Infection by human Coronaviruses (CoVs) such as HCoV-229E, HCoV-OC43, HCoV-NL63, HCoV-HKU1generally results in moderate to severe respiratory and intestinal infections in humans The deadly human CoVs emerging in the last two decades however became the cause of great global concern The severe acute respiratory syndrome (SARS) SARS-CoV, Middle East respiratory syndrome (MERS) (MERS-CoV) and the current SARS-CoV-2 that causes COVID-19 are related respiratory infections with high degree of mortality With currently no available vaccine or approved therapy for COVID-19, the development of directly acting antiviral drugs becomes a sensible strategy Viral infections, like many other disease conditions have been frequently managed using traditional medicine COVID-19 and SARS-CoV-2 infections have also been treated with preparations from traditional Chinese medicine although their efficacy has not yet been well documented Several antiviral agents have also been reported from natural sources and these could provide good opportunity for developing products and therapies that might be applicable in managing COVID-19 In this review, we discuss natural antiviral products that target the various infection stages of the different viruses’ including CoV, which may be useful for direct management of COVID-19 or provide insights for the development of effective therapies
