Pharmacokinetic comparison of a generic coenzyme Q10 solubilizate and a formulation with soybean phytosterols.

Coenzyme Q10 (CoQ10) is essential for all cells, and deficiency has been implicated in cardiovascular disease. Plant phytosterols inhibit cholesterol absorption, and may thereby also reduce cardiovascular risk. This study compared the relative bioavailability of CoQ10 solubilized in low-dose soybean phytosterols (SterolQ10) with a generic CoQ10 solubilizate. In a randomized, cross-over design, 36 healthy males received a single 100 mg dose of CoQ10, as SterolQ10 or generic CoQ10, with a two-week washout between treatments. Plasma CoQ10 was analysed at baseline, and at 2, 4, 6, 8 and 10 h after supplement ingestion. Subjects were then administered either 100 mg/day of generic CoQ10 or SterolQ10 for 4 weeks. Fasting plasma CoQ10 levels were measured at baseline and following supplementation. The two preparations were bioequivalent in regard to the area under the curve (AUC(0-10h) ) and maximum increase in concentration (C(max) ), with geometric mean ratios of 0.89 (CI 0.81-0.98) and 0.88 (CI 0.80-0.96), respectively. Four-weeks of CoQ10 resulted in a comparable twofold increase in CoQ10 levels for both formulations (p < 0.001), which was similar between preparations (p = 0.74). The combined CoQ10 and phytosterol formulation, SterolQ10, showed bioequivalence to the generic CoQ10 following a single CoQ10 dose, and demonstrated comparable bioavailability following multiple dose administration.

Relationship between plasma coenzyme Q10, asymmetric dimethylarginine and arterial stiffness in patients with phenotypic or genotypic familial hypercholesterolemia on long-term statin therapy.

OBJECTIVE: We investigated whether statin-treated heterozygous familial hypercholesterolemic (FH) patients have lower plasma coenzyme Q(10) (CoQ(10)) levels than low-density lipoprotein receptor (LDLR) mutation negative FH patients on equivalent statin doses, and whether lower CoQ(10) concentrations are associated with increased arterial stiffness. METHODS: Thirty LDLR mutation negative patients with clinical FH and 30 mutation positive FH patients matched for gender, statin duration and dose, and a further 30 controls were studied. Plasma CoQ(10) and asymmetric dimethylarginine (ADMA) levels were measured by HPLC and the augmentation index by pulse wave analysis. RESULTS: Plasma CoQ(10) levels, and the ratios of CoQ(10) to total cholesterol and LDL-cholesterol were similar in treated FH patients with identified LDLR mutations to mutation negative patients on equivalent doses of statin therapy (p>0.05). CoQ(10) and lipid levels were also comparable to controls not using any lipid modifying treatment. Arterial stiffness was higher in mutation negative patients (p=0.04) and there was a trend for an increase in mutation positive patients (p=0.09). ADMA was higher in the mutation positive group (p<0.01). The augmentation index corrected for age, blood pressure, and heart rate, was negatively correlated with plasma CoQ(10) within FH patients (p<0.05). CONCLUSION: Long-term, high-dose statin therapy does not lead to subnormal CoQ(10) concentrations in patients with phenotypic or genotypic FH. Arterial stiffness is elevated in FH patients compared to untreated controls, and low CoQ(10) levels are associated with increased arterial stiffness. CoQ(10) supplementation trials are warranted in FH patients.

Coenzyme Q10; an adjunctive therapy for congestive heart failure?

Coenzyme Q10 (CoQ10) is essential for electron transport within the mitochondria and hence for ATP generation and cellular energy production. We recently demonstrated that plasma levels of CoQ10 are an independent predictor of survival in a cohort of 236 patients with chronic heart failure (CHF) followed for a median of 2.69 years. This is consistent with previous studies which have shown myocardial CoQ10 depletion in CHF, and correlated with the severity of the underlying disorder. Several intervention studies have been undertaken with CoQ10 in CHF, including randomized controlled trials with mostly positive outcomes in relation to improvement in plasma levels of CoQ10. A meta-analysis showed that CoQ10 resulted in an improvement in ejection fraction of 3.7% (95%CI 1.59-5.77) and the mean increase in cardiac output was 0.28 L/minute (95%CI 0.03-0.53). In a subgroup analysis, studies with patients not taking ACE inhibitors found a 6.7% increase in ejection fraction. The ongoing Q-SYMBIO trial will address whether CoQ10 supplementation improves survival in CHF patients. CoQ10 depletion may also be a contributory factor for why statin intervention has not improved outcomes in CHF. There is an emerging evidence base in support of CoQ10 as an adjunctive therapy in CHF.

