Oral repeated-dose toxicity studies of coenzyme Q10 in beagle dogs

Adverse hematological profiles associated with chlorpromazine antipsychotic treatment in male rats: Preventive and reversal mechanisms of taurine and coenzyme-Q10

Chlorpromazine (CPZ) is one of the most effective antipsychotic drugs used for managing psychotic related disorders owing to its dopamine receptor blocking action. However, pharmacological investigations against CPZ's cytotoxic effect have remained scarce. Hence, this study investigated the preventive and reversal effects of taurine and coenzyme-Q10 (COQ-10), which are compounds with proven natural antioxidant properties, against CPZ-induced hematological impairments in male rats. In the preventive study, rats received oral saline (10 ml/kg), taurine (150 mg/kg/day), COQ-10 (10 mg/kg/day) or in combination for 56 days, alongside CPZ (30 mg/kg, p.o.) between days 29-56. In the reversal protocol, rats had CPZ repeatedly for 56 days before taurine and COQ-10 treatments or their combination from days 29-56. Rats were also given taurine (150 mg/kg/day), and COQ-10 (10 mg/kg/day) alone for 56 days. Serums were extracted and assayed for hematological, with oxidative and inflammatory markers. CPZ induced decreased red/white blood cells, erythropoietin, platelet count, packed cell volume and hemoglobin, neutrophil, and lymphocyte, which were prevented and reversed by taurine and COQ-10, or their combination. Taurine and COQ-10 improved mean corpuscular volume, hemoglobin concentration, with increased erythropoietin levels relative to CPZ groups. CPZ-induced increased malondialdehyde, tumor necrosis factor-alpha and interleukin-6 levels with decreased interleukin-10, glutathione, and superoxide-dismutase were prevented and reversed by taurine and COQ-10 in comparison with CPZ groups. Taurine and COQ-10 alone notably improved the antioxidant/anti-inflammatory status relative to controls. Among other mechanisms, taurine and COQ-10 abated CPZ-induced hematological deficiencies, via decreased serum levels of oxidative stress, and pro-inflammatory cytokines release, with increased antioxidants and anti-inflammation function.

Screening and Targeting Risk Factors for Prodromal Synucleinopathy: Taking Steps toward a Prescriptive Multi-modal Framework

As the prevalence of Parkinson's disease (PD) grows, so too does the population at-risk of developing PD, those in the so-called prodromal period. This period can span from those experiencing subtle motor deficits yet not meeting full diagnostic criteria or those with physiologic markers of disease alone. Several disease-modifying therapies have failed to show a neuroprotective effect. A common criticism is that neurodegeneration, even in the early motor stages, has advanced too far for neuro-restoration-based interventions to be effective. Therefore, identifying this early population is essential. Once identified, these patients could then potentially benefit from sweeping lifestyle modifications to alter their disease trajectory. Herein, we review the literature on risk factors for, and prodromal symptoms of, PD with an emphasis on ones which may be modifiable in the earliest possible stages. We propose a process for identifying this population and speculate on some strategies which may modulate disease trajectory. Ultimately, this proposal warrants prospective studies.

Depleted Myocardial Coenzyme Q10 in Cavalier King Charles Spaniels with Congestive Heart Failure Due to Myxomatous Mitral Valve Disease

Congestive heart failure (CHF) has been associated with depleted myocardial coenzyme Q10 (Q10) concentrations in human patients. The aim of this study was to investigate associations between myocardial Q10 concentrations and myxomatous mitral valve disease (MMVD) severity in dogs. Furthermore, citrate synthase (CS) activity was analysed to determine if a reduction in myocardial Q10 was associated with mitochondrial depletion in the myocardium. Thirty Cavalier King Charles spaniels (CKCS) in MMVD stages B1 (n = 11), B2 (n = 5) and C (n = 14) according to the American College of Veterinary Internal Medicine (ACVIM) guidelines and 10 control (CON) dogs of other breeds were included. Myocardial Q10 concentration was analysed in left ventricular tissue samples using HPLC-ECD. CKCS with congestive heart failure (CHF; group C) had significantly reduced Q10 concentrations (median, 1.54 µg/mg; IQR, 1.36–1.94), compared to B1 (2.76 µg/mg; 2.10–4.81, p < 0.0018), B2 (3.85 µg/mg; 3.13–4.46, p < 0.0054) and CON dogs (2.8 µg/mg; 1.64–4.88, p < 0.0089). CS activity was comparable between disease groups. In conclusion, dogs with CHF due to MMVD had reduced myocardial Q10 concentrations. Studies evaluating antioxidant defense mechanisms as a therapeutic target for treatment of CHF in dogs are warranted.

