Coenzyme Q metabolism is disturbed in high fat diet-induced non-alcoholic fatty liver disease in rats

The Effect of Adjuvant Therapy with Molecular Hydrogen on Endogenous Coenzyme Q10 Levels and Platelet Mitochondrial Bioenergetics in Patients with Non-Alcoholic Fatty Liver Disease

Molecular hydrogen (H2) has been recognized as a novel medical gas with antioxidant and anti-inflammatory effects. Non-alcoholic fatty liver disease (NAFLD) is a liver pathology with increased fat accumulation in liver tissue caused by factors other than alcohol consumption. Platelet mitochondrial function is considered to reflect systemic mitochondrial health. We studied the effect of adjuvant therapy with hydrogen-rich water (HRW) on coenzyme Q10 (CoQ10) content and platelet mitochondrial bioenergetics in patients with NAFLD. A total of 30 patients with NAFLD and 15 healthy volunteers were included in this clinical trial. A total of 17 patients (H2 group) drank water three × 330 mL/day with tablets producing HRW (>4 mg/L H2) for 8 weeks, and 13 patients (P group) drank water with placebo tablets producing CO2. The concentration of CoQ10-TOTAL was determined by the HPLC method, the parameter of oxidative stress, thiobarbituric acid reactive substances (TBARS), by the spectrophotometric method, and mitochondrial bioenergetics in platelets isolated from whole blood by high-resolution respirometry. The patients with NAFLD had lower concentrations of CoQ10-TOTAL in the blood, plasma, and platelets vs. the control group. Mitochondrial CI-linked LEAK respiration was higher, and CI-linked oxidative phosphorylation (OXPHOS) and CII-linked electron transfer (ET) capacities were lower vs. the control group. Plasma TBARS concentrations were higher in the H2 group. After 8 weeks of adjuvant therapy with HRW, the concentration of CoQ10 in platelets increased, plasma TBARS decreased, and the efficiency of OXPHOS improved, while in the P group, the changes were non-significant. Long-term supplementation with HRW could be a promising strategy for the acceleration of health recovery in patients with NAFLD. The application of H2 appears to be a new treatment strategy for targeted therapy of mitochondrial disorders. Additional and longer-term studies are needed to confirm and elucidate the exact mechanisms of the mitochondria-targeted effects of H2 therapy in patients with NAFLD.

Microarray and qPCR Analysis of Mitochondrial Metabolism Activation during Prenatal and Early Postnatal Development in Rats and Humans with Emphasis on CoQ10 Biosynthesis

At the end of the mammalian intra-uterine foetal development, a rapid switch from glycolytic to oxidative metabolism must proceed. Using microarray techniques, qPCR, enzyme activities and coenzyme Q content measurements, we describe perinatal mitochondrial metabolism acceleration in rat liver and skeletal muscle during the perinatal period and correlate the results with those in humans. Out of 1546 mitochondrial genes, we found significant changes in expression in 1119 and 827 genes in rat liver and skeletal muscle, respectively. The most remarkable expression shift occurred in the rat liver at least two days before birth. Coenzyme Q-based evaluation in both the rat model and human tissues showed the same trend: the total CoQ content is low prenatally, significantly increasing after birth in both the liver and skeletal muscle. We propose that an important regulator of rat coenzyme Q biosynthesis might be COQ8A, an atypical kinase involved in the biosynthesis of coenzyme Q. Our microarray data, a total of 16,557 RefSeq (Entrez) genes, have been deposited in NCBI's Gene Expression Omnibus and are freely available to the broad scientific community. Our microarray data could serve as a suitable background for finding key factors regulating mitochondrial metabolism and the preparation of the foetus for the transition to extra-uterine conditions.

Hepatic steatosis integrated approach: nutritional guidelines and joined nutraceutical administration

BACKGROUND

The nonalcoholic fat liver disease (NAFLD) progresses in 30% of the patients to not alcoholic steatohepatitis (NASH) and subsequently in liver fibrosis and even primary cancer and death. Due to the complex physiopathology of the liver steatosis, NASH is an area orphan of specific drugs, but many authors suggest an integrated treatment based upon diet, lifestyle change, and pharmacology.

