The effects of Vitamin E administration on antioxidant enzyme activities and nitrite-nitrate levels of the reperfused rat kidney tissues were investigated by performing a 60 rain ischemia followed by 24 and 72 hours of reperfusion. Vitamin E administration or the placebo (SF) was applied as 100 mg/kg BW. As expected, catalase (CAT) (p<0.05) and superoxide dismutase (SOD) (p<0.05) activities of ischemia/reperfused (I/R) kidney tissue were lower and malondialdehyde (MDA) levels were higher than control kidneys in both SF and vitamin E treated groups following 24 h reperfusion. During reperfusion of long term (72 h), vitamin E triggered a decrease in the MDA levels in the ischemic tissue, while it did not provoke a significant effect on SOD and catalase activities. Total nitrite levels of ischemic tissues in both of the groups were higher than matched control kidneys and this elevation was more clear in the vitamin E treated group. Our results showed that vitamin E has a protective effect on I/R injury, by a direct chain breaking effect on lipid peroxidation (LPO) and hence preventing the nitric oxide (NO) reservoir of ischemic tissue. Alfa-tocopherol may be a promising agent for the prevention of tissue injury caused by free oxygen radicals.

This paper was designed to investigate whether phototherapy is an oxidative stress in newborn infants undergoing phototherapy. A day-light continuous phototherapy was given to jaundiced 20 term and 16 preterm newborns for 72 hours. We measured serum vitamin E and the activities of red blood cell anti-oxidation enzymes (superoxide dismutase, catalase and glutathione peroxidase) before and after 72 h of phototherapy. Serum vitamin E levels were not different before and after 72 h of phototherapy in both preterm and term infants. In several studies, antioxidant enzyme activities have been shown to increase in response to oxidative stresses. In this study, however, the antioxidant enzyme activities in the hemolysate were similar before and at the end of the phototherapy in both preterm and full term. In conclusion, the results of our in vivo study do not confirm the thesis that phototherapy is an oxidative stress in newborn infants. Therefore, phototherapy would preferably seem to be safe and efficient method of treatment for all neonates presenting with hyperbilirubinemia.

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Trimetazidine (TMZ), an anti-ischemic agent with proposed antioxidant properties, was used in a chronic colitis model in order to evaluate its effectiveness as a therapeutic agent in chronic colitis. Treatment of male Swiss Albino rats with ethanol (50%) and trinitrobenzenesulfonic acid (TNBS) (30 mg/kg) produced colitis as evidenced by histopathologic damage and inflammatory alterations, lipid peroxidation [increased malondialdehyde (MDA) levels], and enhanced neutrophil infiltration [increased myeloperoxidase (MPO) activity] without marked change in glutathione status. Administration of TMZ (5 mg/kg) to TNBS-treated rats failed to affect the TNBS-induced changes in histopathology and MPO activities. Unexpectedly, intrarectal (i.r.) administration of TMZ significantly elevated colonic MDA levels to a greater extent than TNBS alone. Intraperitoneal (i.p.) TMZ treatment seemed to increase total glutathione (tGSH), GSH, and GSH/GSSG values. In conclusion, our results demonstrated that (a) i.r. administration of ethanol and TNBS is an effective way of inducing a chronic colitis model, (b) inflammation and lipid peroxidation augment tissue damage in the chronic colitis model, (c) i.p. TMZ treatment significantly inhibits MDA production in the chronic colitis model, (d) TMZ treatment is more effective via the i.p. compared to i.r. route, and (e) TMZ seems to show its antioxidant effect via preserving the tissue's GSH/GSSG ratios.

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