Antioxidant effect of diphenyl diselenide on oxidative damage induced by smoke in rats: involvement of glutathione.

In the present study, the involvement of glutathione system in the restorative effect of diphenyl diselenide (PhSe)(2) on damage induced by cigarette smoke was investigated. Rat pups were progressively exposed to four, five, and six cigarettes for exposure periods of 15 min during their first, second, and third weeks of life. Thiobarbituric acid reactive species (TBARS) levels, components of the enzymatic antioxidant defenses (superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST) activities), and non-enzymatic antioxidant defenses (vitamin C and non-protein thiol (NPSH) levels) were examined in lungs of pups. The results demonstrated an increase in lipid peroxidation and the alteration in non-enzymatic and enzymatic antioxidant defenses induced by cigarette smoke exposure in lung of pups. Administration of (PhSe)(2) (0.5mg/kg) restored TBARS levels and antioxidant defenses in lungs of rat pups exposed to cigarette smoke. (PhSe)(2) treatment increased NPSH levels and GST activity per se in lungs of rat pups. Together these results indicate that (PhSe)(2) restored oxidative damage induced by cigarette smoke exposure in lungs of rat pups. The glutathione system is involved in antioxidant effect of this compound.

Diphenyl diselenide prevents oxidative damage induced by cigarette smoke exposure in lung of rat pups.

The effect of cigarette smoke exposure on lungs of rat pups was evaluated. Animals were exposed to passive cigarette smoke during 3 weeks and a number of toxicological parameters in lung of pups were examined, such as lipid peroxidation, delta-aminolevulic acid dehydratase (delta-ALA-D) activity, components of the enzymatic antioxidant defenses (superoxide dismutase (SOD) and catalase activities) and non-enzymatic antioxidant defenses (Vitamin C and non-protein thiol (NPSH) levels). Furthermore, a possible protective effect of diphenyl diselenide, (PhSe)(2), was studied. The results demonstrated an increase in lipid peroxidation, an inhibition of delta-ALA-D activity, a reduction of Vitamin C and NPSH levels induced by cigarette smoke exposure, indicating damage in lungs of rat pups. Oral administration of (PhSe)(2) (0.5mg/kg) restored TBARS levels, non-enzymatic antioxidant defenses and activity of delta-ALA-D. These results indicated that exposure to cigarette smoke enhanced oxidative stress, thereby disturbing the tissue defense system. (PhSe)(2) protected against oxidative damage induced by cigarette smoke exposure in lung of rat pups.

Repeated administration of diphenyl diselenide to pregnant rats induces adverse effects on embryonic/fetal development.

The present study was carried out to investigate the effects of diphenyl diselenide, (PhSe)(2), on embryo-fetal development. Dams were treated subcutaneously with 1.5, 3.0 and 6.0 mg/kg (PhSe)(2) from days 6 to 15 of pregnancy. After cesarean section at gestation day (GD) 20, external and skeletal abnormalities were evaluated. A decrease in maternal body weight gain was found in (PhSe)(2) groups, indicating maternal toxicity. There was a reduction in the fetal weight and in crown-rump (CR) length of fetuses at three doses tested. The occipito-nasal length decreased in fetuses from dams exposed to 3.0 mg/kg (PhSe)(2). Signs of delayed ossification in the skull, sternebrae and limbs were observed in all (PhSe)(2) groups, revealing a relation between morphological alterations and growth retardation in fetuses, but none of the changes appeared to be dose-dependent. Exposure of dams to (PhSe)(2) resulted in altered placental morphology that may have contributed to adverse reproductive outcomes. We concluded that (PhSe)(2) is toxic to dams and induces developmental delay of the fetal skeleton, but does not cause externally visible malformations in rat fetuses, in this experimental procedure.

7-Fluoro-1,3-diphenylisoquinoline-1-amine reverses the reduction in self-care behavior induced by maternal separation stress in rats by modulating glutamatergic/GABAergic systems.

