Effects of coenzyme q10 supplementation on serum lipoproteins, plasma fibrinogen, and blood pressure in patients with hyperlipidemia and myocardial infarction

The Role of Antioxidants in the Therapy of Cardiovascular Diseases-A Literature Review

Antioxidants are endogenous and exogenous substances with the ability to inhibit oxidation processes by interacting with reactive oxygen species (ROS). ROS, in turn, are small, highly reactive substances capable of oxidizing a wide range of molecules in the human body, including nucleic acids, proteins, lipids, carbohydrates, and even small inorganic compounds. The overproduction of ROS leads to oxidative stress, which constitutes a significant factor contributing to the development of disease, not only markedly diminishing the quality of life but also representing the most common cause of death in developed countries, namely, cardiovascular disease (CVD). The aim of this review is to demonstrate the effect of selected antioxidants, such as coenzyme Q10 (CoQ10), flavonoids, carotenoids, and resveratrol, as well as to introduce new antioxidant therapies utilizing miRNA and nanoparticles, in reducing the incidence and progression of CVD. In addition, new antioxidant therapies in the context of the aforementioned diseases will be considered. This review emphasizes the pleiotropic effects and benefits stemming from the presence of the mentioned substances in the organism, leading to an overall reduction in cardiovascular risk, including coronary heart disease, dyslipidaemia, hypertension, atherosclerosis, and myocardial hypertrophy.

Coenzyme Q10: A Key Antioxidant in the Management of Diabetes-Induced Cardiovascular Complications-An Overview of Mechanisms and Clinical Evidence

Background

Diabetes mellitus (DM) presents a significant global health challenge with considerable cardiovascular implications. Coenzyme Q10 (CoQ10) has gained recognition for its potential as a natural antioxidant supplement in the management of diabetes and its associated cardiovascular complications.

Aim

This comprehensive review systematically examines the scientific rationale underlying the therapeutic properties of CoQ10 in mitigating the impact of diabetes and its cardiovascular consequences. The analysis encompasses preclinical trials (in vitro and in vivo) and clinical studies evaluating the efficacy and mechanisms of action of CoQ10. Result & Discussion. Findings reveal that CoQ10, through its potent antioxidant and anti-inflammatory attributes, demonstrates significant potential in reducing oxidative stress, ameliorating lipid profiles, and regulating blood pressure, which are crucial aspects in managing diabetes-induced cardiovascular complications. CoQ10, chemically represented as C59H90O4, was administered in capsule form for human studies at doses of 50, 100, 150, 200, and 300 mg per day and at concentrations of 10 and 20 μM in sterile powder for experimental investigations and 10 mg/kg in powder for mouse studies, according to the published research. Clinical trials corroborate these preclinical findings, demonstrating improved glycemic control, lipid profiles, and blood pressure in patients supplemented with CoQ10.

Conclusion

In conclusion, CoQ10 emerges as a promising natural therapeutic intervention for the comprehensive management of diabetes and its associated cardiovascular complications. Its multifaceted impacts on the Nrf2/Keap1/ARE pathway, oxidative stress, and metabolic regulation highlight its potential as an adjunct in the treatment of diabetes and related cardiovascular disorders. However, further extensive clinical investigations are necessary to fully establish its therapeutic potential and assess potential synergistic effects with other compounds.

Swimming improves platelet dysfunction in mice fed with a high-fat diet

BACKGROUND

We investigated the effects and mechanism of swimming on platelet function in mice fed with a high-fat diet.

MATERIAL AND METHODS

Mice were randomly divided into the control group (NC), high-fat group (HF), and high-fat diet combined with swimming group (FE). The FE group swam for 60 min a day, 5 days a week, for 8 weeks.

RESULTS

Compared with the NC group, the HF group had significant weight gain, dyslipidemia, abbreviated bleeding time after tail breakage, increased clot retraction, increased platelet aggregation rate, increased spread of platelets on fibrinogen, and increased pAKT level in platelets. Compared with the HF group, the FE group had lower body weight, improved dyslipidemia, prolonged bleeding time, reduced clot retraction, reduced platelet aggregation rate, decreased spread of platelets on fibrinogen, and decreased pAKT level in platelets.

CONCLUSIONS

By inhibiting the level of pAKT in platelets, swimming improves platelet dysfunction in mice fed with a high-fat diet.

