In the present study, we investigated whether DL-alpha-lipoic acid (LA) supplementation could have prooxidant or antioxidant effects on oxidative protein damage parameters such as protein carbonyl (PCO), nitrotyrosine (NT), advanced oxidation protein products (AOPP), and protein thiol (P-SH), as well as oxidative stress parameters such as total thiol (T-SH), non-protein thiol (Np-SH), and lipid hydroperoxide (LHP) in the brain and the skeletal muscle tissue of aged rats. PCO, and NT levels were increased, AOPP and P-SH levels were not changed in the brain tissue of aged rats given LA supplementation. On the other hand, TSH, Np-SH, and LHP levels were decreased in the brain tissue of aged rats given LA supplementation. The levels of the same parameters were not significantly different in the skeletal muscle tissue of aged rats given LA supplementation. The increased levels of protein oxidation markers such as PCO, and NT in the brain tissue of LA-supplemented aged rats compared with non-supplemented aged rats may suggest that oxidative protein damage is increased in LA-supplemented aged rats. We assume that an explanation for our findings regarding LA supplementation on protein oxidation markers in the brain tissue of aged rats may be due to the prooxidant effects of LA. Depending on post-mitotic tissue type and dosage of LA, the prooxidant effects of LA supplementation, should be considered in future studies.

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This experiment shows the protective effect of PJ in the EG-induced crystal depositions in renal tubules.

Hydrocephalus causes damage to periventricular white matter at least in part through chronic ischemia. Emphasizing the periventricular ischemia/hypoxia in hydrocephalus, various authors indicated the secondary biochemical impairment and oxidative damage in experimentally induced and congenital hydrocephalic rat brain. (-)-Epigallocatechin gallate (EGCG), the main constituent of green tea polyphenols, has been shown to be of some protective value in various models of neurological injury as a free oxygen radical scavenger. In the present study the effects of EGCG were examined on the periventricular oxidative damage in experimental childhood-onset hydrocephalus. Hydrocephalus was induced in 3 weeks-old rat pups by kaolin injection into the cisterna magna. A single daily dose of 50 mg/kg of EGCG injected into the peritoneum of the rats for 15 days significantly reduced periventricular white matter malondialdehyde levels when compared to non-treated hydrocephalic animals. Our results indicate that EGCG may have a protective effect against periventricular white matter oxidative damage in hydrocephalus induced infantile rats.

OBJECTIVE To investigate the effect of selective nuclear factor κ‐B (NFκ‐B) inhibitors, pyrolidium dithiocarbamate (PD) and sulfasalazine (SZ) on renal tubular necrosis and inducible nitric oxide synthase (iNOS) and NFκ‐B expression induced by gentamicin in rats. MATERIALS AND METHODS In all, 48 adult male Sprague‐Dawley rats were divided into six equal groups; group 1, control; group 2, injected with gentamicin for 10 days (100 mg/kg/day, intraperitoneal, i.p.); group 3, injected with gentamicin plus PD (100 mg/kg/day, i.p.); group 4, injected with gentamicin plus SZ (75 mg/kg/day, i.p.); group 5, injected with gentamicin plus distilled water (vehicle for PD); and group 6, injected with gentamicin plus ammonium hydroxide (75 mg/day, 1 m, vehicle for SZ) for 10 days. At 24 h after the last injection, rats were killed and the renal cortex separated from the medulla. A small sample was fixed in formaldehyde solution for histological and immunohistochemical examination. Blood samples were also taken to assess the serum levels of urea, creatinine, Na+, K+ and γ‐glutamyl transpeptidase (GT). Crude extracts of the cortex were used to determine reduced glutathione (GSH‐Px), NO and malondialdehyde (MDA). Immunohistochemically, iNOS and the active subunit of NFκB, P65, were evaluated using mouse monoclonal antibodies. RESULTS On haematoxylin and eosin staining, compared with the controls rats, gentamicin caused widespread tubular necrosis (grade 3 and 4) but in group 3 and 4 there was a marked reduction in the extent of tubular damage. Immunohistochemically there was more marked staining for iNOS and P65 expression in rats given gentamicin than in the control and group 3 and 4 (P < 0.001). In groups 3 and 4 iNOS and P65 expression were significantly less than in rats given only gentamicin. There was no significant difference in serum levels of Na+, K+, blood urea nitrogen and creatinine. Compared with control rats, gentamicin caused hyperproteinuria, a marked increase in levels of serum γ‐GT, MDA and NO, and a decrease in GSH‐Px (P < 0.001). CONCLUSION These results indicate that gentamicin induces iNOS expression through activation of NFκ‐B (P65). It is possible to prevent gentamicin‐induced nephrotoxicity using selective NFκ‐B inhibitors.

Purpose: To assess estrogen-related changes in the redox status of the brain and liver proteins as well as the systemic oxidative stress in ovarectomised (OVX) rats Methods: Twelve-week-old, sexually mature female Sprague–Dawley rats (200-250g) were randomly divided into four groups: The following treatment combinations were administrated daily to all in 0.05 ml 96% ethanol solution by gastric gavage. (1) Sham operation (2) OVX rats (3) OVX rats [0.02 mg/kg/day of 17?-estradiol (E2) and 0.01 mg/kg/day of norethisterone acetate] (4) OVX rats [E2 (0.01 mg/kg/day) and drospirenon (0.02 mg/kg/day)]. Estrogen levels were determined using routine clinical-chemistry methods. We also measured protein oxidation parameters such as protein carbonyl (PCO), total thiol (T-SH) and the other oxidative stress markers malondialdehyde (MDA) and glutathione (GSH). Results: Ovariectomy resulted in abnormal elevation of plasma and tissue oxidative stress markers and changes in redox status of the proteins in tissue dependent manner. Supplementation of various estrogens combinations partially alleviated these abnormalities and restored redox homeostasis of proteins after the ovariectomy. Among the studied protein oxidation parameters, plasma and tissue PCO levels of the OVX rats were higher than those of the control groups (P < 0.01). Hormone replacement therapies (HRT) caused a decrease in PCO and MDA in both plasma and tissue of the OVX rats (P < 0.01). HRT in OVX rats decreased plasma MDA and increased liver and brain GSH (P < 0.01). Liver MDA levels of the Drospirenon-treated rats were lower than in the norethisterone acetate group (P < 0.01). On the other hand, Drospirenon increases brain GSH s more effectively than norethisterone acetate (P < 0.01). After bilateral oopherectomy, plasma and tissue T-SH levels decreased in the OVX group compared with control (P < 0.01). Norethisterone acetate increased plasma T-SH more effectively than Drospirenon (P < 0.05) Conclusions: The study showed the extent of oxidative protein damage (OPD) in this model of estrogen deficiency. The protective effect of estrogens against tissue specific OPD suggests that estrogens play an important role within the antioxidant defense systems in plasma, liver and brain. The exact molecular mechanisms leading to these findings are not yet completely known. Meanwhile, hormone replacement therapy for the prevention of OPD in a tissue specific manner may be required.

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