Broad applications of iron oxide nanoparticles require an improved understanding of their potential effects on human health. In the present study, we explored the underlying mechanism through which iron oxide nanoparticles induce toxicity in human breast cancer cells (MCF-7). MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) and lactate dehydrogenase assays were used to examine mechanisms of cytotoxicity. Concentration- and time-dependent cytotoxicity was observed in MCF-7 cells. Iron oxide nanoparticles were found to induce oxidative stress evidenced by the elevation of reactive oxygen species generation, lipid peroxidation, and depletion of superoxide dismutase, glutathione, and catalase activities in MCF-7 cells. Nuclear staining was performed using 4', 6-diamidino-2-phenylindole (DAPI), and cells were analyzed with a fluorescence microscope. Iron oxide nanoparticles (60 μg/ml) induced substantial apoptosis that was identified by morphology, condensation, and fragmentation of the nuclei of the MCF-7 cells. It was also observed that the iron oxide NPs induced caspase-3 activity. DNA strand breakage was detected by comet assay, and it occurred in a concentration- and time-dependent manner. Thus, the data indicate that iron oxide nanoparticles induced cytotoxicity and genotoxicity in MCF-7 cells via oxidative stress. This study warrants more careful assessment of iron oxide nanoparticles before their industrial applications.

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Stigmasterol (99.9% pure) was isolated from Azadirachta indica and its chemopreventive effect on 7,12-dimethylbenz[a]anthracene (DMBA)-induced skin cancer was investigated in Swiss albino mice. Skin tumors were induced by topical application of DMBA and promoted by croton oil. To assess the chemopreventive potential of stigmasterol, it was orally administered at a concentration of 200 mg/kg and 400 mg/kg three times weekly for 16 weeks. Reduction in tumor size and cumulative number of papillomas were seen as a result of treatment with stigmasterol. The average latency period was significantly increased as compared with the carcinogen-treated control. Stigmasterol induced a significant decrease in the activity of serum enzymes, such as aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and bilirubin as compared with the control. Stigmasterol significantly increased glutathione, superoxide dismutase, and catalase as compared with the control. Elevated levels of lipid peroxide and DNA damage in the control group were significantly inhibited by administration of stigmasterol. From the present study, it can be inferred that stigmasterol has chemopreventive activity in an experimental model of cancer. This chemopreventive activity may be linked to the oxidative stress of stigmasterol. The antigenotoxic properties of stigmasterol are also likely to contribute to its chemopreventive action.

Flax (Linum usitatissimum L.) is an important oil seed crop that is mostly cultivated in temperate climates. In addition to many commercial applications, flax is also used as a fibrous species or for livestock feed (animal fodder). For the last 40 years, flax has been used as a phytoremediation tool for the remediation of different heavy metals, particularly for phytoextraction when cultivated on metal contaminated soils. Among different fibrous crops (hemp, jute, ramie, and kenaf), flax represents the most economically important species and the majority of studies on metal contaminated soil for the phytoextraction of heavy metals have been conducted using flax. Therefore, a comprehensive review is needed for a better understanding of the phytoremediation potential of flax when grown in metal contaminated soil. This review describes the existing studies related to the phytoremediation potential of flax in different mediums such as soil and water. After phytoremediation, flax has the potential to be used for additional purposes such as linseed oil, fiber, and important livestock feed. This review also describes the phytoremediation potential of flax when grown in metal contaminated soil. Furthermore, techniques and methods to increase plant growth and biomass are also discussed in this work. However, future research is needed for a better understanding of the physiology, biochemistry, anatomy, and molecular biology of flax for increasing its pollutant removal efficiency.

Cadmium exposure induces nephrotoxicity by mediating oxidative stress, inflammation, and apoptosis. The purpose of this study was to examine the protective effect of royal jelly on Cd-induced nephrotoxicity. Adult male mice were distributed randomly into 4 clusters: untreated, royal jelly-treated (85 mg/kg, oral), CdCl 2 -treated (6.5 mg/kg, intraperitoneal), and pretreated with royal jelly (85 mg/kg) 2 h before CdCl 2 injection (6.5 mg/kg, intraperitoneal) for seven consecutive days. Cd concentration in the renal tissue and absolute kidney weight of the Cd-treated mice were significantly higher than those of control group. The levels of kidney function markers, kidney injury molecules-1 (KIM-1), metallothionein, lipid peroxidation, nitric oxide, tumor necrosis factor-α, interleukin-1β, and the apoptosis regulators Bax and caspases-3 also increased significantly in the renal tissue of Cd-treated mice, whereas the levels of glutathione, antioxidant enzyme activities, and the apoptosis inhibitor Bcl-2 were significantly reduced in the renal tissue of Cd-treated group. Histopathological studies showed vacuolation and congested glomeruli in the kidney tissue of Cd-treated mice. However, all aforementioned Cd-induced changes were attenuated by pretreatment with royal jelly. We therefore concluded that royal jelly attenuated Cd-induced nephrotoxicity and it is suggested that this nephroprotective effect could be linked to its ability to promote the nuclear factor erythroid 2–related factor 2 (Nrf2)/antioxidant responsive element (ARE) pathway.