Inactivation of Murine Norovirus Using Polymeric Nanoparticle loaded with Oregano Essential Oil for Food and Environmental Applications

Noroviruses are the leading cause of gastroenteritis outbreaks in humans worldwide. Their unique properties ensure stability over extended periods under adverse conditions, which enhances their risk as food and water contaminants. In recent years, intensive research has focused on the natural antimicrobial potential of plant metabolites as disinfectants against environmental pathogens. The oregano essential oil (OEO) has gained attention due to its valuable properties, including antimicrobial, antioxidant, antiviral, and antifungal activities. However, the susceptibility of OEO to degradation and oxidation under environmental or storage conditions, coupled with its low water solubility, has limited its practical applications. Nanoencapsulation has emerged as a promising strategy to overcome these limitations by prolonging shelf life, improving stability, enabling controlled release, and expanding its potential uses. In this study, we evaluated the virucidal potential of chitosan-based polymeric nanoparticles incorporating Origanum vulgare essential oil against murine norovirus 1 (MNV-1) for food and environmental applications. To assess the virucidal effect of the OEO nanoparticles, the reduction in viral infectivity was determined by comparing the TCID₅₀/mL values of untreated viral suspensions with those treated with the tested compounds at varying concentrations. The results demonstrated effective viral inactivation at all tested concentrations, with the undiluted formulation (40 mg/mL incorporated OEO) achieving the highest inactivation rate (99.72%). The blank formulation showed no significant virucidal activity, while the pure OEO exhibited cytotoxicity at most tested concentrations. These findings support the development of a biotechnological disinfectant with potential applications in both environmental and controlled conditions.