Biosynthesis of Silver Nanoparticles Using Azadirachta indica and Their Antioxidant and Anticancer Effects in Cell Lines.

In the present study, silver nanoparticles (Ag-NPs) were synthesized using Azadirachta indica extract and evaluated for their in vitro antioxidant activity and cytotoxicity efficacy against MCF-7 and HeLa cells. The silver nanoparticles (Ag-NPs) were formed within 40 min and after preliminary confirmation by UV-visible spectroscopy (peak observed at 375 nm), they were characterized using a transmission electron microscope (TEM) and dynamic light scattering (DLS). The TEM images showed the spherical shape of the biosynthesized Ag-NPs with particle sizes in the range of 10 to 60 nm, and compositional analysis was carried out. The cytotoxicity and antioxidant activity of various concentrations of biosynthesized silver nanoparticles, Azadirachta indica extract, and a standard ranging from 0.2 to 1.0 mg/mL were evaluated. The 2,2-Diphenyl-1-picrylhydrazyl (DPPH) activity of the biosynthesized Ag-NPs and aqueous leaf extract increased in a dose-dependent manner, with average IC50 values of the biosynthesized Ag-NPs, aqueous leaf extract, and ascorbic acid (standard) of 0.70 ± 0.07, 1.63 ± 0.09, and 0.25 ± 0.09 mg/mL, respectively. Furthermore, higher cytotoxicity was exhibited in both the MCF-7 and HeLa cell lines in a dose-dependent manner. The average IC50 values of the biosynthesized Ag-NPs, aqueous leaf extract, and cisplatin (standard) were 0.90 ± 0.07, 1.85 ± 0.01, and 0.56 ± 0.08 mg/mL, respectively, with MCF-7 cell lines and 0.85 ± 0.01, 1.76 ± 0.08, 0.45 ± 0.10 mg/mL, respectively, with HeLa cell lines. Hence, this study resulted in an efficient green reductant for producing silver nanoparticles that possess cytotoxicity and antioxidant activity against MCF-7 and HeLa cells.

A comparison of poly-ethylene-glycol-coated and uncoated gold nanoparticle-mediated hepatotoxicity and oxidative stress in Sprague Dawley rats.

BACKGROUND: Gold nanoparticles (GNPs) and their functional derivatives are of great interest because of their many biomedical applications. GNPs are increasingly being incorporated into new diagnostic and therapeutic approaches in medicine. Consequently, there has been a strong push to fully understand their interactions with blood components. The agglomeration of cells reflects the interaction of nanoparticles with blood components. METHODS: The main aim of this study was to compare the effects of poly-ethylene-glycol (PEG)-oated and uncoated GNPs on the generation of reactive oxygen species (ROS); on the actions of distinct hepatotoxicity biomarkers such as alanine (ALT) and aspartate (AST) aminotransferases, and alkaline phosphatase (ALP); and on the histology of liver tissues in the rat model. Four distinct doses of PEG-coated and uncoated GNPs (12.5, 25, 50, and 100 µg/kg body weight) were used. Each group consisted of three rats receiving an oral administration of PEG-coated and uncoated GNPs for 5 days with one dose per 24 hours. The control group consisted of three rats that received deionized water. Twenty-four hours after the last treatment, samples were collected following standard procedures. RESULTS: PEG-coated and uncoated GNPs enhanced the generation of ROS and the activity of serum aminotransferases (ALT/AST) and ALPs relative to the negative control. A liver histology assessment of GNP-exposed rats revealed statistically significant responses in the variation of the morphologies of tissues relative to those of the negative control. Nonetheless, uncoated GNPs demonstrated enhanced hepatotoxic outcomes relative to those of PEG-coated GNPs. The results demonstrated that both GNPs may be able to promote hepatotoxicity in Sprague Dawley rats through mechanisms of oxidative stress. However, uncoated GNPs have more harmful effects than PEG-coated GNPs relative to the negative control. CONCLUSION: Taken together, the results of this study indicate that PEG-coated GNPs may be safer to use in nanomedicinal applications than uncoated GNPs. However, more studies must be performed to confirm the outcomes of PEGylation.

Biochemical and histopathological evaluation of Al2O3 nanomaterials in kidney of Wistar rats.