Dose-Response Effect of Coenzyme Q10 Supplementation on Blood Pressure among Patients with Cardiometabolic Disorders: A Grading of Recommendations Assessment, Development, and Evaluation (GRADE)-Assessed Systematic Review and Meta-Analysis of Randomized Controlled Trials

Previous studies have shown beneficial effects of coenzyme Q10 (CoQ10) supplementation on blood pressure (BP). However, the optimal intake of CoQ10 for BP regulation in patients with cardiometabolic disorders is unknown, and its effect on circulating CoQ10 is also unclear. We aimed to assess the dose-response relation between CoQ10 and BP, and quantify the effect of CoQ10 supplementation on the concentration of circulating CoQ10 by synthesizing available evidence from randomized controlled trials (RCTs). A comprehensive literature search was performed in 3 databases (PubMed/MEDLINE, Embase, and Cochrane Library) to 21 March, 2022. A novel 1-stage restricted cubic spline regression model was used to evaluate the nonlinear dose-response relation between CoQ10 and BP. Twenty-six studies comprising 1831 subjects were included in our meta-analysis. CoQ10 supplementation significantly reduced systolic blood pressure (SBP) (-4.77 mmHg, 95% CI: -6.57, -2.97) in patients with cardiometabolic diseases; this reduction was accompanied by a 1.62 (95% CI: 1.26, 1.97) μg/mL elevation of circulating CoQ10 compared with the control group. Subgroup analyses revealed that the effects of reducing SBP were more pronounced in patients with diabetes and dyslipidemia and in studies with longer durations (>12 wk). Importantly, a U-shaped dose-response relation was observed between CoQ10 supplementation and SBP level, with an approximate dose of 100-200 mg/d largely reducing SBP (χ2 = 10.84, Pnonlinearity = 0.004). The quality of evidence was rated as moderate, low, and very low for SBP, diastolic blood pressure (DBP), and circulating CoQ10 according to the Grading of Recommendations, Assessment, Development, and Evaluation approach (GRADE), respectively. The current finding demonstrated that the clinically beneficial effects of CoQ10 supplementation may be attributed to the reduction in SBP, and 100-200 mg/d of CoQ10 supplementation may achieve the greatest benefit on SBP in patients with cardiometabolic diseases. This study was registered on PROSPERO as CRD42021252933.

Coenzyme Q10 as Adjunctive Therapy for Cardiovascular Disease and Hypertension: A Systematic Review

BACKGROUND

Mitochondrial ATP production requires a small electron carrier, coenzyme Q10 (CoQ10), which has been used as adjunctive therapy in patients with cardiovascular disease (CVD) and hypertension (HTN) because of its bioenergetics and antioxidant properties. Randomized controlled trials (RCTs) beyond the last 2 decades evaluating CoQ10 added to conventional therapy resulted in mixed results and were underpowered to address major clinical endpoints.

OBJECTIVES

The objective of this systematic review was to examine the impact of CoQ10 supplementation on older adults with CVD or HTN in the last 2 decades (2000-2020).

METHODS

PubMed/Medline, Cochrane Database, CINAHL, and Google Scholar databases were searched systematically, and references from selected studies were manually reviewed, to identify RCTs or crossover studies evaluating the efficacy of CoQ10 supplementation. Data extracted from selected studies included trial design and duration, treatment, dose, participant characteristics, study variables, and important findings.

RESULTS

A total of 14 studies (1067 participants) met the inclusion criteria. The effect of CoQ10 supplementation was examined among predominantly older adult males with heart failure (HF) (n = 6), HTN (n = 4), and ischemic heart disease (n = 3), and preoperatively in patients scheduled for cardiac surgery (n = 1). CoQ10 supplementation in patients with HF improved functional capacity, increased serum CoQ10 concentrations, and led to fewer major adverse cardiovascular events. CoQ10 had positive quantifiable effects on inflammatory markers in patients with ischemic heart disease. Myocardial hemodynamics improved in patients who received CoQ10 supplementation before cardiac surgery. Effects on HTN were inconclusive.

CONCLUSIONS

In predominantly older adult males with CVD or HTN, CoQ10 supplementation added to conventional therapy is safe and offers benefits clinically and at the cellular level. However, results of the trials need to be viewed with caution, and further studies are indicated before widespread usage of CoQ10 is recommended in all older adults.

