Plasma antioxidants are strongly affected by iron-induced lipid peroxidation in rats subjected to physical exercise and different dietary fats

Ageing and the Mediterranean diet: a review of the role of dietary fats

Consumers are becoming increasingly aware of the relationship between food and health. Concerns have been raised about dietary fats and their relative nutritional advantages or disadvantages. In investigations of the associations between health and fat intake, special emphasis has been placed on the benefits of virgin olive oil for counteracting certain neurodegenerative diseases and ageing. With respect to ageing, accumulating evidence indicates that an improvement in quality of life can be reached by modulation of the extrinsic factors that influence many ageing processes. Of the modifiable factors, nutrition appears to be one of the strongest elements known to influence the rate of ageing as well as the incidence of age-associated diseases such as atherosclerosis and neurodegenerative pathologies. This paper reviews the theory of ageing and the role of fatty acids in the mechanisms affecting its evolution. It also confirms that virgin olive oil, an essential component of the Mediterranean diet, provides large amounts of stable and not easily oxidizable fatty acids as well as remarkable quantities of powerful antioxidant molecules.

Oxidative stress in patients undergoing cardiac surgery: comparative study of revascularization and valve replacement procedures

OBJECTIVE

The aim of this study was to evaluate the time course of oxidative stress markers in plasma and erythrocyte from patients undergoing open heart surgery with cardiopulmonary bypass (CPB) and to examine whether the type of surgical technique used (valve replacement or coronary revascularization) produces any differences in these makers.

PATIENTS AND METHODS

Twenty-two patients undergoing cardiac surgery with CPB were divided in 2 groups (valve replacement or coronary revascularization). We took 5 blood samples at different times during cardiac surgery and analyzed thiobarbituric acid reactive substances (TBARS), alpha-tocopherol, coenzyme Q, and retinol in plasma and TBARS (baseline levels and induced by Fe(2+)-ascorbate oxidation), alpha-tocopherol, coenzyme Q and catalase, superoxide dismutase, and glutathione peroxidase activity in erythrocyte.

RESULTS

Plasma alpha-tocopherol content decreased after starting CPB in both groups. In contrast, in erythrocytes there was an increase in the activity or concentration of all of the antioxidants. Erythrocyte TBARS contents, both baseline levels and induced levels, were higher in coronary revascularization group.

CONCLUSION

Although both groups suffered an increase in oxidative stress after CPB, this increase was higher in coronary revascularization group and therefore the possibility of post-CPB complications could be more severe in this group. As the groups followed a different pattern of antioxidant response, a different therapeutic approach may be required for each.

Abnormal age-related changes of plasma antioxidant proteins in schizophrenia

Albumin and bilirubin are metal-binding proteins, shown to possess free radical scavenging properties, and may thus be selective antioxidants. In the present study we examined whether individual plasma antioxidants such as albumin and bilirubin, which significantly contribute to total antioxidant status (TAS), are reduced in patients with schizophrenia. We prospectively studied plasma antioxidant proteins, i.e. albumin and bilirubin, in male veteran schizophrenic patients using a within-subject, repeated measures, on-off-on haloperidol treatment design, as well as age- and sex-matched healthy volunteers. Male patients with schizophrenia either during haloperidol treatment (n=46) or in a drug-free condition (n=35) had significantly lower levels of both plasma albumin and bilirubin compared with age- and sex-matched healthy volunteers (n=31). Such reductions of plasma antioxidant proteins in schizophrenic patients appear to be age-related changes, in contrast to those observed in healthy volunteers. On the other hand, levels of plasma albumin and bilirubin were not significantly affected by haloperidol treatment, haloperidol withdrawal, or length of drug-free period. Moreover, plasma TAS was not influenced significantly by cigarette smoking, even though it may selectively decrease plasma bilirubin but not albumin levels. The present findings, taken together with our previous results of reduced plasma TAS and uric acid, as well as an increased Red blood cell superoxide dismutase, lend further support to the hypothesis that a defect in the antioxidant defense system exists in schizophrenia that may lead to oxidative damage.

Olive oil supplemented with vitamin E affects mitochondrial coenzyme Q levels in liver of rats after an oxidative stress induced by adriamycin

In this study we have evaluated the supplementation of olive oil with vitamin E on coenzyme Q concentration and lipid peroxidation in rat liver mitochondrial membranes. Four groups of rats were fed on virgin olive, olive plus 200 mg/kg of vitamin E or sunflower oils as lipid dietary source. To provoke an oxidative stress rats were administered intraperitoneally 10 mg/kg/day of adriamycin the last two days of the experiment. Animals fed on olive oil plus vitamin E had significantly higher coenzyme Q and vitamin E levels but a lower mitochondrial hydroperoxide concentration than rats fed on olive oil. Retinol levels were not affected, by either different diets or adriamycin treatment. In conclusion, an increase in coenzyme Q and alpha-tocopherol in these membranes can be a basis for protection against oxidation and improvement in antioxidant capacity.