Radioprotective efficacy of zinc oxide nanoparticles on gamma-ray-induced nuclear DNA damage in Vicia faba L. as evaluated by DNA bioassays

Abstract

This study aimed to assess the radioprotective efficacy of zinc oxide nanoparticles (nano-ZnO) against γ-radiation-induced DNA lesions in Vicia faba employing flow cytometry (FCM), comet assay, and RAPD-PCR bioassays. Each dose of γ-irradiated seeds was post-treated with three nano-ZnO concentrations. Exposure time pre- and post-ZnO treatments were 24 h. Dose-dependent nano-ZnO and γ-ray treatments showed specific interference with DNA. Three bioassays could successfully detect the positive action of two nano-ZnO concentrations (500 and 2000 mg L-1) on DNA compared to control while high concentration nano-ZnO showed a negative interference with DNA. On the contrary, three doses of γ-ray induced major lesions in V. faba DNA. Data obtained illustrated that combination of 2000 mgL-1 nano-ZnO concentration with each γ-ray dose had a good ability to protect DNA against their damage when compared to the equivalent γ-ray doses prior nano-ZnO treatment. This was evident through the significant amelioration of DNA parameters which manifested in increasing nuclear DNA content and genome size, reducing the DNA damage (tail length, Tailed DNA% and tail moment), scoring new amplified DNA bands, and increasing their number. This study concluded that nano-ZnO can be used as a potent mutant and an efficient nano-radioprotector for the protection of crop plants' DNA.