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

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 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
the dose had a good ability to protect DNA against their damaging when compared to the equivalent
γ-ray doses prior to nano-ZnO treatment. This was evident through the significant amelioration of
DNA parameters which manifested in increasing nuclear DNA content and genome size, reduction
the DNA damage (tail length, Tailed DNA% and tail moment), and scoring new amplified
DNA bands and increasing their number. This study concluded that nano-ZnO can be used as
potent mutant and an efficient nano-radioprotector for the protection of crop plant DNA.