Background: The impact of chromium exposure was studied on liver, kidney, testis, spleen, cerebrum and cerebellum of male Wistar rats (80-100 g body weight).Methods: It was observed that treatments of rats with chromium (i.p. at a dose of 0.8 mg / 100 g body weight per day) for a period of 28 days caused significant increase in chromium content while declining the body weight along with the organ weight, except liver.Results: Decreased acid phosphatase (ACP) and alkaline phosphatase (ALP) activities were observed in most of the organs. Significant increases in the cholesterol contents of all the organs were associated with the significant decreases in the level of phospholipids. Lipid peroxidation decreased in liver and kidney while it increased in testis, cerebrum and cerebellum. Reduced glutathione (GSH) level was found to be increased in liver, spleen and cerebrum, and decreased in kidney and testis. Catalase acti It is suggested that chromium treatment at the present dose and duration induces general tissue toxicity by causing membrane damage due to changes in the relative proportion of cholesterol and phospholipids in the membrane structure. In addition, tissue specific toxicity is affected by lipid peroxidation in testis, cerebrum and cerebellum, and in other tissues increased GSH level or enhanced catalase activity prevents lipid peroxidation to occur due to reactive oxygen species produced from chromium transformation.

Nowadays, multi-walled carbon nanotubes (MWCNTs) are used in various industries. Considering the exposure probability of these nanomaterials to humans, the purpose of the present study is to assess the effect of MWCNTs on cellular toxicity of human alveolar epithelial. The A549 cells were cultured and treated to various doses of MWCNTs at three different times. Finally, the Tetrazolium colorimetric (MTT) assay was implemented for evaluating the cellular viability. The results indicated that the cytotoxicity for MWCNTs on the human alveolar epithelial cells is related to dose and time of exposure. The inhibitory concentration of 50% (IC50) and non-observed adverse effect concentration (NOAEC) are calculated to be 103. 6 as well as 0. 65μ g/mL, respectively. The findings of this present study could contribute to a better understanding of MWCNTs substances and might be useful as a basis for the future risk evaluation studies of exposed population in industries.

Purpose: The wide application of cupric oxide nanoparticles (copper (II) oxide, CuO-NPs) in various fields has increased exposure to the kind of active nanomaterials, which can cause negative effects on human and environment health. Although CuO-NPs were reported to be harmful to human, there is still a lack information related to their toxic potentials. In the present study, the toxic potentials of CuO-NPs were evaluated in the liver (HepG2 hepatocarcinoma) and intestine (Caco-2 colorectal adenocarcinoma) cells. Methods: After the characterization of particles, cellular uptake and morphological changes were determined. The potential of cytotoxic, genotoxic, oxidative and apoptotic damage was investigated with several in vitro assays. Results: The average size of the nanoparticles was 34. 9 nm, about 2%-5% of the exposure dose was detected in the cells and mainly accumulated in different organelles, causing oxidative stress, cell damages, and death. The IC50 values were 10. 90 and 10. 04 µ g/mL by MTT assay, and 12. 19 and 12. 06 µ g/mL by neutral red uptake (NRU) assay, in HepG2 and Caco-2 cells respectively. Apoptosis assumes to the main cell death pathway; the apoptosis percentages were 52. 9% in HepG2 and 45. 5% in Caco-2 cells. Comet assay result shows that the highest exposure concentration (20 µ g/mL) causes tail intensities about 9. 6 and 41. 8%, in HepG2 and Caco-2 cells, respectively. Conclusion: CuO-NPs were found to cause significant cytotoxicity, genotoxicity, and oxidative and apoptotic effects in both cell lines. Indeed, CuO-NPs could be dangerous to human health even if their toxic mechanisms should be elucidated with further studies.