METHODS

Our clinical study selected from a wider patient cohort, 13 subjects, appealing to the Second Opinion Medical Consulting Network, for liver and nutritional problems. The diet was integrated with regular prescription of an herbal derivative based on Chrysanthellum americanum and Pistacia lentiscus L. extracts. Clinical data of the recruited patients including body weight, Body Mass Index, were recorded before and after treatment. Each patient underwent pre-post accurate clinical examination and lab exams. The liver stiffness and liver steatosis were evaluated by a trained hepatologist with FibroScan^®.

RESULTS

A significant reduction of anthropometric parameters was detected in all the patients at the end of the study; liver fibrosis and steatosis were instrumentally decreased in 8 subjects, but not significant changes in lab exams and no adverse effects were reported.

CONCLUSIONS

Chrysanthellum americanum and Pistacia lentiscus L. extracts were absolutely safe and effective and gave a substantial contribution to the life quality benefit, metabolic balance and gut function in patients with hepatic steatosis.

Resveratrol Regulates the Expression of Genes Involved in CoQ Synthesis in Liver in Mice Fed with High Fat Diet

Resveratrol (RSV) is a bioactive natural molecule that induces antioxidant activity and increases protection against oxidative damage. RSV could be used to mitigate damages associated to metabolic diseases and aging. Particularly, RSV regulates different aspects of mitochondrial metabolism. However, no information is available about the effects of RSV on Coenzyme Q (CoQ), a central component in the mitochondrial electron transport chain. Here, we report for the first time that RSV modulates COQ genes and parameters associated to metabolic syndrome in mice. Mice fed with high fat diet (HFD) presented a higher weight gain, triglycerides (TGs) and cholesterol levels while RSV reverted TGs to control level but not weight or cholesterol. HFD induced a decrease of COQs gene mRNA level, whereas RSV reversed this decrease in most of the COQs genes. However, RSV did not show effect on CoQ₉, CoQ₁₀ and total CoQ levels, neither in CoQ-dependent antioxidant enzymes. HFD influenced mitochondrial dynamics and mitophagy markers. RSV modulated the levels of PINK1 and PARKIN and their ratio, indicating modulation of mitophagy. In summary, we report that RSV influences some of the metabolic adaptations of HFD affecting mitochondrial physiology while also regulates COQs gene expression levels in a process that can be associated with mitochondrial dynamics and turnover.

Hepatitis B virus infection is not associated with fatty liver disease: Evidence from a cohort study and functional analysis

Chronic hepatitis B virus (HBV) infection has been reported to be associated with the prevalence of non-alcoholic fatty liver disease (NAFLD). However, the present study demonstrated that the incidence of fatty liver disease in HBV-infected subjects (16/152, 10.5%) was not significantly different from in non-HBV-infected subjects (292/1,714, 17%), following adjustment for age (odds ratio=0.656; 95% confidence interval=0.379–1.134; P=0.131). Hepatitis B protein X (HBx) is considered a key regulator in HBV infection and several studies have confirmed that HBx serves a pivotal role in the process of fatty liver disease. In the present study, it was demonstrated that HBx-expressing cells exhibited increased mitochondrial membrane potential, ATP generation, and endogenous mitochondrial respiration. In addition, higher levels of mitochondrial reactive oxygen species (ROS) were detected in HBx-expressing cells compared with in control cells. Increased ROS production may contribute to increased lipid droplet formation in HBx-expressing cells, whereas the removal of ROS with N-acetylcysteine may decrease the accumulation of lipid droplets in a time-dependent manner. In conclusion, the present findings indicated that HBV, and perhaps more specifically HBx, was not a protective factor against NAFLD. HBx may function as a risk factor for fatty liver disease, based on the findings of the present functional study; however, further studies are required to clarify the effects of HBx on hepatic steatosis.

