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Introduction: In spite of increasing usage of metal nanoparticles, few studies have been conducted on their side effects, particularly under in-vivo conditions. Hence, the present study aimed to assess the effect of magnesium oxide nanoparticles (MgONPS) on the liver and kidney function of rats in vivo Methods: Concentrations of 62.5, 125, 250 and 500 ppm of MgONPS (10-15 nm size) were intraperitoneally injected into rats, and then the liver and kidney function were investigated. Results: The study results revealed that MgONPS caused different changes in liver enzymes. In fact, the AST and ALP values were significantly increased compared with the control group, whereas the levels of ALT, Urea and Creatinine did not demonstrate any significant differences. In addition, no histological disorders were observed in the kidney tissue, in contrary to liver tissue in which some alternations were observed such as apoptosis and proliferation of small bile ductules indicating damage of tissue in expose of high doses of MgONPS. Conclusions: The study findings indicated that magnesium oxide nanoparticles in higher doses of 250 ppm can have toxic effects on the liver, therefore their toxicity should be considered, while applying them in different fields of industries.

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Introduction: Nanoparticles (NPs) are one of the antibacterial substances, among them nanoparticles type MgO and Fe₂O₃ are less toxic to mammalian cells. So, the aim of this study was investigation of combination effects of iron oxide and magnesium oxide nanoparticles on the growth of Staphylococcus aureus and Escherichia coli (E.coli) to achieve the optimum combination of nanoparticles inhibit the growth of Staphylococcus aureus and Escherichia coli in food (juice).

Methods: In this experimental research, the effect of MgO and Fe₂O₃ Nanoparticles compound on Staphylococcus aureus and Escherichia coli bacteria in liquid environment was investigated, and then their effect was investigated separately in juices of carrot, pomegranate and apple via colony count approach. Also, scanning electron microscopy was used to characterize the morphological changes of Staphylococcus aureus and Escherichia coli after antimicrobial treatments. The results of the research were analyzed using one way ANNOVA.

Results: The results of the research indicated that in liquid medium, these nanoparticles lead to reduce the growth of both bacteria. compound of 1.5Mg+0.5Fe₂O₃ was introduced as the most appropriate antibacterial compounds; Staphylococcus aureus sensitivity to Escherichia coli was higher against nanoparticles. The findings of research about the juices revealed that the combined effect of nanoparticles reduced the growth of both bacteria. the combined effect of Fe₂o₃ and MgO nanoparticles treatments distorted and damaged the cell membrane, resulting in a leakage of intracellular contents and eventually the death of bacterial cells.

Conclusion: Nanoparticles in the allowed concentrations have significant effect on Staphylococcus aureus and Escherichia coli bacteria.