Comparative analysis of the relative potential of silver, Zinc-oxide and titanium-dioxide nanoparticles against UVB-induced DNA damage for the prevention of skin carcinogenesis

Abstract

Sunscreen formulations containing UVB filters, such as Zinc-oxide (ZnO) and titanium-dioxide (TiO2) nanoparticles (NPs) have been developed to limit the exposure of human skin to UV-radiations. Unfortunately, these UVB protective agents have failed in controlling the skin cancer incidence. We recently demonstrated that silver nanoparticles (Ag-NPs) could serve as novel protective agents against UVB-radiations. Here our goal was to perform comparative analysis of direct and indirect UVB-protection efficacy of ZnO-, TiO2- and Ag-NPs. Sun-protection-factor calculated based on their UVB-reflective/absorption abilities was the highest for TiO2-NPs followed by Ag- and ZnO-NPs. This was further confirmed by studying indirect protection of UVB radiation-induced death of HaCaT cells. However, only Ag-NPs were active in protecting HaCaT cells against direct UVB-induced DNA-damage by repairing bulky-DNA lesions through nucleotide-excision-repair mechanism. Moreover, Ag-NPs were also effective in protecting HaCaT cells from UVB-induced oxidative DNA damage by enhancing SOD/CAT/GPx activity. In contrast, ZnO- and TiO2-NPs not only failed in providing any direct protection from DNA-damage, but rather enhanced oxidative DNA-damage by increasing ROS production. Together, these findings raise concerns about safety of ZnO- and TiO2-NPs and establish superior protective efficacy of Ag-NPs.

The β-Blocker Carvedilol Prevented Ultraviolet-Mediated Damage of Murine Epidermal Cells and 3D Human Reconstructed Skin

“…Previous studies have demonstrated that UV or other carcinogens decreased expression or activity of DNA repair enzymes: tobacco smoke reduced DNA repair enzymes, XPC and OGG1, in lung tissue [32,33]; infrared radiation reduced GADD45a in cultured human fibroblasts [34]. In other studies, UV increased expression of DNA repair enzymes GADD45a [35], XPA, XPC, and RPA1 [36]. Thus, the effects on DNA repair is dependent on the UV dose and time point.…”

Toxic and Genotoxic Effects of Silver Nanoparticles in Drosophila

“…Sod2 overexpression following AgNPs exposure was reported in different in vivo studies like in C. elegans (Roh et al ) and in the Cape River crab Potamonautes perlatus (Walters et al ). In addition, different in vitro studies like in human immortalized keratinocytes (HaCaT) cells have shown the ability of AgNPs exposure to enhancing Sod2/Cat/Gpx activity (Tyagi et al ). Cat expression showed relevant changes only after silver nitrate exposure, with different patterns according exposure: over‐expression at low dose and downregulation at the highest tested dose.…”

The Roles of Autophagy and the Inflammasome during Environmental Stress-Triggered Skin Inflammation

“…The biological effects of TiO 2 NP exposure are still unclear, yet many TiO 2 NP-induced toxic effects have been reported. TiO 2 NPs can cause several adverse effects on mammalian cells, including ROS production [62,63], DNA damage responses [64], proliferation, and the induction of apoptosis [65,66]. Hiroike et al suggested that acicular, but not globular TiO 2 NPs stimulate keratinocytes to produce pro-inflammatory cytokines such as IL-1α, IL-1β, IL-6, TNF-α, and IL-8 [67].…”