Improved cognitive performance after dietary supplementation with a Pinus radiata bark extract formulation.

Dietary interventions may have the potential to counter age-related cognitive decline. Studies have demonstrated an improvement in age-related cognitive impairment in animals after supplementation with plant extracts containing flavonoids but there are few human studies. This double-blind, controlled study examined the effects on cognitive performance of a 5 week supplementation with Enzogenol Pinus radiata bark extract containing flavonoids, in 42 males aged 50-65 years, with a body mass index >25. Participants were supplemented for 5 weeks either with Enzogenol plus vitamin C, or with vitamin C only. A battery of computerized cognitive tests was administered, and cardiovascular and haematological parameters were assessed prior to and following supplementation. The speed of response for the spatial working memory and immediate recognition tasks improved after supplementation with Enzogenol plus vitamin C, whereas vitamin C alone showed no improvements. A trend in a reduction of systolic blood pressure was observed with Enzogenol plus vitamin C, but not with vitamin C alone. The blood safety parameters were unchanged. The findings suggest a beneficial effect of supplementation with Enzogenol on cognition in older individuals. Larger studies are needed to ascertain its potential as a preventive treatment for age-related cognitive decline.

Effect of coenzyme Q(10) supplementation on simvastatin-induced myalgia.

Myalgia is the most frequently reported adverse side effect associated with statin therapy and often necessitates reduction in dose, or the cessation of therapy, compromising cardiovascular risk management. One postulated mechanism for statin-related myalgia is mitochondrial dysfunction through the depletion of coenzyme Q(10), a key component of the mitochondrial electron transport chain. This pilot study evaluated the effect of coenzyme Q(10) supplementation on statin tolerance and myalgia in patients with previous statin-related myalgia. Forty-four patients were randomized to coenzyme Q(10) (200 mg/day) or placebo for 12 weeks in combination with upward dose titration of simvastatin from 10 mg/day, doubling every 4 weeks if tolerated to a maximum of 40 mg/day. Patients experiencing significant myalgia reduced their statin dose or discontinued treatment. Myalgia was assessed using a visual analogue scale. There was no difference between combined therapy and statin alone in the myalgia score change (median 6.0 [interquartile range 2.1 to 8.8] vs 2.3 [0 to 12.8], p = 0.63), in the number of patients tolerating simvastatin 40 mg/day (16 of 22 [73%] with coenzyme Q(10) vs 13 of 22 [59%] with placebo, p = 0.34), or in the number of patients remaining on therapy (16 of 22 [73%] with coenzyme Q(10) vs 18 of 22 [82%] with placebo, p = 0.47). In conclusion, coenzyme Q(10) supplementation did not improve statin tolerance or myalgia, although further studies are warranted.

Comparative effects of enzogenol and vitamin C supplementation versus vitamin C alone on endothelial function and biochemical markers of oxidative stress and inflammation in chronic smokers.

Chronic smoking is associated with endothelial dysfunction and inflammation, with oxidative stress contributing to both these processes. In this study, we investigated the effect of combined antioxidant treatment with Enzogenol, a flavonoid extract from the bark of Pinus radiata and vitamin C, over and above vitamin C alone, on endothelial function, plasma markers of inflammation and oxidative stress, blood pressure (BP) and anthropometrics. Forty-four chronic smokers without established cardiovascular disease were assigned randomly to receive either 480 mg Enzogenol and 60 mg vitamin C, or 60 mg vitamin C alone daily for 12 weeks. Endothelial function in the brachial artery was assessed by flow-mediated vasodilation (FMD). FMD improved in both treatment groups (p < 0.001), with no significant difference between the two groups (p = 0.84). In the group receiving Enzogenol and vitamin C, protein carbonyl levels were significantly reduced compared to the group taking vitamin C alone (p = 0.03). Enzogenol and vitamin C resulted in a significant reduction in fibrinogen levels in heavy smokers compared with vitamin C alone (p < 0.009). These findings demonstrated that co-supplementation with Enzogenol and vitamin C in smokers conferred no additional beneficial effect on macrovascular endothelial function over and above that seen in the vitamin C alone group. However, Enzogenol did demonstrate additional favourable effects on protein oxidative damage and fibrinogen levels.