Biochemical Alterations in Semen of Varicocele Patients: A Review of the Literature

Oxidative stress is a mechanism underlying different kinds of infertility in human males. However, different results can be observed in relation to the method used for its evaluation. Varicocele patients show a number of biochemical abnormalities, including an altered distribution of coenzyme Q between seminal plasma and sperm cells and also an apparent defect in the utilization of antioxidants. Moreover, an influence of systemic hormones on seminal antioxidant system was observed too. Finally, the effects of surgical treatment on oxidativestress indexes and the possible usefulness of some medical therapies, like coenzyme Q supplementation, are discussed. In conclusion, published data show a role of oxidative stress in varicocele-related male infertility, but at present we do not know the precise molecular mechanisms underlying these phenomena

Coenzyme Q 10: multiple benefits in one ingredient

Coenzyme Q is a lipid molecule widely diffused in nature; in humans and other mammals it is present as coenzyme Q10. (CoQ10). The first recognized role of CoQ10 was in mitochondrial bioenergetics, where it plays a central role in the production of ATP. It is also present in other subcellular organelles, both in its oxidized and in its reduced state (ubiquinol-10). The reduced form of CoQ10 is endowed with powerful antioxidant activity: it acts as a chain-breaking antioxidant and is also capable of egenerating alpha-tocopherol, the active form of vitamin E. By these mechanisms CoQ10, together with vitamin E, protects lipoproteins from oxidation a process which bears considerable interest in preventing atherosclerosis. CoQ10 has also been found to support cardiovascular function and the latest findings indicate an active role in counteracting endothelial dysfunction, which is closely implicated in cardiovascular disease. CoQ10 also improves sperm motility, an effect which might be related both to its antioxidant and to its bioenergetic properties. Oxidative stress might be involved in neurodegenerative disease, and in migraine, two fields where the positive effects of CoQ10 have been documented. CoQ10 is synthesized by our body but is also present in food and can be taken as a nutritional supplement. The main source of industrially produced CoQ10 is yeast fermentation. The process results in CoQ10 which is identical to the naturally occurring molecule. Ubiquinol, the reduced form of CoQ10, has recently become available

Coenzyme Q

Coenzyme Q is a lipid molecule widely diffused in nature; in humans and other mammals it is present as coenzyme Q10. (CoQ10). The first recognized role of CoQ10 was in mitochondrial bioenergetics, where it plays a central role in the production of ATP. It is also present in other subcellular organelles, both in its oxidized and in its reduced state (ubiquinol-10). The reduced form of CoQ10 is endowed with powerful antioxidant activity: it acts as a chain-breaking antioxidant and is also capable of egenerating alpha-tocopherol, the active form of vitamin E. By these mechanisms CoQ10, together with vitamin E, protects lipoproteins from oxidation a process which bears considerable interest in preventing atherosclerosis. CoQ10 has also been found to support cardiovascular function and the latest findings indicate an active role in counteracting endothelial dysfunction, which is closely implicated in cardiovascular disease. CoQ10 also improves sperm motility, an effect which might be related both to its antioxidant and to its bioenergetic properties. Oxidative stress might be involved in neurodegenerative disease, and in migraine, two fields where the positive effects of CoQ10 have been documented. CoQ10 is synthesized by our body but is also present in food and can be taken as a nutritional supplement. The main source of industrially produced CoQ10 is yeast fermentation. The process results in CoQ10 which is identical to the naturally occurring molecule. Ubiquinol, the reduced form of CoQ10, has recently become available

) Bioenergetic and Antioxidant Properties of Coenzyme Q10: Recent Developments

For a number of years, coenzyme Q (CoQ10 in humans) was known for its key role in mitochondrial bioenergetics; later studies demonstrated its presence in other subcellular fractions and in plasma, and extensively investigated its antioxidant role. These two functions constitute the basis on which research supporting the clinical use of CoQ10 is founded. Also at the inner mitochondrial membrane level, coenzyme Q is recognized as an obligatory co-factor for the function of uncoupling proteins and a modulator of the transition pore. Furthermore, recent data reveal that CoQ10 affects expression of genes involved in human cell signalling, metabolism, and transport and some of the effects of exogenously administered CoQ10 may be due to this property. Coenzyme Q is the only lipid soluble antioxidant synthesized endogenously. In its reduced form, CoQH2, ubiquinol, inhibits protein and DNA oxidation but it is the effect on lipid peroxidation that has been most deeply studied. Ubiquinol inhibits the peroxidation of cell membrane lipids and also that of lipoprotein lipids present in the circulation. Dietary supplementation with CoQ10 results in increased levels of ubiquinol-10 within circulating lipoproteins and increased resistance of human low-density lipoproteins to the initiation of lipid peroxidation. Moreover, CoQ10 has a direct anti-atherogenic effect, which has been demonstrated in apolipoprotein E-deficient mice fed with a high-fat diet. In this model, supplementation with CoQ10 at pharmacological doses was capable of decreasing the absolute concentration of lipid hydroperoxides in atherosclerotic lesions and of minimizing the size of atherosclerotic lesions in the whole aorta. Whether these protective effects are only due to the antioxidant properties of coenzyme Q remains to be established; recent data point out that CoQ10 could have a direct effect on endothelial function. In patients with stable moderate CHF, oral CoQ10 supplementation was shown to ameliorate cardiac contractility and endothelial dysfunction. Recent data from our laboratory showed a strong correlation between endothelium bound extra cellular SOD (ecSOD) and flow-dependent endothelial-mediated dilation, a functional parameter commonly used as a biomarker of vascular function. The study also highlighted that supplementation with CoQ10 that significantly affects endothelium-bound ecSOD activity. Furthermore, we showed a significant correlation between increase in endothelial bound ecSOD activity and improvement in FMD after CoQ10 supplementation. The effect was more pronounced in patients with low basal values of ecSOD. Finally, we summarize the findings, also from our laboratory, on the implications of CoQ10 in seminal fluid integrity and sperm cell motility

Olive oil supplemented with menaquinone-7 significantly affects osteocalcin carboxylation.

Menaquinone-7 (MK-7), a member of the vitamin K2family, performs several functions, all related to its recognised effect on post-translational carboxylation of certain protein-bound glutamate residues. Due to its lipophilic structure MK-7 is soluble in olive oil, so the aim of the present study was to test whether extra-virgin (EV) olive oil enriched with MK-7 significantly increases MK-7 plasma levels and has an effect on osteocalcin and its carboxylation status. Healthy young volunteers (n12) were administered 20 ml EV olive oil per d for 2 weeks, followed by 2 weeks of the same amount of olive oil enriched with 45 μg and then 90 μg MK-7, with an appropriate washout time in between. Blood was collected and plasma separated in each phase of the study. We found that integration of the diet with EV olive oil alone did not produce any significant variation of MK-7 plasma levels compared with baseline. Supplementation with MK-7-enriched olive oil resulted in a significant and dose-dependent increase in plasma levels. The high dose also significantly increased carboxylated osteocalcin (cOC) and decreased undercarboxylated osteocalcin (ucOC) plasma levels, resulting in a significant increase in the cOC:ucOC ratio. A significant correlation was also found between percentage variation of plasma cOCA:ucOC ratio and increase in plasma MK-7 levels. We conclude that regular consumption of MK-7-enriched olive oil may constitute a valid approach in order to preserve some key biochemical mechanisms controlling bone mineralisation.</jats:p