- [Show abstract] [Hide abstract] ABSTRACT: Background: In our earlier studies both corticosterone and cortisol had antioxidant effect in vitro.Objectives: Our aim was to clarify whether corticosterone and cortisol oral administration results in beneficial antioxidant changes in Sprague-Dawley adult male rats in vivo.Methods: Experimental animals were fed a lipid rich diet and treated with corticosterone or cortisol in the drinking fluid. Control group was fed only lipid rich diet with untreated drinking water. The untreated group was fed a normal diet with untreated water. Total scavenger capacity (TSC) was measured before and after 4 weeks of treatment in blood samples using a chemiluminometric assay.Results: Both corticosterone and cortisol treatment caused increased TSC. The control group and the untreated group showed no significant changes in TSC. Conclusion: Our results support the hypothesis that corticosterone and cortisol administration can improve the antioxidant status not only in vitro but also in vivo.
- [Show abstract] [Hide abstract] ABSTRACT: Steroid hormones influence the antioxidant processes of cells. However, the molecular mechanism of this effect is not fully clear. Our aim was to examine how steroid hormones affect the expression of certain genes that play a role in antioxidant processes. Blood was taken from ten healthy volunteers. Neutrophil granulocytes were separated and treated either with 17-β-estradiol, progesterone, testosterone, or cortisol. Whole RNA was isolated and reverse transcription was carried out in treated and control groups. Relative quantification was performed with SYBR Green assay and gene-specific oligonucleotides. We found that the expression of Mn-superoxide dismutase was significantly increased by 17-β-estradiol and testosterone, myeloperoxidase expression was significantly elevated by cortisol and progesterone, and the expression of NADPH oxidase was significantly decreased by progesterone. We conclude that the antioxidant effect of steroid hormones is in part carried out through transcriptional regulation of certain enzymes. Subsequent studies are required in order to examine the non-genomic, membrane receptor mediated effect of steroids on antioxidant processes.
- [Show abstract] [Hide abstract] ABSTRACT: Selegiline is a selective irreversible inhibitor of the B-type of monoamine oxidase (MAO-B). The spectrum of its pharmacological activity is wide, possesses antioxidant, antiapoptotic and neuroprotective properties and, additionally, we found it is effective on the total scavenger capacity (TSC), and the regulation of fat content in rat liver kept on lipid-rich diet. Our aim was to clarify whether the oral treatment with selegiline is protective on oxidative damage of Sprague-Dawley adult rats in vivo. Four groups of rats (five animals in a group) were examined: (1) lipid-rich diet, (2) normal rat food, (3) lipid-rich diet + selegiline and (4) normal rat food + selegiline. Selegiline solution (2.5 µg/ml) was supplied with the drinking water, which was freely available for the animals. Regarding the drinking habit of the rats (20-30 ml/day), the daily dose was roughly equal with that used in the human therapy (5-10 mg/day). TSC was determined both at the beginning (0 day) and at the end of the study (28 days), when the blood samples were taken for chemiluminometric assay. Fat content of the liver was determined in the freshly frozen tissue by Sudan staining. TSC was increased in both the selegiline-treated groups. Selegiline treatment prevented the increase of liver fat in the group fed with lipid-rich diet. Our results led us to the conclusion that prolonged selegiline administration can raise the antioxidant capacity of the animals and prevents the accumulation of fat in their livers.