Coenzyme Q10 supplementation for the treatment of statin-associated muscle symptoms

Aim: To determine the association of coenzyme Q10 (CoQ10) use with the resolution of statin-associated muscle symptoms (SAMS). Patients & methods: Retrospective analysis of a large, multicenter survey study of SAMS (total n = 511; n = 64 CoQ10 users). Univariate and multivariate logistic regression models assessed the association between CoQ10 use and the resolution of SAMS. Results: The frequency of SAMS resolution was similar between CoQ10 users and non-users (25% vs 31%, respectively; unadjusted odds ratio [OR]: 0.75 [95% CI: 0.41-1.38]; p = 0.357). Similarly, CoQ10 use was not significantly associated with the resolution of SAMS in multivariable models adjusted for SAMS risk factors (OR: 0.84 [95% CI: 0.45-1.55]; p = 0.568) or adjusted for significant differences among CoQ10 users and non-users (OR: 0.82 [95% CI: 0.45-1.51]; p = 0.522). Conclusion: CoQ10 was not significantly associated with the resolution of SAMS.

Coenzyme Q10 and Cardiovascular Diseases

Coenzyme Q₁₀ (CoQ₁₀), which plays a key role in the electron transport chain by providing an adequate, efficient supply of energy, has another relevant function as an antioxidant, acting in mitochondria, other cell compartments, and plasma lipoproteins. CoQ₁₀ deficiency is present in chronic and age-related diseases. In particular, in cardiovascular diseases (CVDs), there is a reduced bioavailability of CoQ₁₀ since statins, one of the most common lipid-lowering drugs, inhibit the common pathway shared by CoQ₁₀ endogenous biosynthesis and cholesterol biosynthesis. Different clinical trials have analyzed the effect of CoQ₁₀ supplementation as a treatment to ameliorate these deficiencies in the context of CVDs. In this review, we focus on recent advances in CoQ₁₀ supplementation and the clinical implications in the reduction of cardiovascular risk factors (such as lipid and lipoprotein levels, blood pressure, or endothelial function) as well as in a therapeutic approach for the reduction of the clinical complications of CVD.

Effects of coenzyme Q10 on health-related quality of life, clinical disease activity and blood pressure in patients with mild to moderate ulcerative colitis: a randomized clinical trial

Background: Ulcerative colitis (UC) is specified by a chronic mucosal inflammation that has a deleterious impact on the quality of life (QoL). Coenzyme Q10 (CoQ10) appears to influence disease activity by its obvious properties. Therefore, the current research intends to assess the impacts of CoQ10 on QoL, disease activity, and blood pressure in UC patients. Methods: This clinical trial performed on men and women with UC in 2017 who were attended the gastrointestinal center of Hazrat Rasool Akram Hospital and private clinic. Eighty-eight UC patients were randomly allocated to receive either CoQ10 (200 mg/day) or placebo for 8 weeks. The anthropometric parameters, blood pressure, inflammatory bowel disease questionnaire-32 (IBDQ-32) score, and the Simple Clinical Colitis Activity Index (SCCAI) score were measured pre and post-intervention. P-value <0.05 was considered to be statistically significant. All statistical analysis was done using SPSS software version 24. Results: Eighty-six UC patients (44 males) with a mean age of 39.29 (10.19) years completed the trial. The results of between- and within-group analysis revealed that the SCCAI score (p<0.001 and p<0.001, respectively), diastolic blood pressure (p=0.025 and p=0.001, respectively), and systolic blood pressure (p=0.001 and p<0.001, respectively) decremented significantly; while, the mean IBDQ-32 (p<0.001 and p=0.001, respectively) increased substantially in the CoQ10 group; whereas there was no significant difference in anthropometric indices in both groups. Conclusion: Findings suggest that CoQ10 can be used as a potential intervention for diminishing the disease severity and blood pressure and may improve QoL and UC patients. IRCT number: IRCT20090822002365N17.

Targeted Treatment of Age-Related Fibromyalgia with Supplemental Coenzyme Q10

Fibromyalgia is a common chronic pain condition of unknown aetiology, although mitochondrial dysfunction, oxidative stress, and inflammation have been implicated in the pathophysiology of this disorder. Treatment generally involves physiotherapy, anticonvulsants, and antidepressant therapy; however, the symptomatic relief conferred by these treatments can be very variable, and there is a need for additional therapeutic strategies. One such treatment which is gaining a lot of interest is the use of coenzyme Q10 (CoQ10) supplementation. The therapeutic efficacy associated with CoQ10 supplementation is thought to arise from the ability of supplementation to restore an underlying deficit in CoQ10 status which has been associated with fibromyalgia together with the ability of CoQ10 to improve mitochondrial activity, restore cellular antioxidant capacity, and ameliorate inflammation. This chapter outlines the evidence supporting the therapeutic utility of CoQ10 in the treatment of fibromyalgia.

