Natural compounds as antivirals against influenza, SARS-CoV-2, and other respiratory viruses: A therapeutic perspective

Respiratory viruses—including influenza, severe acute respiratory syndrome coronavirus 2, and respiratory syncytial virus—remain major global health challenges, contributing to substantial morbidity, mortality, and socioeconomic burden. Although vaccines and antiviral agents, such as oseltamivir, ribavirin, and Paxlovid (nirmatrelvir/ritonavir), have advanced disease management, their effectiveness is often compromised by the rapid mutation of viruses, the emergence of drug-resistant strains, and adverse toxicities. These limitations underscore the urgent need for novel therapeutic strategies. Natural products have attracted growing attention as promising antiviral candidates due to their remarkable structural diversity, multi-target mechanisms, and generally favorable safety profiles. They can inhibit viral entry, replication, and assembly while simultaneously modulating host immune and inflammatory responses. In addition, natural compounds may act synergistically with existing antivirals, enhancing efficacy and reducing the risk of resistance. Despite ongoing challenges in pharmacokinetics, standardization, and clinical validation, natural products represent a compelling frontier for the development of broad-spectrum, safe, and effective antiviral therapeutics.