The Future of Natural Phytomolecules: A Lesson Learned from COVID-19

The COVID-19 pandemic, caused by SARS-CoV-2, still lacks a valid treatment strategy. Various plant-derived compounds, such as alkaloids, phenolics, tannins, lecithin, coumarins, lignans, and anthocyanidins, have been extensively studied for their antiviral properties. These compounds have shown efficacy against a range of viruses, such as coxsackievirus (CV), dengue virus (DENV), enterovirus 71 (EV71), hepatitis B (HBV) and C (HCV) viruses, herpes simplex virus, HIV, influenza, measles virus (MV), respiratory syncytial virus (RSV), avian infectious bronchitis virus (IBV), and SARS-Co-V . The use of plant-based remedies to treat viral infections is a traditional approach passed down through generations and has now been used for drug discovery. These natural products are often valued for their non-toxicity, easy availability, low cost, and potential as nutraceuticals with minimal side effects. Phytochemicals are increasingly seen as promising agents for long-term, supportive therapy. In light of this, we aim to review the potential of specific phytochemicals as immunomodulatory agents and preventive measures against COVID-19. Herbal medicines are widely utilized for treating viral infections, but research into the specific antiviral constituents, their mechanisms of action, bioavailability, absorption, and metabolism remains limited. Recent studies have provided valuable insights into how these natural compounds interact with the viral lifecycle, including viral entry, replication, assembly, release, and the interaction between the virus and the host. This review highlights the key phytochemicals found in herbs that have demonstrated significant antiviral activity, particularly against COVID-19, and their potential role in managing viral infections.