Nickel, a potent toxic metal, is very harmful to the environment and to humans because of its in vivo accumulation in liver. The present study was conducted to investigate the protective effect of selenium (Se) against nickel toxicity on liver function in preimplanted Wistar albino rats. NiCl2 was given on day three of pregnancy either in distilled drinking water at a dose of 20 mg/L/day) for 16 consecutive days or as a single s.c. dose of 25, 50, or 100 mg/kg. Se was given as an s.c. injection (0.3 mg/kg) together with the higher dose (100 mg/kg) of NiCl2. Changes in plasma glucose, triglycerides and total cholesterol were measured in treated and control groups on days five and 20 of gestation. NiCl2 s.c. induced on day five of gestation showed a significant (<0.05) decrease in plasma triglycerides, with a dose of 100 mg / kg (-48 percent). This decrease was maintained at day 20 of gestation with doses of 50 mg / kg (-36 percent) and 100 mg / kg (-31 percent). In contrast, the low dose induced an increase of + 50 percent in plasma triglyceride compared to controls. In addition, NiCl2 s.c. caused on day five of gestation a significant decrease (p <0.05) in plasma total cholesterol with the low (-50 percent) and medium doses (-26 percent). However, the dose of 100 mg / kg induced a significant increase (114 percent) in plasma total cholesterol on day 20 of gestation compared to controls. NiCl2 s.c. induced a significant increase in plasma glucose (+125 percent) on day 20 of pregnancy. The pretreatment with Se counteracted the effects of NiCl2 on plasma glucose, total cholesterol and triglycerides.

NiCl2 administered in the drinking water induced a significant increase (<0.05) in plasma triglycerides (+68 percent) and cholesterol (+49 percent) on day 20 of gestation, while on day five of gestation NiCl2 s.c. induced a significant decrease in cholesterol (-31 percent) compared to controls. All doses of NiCl2 induced an alteration of liver architecture. Co-administration of Se with NiCl2 restored the structure of the liver.

These results suggested that selenium has a hepatoprotective role against the toxicity induced by NiCl2 administered subcutaneously in preimplanted rats. 

The environmental exposure to nickel may have a disastrous impact on human and animal public health. In this study we evaluated the protective effects of selenium against the nephrotoxic effects of NiCl2 in the preimplanted rats. NiCl2 was given on day 3 of pregnancy either as a single subcutaneous (sc) dose of 25, 50 or 100 mg/kg or in distilled drinking water at a dose of 20 mg/L/day for 16 consecutive days. Selenium was given as a sc injection (0.3 mg/kg) together with the higher dose (100 mg/kg) of NiCl2. Changes in plasma creatinine and urea were measured in treated and control groups on days 5 and 20 of gestation. The results showed that 100 mg / kg NiCl2 sc induced a significant increase in plasma creatinine on day 5 of gestation compared with controls. In contrast, on day 20 of gestation the NiCl2 induced a significant decrease in creatinine induced by doses of 25 and 50 mg / kg, whereas dose of 100 mg / kg increased plasma creatinine. Coadministration of selenium with NiCl2 significantly improved plasma creatinine on 5 and 20 days of gestation compared with NiCl2 administered alone. Moreover, on day 5 of gestation the NiCl2 increased significantly plasma concentrations of urea with the low and medium doses which became very significant with the highest dose. On day 20 of gestation, 50 mg / kg NiCl2 induced a significant decrease in plasma urea while the dose of 100 mg / kg induced an increase. Coadministration of selenium did not improve the concentrations of urea induced by NiCl2 alone. The NiCl2 administered in drinking water had no effect on plasma creatinine and urea. 3 doses of NiCl2 (sc) induced an alteration of renal architecture which is markedly improved by Selenium. The NiCl2 taken orally affects the medulla. These results suggested that selenium had no effect against nephrotoxicity induced by NiCl2 administered subcutaneously in pregnant rats.

