Plant Gel-Mediated Synthesis of Gold-Coated Nanoceria Using Ferula gummosa: Characterization and Estimation of Its Cellular Toxicity toward Breast Cancer Cell Lines.

In this study, a novel method using Ferula gummosa gums as a capping agent was used to synthesize the nanoceria for the first time. The method was economical and performed at room temperature. Furthermore, it was coated with gold (Au/nanoceria) and fully characterized using X-ray powder diffraction (XRD), field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy (FESEM-EDX), Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), and zeta potential (ζ potential). The crystallite size obtained from the results was 28.09 nm for Au/nanoceria. The energy-dispersive X-ray spectroscopy (EDX) analysis of Au/nanoceria revealed the compositional constituents of the product, which display the purity of the Au/nanoceria. The cell toxicity properties of the non-doped and Au-coated nanoceria were identified by a MTT analysis on a breast cancer cell line (MCF7). Additionally, human foreskin fibroblast cells (HFF) were used as a normal cell line. The cytotoxicity results indicated that the toxicological effect of Au/nanoceria on cancer cells was significant while having little toxic effect on normal cells. The toxicity effect of nanoceria clearly shows the dependence on dose and time, so, with increasing the dose of Au/nanoceria, the death of cancer cells also increases.

Assessment of phytoremediation potential of native plant species naturally growing in a heavy metal-polluted saline-sodic soil.

Many areas throughout the world, mainly arid and semi-arid regions, are simultaneously affected by salinity stress and heavy metal (HM) pollution. Phytoremediation of such environments needs suitable plants surviving under those combined stresses. In the present study, native species naturally growing under an extreme condition, around Qaleh-Zari copper mine located in the eastern part of Iran, with HM-contaminated saline-sodic soil, were identified to find suitable plant species for phytoremediation. For this purpose, the accumulation of HMs (Cu, Zn, Cd, and Pb) in the root and shoot (stem and leaf) of the plants and their surrounding soils was determined to find their main phytoremediation strategies: phytoextraction or phytostabilization. Seven native species surviving in such extreme condition were found, including Launaea arborescens (Batt.) Murb, Artemisia santolina Schrenk, Pulicaria gnaphalodes (Vent.) Boiss, Zygophyllum eurypterum Boiss. & Buhse, Peganum harmala L., Pteropyrum olivieri Jaub. & Spach, and Aerva javanica (Burm. f.) Juss. ex Schult. Evaluation of phytoremediation potential of the identified species based on the calculated HM bioconcentration in roots, HM translocation from roots to shoots, and HM accumulation in the shoots revealed that all of the species were metal phytostabilizers rather than hyperaccumulators. Therefore, these native species can be used for phytostabilization in the HM-contaminated saline soils to prevent HMs entering the uncontaminated areas and groundwater. Compared with the biennial low-biomass hyperaccumulators, some native species such as Z. eurypterum and A. javanica may have more economic value for phytoremediation because of a significant accumulation of HMs in their relatively higher biomass.

Optimization of Callus Induction with Enhancing Production of Phenolic Compounds Production and Antioxidants Activity in Callus Cultures of Nepeta binaloudensis Jamzad (Lamiaceae).

BACKGROUND: World Health Organization (WHO) reported that more than 80% of people in the world use herbal traditional medicines nowadays. Many endemic medicinal plants, especially Nepeta species, are facing to extinction as a result of high harvesting, limited distribution, and habitat destruction.Tissue culture is a successful method for plant secondary metabolites production. Nepeta binaloudensis is a medicinal plant belonging to family Lamiaceae. OBJECTIVE: Our study was focused on devising an optimum procedure for callus induction and phenolic compounds production in N. binaloudensis. First, we are focused on finding suitable explants and media for callus induction. Then, subsequent experiments were conducted to find an optimal concentration of plant growth regulators (PGRs) and reduced- glutathione for maximum biomass production, and phenolic compounds production in calli. MATERIAL AND METHOD: In this study, the usage of whole plant grown in Hoagland nutrient solution, were used as a source of explants. Also, different media including, ½ MS, MS, and B5 and different combination of PGRs (NAA and BAP) were used for optimization of calli induction. RESULTS: Based on the results of the first experiment, leaf-originated explants, and macro half strength MS (½ MS) medium were used for the next experiments. The highest FW (Fresh Weight) and DW (Dry Weight) of calli were observed in ½ MS medium, supplemented with 2 µM/L reduced-glutathione, 2 mg.L-1 BAP, and 2 mg.L-1 NAA. The maximum amount of total phenolic, flavonoid, tannin contents and free-radical scavenger were observed in calli which were grown in ½ MS medium supplemented with 2 µM/L reduced-glutathione, 2 mg.L-1 BAP, and 2 mg.L-1 NAA. CONCLUSION: Our study finds the optimum condition for calli induction and phenolic compounds production in N. binaloudensis.

Long-term exposure of rapeseed (Brassica napus L.) to ZnO nanoparticles: anatomical and ultrastructural responses.

Rapid development of nanotechnology in recent years has raised concerns about nanoparticle (NPs) release into the environment and its adverse effects on living organisms. The present study is the first comprehensive report on the anatomical and ultrastructural changes of a variety of cells after long-term exposure of plant to NPs or bulk material particles (BPs). Light and electron microscopy revealed some anatomical and ultrastructural modifications of the different types of cell in the root and leaf, induced by both types of treatment. Zinc oxide (ZnO) BPs-induced modifications were surprisingly more than those induced by ZnO NPs. The modifications induced by ZnO BPs or ZnO NPs were almost similar to those induced by excess Zn. Zn content of the root and leaf of both ZnO NPs- and ZnO BPs-treated plants was severely increased, where the increase was greater in the plants treated with ZnO BPs. Overall, these results indicate that the modifications induced by ZnO particles can be attributed, at least partly, to the Zn(2+) dissolution by ZnO particles rather than their absorption by root and their subsequent effects.