Attenuating effects of selenium and zinc against hexavalent chromium-induced oxidative stress, hormonal instability, and placenta damage in preimplanted rats.

As a toxic metal, hexavalent chromium (CrVI) has effects on both the reproductive and endocrine systems. This study aimed to evaluate the protective effects of selenium (Se) and zinc (Zn) against the toxicity of chromium on the placenta in pregnant Wistar albino rats. Thirty pregnant Wistar rats were divided into control and four treated groups, receiving subcutaneously (s.c) on the 3rd day of pregnancy, K2Cr2O7 (10 mg/kg body weight (bw)) alone, or in association with Se (0.3 mg/kg bw), ZnCl2 (20 mg/kg bw), or both of them simultaneously. Plasma steroid hormones, placenta histoarchitecture, oxidative stress profile, and developmental parameters were investigated. These results showed that K2Cr2O7 exposure induced a significant increase in the levels of both plasma estradiol (E2) and placenta malondialdehyde (MDA), the number of fetal resorptions, and percent of post-implantation loss. On the other hand, K2Cr2O7 significantly reduced developmental parameters, maternal body and placenta weight, and plasma progesterone (P) and chorionic gonadotropin hormone (ß HCG) levels. However, K2Cr2O7 significantly decreased the placenta activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), reduced glutathione (GSH), and nonprotein sulfhydryl (NPSH). These changes have been reinforced by histopathological evaluation of the placenta. Se and/or ZnCl2 supplementation provoked a significant improvement in most indices. These results suggest that the co-treatment with Se or ZnCl2 strongly opposes the placenta cytotoxicity induced by K2Cr2O7 through its antioxidant action.

Nephroprotective Efficacy of Selenium and Zinc Against Potassium Dichromate-Induced Renal Toxicity in Pregnant Wistar Albino Rats.

Hexavalent chromium (CrVI) compounds are potent toxicants commonly used in numerous industries. Thus, potential toxic effects and health hazards are of high relevance. Selenium (Se) and zinc (Zn) are known for their antioxidant and chemoprotective properties. However, little is known about their protective effects against CrVI-induced renal damage during pregnancy. In this context, the present study aimed to investigate the protective efficacy of these two essential elements against potassium dichromate-induced nephrotoxicity in pregnant Wistar Albino rats. Female rats were divided into control and four treated groups of six each receiving subcutaneously on the 3rd day of pregnancy, K2Cr2O7 (10 mg/kg, s.c. single dose) alone, or in association with Se (0.3 mg/kg, s.c. single dose), ZnCl2 (20 mg/kg, s.c. single dose) or both of them simultaneously. The nephrotoxic effects were monitored by the evaluation of plasma renal parameters, oxidative stress biomarkers, DNA damage, and renal Cr content. The obtained results showed that K2Cr2O7 disturbed renal biochemical markers, induced oxidative stress and DNA fragmentation in kidney tissues, and altered renal histoarchitecture. The co-administration of Se and/or ZnCl2 has exhibited pronounced chelative, antioxidant, and genoprotective effects against K2Cr2O7-induced renal damage and attenuated partially the histopathological alterations. These results suggest that Se and Zn can be used as efficient nephroprotective agents against K2Cr2O7-induced toxicity in pregnant Wistar Albino rats.

Protective Effects of Selenium and Zinc Against Nickel Chloride-Induced Hormonal Changes and Oxidative Damage in Thyroid of Pregnant Rats.

