The biological fate of the fish feed additive, ethoxyquin (EQ) was examined in the muscle of Atlantic salmon during 12 weeks of feeding followed by a 2 weeks depuration period. Parent EQ (1,2-dihydro-6-ethoxy-2,2,4-trimethylquinoline), quinone imine (2,6-dihydro-2,2,4-trimethyl-6-quinolone), de-ethylated EQ (6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline) and EQDM (EQ dimer or 1,8'-di(1,2-dihydro-6-ethoxy-2,2,4-trimethyl-quinoline) were found to be the ubiquitous metabolites of dietary EQ, with EQDM as a main metabolite. A rapid decrease in the level of EQ (2.4 days of half-life) was balanced by an increase in EQDM, giving an unchanged net sum following 2 weeks of depuration. The mandatory 14 days depuration period prior to slaughtering of farmed salmon in Norway was not sufficient for complete elimination of EQ-derived residuals. Post depuration, EQDM accounted for 99% of sum of the two compounds in all treatment groups; possible toxicological effects of EQDM are not known. The individual concentrations of EQ and EQDM and their sum are dependent on EQ level in the feed, consequently, their residual concentrations may be controlled. The theoretical amount of EQ and EQDM consumed in one meal of farmed salmon would be under the recommended ADI, provided that the fish were raised on feed with no more than 150 mg EQ/kg feed, which is the EU maximum limit for EQ in fish feed.
In 62 patients with ovarial cancer of III-IV stage under the influence of enterosorption using polysorb the contents of primary and intermediate products of peroxidal oxidation of lipids have reduced and the antioxidant system indexes did not change.
The state of enzymatic antioxidant system and thyroid status in the rat tissues under early postnatal overnutrition leading to shortening of life-span and calorie-restricted diet extending lifespan have been studied. It was found that the concentration of thyroxine, body weight and content of lipid hydroperoxides in the blood serum and liver post-mitochondrial fraction of rats had been reliably increased. At the same time the concentration of GSH and GSSG, superoxide dismutase, Se-dependent glutathione peroxidase (GP) activities in the liver and GP activity in the blood serum of experimental rats were reduced. The use of calorie-restricted diet for 2 months showed considerable decrease of thyroxine and triiodothyronine concentration, body weight and the content of lipid hydroperoxides in the blood serum of experimental rats compared with control. At the same time GP activity in the liver, Se-dependent GP activity and content of ceruloplasmin in blood of experimental rats were essentially enhanced. The obtained results allow to conclude that from all studied indices the activity of GSH-dependent antioxidant system (especially Se-dependent GP activity) and thyroid status revealed the most sensible changes in response to the used kind of nutrition. Unlike hypocaloric diet overnutrition results in a decrease of Se-dependent GP activity in the liver and blood of rats. That may be the most crucial moment in the maintenance of prooxidant-antioxidant balance of tissues.
The role of the glutathione-dependent antioxidant system in the prooxidant-antioxidant balance support was studied in the experiments with Wistar male rat under single gamma-irradiation (8 Gr dose), fed with unbalanced (as to animal proteins and antioxidant vitamins) diet and with addition of Aronia melanocarpa. Single gamma-irradiation of animals led to the decrease of selenium-dependent glutathione-peroxidase activity in the blood plasma and glutathione-S-transferase activity decrease in rat liver mitochondria. Animals which received the unbalanced food allowance under irradiation showed more expressed change of glutathione-dependent antioxidant enzymes activity, namely--proved decrease of glutathione-peroxidase and glutathione-S-transferase activity in liver microsomes and less expressed activation of selenium-dependent glutathione-peroxidase activity in the postmitochondrial fraction of laboratory animals liver. Introduction of the A. melanocarpa food supplement in the unbalanced diet of the laboratory animals which in vitro demonstrated expressed antioxidant and antiradical activity had no effect upon glutathione-peroxidase activity in the investigated tissues. Obtained data concerning significant decrease of the activity of glutathione-dependent antioxidant system and, particularly, of the selenium-dependent glutathione-peroxidase activity under the unbalanced diet condition may be useful in maintenance of prooxidant-antioxidant balance in the tissues of irradiated animals. Allowing for the above stated it is advisable to seek for new food additives which increase activity of the endogenous glutathione-dependent antioxidant enzymes for human tolerance improvement, especially under the unbalanced food allowance condition.