Primary and secondary silylated alcohols are easily converted to bis(methoxyphenyl)methyl (BMPM) ethers in good yields using CuBr2 as catalyst in acetonitrile at room temperature. Various other protecting groups are compatible with this mild and convenient process.

Graphical abstract

Primary and secondary silylated alcohols are easily and rapidly converted to bis(methoxyphenyl)methyl (BMPM) ethers in good yields using CuBr₂ as catalyst in acetonitrile at room temperature. Various other protecting groups are compatible with this mild and convenient process.

Primary and secondary silylated alcohols are easily converted to bis(methoxyphenyl)methyl (BMPM) ethers in good yields using CuBr₂ as catalyst in acetonitrile at room temperature. Various other protecting groups are compatible with this mild and convenient process.

Graphical abstract

Primary and secondary silylated alcohols are easily and rapidly converted to bis(methoxyphenyl)methyl (BMPM) ethers in good yields using CuBr₂ as catalyst in acetonitrile at room temperature. Various other protecting groups are compatible with this mild and convenient process.

Cancer register in the Wilaya of Batna is a population based register that covers 1,173,852 inhabitants in 2011 (estimation made with a rate of population increase of 1.58% beginning from the 2008 RGPH census). A total number of 768 new cases has been identified, which represents a standardized incidence of 78.2 cases per 100,000. The most prevalent cancers in males were lung cancer (12.2 cases / 100,000 inhabitants), colorectal cancers and bladder cancers, respectively. In females, breast cancer was largely the most prevakent type, representing 30% of the total cancers, followed by colorectal cancers and thyroid cancer. In children aged 0 to 14, the standardized prevalence was 1.9 per 100,000 inhabitants, largely dominated by malignant blood and lymphoid organs cancers.

Objective: Potassium dichromate (K₂Cr₂O₇) is a potent pollutant for human and animal health. The purpose of the current work is to compare the effect of K₂Cr₂O₇ using variations in the dose, route of administration and duration of exposure in male and female Wistar albino rats and to research the interaction of chromium and selenium with a special focus on hematopoiesis. 

Materials and methods: K₂Cr₂O₇ was subcutaneously administered alone (10, 50 and 100 mg/kg body weight) or K₂Cr₂O₇ (10 mg/kg) in association with selenium (0.3 mg/kg) was administered to female Wistar albino rats. Male rats received in their drinking water K₂Cr₂O₇ (30 mg/L/day) alone or in association with Se (0.3 mg/L/day) for 20 consecutive days. The hematological parameters were evaluated on days 3, 6 and 21 after subcutaneous (sc.) treatment in female rats and on days 10 and 20 after oral administration in male rats. 

Results: K₂Cr₂O₇₋ induced during the first three days a significant (p < 0.05) dose-dependent decrease in the number of erythrocytes, platelets, leucocytes, lymphocytes and the hematocrit levels, and a dose-dependent increase in the number of granulocytes and monocytes. In the drinking water, chromium sc. significantly decreased the number of leucocytes and lymphocytes on day 10 after treatment and elevated the number of granulocytes and monocytes 20 days later. Selenium sc. counterbalanced the hematotoxic effects of chromium in female rats. 

Conclusion: These results suggest that the selenium has a protective role against the hematotoxicity of subcutaneous chromium in female Wistar rats.