Nickel chloride (NiCl2) is a heavy metal that may affect the function of the thyroid. Selenium (Se) and zinc (Zn) are essential trace elements involved in thyroid hormone metabolism. However, little is reported about thyrotoxicity during gestation. The current study aimed to investigate the protective effects of selenium and zinc against NiCl2-induced thyrotoxicity in pregnant Wistar rats. Female rats were treated subcutaneously (s.c.) on the 3rd day of pregnancy, with NaCl 0.9% and served as control, NiCl2 (100 mg/kg body weight (BW)) alone, or in association with Se (0.3 mg/kg, s.c.), ZnCl2 (20 mg/kg, s.c.), or both of them simultaneously. Oxidative stress parameters, thyroid biomarkers, and histopathological examination were evaluated. Results showed that NiCl2 exposure caused a significant decrease in maternal body weight and an increase in absolute and relative thyroid weight compared to the controls. NiCl2 administration also led to decreased plasma triiodothyronine (T3) and thyroxine (T4) with a concomitant significant increase in thyroid-stimulating hormone (TSH) levels when compared to that of control. In addition, an overall pro-oxidant effect was associated with a decrease in the reduced glutathione (GSH) and nonprotein thiol (NPSH) contents and the enzymatic activity of glutathione peroxidase (GPx) and superoxide dismutase (SOD), and an increase in malondialdehyde (MDA). These biochemical disturbances were confirmed by histological changes. However, the co-treatment of Se and/or ZnCl2 attenuates NiCl2-induced changes. Our findings suggested that Se and ZnCl2 ameliorated NiCl2-induced thyrotoxicity in pregnant Wistar rats by exhibiting antioxidant effects.

Protective effects of selenium and zinc against potassium dichromate-induced thyroid disruption, oxidative stress, and DNA damage in pregnant Wistar rats.

Hexavalent chromium (CrVI) is an environmental pollutant and an endocrine-disrupting metal. Se and Zn are essential trace elements, known to play a crucial role in thyroid homeostasis. However, there is a lack of data reporting thyrotoxicity during gestation. In this study, we investigated the protective effects of selenium and zinc against potassium dichromate-induced thyrotoxicity in pregnant Wistar rats. Thirty pregnant Wistar rats were divided into control and four treated groups receiving subcutaneously (s.c) on the 3rd day of pregnancy, K2Cr2O7 (10 mg/kg, s.c) alone, or in association with Se (0.3 mg/kg, s.c), ZnCl2 (20 mg/kg, s.c), or both of them simultaneously. The hormonal profile, oxidative stress biomarkers, DNA damage, and histological modifications were evaluated. Our main findings showed that K2Cr2O7 promoted hypothyroidism, oxidative stress, genotoxicity, and histological alterations in the thyroid gland. The co-treatment with Se or ZnCl2 has mitigated K2Cr2O7-induced thyrotoxicity in pregnant Wistar rats by exhibiting antioxidant and genoprotective effects. However, the combined co-treatment of both of them was less thyroprotective, and therefore, further investigations on the synergetic interaction of Se and Zn against CrVI toxicity using different doses and exposure routes are required.

The toxic effects of nickel chloride on liver, erythropoiesis, and development in Wistar albino preimplanted rats can be reversed with selenium pretreatment.

The exposure to nickel chloride (NiCl2) can cause hematotoxicity and hepatotoxicity and canaffect development. The present study pertains to the protective effect of selenium (Se) against NiCl2-induced toxicity in preimplanted Wistar albino rats. The subcutaneous (s.c.) administration of 25 or 50 mg/kg of NiCl2 to Wistar albino rats on day 3 of gestation induced an immediate and significant decrease in maternal body weight and anemia 2 days after treatment. In addition, an increase in plasma aspartate aminotransferase (AST) was observed. These effects were maintained on day 20 of gestation. Moreover, a significant increase in plasma alanine aminotransferase (ALT) levels was observed with the administration of 25 mg/kg of NiCl2. Conversely, administration of 50 mg/kg of NiCl2 by s.c. injection increased erythropoiesis at day 20 of gestation and decreased platelets counts. In addition, administration of 100 mg/kg of NiCl2 markedly reduced the maternal body weight and number of live fetuses and increased fetal loss, predominantly at the end of the experimental period. All dose levels of NiCl2 caused an alteration in the hepatic histoarchitecture. When 0.3-mg/kg Se was injected s.c. with 100-mg/kg NiCl2, the levels of plasma AST and ALT and the structure of the liver were restored. Administration of 20 mg/L/day of NiCl2 in the drinking water significantly reduced the maternal body weight at day five of gestation as well as erythropoiesis during the exposure period. The present study suggests that Se can counteract the nocuous effect of nickel on the liver; however this antioxidant did not prevent alterations in development and erythropoiesis.