Potential Therapeutic Benefits of Herbs and Supplements in Patients with NAFLD

Our aim is to review the efficacy of various herbs and supplements as a possible therapeutic option in the treatment and/or prevention of nonalcoholic fatty liver disease (NAFLD). We performed a systematic review of medical literature using the PubMed Database by searching the chemical names of many common herbs and supplements with “AND (NAFLD or NASH)”. Studies and medical literature that discussed the roles and usage of herbs and supplements in NAFLD and nonalcoholic steatohepatitis (NASH) from inception until 20 June 2018 were reviewed. Many studies have claimed that the use of various herbs and supplements may improve disease endpoints and outcomes related to NAFLD and/or NASH. Improvement in liver function tests were noted. Amelioration or reduction of lobular inflammation, hepatic steatosis, and fibrosis were also noted. However, well-designed studies demonstrating improved clinical outcomes are lacking. Furthermore, experts remain concerned about the lack of regulation of herbs/supplements and the need for further research on potential adverse effects and herb–drug interactions. In conclusion, preliminary data on several herbs have demonstrated promising antioxidant, anti-inflammatory, anti-apoptotic, and anti-adipogenic properties that may help curtail the progression of NAFLD/NASH. Clinical trials testing the safety and efficacy must be completed before widespread use can be recommended.

Oxidative Stress as a Critical Factor in Nonalcoholic Fatty Liver Disease Pathogenesis

SIGNIFICANCE

Nonalcoholic fatty liver disease (NAFLD), characterized by liver triacylglycerol build-up, has been growing in the global world in concert with the raised prevalence of cardiometabolic disorders, including obesity, diabetes, and hyperlipemia. Redox imbalance has been suggested to be highly relevant to NAFLD pathogenesis. Recent Advances: As a major health problem, NAFLD progresses to the more severe nonalcoholic steatohepatitis (NASH) condition and predisposes susceptible individuals to liver and cardiovascular disease. Although NAFLD represents the predominant cause of chronic liver disorders, the mechanisms of its development and progression remain incompletely understood, even if various scientific groups ascribed them to the occurrence of insulin resistance, dyslipidemia, inflammation, and apoptosis. Nevertheless, oxidative stress (OxS) more and more appears as the most important pathological event during NAFLD development and the hallmark between simple steatosis and NASH manifestation.

CRITICAL ISSUES

The purpose of this article is to summarize recent developments in the understanding of NAFLD, essentially focusing on OxS as a major pathogenetic mechanism. Various attempts to translate reactive oxygen species (ROS) scavenging by antioxidants into experimental and clinical studies have yielded mostly encouraging results.

FUTURE DIRECTIONS

Although augmented concentrations of ROS and faulty antioxidant defense have been associated to NAFLD and related complications, mechanisms of action and proofs of principle should be highlighted to support the causative role of OxS and to translate its concept into the clinic. Antioxid. Redox Signal. 26, 519-541.

Molecular Pathogenesis of NASH

Nonalcoholic steatohepatitis (NASH) is the main cause of chronic liver disease in the Western world and a major health problem, owing to its close association with obesity, diabetes, and the metabolic syndrome. NASH progression results from numerous events originating within the liver, as well as from signals derived from the adipose tissue and the gastrointestinal tract. In a fraction of NASH patients, disease may progress, eventually leading to advanced fibrosis, cirrhosis and hepatocellular carcinoma. Understanding the mechanisms leading to NASH and its evolution to cirrhosis is critical to identifying effective approaches for the treatment of this condition. In this review, we focus on some of the most recent data reported on the pathogenesis of NASH and its fibrogenic progression, highlighting potential targets for treatment or identification of biomarkers of disease progression.