Pharmacokinetics of Repeated Oral Dosing with Coenzyme Q10 in Cavalier King Charles Spaniels with Myxomatous Mitral Valve Disease

Coenzyme Q10 (Q10) is a mitochondrial cofactor and an antioxidant with the potential to combat oxidative stress in heart failure. This study aims to determine the pharmacokinetics of repeated oral dosing of Q10 in Cavalier King Charles Spaniels (CKCS) with spontaneous myxomatous mitral valve disease (MMVD) and to evaluate echocardiographic parameters, circulating cardiac biomarkers, and quality of life (QoL) after treatment. The study is a randomized, placebo-controlled, single-blinded crossover study. Nineteen CKCS with MMVD were randomized to receive 100 mg Q10 (ubiquinone) bi-daily for three weeks, then placebo (or in reverse order). Clinical examination, blood sampling, echocardiography, and QoL assessment were performed before and after each treatment phase. Q10 plasma concentrations were determined in plasma using a validated high-performance liquid chromatography method using electrochemical detection (HPLC-ECD). Eighteen CKCS were included in the analyses. Total plasma concentration of Q10 increased significantly (p < 0.0001) from baseline (median, 0.92 µg/mL; interquartile range (IQR), 0.70-1.26) to after treatment (median, 3.51 µg/mL; IQR, 2.30-6.88). Thirteen dogs reached the threshold of a total plasma Q10 concentration of ≥2.0 µg/mL. The average half-life (T_1/2) of Q10 was 2.95 days (IQR, 1.75-4.02). No significant differences were observed in clinical MMVD severity, and the owner perceived QoL between Q10 and placebo treatment. The solubilized Q10 formulation was well-tolerated in the dogs. Individual variation in plasma concentrations was observed following oral treatment. A long-term placebo-controlled trial is warranted in dogs with MMVD to determine long-term efficacy on the clinical severity of MMVD.

Determination of Reduced and Oxidized Coenzyme Q10 in Canine Plasma and Heart Tissue by HPLC-ECD: Comparison with LC-MS/MS Quantification

Coenzyme Q₁₀ (Q₁₀) plays an important role in mammals for energy production in the mitochondria, and as a potent antioxidant. Oxidation ratio (% oxidized in relation to total Q₁₀) has been proposed as an important biomarker. A sensitive and reproducible HPLC-ECD method was developed for determination of reduced and oxidized Q₁₀ in canine plasma and heart tissue. Chromatographic separation was achieved in 10 min using a Waters Nova-pak C₁₈ column and a mobile phase with lithium perchlorate in ethanol/methanol/2-propanol. The validation showed satisfying results. Excellent linear correlation was found (r² > 0.9997), intra- and inter-day precisions were below 6.5% (n = 5) and recoveries were between 89 and 109% (n = 5). Sensitivity stated as Lower Limit of Quantification (LLOQ) was 10 nM. Acceptable stability of both extracted and un-extracted samples was observed. The plasma concentration range of total Q₁₀ was found to be between 0.64 and 1.24 µg/mL. Comparison with a developed LC-MS/MS method showed a correlation of r = 0.85 for reduced Q₁₀ and r = 0.60 for oxidized Q₁₀ (N = 17). However, average results were around 30% lower for ubiquinol using the LC-MS/MS method as compared with the HPLC-ECD analysis. The two methods are therefore not considered to be interchangeable.

A randomized, double-blind, placebo-controlled trial of coenzyme Q10 in Huntington disease

OBJECTIVE

To test the hypothesis that chronic treatment of early-stage Huntington disease (HD) with high-dose coenzyme Q10 (CoQ) will slow the progressive functional decline of HD.

METHODS

We performed a multicenter randomized, double-blind, placebo-controlled trial. Patients with early-stage HD (n = 609) were enrolled at 48 sites in the United States, Canada, and Australia from 2008 to 2012. Patients were randomized to receive either CoQ 2,400 mg/d or matching placebo, then followed for 60 months. The primary outcome variable was the change from baseline to month 60 in Total Functional Capacity score (for patients who survived) combined with time to death (for patients who died) analyzed using a joint-rank analysis approach.

RESULTS

An interim analysis for futility revealed a conditional power of <5% for the primary analysis, prompting premature conclusion in July 2014. No statistically significant differences were seen between treatment groups for the primary or secondary outcome measures. CoQ was generally safe and well-tolerated throughout the study.

CONCLUSIONS

These data do not justify use of CoQ as a treatment to slow functional decline in HD.

CLINICALTRIALSGOV IDENTIFIER

NCT00608881.

CLASSIFICATION OF EVIDENCE

This article provides Class I evidence that CoQ does not slow the progressive functional decline of patients with HD.