Protective effects of melatonin on the activity of SOD, CAT, GSH-Px and GSH content in organs of mice after administration of SNP.

Sodium nitroprusside (SNP) is an antihypertensive drug with proven dose-dependent toxic effects attributed mainly to the production of cyanide but also excesive nitric oxide (NO) and derived reactive species. The present study evaluated whether melatonin administration would have time-dependent protective effect against SNP−induced toxicity. Male Swiss mice were used in this study. Control mice were treated with 0.9% NaCl; the second group was injected with 10 mg melatonin (MEL)/kg body weight (b.w.); the third group was given SNP at the dose of 3,6 mg/kg b.w.; the fourth group received both MEL and SNP at the same doses. In homogenates of brain, liver and kidneys, activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were estimated after 3, 6 and 24 h of drugs administration. The concentration of reduced glutathione (GSH) was also evaluated in the blood, brain, liver and kidneys of mice at the same time intervals. In animals receiving MEL, the highest levels of GSH were observed in all the organs as compared to the control after 3, 6 h. Meanwhile, SNP decreased GSH concentration in the blood, brain, liver and kidneys in all time intervals. Administration of MEL in combination with SNP increased the GSH levels in all organs, as compared to the administration of SNP alone; this effect was observed after 3, 6 and 24 h. The activity of SOD, CAT and GSH-Px in the MEL-treated group increased after 3 h in all the organs, while in liver and kidney the increase was also observed after 6 h. Conversely, the SNP intoxication caused a decrease of the activity of enzymes in the tested organs in all intervals, while administration of MEL + SNP resulted in increased activities of SOD, CAT and GSH-Px in all the organs after 3 h and 6 h. The investigation carried out in the present study provide new data to add to the study of antioxidant properties of MEL and SNP-induced oxidative stress with regard to time-dependent properties in different types of tissues.

Antioxidative effects of α-lipoic acid in the brain, liver and kidneys in selected mouse organs exposed to zymosan.

This study investigated the role of exogenous α-lipoic acid (ALA) in the inflammation caused by zymosan application. Seventy-two adult male white mice were divided into twelve groups: three control groups, three Zymosan groups, three ALA groups and three groups being the combination of Zymosan and ALA. In the experimental groups, the animals were decapitated after 3, 6 and 24 hours after the injection. The activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were determined in the brain, liver and kidneys of the mice. After the injection of Zymosan, it was found that the activity of SOD, CAT and GSH-Px in the brain, liver and kidneys of mice was significantly lower in all time periods. The administration of ALA resulted in an opposite effect, namely, it increased the activity of the enzymes studied in the selected organs of mice. The Zymosan and ALA combination significantly inhibited the decrease in the activity of the enzymes compared with the values obtained in the groups of animals which received Zymosan only. The results of our study, using the Zymosan-induced inflammation, clearly indicate that ALA is an anti-inflammatory agent.

Influence of zymosan A on the content of ascorbic acid in mice.

The aim of the study was to determine the effects of single intraperitoneal injections of zymosan A on changes in the content of ascorbic acid (ASC) in the brain, liver, spleen and kidneys of mature male mice, line Swiss. The experiments were carried out on 54 mice divided into 3 control groups and 6 experimental groups. Samples for analysis were collected after 3 h (experimental group I), 6 h (experimental group II) and 24 h (experimental group III) after the injection of zymosan A at the dose of 1 mg/kg body weight (b.w.). For groups IV, V and VI, the organs were removed at the same time as for the previous groups, but the animals were administered zymosan A at the dose of 100 mg/kg b.w. The content of ASC was then determined. The results showed that zymosan A significantly reduced the content of ASC in the brain of the mice in all the experimental groups, in the spleen in all the experimental groups except of group I (after 3 h since injection of zymosan A at 1 mg/kg b.w.), in the liver only in experimental groups IV, V and VI (after the injection of zymosan A at 100 mg/kg b.w.), while in the kidneys the effects were observed for groups III, V and VI. The data suggest that the observed decrease in the content of ASC is caused by the oxidative activity of zymosan A.