Coenzyme Q10 Supplementation for the Reduction of Oxidative Stress: Clinical Implications in the Treatment of Chronic Diseases

Apart from its main function in the mitochondria as a key element in electron transport, Coenzyme Q₁₀ (CoQ₁₀) has been described as having multiple functions, such as oxidant action in the generation of signals and the control of membrane structure and phospholipid and cellular redox status. Among these, the most relevant and most frequently studied function is the potent antioxidant capability of its coexistent redox forms. Different clinical trials have investigated the effect of CoQ₁₀ supplementation and its ability to reduce oxidative stress. In this review, we focused on recent advances in CoQ₁₀ supplementation, its role as an antioxidant, and the clinical implications that this entails in the treatment of chronic diseases, in particular cardiovascular diseases, kidney disease, chronic obstructive pulmonary disease, non-alcoholic fatty liver disease, and neurodegenerative diseases. As an antioxidant, CoQ₁₀ has proved to be of potential use as a treatment in diseases in which oxidative stress is a hallmark, and beneficial effects of CoQ₁₀ have been reported in the treatment of chronic diseases. However, it is crucial to reach a consensus on the optimal dose and the use of different formulations, which vary from ubiquinol or ubiquinone Ubisol-Q₁₀ or Qter^®, to new analogues such as MitoQ, before we can draw a clear conclusion about its clinical use. In addition, a major effort must be made to demonstrate its beneficial effects in clinical trials, with a view to making the implementation of CoQ₁₀ possible in clinical practice.

The effects of coenzyme Q10 supplement on blood lipid indices and hepatic antioxidant defense system in SD rats fed a high cholesterol diet

A total of 24 SD rats were allotted to four treatment groups such as the control (CON), 1% of cholesterol diet (CHO), 0.5% of coenzyme Q₁₀ (COQ) and 1% of cholesterol plus 0.5% of coenzyme Q₁₀ (CHCQ) groups to determine the effects of coenzyme Q₁₀ (CoQ₁₀) on the antioxidant defense system in rats. The body weight, weight gain, liver weight and abdominal fat pads were unaffected by 0.5% of CoQ₁₀ supplement in the rats. The level of triglyceride and HDL-cholesterol levels in the blood was significantly increased (p < 0.05) by the 1% of cholesterol supplement (CHO), whereas 0.5% of CoQ₁₀ supplement (COQ) did not alter these blood lipid indices. In the mRNA expression, there was a significant effect (P < 0.05) of the CoQ₁₀ supplement on the mRNA expression of superoxide dismutase (SOD), although the mRNA expression of glutathione peroxidase (GPX) and glutathione S-transferase (GST) was unaffected by cholesterol or the CoQ₁₀ supplement. Similar to mRNA expression of SOD, its activity was also significantly increased (P < 0.05) by CoQ₁₀, but not by the cholesterol supplement effect. The activities hepatic GPX and GST were unaffected by CoQ₁₀ and cholesterol supplements in rats. Lipid peroxidation in the CHO group resulted in a significant (p < 0.05) increase compared with that in the other groups, indicating that the CoQ₁₀ supplement to 1% of cholesterol-fed rats alleviated the production of lipid peroxidation in the liver. In conclusion, 0.5% of the CoQ₁₀ supplement resulted in positive effects on the hepatic antioxidant defense system without affecting blood lipid indices in 1% of cholesterol fed rats.

Characteristics of Selected Antioxidative and Bioactive Compounds in Meat and Animal Origin Products

Meat and meat products have a high nutritional value. Besides major components, meat is rich in bioactive components, primarily taurine, l-carnitine, choline, alpha-lipoic acid, conjugated linoleic acid, glutathione, creatine, coenzyme Q10 and bioactive peptides. Many studies have reported their antioxidant and health-promoting properties connected with their lipid-lowering, antihypertensive, anti-inflammatory, immunomodulatory activity and protecting the organism against oxidative stress. The antioxidant activity of meat components results, among others, from the capability of scavenging reactive oxygen and nitrogen species, forming complexes with metal ions and protecting cells against damage. This review is focused to gather accurate information about meat components with antioxidant and biological activity.