Hexavalent chromium is a potent toxic agent. It has been found to be carcinogenic in human and animal. The purpose of the current work is to compare the effect of potassium dichromate (K₂Cr₂O₇) using variations in the dose, route of administration, and duration of exposure in male and female wistar albino rats with special focus on hematological parameters. K₂Cr₂O₇ was administered either in the drinking water with a dose of 30 mg/l for 20 consecutive days to male wistar albino rats, or as a single dose subcutaneously (s.c) at 10, 50 and 100 mg/Kg body weight (b w) to female wistar albino rats. Control groups received NaCl 0.9% (0.3 ml s.c), or drinking distilled water. Haematological parameters were recorded on day 3, 6, and 21 after subcutaneous exposure, or on day 10 and 20 after oral treatment. 10 mg/Kg b w of K₂Cr₂O₇ given subcutaneously induced during the first three days a marked decrease in the number of erythrocytes (-6%) of leucocytes (-30%) of platelets (-48%) and of hematocrit values (-15%), while the number of granulocytes is augmented (+124%) in comparison with control. Hemoglobin concentration and lymphocyte counts decreased markedly on day 6 after exposure. Chromium 50 mg/Kg b w, s.c mainly affected during the first three days the leucopoietic indices inducing leucopoenia (-55%), lymphopoenia
(-57%), monocytosis (+104%), granulocytosis (+204%), and thrombocytosis (+38%) if compared with control, while the erythrocytic counts and hemoglobin concentration decreased from day 6 (-22%) and (-21%) respectively until day 21 (-41%) and (-36%) respectively, and hematocrit values decreased at the end of experiment (-36%) in comparison with control. The higher dose of chromium (100 mg/Kg b w, s.c) reduced during the first three days the number of erythrocytes (-20%), platelets (-20%), total leucocytes (-55%), lymphocytes (-59%) and augmented the number of monocytes (+56 %), and granulocytes (+166%), while on day 6 the number of platelets augmented (+27%) in comparison with control. In drinking water, 30 mg/l of chromium given to male wistar albino rats had no effect on all erythropoietic parameters studied with the exception of the elevation (+21%) in platelet counts at the end of exposure, while the number of lymphocytes and total leucocytes were significantly reduced on day 20 after exposure (-37%) and (-37%) respectively. Conversely, the number of granulocytes and monocytes markedly increased on day 10 after exposure (+42%) and (+22%) respectively if compared with control. Short-term exposures to low dose of K₂Cr₂O_7, s.c induce in female wistar albino rats erythrocytopenia, thrombocytopenia, leucopoenia, lymphopaenia, granulocytosis, monocytosis, and a decrease in hematocrit values and hemoglobin concentration while in drinking water chromium was susceptible to affect in male rats the immune response inducing leucopoenia, lymphopoenia, monocytosis, and granulocytosis, while this oral route of exposure had no effect on erythropoietic parameters.

Several reports have suggested that soluble salts nickel may affect on hematopoiesis and development. In this study female Wistar albino rats (180-300g) received NiCl2, 6H2 O, subcutaneously (25, 50 and 100 mg/kg body weight (b w) or in drinking water (20 mg/100 ml). Selenium (0.3 mg/kg b w, s.c.) was combined to NiCl2 (100 mg/kg b w, s.c.). Control groups received NaCl 0.9% (0.3 ml s.c) or drinking distilled water. All groups of rats were injected on day 4 of pregnancy in pre-implantation period. Haematological parameters were recorded on day 6 and 21 of pregnancy. Developmental parameters were assessed on day 21 of pregnancy. 25 mg/kg b w, of NiCl2 s.c, induced on day 6 an immediate and significant decrease in erythrocyte counts, hematocrit values, and haemoglobin concentrations. This depletion was maintained on day 21 of pregnancy compared to control values.On other hand 50 mg/k b w, NiCl2, s.c, reduced on day 6 of pregnancy the erythrocyte counts, hematocrit values and platelets counts. Inversely, on day 21 this dose elevated the erythrocyte counts, hematocrit values and haemoglobin concentrations ,with depletion of the platelets counts compared to control values. In group introduced 100 mg/kg b w, of NiCl2, s.c had no effect on all haematological parameters studied. NiCl2, significantly reduced the maternal body weight on day 6 and 21 of pregnancy in a dose – dependent manner in rats treated subcutaneously and in drinking water compared with control values. NiCl2, s.c. (100 mg/kg b w) markedly reduced the number of live fetuses and elevated the number of abortions on day 21 of pregnancy compared to control values. NiCl2, s.c or in drinking water had no effect on fetal body weight. Selenium (0.3 mg/kg b w, s.c.) combined to NiCl2 (100 mg/kg b w, s.c.) did not improve the effect of NiCl2.