In silico, in vitro, and in vivo evaluation of the antiviral potential of glycyrrhizic acid and chitosan nanoparticles against foot and mouth disease virus.

BACKGROUND: Foot-and-mouth disease (FMD) considers as one of the extremely infectious diseases with major economic impact on cloven-hoofed animals globally. The causative agent of the disease, Foot and Mouth Disease Virus (FMDV), comprises seven serotypes designated as; O, A, SAT1, SAT2, SAT3, C, and Asia1. Over the past decades, studies have shown that glycyrrhizic acid, the primary bioactive compound of licorice root, and chitosan, as a biodegradable and biocompatible natural polymer derived from crustacean shells, are potent candidates for inhibition of FMDV activity. The current work evaluated the potential antiviral efficacy of glycyrrhizic acid nanoparticles (GA-NPs) and chitosan nanoparticles (Ch-NPs) against different FMDV serotypes through computational (molecular docking), in vitro and in vivo assays. MATERIALS AND METHODS: The study included the use of field isolates from local FMD viral outbreaks (O PanAsia-2, A Iran 05, A Africa 2020, A Africa G IV Egypt 2022, A Venezuela, and SAT2/EGY/2012); Glycyrrhizic acid and chitosan nanoparticles were prepared and characterized; antiviral activity was assessed by molecular docking analysis, BHK-21 cell assays, and experimental animal studies using representative FMDV serotypes. RESULTS: Molecular docking showed that GA-NPs exhibited stronger binding affinity toward the FMDV RNA-dependent RNA polymerase (3Dpol) with binding energies of -8.974 kcal/mol while Ch-NPs demonstrated superior binding affinity toward the FMDV VP3 protein with binding energies of -7.173 kcal/mol, respectively. At a concentration of 2 × 10- 1 mg/ml, both nanoparticles significantly suppressed viral replication, yielding a reduction in viral titers 8, 7.5, 7, 7, 7.5, and 6.5 log₁₀ TCID₅₀/ml for O PanAsia-2, A Iran 05, A Africa 2020, A Africa G IV Egypt 2022, A Venezuela, and SAT2/EGY/2012, respectively which can aid in the disease restriction during outbreaks. Otherwise, at 2 × 10- 2 mg/ml, treatment markedly reduced viral dissemination in treated guinea pigs, providing protection rates of 66.7%; 44.4%; 66.7%; 100%; and 77.8% and 100% against serotype O; A Iran 05; A Africa 2020; A Africa G IV Egypt 2022; A Venezuela; and SAT2, compared with untreated controls. CONCLUSION: These findings highlighted that GA-NPs and Ch-NPs possess broad-spectrum antiviral activity against six FMDV serotypes, supporting their further development as nanoparticle-based antiviral agents for the control of FMD.