Clinical Advances in Immunonutrition and Atherosclerosis: A Review

Atherosclerosis is a chronic low-grade inflammatory disease that affects large and medium-sized arteries and is considered to be a major underlying cause of cardiovascular disease (CVD). The high risk of mortality by atherosclerosis has led to the development of new strategies for disease prevention and management, including immunonutrition. Plant-based dietary patterns, functional foods, dietary supplements, and bioactive compounds such as the Mediterranean Diet, berries, polyunsaturated fatty acids, ω-3 and ω-6, vitamins E, A, C, and D, coenzyme Q10, as well as phytochemicals including isoflavones, stilbenes, and sterols have been associated with improvement in atheroma plaque at an inflammatory level. However, many of these correlations have been obtained in vitro and in experimental animals' models. On one hand, the present review focuses on the evidence obtained from epidemiological, dietary intervention and supplementation studies in humans supporting the role of immunonutrient supplementation and its effect on anti-inflammatory response in atherosclerotic disease. On the other hand, this review also analyzes the possible molecular mechanisms underlying the protective action of these supplements, which may lead a novel therapeutic approach to prevent or attenuate diet-related disease, such as atherosclerosis.

Effect of Q10 supplementation on body weight and body mass index: A systematic review and meta-analysis of randomized controlled clinical trials

AIMS

This meta-analysis study was carried out to assess the effects of coenzyme Q10 supplementation on body weight and body mass index of patients in randomized controlled clinical trial studies.

MATERIALS AND METHODS

A comprehensive systematic search of literature was performed through ISI web of sciences, PubMed, Scopus and Cochrane library databases up to February 2018 which was supplemented by manual search of the references list of included studies. From a total of 1579 identified articles, only 17 trials with 14 and 14 effect-sizes were included for pooling the effects of co-enzyme Q10 supplementation on body weight and body mass index, respectively.

RESULTS

Results of random-effect size meta-analysis showed that supplementation with coenzyme Q10 had no significant decreasing effects on body weight (WMD: 0.28 kg; 95% CI = -0.91, 1.47; P = 0.64) and BMI (WMD: -0.03; 95% CI = -0.4, 0.34; P = 0.86) of study participants. Subgroup analysis revealed that dosage of Q10 and trial duration could not differ the results of Q10 supplementation.

CONCLUSION

Results of this meta-analysis study failed to show any beneficial effect of coenzyme Q10 supplementation on body weight and BMI of patients in clinical trial studies.

Intracellular cholesterol accumulation and coenzyme Q10 deficiency in Familial Hypercholesterolemia

Familial Hypercholesterolemia (FH) is an autosomal co-dominant genetic disorder characterized by elevated low-density lipoprotein (LDL) cholesterol levels and increased risk for premature cardiovascular disease. Here, we examined FH pathophysiology in skin fibroblasts derived from FH patients harboring heterozygous mutations in the LDL-receptor. Fibroblasts from FH patients showed a reduced LDL-uptake associated with increased intracellular cholesterol levels and coenzyme Q₁₀ (CoQ₁₀) deficiency, suggesting dysregulation of the mevalonate pathway. Secondary CoQ₁₀ deficiency was associated with mitochondrial depolarization and mitophagy activation in FH fibroblasts. Persistent mitophagy altered autophagy flux and induced inflammasome activation accompanied by increased production of cytokines by mutant cells. All the pathological alterations in FH fibroblasts were also reproduced in a human endothelial cell line by LDL-receptor gene silencing. Both increased intracellular cholesterol and mitochondrial dysfunction in FH fibroblasts were partially restored by CoQ₁₀ supplementation. Dysregulated mevalonate pathway in FH, including increased expression of cholesterogenic enzymes and decreased expression of CoQ₁₀ biosynthetic enzymes, was also corrected by CoQ₁₀ treatment. Reduced CoQ₁₀ content and mitochondrial dysfunction may play an important role in the pathophysiology of early atherosclerosis in FH. The diagnosis of CoQ₁₀ deficiency and mitochondrial impairment in FH patients may also be important to establish early treatment with CoQ₁₀.

Coenzyme Q10 in Cardiovascular and Metabolic Diseases: Current State of the Problem

The burden of cardiovascular and metabolic diseases is increasing with every year. Although the management of these conditions has improved greatly over the years, it is still far from perfect. With all of this in mind, there is a need for new methods of prophylaxis and treatment. Coenzyme Q10 (CoQ10) is an essential compound of the human body. There is growing evidence that CoQ10 is tightly linked to cardiometabolic disorders. Its supplementation can be useful in a variety of chronic and acute disorders. This review analyses the role of CoQ10 in hypertension, ischemic heart disease, myocardial infarction, heart failure, viral myocarditis, cardiomyopathies, cardiac toxicity, dyslipidemia, obesity, type 2 diabetes mellitus, metabolic syndrome, cardiac procedures and resuscitation.