7-Fluoro-1,3-diphenylisoquinoline-1-amine (FDPI) is a promising isoquinoline that elicits an antidepressant-like action in rodents. In this study, an animal model of stress induced by maternal separation was used to investigate the effects of FDPI in Wistar rats of 30 and 90 days of age. It was investigated the effects of maternal separation in the self-care behavior and the contribution of glutamatergic and gamma-aminobutyric acid (GABA)ergic systems in the FDPI action. Male Wistar rats were separated from their mothers for 3 h/day from postnatal day (PND) 1-10. The rats were treated at different ages (PND-30 and PND-90) with FDPI (5 mg/kg, intragastrically/7 days) and performed the splash test. Maternal separation reduced total grooming time in the splash test, an index of motivational and self-care behavior, and FDPI treatment was effective in reversing this behavior in rats at both ages. The neurochemical parameters were differently affected, dependent on the age of rats, by maternal separation and FDPI. Maternal separation increased the GABA uptake and the excitatory amino acid transporter 1 levels in the prefrontal cortices of rats at PND-30 and FDPI was effective against these alterations. At PND-90, maternal separation decreased the glutamate uptake and increased the GABA uptake and the N-methyl-D-aspartate (NMDA) receptor 2B levels in the prefrontal cortices of rats. FDPI reversed the neurochemical alterations caused by maternal separation in the prefrontal cortices of rats at PND-90. The results of this study demonstrated that FDPI reversed the reduction in self-care behavior induced by maternal separation stress in rats by modulating the glutamatergic/GABAergic systems in rats.

Exposure of mothers to diphenyl ditelluride during the suckling period changes behavioral tendencies in their offspring.

The long-lasting possible influence of maternal exposure to 0.03 mg/kg of diphenyl ditelluride during the first 14 days of lactational period on later offspring behavior was examined in Wistar rats. Open-field locomotor activity, spontaneous alternation in the T-maze, behavior in the elevated plus-maze, motor coordination in the coat-hanger and rotorod tasks were evaluated in 30 day old pups. There were no significant specific overt signs of maternal intoxication. There were a small (less than 5%) but significant transitory differences in the body weight gain of pups between exposed and control groups, which were apparent from day 30 of suckling. Locomotor activity in the open-field task was similar between telluride and control groups. In the coat-hanger test, the latency before falling for the tellurium group was higher than that of the control group. However, the behavior of both groups was similar in the rotorod test and spontaneous alternation in the T-maze. Tellurium-treated pups presented a higher number of entries and spent more time in the open arms of the elevated plus-maze than control pups. The behavioral alterations observed here after tellurium exposure can be cautiously interpreted as an indication of behavioral disinhibition. In conclusion, this study demonstrated that dam exposure to diphenyl ditelluride can cause subtle behavioral changes in the offspring, which can be related to neurotoxic effects of diphenyl ditelluride.

p-Chloro-diphenyl diselenide reverses memory impairment-related to stress caused by corticosterone and modulates hippocampal [(3)H]glutamate uptake in mice.

Chronic stress or chronically high levels of glucocorticoids can result in memory impairment. This study aimed to investigate if 4,4'-dichloro-diphenyl diselenide (p-ClPhSe)2 reverses memory impairment-related to stress caused by corticosterone administration in mice and its possible mechanism of action. Swiss mice received corticosterone (20µg/ml) in their drinking water during four weeks. In the last week, the animals were treated with (p-ClPhSe)2 (1 or 5mg/kg) by the intragastric route (i.g.) once a day for 7days. The cognitive performance of mice was assessed through the object recognition test (ORT), the object location test (OLT) and the step-down passive avoidance test (SDPA), some of predictive tests of memory. Biochemical parameters were determined and locomotor activity of mouse was performed to gain insight in (p-ClPhSe)2 toxicity. The findings demonstrated that treatment with (p-ClPhSe)2 in both doses was effective in reversing memory deficits in the ORT, the OLT and the SDPA caused by corticosterone exposure in mice. Treatment with (p-ClPhSe)2 at both doses reversed the increase in the [(3)H] glutamate uptake by hippocampal slices of mice treated with corticosterone. By contrast, [(3)H] glutamate uptake by brain cortical slices was not altered in mice exposed to corticosterone. The Na(+)K(+)ATPase activity was not altered in hippocampus and cerebral cortices of mice treated with corticosterone. There was no sign of toxicity in mice treated with (p-ClPhSe)2. This organoselenium compound reversed memory impairment-related to stress caused by corticosterone and modulated hippocampal [(3)H]glutamate uptake in mice.

