Objective: Coronaviruses often cause acute complications in the respiratory system with cold-like symptoms. A number of them, such as Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS) and Coronavirus Disease 2019 (COVID-19) have killed thousands of people and have caused epidemics and pandemics. This review study aims to investigate the most common medicinal plants in Iran and introduce their natural products with antiviral effects on coronaviruses and strengthening the immune system in order to prevent and control them. Methods: In this review study, a search was conducted in national and international databases such as Web of Science, Scopus, PubMed, Science Direct, Google Scholar, SID, MagIran and IranMedex by using keywords such as COVID-19, Coronaviruses, SARS, MERS, SARS-CoV-2, PEDV in both Persian and English for studies published until 2020, and finally 51 articles were selected. Results: There are 10 plants with antiviral effects on members of the family Coronaviridae among which Ginger, Galangal, Cinnamon, Fennel flower, Grapefruit (peel), and Purple coneflower were effective on COVID-19. Elder, Ginseng, Aloe vera, Milkvetch, and Shirazi Thyme plants were effective in boosting the immune system and preventing viral diseases. Conclusion: Inhibiting the replication of viruses is the common mechanism in antiviral drugs, but natural compounds usually counteract it by disrupting key proteins and virulence factors of viruses. Therefore, the use of the antiviral components of reported plants can be useful in producing drugs for these viruses, especially the one causing COVID-19.