A study of pro- and antioxidant status in healthy boys and girls adolescents' representatives Tofalars and Evenks compared to Caucasians newcomers. Revealed activation of the adaptive-compensatory processes in the body young men and women, indigenous peoples of the North as compared to Caucasians alien population, which was reflected statistically significant increase in non-enzymatic components of antioxidant defense system.
The blood plasma antioxidant activity was studied in the Russian and Kazakh aborigines of the southern Altai low and high mountains. There was established a decrease of the blood plasma antioxidant activity with age and a relatively low plasma antioxidant activity in the mid-mountain population; in its senior age groups, the gender differences of this parameter were revealed.
Previous studies have shown that testosterone production by the Leydig cells of aged Brown Norway rats is reduced from the relatively high levels produced by Leydig cells of young rats and that this reduction is not secondary to decreased serum luteinizing hormone concentration. The free radical theory of aging proposes that imbalance between pro-oxidants and the antioxidant defense system ultimately results in oxidative damage to cellular processes. With this in mind, we hypothesized herein that age-related reductions in steroidogenesis by Brown Norway rat Leydig cells may be associated with the impairment of the antioxidant defense system of these cells. To begin to test this hypothesis, we compared the activities and steady-state mRNA and protein levels of the antioxidant enzymes copper zinc (CuZn) superoxide dismutase (CuZnSOD, SOD1), manganese (Mn) superoxide dismutase (MnSOD, SOD2), and glutathione peroxidase (GPx) and the levels of reduced and oxidized glutathione in Leydig cells isolated from the testes of young (4-month-old) and aged (20-month-old) Brown Norway rats. For some studies, Leydig cells were isolated separately from aged testes that either had regressed because of age-related losses of germ cells or that were nonregressed. SOD (total) and GPx activities were found to decrease significantly with age whether or not the testes were regressed. CuZnSOD and MnSOD mRNA levels decreased with aging, though the magnitude of the decreases were considerably lower than the respective decreases in enzyme activities. GPx mRNA levels also decreased, which is consistent with the decreases seen in enzyme activity. MnSOD protein expression declined with age, and to a lesser extent, CuZnSOD did as well. Reduced and oxidized glutathione also exhibited age-related reductions in cells from both normal and regressed aged testes. The age-related decreases in Leydig cell antioxidant enzyme activities, gene expression, and protein levels and in glutathione were consistent with the hypothesis that the loss of steroidogenic function that accompanies Leydig cell aging may result in part from a decrease in the fidelity of the cellular antioxidant defense system.
In 3 groups of patients with neoplasms plasma antioxidant activity was measured by the yield of TBA-reactive products generated in lecithin-Fe(2+) model system. Patients with laryngeal, tongue, oropharyngeal, oral, and laryngopharyngeal tumors showed lower plasma antioxidant activity compared to patients with breast, lung, and bronchial cancer (p
Due to the points about dependence antioxidant activity of organism of human on a nationality, climatic conditions, quality of nutrition are scanty under study a estimate antioxidant activity of blood plasma of Altai's low and medium height altitude aborigines. As a result there has been discovered a dependence of antioxidant activity of blood plasma more upon age and at least geographical and climatic conditions, sex and quality of nutrition.
Due to the fact that age change theories are still under discussion a study has been conducted on the estimation of antioxidant and antiradical activity of blood plasma. For the experiment was taken a homogeneous group of people which separate populations differ in geographical and climatic parameters of their living conditions. As a result there has been discovered a dependence of Altaians' antioxidant system upon geographical and climatic conditions, and age.