Evaluations of Potential Antiviral Effects of Green Zinc Oxide and Silver Nanoparticles against Bovine Herpesvirus-1

Viral infection is one of the most important life-threatening animals health. The emergence of new viral disease increases the demand for new therapeutic drugs. Current antiviral drugs have certain limitations for treating viral infection. The objective of the present study was aimed to use the plant extracts of olive leaves and natural honey for green synthesis of zinc oxide (ZnONPs) and silver nanoparticles (AgNPs) and investigate potential antiviral activities against bovine herpesvirus-1(BoHV-1) in vitro and in vivo. The formation of green NPs was confirmed by visible color change, transmission electron microscope (TEM), and UV- spectrophotometer. For determining ZnONPs and AgNPs cytotoxicity on MDBK cell culture using modified enzyme-linked immunosorbent assays (ELISA) and cytopathic effects (CPEs) to monitor the cytopathogenic changed. The antiviral activity of the green nanoparticles was evaluated using MDBK cell culture and experimental animals. The early signs observed that ZnONPs and AgNPs formation were color change from whitish to brownish color. The Transmission electron microscopy (TEM) analysis of NPs showed spherical nanoparticles and prismatic shapes showed size ranges between 10 nm to 50 nm. The UV- spectrophotometer analysis showed an absorption peak at 415 to 450 nm. Green ZnONPs and AgNPs are safe in MDBK cell culture at concentration ranged from 24 μg/mL to 50 μg /mL and they were protected the MDBK cell culture from BoHV-1 infection at nontoxic concentrations 25 μg/mL Green ZnO and AgNPs were safe in MDBK cell culture and in experimental animals. Although, the highest concentrations of ZnONPs and AgNPs cytotoxic effect with different degrees. ZnO and AgNPs protected the MDBK cell culture and experimental rabbits from experimentally infected with BoHV-1 infection when treating cell culture with green ZnONPs and AgNPs suspension. However, molecular redetection by polymerase chain reaction (PCR) was able to detect BoHV-1 in nasal swabs collected from control positive rabbit groups at the first 2 days after infection but failed to detect virus in treated groups with green ZnONPs and AgNPs suspension. Green ZnO and AgNPs can use in vitro and in vivo to protect cell culture and animals against BoHV-1viral infections. ZnO and AgNPs nontoxic and they are able to inhibit BoHV-1.