Recent Developments in the Role of Coenzyme Q10 for Coronary Heart Disease: a Systematic Review

PURPOSE OF REVIEW

This review examines recent randomized clinical trials evaluating the role of coenzyme Q10 (CoQ10) in the management of coronary heart disease.

RECENT FINDINGS

CoQ10 is one of the most commonly used dietary supplements in the USA. Due to its antioxidant and anti-inflammatory effects, CoQ10 has been studied extensively for possible use in managing coronary heart disease. One of the most common applications of CoQ10 is to mitigate statin-associated muscle symptoms (SAMS) based on the theory that SAMS are caused by statin depletion of CoQ10 in the muscle. Although previous studies of CoQ10 for SAMS have produced mixed results, CoQ10 appears to be safe. Because CoQ10 is a cofactor in the generation of adenosine triphosphate, supplementation has also recently been studied in patients with heart failure, which is inherently an energy deprived state. The Q-SYMBIO trial found that CoQ10 supplementation in patients with heart failure not only improved functional capacity, but also significantly reduced cardiovascular events and mortality. Despite these positive findings, a larger prospective trial is warranted to support routine use of CoQ10. Less impressive are the effects of CoQ10 on specific cardiovascular risk factors such as blood pressure, dyslipidemia, and glycemic control. Current evidence does not support routine use of CoQ10 in patients with coronary heart disease. Additional studies are warranted to fully determine the benefit of CoQ10 in patients with heart failure before including it in guideline-directed medical therapy.

The Effects of Coenzyme Q10 Supplementation on Blood Pressures Among Patients with Metabolic Diseases: A Systematic Review and Meta-analysis of Randomized Controlled Trials

INTRODUCTION

Although several trials have assessed the effect of coenzyme Q10 (CoQ10) supplementation on blood pressures among patients with metabolic diseases, findings are controversial.

AIM

This review of randomized controlled trials (RCTs) was performed to summarize the evidence on the effects of CoQ10 supplementation on blood pressures among patients with metabolic diseases.

METHODS

Randomized-controlled trials (RCTs) published in PubMed, EMBASE, Web of Science and Cochrane Library databases up to 10 August 2017 were searched. Two review authors independently assessed study eligibility, extracted data, and evaluated risk of bias of included studies. Heterogeneity was measured with a Q-test and with I₂ statistics. Data were pooled by using the fix or random-effect model based on the heterogeneity test results and expressed as standardized mean difference (SMD) with 95% confidence interval (CI).

RESULTS

A total of seventeen randomized controlled trials (684 participants) were included. Results showed that CoQ10 supplementation significantly decreased systolic blood pressure (SBP) (SMD - 0.30; 95% CI - 0.52, - 0.08). However, CoQ10 supplementation decreased diastolic blood pressure (DBP), but this was not statistically significant (SMD - 0.08; 95% CI - 0.46, 0.29).

CONCLUSIONS

CoQ10 supplementation may result in reduction in SBP levels, but did not affect DBP levels among patients with metabolic diseases. Additional prospective studies regarding the effect of CoQ10 supplementation on blood pressure in patients with metabolic diseases are necessary.

Modulation of Hypercholesterolemia-Induced Oxidative/Nitrative Stress in the Heart

Hypercholesterolemia is a frequent metabolic disorder associated with increased risk for cardiovascular morbidity and mortality. In addition to its well-known proatherogenic effect, hypercholesterolemia may exert direct effects on the myocardium resulting in contractile dysfunction, aggravated ischemia/reperfusion injury, and diminished stress adaptation. Both preclinical and clinical studies suggested that elevated oxidative and/or nitrative stress plays a key role in cardiac complications induced by hypercholesterolemia. Therefore, modulation of hypercholesterolemia-induced myocardial oxidative/nitrative stress is a feasible approach to prevent or treat deleterious cardiac consequences. In this review, we discuss the effects of various pharmaceuticals, nutraceuticals, some novel potential pharmacological approaches, and physical exercise on hypercholesterolemia-induced oxidative/nitrative stress and subsequent cardiac dysfunction as well as impaired ischemic stress adaptation of the heart in hypercholesterolemia.

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.