Teratogenic effects of diphenyl diselenide in Wistar rats.

Diphenyl diselenide is an organoselenium compound with potential therapeutic use. The present study evaluates the effects of single maternal subcutaneous injection of 50 and 100mg/kg diphenyl diselenide [(PhSe)2] at gestational days (GD) 6, 10 or 17 in Wistar rats. The highest dose of (PhSe2 was also administered at GD 7-12. External and internal fetal soft-tissue examination was performed at GD 20. No mortality was observed in fetuses or dams at any (PhSe)2 treatment group. Neither did exposure to (PhSe)2 cause significant changes to fetal body weight, organ weight, or fetal size when administered at GD 6-8, 10-12 or 17. Exposure to 100mg/kg (PhSe)2 at GD 9 produced significant changes in fetal biometry (crown-rump (CR) length) and body weight. No significant increase in the proportion of fetuses with external visible abnormalities was observed in groups exposed to (PhSe)2. Skeletal anomalies were observed in fetuses in the GD 9-11 treatment groups and included incomplete ossification of cranial bones, misshapen and incomplete ossification of sternebrae, reduced sternebrae number, wavy and extra ribs, incomplete ossification of fore and hindpaw bones and incomplete ossification of sacral and caudal bones. We conclude that maternal administration of (PhSe)2 during GD 7-12 led to increased incidences of these skeletal variations or anomalies, but did not cause externally visible malformations in rat fetuses.

Diphenyl diselenide-induced seizures in rat pups: possible interaction with glutamatergic system.

The aims of the present study were to investigate the possible involvement of glutamatergic system in seizures induced by diphenyl diselenide in rat pups (postnatal day, 12-14) and to evaluate the role of oxidative stress in seizures induced by diphenyl diselenide/glutamate. Glutamate (4 g/kg of body weight) administered in association with diphenyl diselenide (500 mg/kg of body weight) increased the latency for the appearance of the first seizure episode, reduced lipid peroxidation levels and catalase, Na+,K+-ATPase and delta-ALA-D activities. At the lowest dose (5 mg/kg of body weight), diphenyl diselenide reduced the appearance of seizure episodes induced by glutamate but did not alter the latency for the onset of the first episode. Glutamate uptake was inhibited in glutamate, diphenyl diselenide (the highest dose) and in the association of diphenyl diselenide (both doses) and glutamate groups. Pre-treatment with a N-methyl-D-aspartate (NMDA) receptor antagonist, MK-801 (5S,10R-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate), significantly prolonged the latency for the onset for the first convulsive episode. A non-NMDA receptor antagonist, DNQX (6,7-dinitroquinoxaline-2,3-dione), did not protect seizures induced by diphenyl diselenide. The results of the present study demonstrated that: (a) when diphenyl diselenide and glutamate were administered concomitantly in pups, glutamate was the main responsible for the neurotoxic effects; (b) oxidative stress was not involved in glutamate-induced seizures; (c) NMDA glutamatergic receptors, were at least in part, involved in diphenyl diselenide- induced seizures; and (d) diphenyl diselenide, at the lowest dose, protected seizures induced by glutamate.

Copper-promoted carbon-nitrogen bond formation with 2-iodo-selenophene and amides.

We present here carbon-nitrogen bond formation via a coupling reaction of 2-iodo-selenophene catalyzed by Cu(I) in the presence of a base and an inexpensive ligand, and establish the first route to obtaining 2-nitrogen-selenophene derivatives in good yields. We can anticipate that this reaction works well with oxazolidinones, lactams, and aliphatic and aromatic amides, as nitrogen sources, in the absence of any supplementary additives. In addition, the reaction proceeded cleanly under mild reaction conditions and was sensitive to the ratio of amide/2-iodo-selenophene, as well as the nature of the ligand, base, and solvent.