fully understood. Naofen was found as a Shiga toxin (Stx)-2-related protein. Based on renal dysfunction in infection with Stx-producing Escherichia coli and on participation of naofen in apoptosis of human embryonic kidney cells, the present study was undertaken to investigate the mechanism of renal dysfunction in diabetes mellitus with particular reference to naofen.

METHODS

In in vivo studies utilizing streptozotocin (STZ)-induced diabetic rats, and also in in vitro cultured rat kidney epithelial (NRK52E) cells, naofen messenger RNA (mRNA) and protein expressions were analyzed. Naofen mRNA location in diabetic kidney was studied by in situ hybridization. Apoptosis was assessed by caspase-3 activity assay.

RESULTS

Rat diabetic kidney showed significant increases in caspase-3 activities and naofen mRNA. Naofen was mainly observed at both proximal and distal urinary tubules. Incubation of NRK52E cells in high glucose medium resulted in elevated naofen mRNA expression, whereas neither interleukin-1, interleukin-6, nor tumor necrosis factor-alpha elicited such action. Moreover, treatment of NRK52E cells with naofen small interfering RNA (siRNA) inhibited naofen mRNA expression induced by high glucose and blocked the increase in caspase-3 activity.

CONCLUSIONS

These data suggest that naofen expression may be upregulated by hyperglycemia, with possible correlation to apoptosis of tubular epithelial cells and thereby to diabetic nephropathy.