Assessing the toxicity of silver nanoparticles in cell suspension culture of Nicotiana tabacum

Abstract

Silver nanoparticles (Ag NPs) are one of the commercialized nanomaterials that are involved in quite a lot of industrial and biomedical utilization. Although some efforts have been made to examine the possible toxicity of Ag NPs on plant systems, but no consensus has been reached on this issue. To determine the effect of Ag NPs on antioxidant defense system in cell suspension cultures of Nicotiana tabacum, we evaluated the changes in multiple biomarkers of oxidative stress. Ag NPs were synthesized using photo reduction method and characterized as NPs with spherical shape and diameters in the range of 10-100 nm by means of XRD, DLS, and SEM techniques. A significant decline in the cell growth and viability even at low concentration of Ag NPs (5 mg L-1) were evident. Interestingly, a progressive decline in hydrogen peroxide levels was observed, while the contents of malondialdehyde did not change. The activity of ROS scavenging enzymes augmented with the increasing concentration of Ag NPs. Additionally, the contents of phenolic and flavonoid contents were reduced after exposure of the cells to higher concentrations (15, 20, and 25 mg L-1) of Ag NPs. These findings confirmed that Ag NPs triggered oxidative stress in cell suspension culture of N. tabacum.