Background: High oxidative stress and chronic inflammation can contribute to the pathogenesis of coronary artery disease (CAD). Coenzyme Q10 is an endogenous lipid-soluble antioxidant. Statins therapy can reduce the biosynthesis of coenzyme Q10. The purpose of this study was to investigate the effects of a coenzyme Q10 supplement (300 mg/d; 150 mg/b.i.d) on antioxidation and anti-inflammation in patients who have CAD during statins therapy. Methods: Patients who were identified by cardiac catheterization as having at least 50% stenosis of one major coronary artery and who were treated with statins for at least one month were enrolled in this study. The subjects (n = 51) were randomly assigned to the placebo (n = 24) and coenzyme Q10 groups (Q10-300 group, n = 27). The intervention was administered for 12 weeks. The concentrations of coenzyme Q10, vitamin E, antioxidant enzymes activities (superoxide dismutase, catalase, and glutathione peroxidase), and inflammatory markers [C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6)] were measured in the 42 subjects (placebo, n = 19; Q10-300, n = 23) who completed the study. Results: The levels of the plasma coenzyme Q10 (P < 0.001) and antioxidant enzymes activities (P < 0.05) were significantly higher after coenzyme Q10 supplementation. The levels of inflammatory markers (TNF-α, P = 0.039) were significantly lower after coenzyme Q10 supplementation. The subjects in the Q10-300 group had significantly higher vitamin E (P = 0.043) and the antioxidant enzymes activities (P < 0.05) than the placebo group at week 12. The level of plasma coenzyme Q10 was significantly positively correlated with vitamin E (P = 0.008) and antioxidant enzymes activities (P < 0.05) and was negatively correlated with TNF-α (P = 0.034) and IL-6 (P = 0.027) after coenzyme Q10 supplementation. Conclusion: Coenzyme Q10 supplementation at 300 mg/d significantly enhances antioxidant enzymes activities and lowers inflammation in patients who have CAD during statins therapy. Trial registration: Clinical Trials.gov Identifier: NCT01424761.

Cardiovascular disease is the leading cause of death worldwide. Higher oxidative stress may contribute to the pathogenesis of coronary artery disease (CAD). The purpose of this study was to investigate the effect of L-carnitine (LC, 1000 mg/d) on the markers of oxidative stress and antioxidant enzymes activities in CAD patients.

Metabolic syndrome (MS) represents a cluster of physiological and anthropometric abnormalities. The purpose of this study was to investigate the relationships between the levels of inflammation, adiponectin, and oxidative stress in subjects with MS. The inclusion criteria for MS, according to the Taiwan Bureau of Health Promotion, Department of Health, were applied to the case group (n = 72). The control group (n = 105) comprised healthy individuals with normal blood biochemical values. The levels of inflammatory markers [high sensitivity C-reactive protein (hs-CRP) and interleukin-6 (IL-6), adiponectin, an oxidative stress marker (malondialdehyde), and antioxidant enzymes activities [catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx)] were measured. Subjects with MS had significantly higher concentrations of inflammatory markers and lower adiponectin level, and lower antioxidant enzymes activities than the control subjects. The levels of inflammatory markers and adiponectin were significantly correlated with the components of MS. The level of hs-CRP was significantly correlated with the oxidative stress marker. The IL-6 level was significantly correlated with the SOD and GPx activities, and the adiponectin level was significantly correlated with the GPx activity. A higher level of hs-CRP (≥1.00 mg/L), or IL-6 (≥1.50 pg/mL) or a lower level of adiponectin (<7.90 µg/mL) were associated with a significantly greater risk of MS. In conclusion, subjects suffering from MS may have a higher inflammation status and a higher level of oxidative stress. A higher inflammation status was significantly correlated with decreases in the levels of antioxidant enzymes and adiponectin and an increase in the risk of MS.

It has been reported that higher levels of oxidative stress and inflammation play a key role in the progression of hepatocellular carcinoma (HCC) after surgery. Coenzyme Q10 is an endogenous lipid-soluble antioxidant. To date, no intervention study has investigated coenzyme Q10 supplementation in HCC patients after surgery. The purpose of this study was to investigate oxidative stress, antioxidant enzymes activity, and inflammation levels in HCC patients after surgery following administration of coenzyme Q10 (300 mg/day). This study was designed as a single-blinded, randomized, parallel, placebo-controlled study. Patients who were diagnosed with primary HCC (n = 41) and were randomly assign to a placebo (n = 20) or coenzyme Q10 (300 mg/day, n = 21) group after surgery. The intervention lasted for 12 weeks. Plasma coenzyme Q10, vitamin E, oxidative stress antioxidant enzymes activity and inflammatory markers levels were measured. The oxidative stress (p = 0.04) and inflammatory markers (hs-CRP and IL-6, p < 0.01) levels were significantly decreased, and the antioxidant enzymes activity was significantly increased (p < 0.01) after 12 weeks of coenzyme Q10 supplementation. In addition, the coenzyme Q10 level was significantly negatively correlated with the oxidative stress (p = 0.01), and positively correlated with antioxidant enzymes activity (SOD, p = 0.01; CAT, p < 0.05; GPx, p = 0.04) and vitamin E level (p = 0.01) after supplementation. In conclusion, we demonstrated that a dose of 300 mg/d of coenzyme Q10 supplementation significantly increased the antioxidant capacity and reduced the oxidative stress and inflammation levels in HCC patients after surgery. Clinical Trials.gov Identifier: NCT01964001

Diabetes is considered an oxidative stress and a chronic inflammatory disease. The purpose of this study was to investigate the correlations between vitamin B-12 status and oxidative stress and inflammation in diabetic vegetarians and omnivores. We enrolled 154 patients with type 2 diabetes (54 vegetarians and 100 omnivores). Levels of fasting glucose, glycohemoglobin (HbA1c), lipid profiles, oxidative stress, antioxidant enzymes activity, and inflammatory makers were measured. Diabetic vegetarians with higher levels of vitamin B-12 (>250 pmol/L) had significantly lower levels of fasting glucose, HbA1c and higher antioxidant enzyme activity (catalase) than those with lower levels of vitamin B-12 (≤250 pmol/L). A significant association was found between vitamin B-12 status and fasting glucose (r = −0.17, p = 0.03), HbA1c (r = −0.33, p = 0.02), oxidative stress (oxidized low density lipoprotein-cholesterol, r = −0.19, p = 0.03), and antioxidant enzyme activity (catalase, r = 0.28, p = 0.01) in the diabetic vegetarians; vitamin B-12 status was significantly correlated with inflammatory markers (interleukin-6, r = −0.33, p < 0.01) in diabetic omnivores. As a result, we suggest that it is necessary to monitor the levels of vitamin B-12 in patients with diabetes, particularly those adhering to a vegetarian diet.