The Emerging Role of Disturbed CoQ Metabolism in Nonalcoholic Fatty Liver Disease Development and Progression

Although non-alcoholic fatty liver disease (NAFLD), characterised by the accumulation of triacylglycerol in the liver, is the most common liver disorder, the causes of its development and progression to the more serious non-alcoholic steatohepatitis (NASH) remain incompletely understood. Oxidative stress has been implicated as a key factor in both these processes, and mitochondrial dysfunction and inflammation are also believed to play a part. Coenzyme Q (CoQ) is a powerful antioxidant found in all cell membranes which has an essential role in mitochondrial respiration and also has anti-inflammatory properties. NAFLD has been shown to be associated with disturbances in plasma and liver CoQ concentrations, but the relationship between these changes and disease development and progression is not yet clear. Dietary supplementation with CoQ has been found to be hepatoprotective and to reduce oxidative stress and inflammation as well as improving mitochondrial dysfunction, suggesting that it may be beneficial in NAFLD. However, studies using animal models or patients with NAFLD have given inconclusive results. Overall, evidence is now emerging to indicate that disturbances in CoQ metabolism are involved in NAFLD development and progression to NASH, and this highlights the need for further studies with human subjects to fully clarify its role.

Functions of Coenzyme Q10 Supplementation on Liver Enzymes, Markers of Systemic Inflammation, and Adipokines in Patients Affected by Nonalcoholic Fatty Liver Disease: A Double-Blind, Placebo-Controlled, Randomized Clinical Trial

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disorder related to inflammation. Coenzyme Q10 (CoQ10) is a natural compound that has recently been considered as an anti-inflammatory factor. In the current study we aimed to evaluate the effects of CoQ10 supplementation on liver enzymes, inflammation status, and adipokines in patients with NAFLD.

METHODS

Forty-one subjects with NAFLD participated in the current randomized, double-blind, placebo-controlled trial. The participants were randomly divided into 2 groups: one group received CoQ10 capsules (100 mg once a day) and the other received placebo for 12 weeks. Blood samples of each patient were taken before and after the 12-week intervention period for measurement of liver aminotransferases, inflammatory biomarkers, and adipokines (adiponectin and leptin).

RESULTS

Taking 100 mg CoQ10 supplement daily resulted in a significant decrease in liver aminotransferases (aspartate aminotransferase [AST] and gamma-glutamyl transpeptidase [GGT]), high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor α, and the grades of NAFLD in the CoQ10 group in comparison to the control group (p < 0.05). In addition, patients who received CoQ10 supplement had higher serum levels of adiponectin (p = 0.016) and considerable changes in serum leptin (p = 0.053). However, no significant changes occurred in serum levels of interleukin-6 in both groups.

CONCLUSION

The present study suggested that CoQ10 supplement at a dosage of 100 mg could be effective for improving the systemic inflammation and biochemical variables in NAFLD.

Oral coenzyme Q10 supplementation in patients with nonalcoholic fatty liver disease: effects on serum vaspin, chemerin, pentraxin 3, insulin resistance and oxidative stress

BACKGROUNDS AND AIMS

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver injury. Chronic exposure to oxidative stress leads to depletion of liver antioxidants and abnormal cytokine production; antioxidant therapy is one of the main therapeutic lines in NAFLD. In the current study we aimed to investigate the effect of coenzyme Q10 (coQ10) therapy on several adipocytokines and insulin resistance in patients with NAFLD.

METHODS

In the current randomized double-blind placebo controlled trial 44 NAFLD patients were enrolled. After randomization into two groups, 22 patients received 100 mg/day coQ10 capsules and 22 patients received placebo daily for 4 weeks. BMI and WHR were calculated for patients at the beginning and end of the study and blood samples were obtained from the patients to measure serum concentrations of aspartate aminotransferase (AST), alanine aminotransferase (ALT), fasting serum glucose (FSG), insulin resistance (IR), vaspin, chemerin, pentraxin 3 (PTX3) and markers of oxidative stress including total antioxidant capacity (TAC) and malondialdehyde (MDA).

RESULTS

After 4 weeks of coQ10 supplementation, waist circumference (WC) and serum AST and TAC concentrations significantly decreased in intervention group (p <0.05) but no significant changes occurred in placebo-treated group. In stepwise multivariate linear regression model, change in serum FSG was a significant predictor of changes in serum vaspin, chemerin and pentraxin 3 (p <0.001).

CONCLUSIONS

The present study showed a potential for coQ10 therapy in improving several anthropometric and biochemical variables in NAFLD. Longer studies with higher doses of coQ10 are required to further evaluate this potential benefit.