The present study was conducted to evaluate the response of kidneys in Wistar rats following long-term exposure to Al2O3 nanomaterials (NMs). To achieve this objective, Al2O3 of three different sizes (30 nm, 40 nm and bulk) was orally administered for 28 days to 9 groups of 10 Wistar rats each at the dose of 500, 1000 and 2000 mg/kg/rat. A tenth group of 10 rats received distilled water and served as control. After 28 days of exposure the animals were sacrificed and the serum was collected and tested for the activity levels of creatinine and urea following standard methods. Induction of oxidative stress was also investigated by assessing thiobarbituric acid reactive substances (TBARS) (MDA), protein carbonyl, reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) activities. A histopathological evaluation was also performed to determine the extent of kidney damage. The results showed that both serum creatinine and serum urea levels increased significantly in the treated rats compared to control animals. The increase was found to be more in Al2O3-30 nm treated rats followed by Al2O3-40 nm and Al2O3-bulk treated rats in a dose-dependent manner. Further administration of Al2O3 significantly increased the activities of TBARS, protein carbonyl, catalase and decreased the activities of GSH and SOD in a dose-dependent manner in the kidney of rats compared with the control group. Histopathological evaluation showed significant morphological alterations in kidney tissues of treated rats in accordance with biochemical parameters. Taken together, the results of this study demonstrate that Al2O3 is nephrotoxic and its toxicity may be mediated through oxidative stress. Further, the results suggest that prolonged oral exposure to Al2O3 NMs has the potential to cause biochemical and histological alterations in kidney of rats at high concentration.

Toxicity Evaluation of Graphene Oxide in Kidneys of Sprague-Dawley Rats.

Recently, graphene and graphene-related materials have attracted a great deal of attention due their unique physical, chemical, and biocompatibility properties and to their applications in biotechnology and medicine. However, the reports on the potential toxicity of graphene oxide (GO) in biological systems are very few. The present study investigated the response of kidneys in male Sprague-Dawley rats following exposure to 0, 10, 20 and 40 mg/Kg GO for five days. The results showed that administration of GOs significantly increased the activities of superoxide dismutase, catalase and glutathione peroxidase in a dose-dependent manner in the kidneys compared with control group. Serum creatinine and blood urea nitrogen levels were also significantly increased in rats intoxicated with GO compared with the control group. There was a significant elevation in the levels of hydrogen peroxide and lipid hydro peroxide in GOs-treated rats compared to control animals. Histopathological evaluation showed significant morphological alterations of kidneys in GO-treated rats compared to controls. Taken together, the results of this study demonstrate that GO is nephrotoxic and its toxicity may be mediated through oxidative stress. In the present work, however, we only provided preliminary information on toxicity of GO in rats; further experimental verification and mechanistic elucidation are required before GO widely used for biomedical applications.

Hepatotoxicity and Ultra Structural Changes in Wistar Rats treated with Al2O3 Nanomaterials.

The present study was designed to evaluate the hepatotoxicity of aluminium oxide (Al2O3). To achieve this objective, Al2O3 of three different sizes (30nm, 40nm and bulk) was orally administered for 28 days to 9 groups of 10 Wistar rats each, at the dose of 500, 1000 and 2000 mg/Kg/rat. A tenth group of 10 rats received distilled water and served as control. After 28 days of exposure, the animals were sacrificed and the serum was collected and tested for the activity levels of aminotransferases (AST or GOT and ALT or GPT), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) enzymes following standard testing methods. Reduced glutathione (GSH) content was also measured in the liver tissue to study the oxidative stress. A histopathological evaluation was also performed to determine the extent of liver injury. Study results indicated that the activity of both the aminotransferases (AST and ALT), ALP and LDH increased significantly in Al2O3 treated rats compared to control animals. The increase was found to be more pronounced with Al2O3 - 30nm followed by Al2O3 - 40nm and Al2O3 - bulk treated rats in a dose dependent manner. However reduced glutathione content showed a decline in the activity. Ultra structural assessment showed significant morphological changes in the liver tissue in accordance with biochemical parameters. Taken together, the results of this study demonstrated that Al2O3 is hepatotoxic and the smaller size of this nanomaterial appeared to be the most toxic while the compound in the bulk form seemed to be the least toxic.