Potentials of Medicinal Plants with Antiviral Properties: The Need for a Paradigm Shift in Developing Novel Antivirals Against COVID-19

The menace of COVID-19 continues to ravage the world despite deployment of vaccines, and the development of oral antiviral pills whose effectiveness are still being evaluated. As the problems persist, Scientists are continuously searching for new resources and re-evaluating old ones that be used to effectively contain the pandemic. A search through literature has shown a huge amount of scientific resources in medicinal plant research which could be leverage. Many medicinal plants have been demonstrated to possess various antiviral activities against influenza virus, SARS-CoV, herpes simplex virus, vesicular stomatitis virus, hepatitis B virus, hepatitis C virus, human immunodeficiency virus, simian immunodeficiency virus, echovirus, adenovirus, Newcastle disease virus, duck plague virus, measles virus, polio viruses, yellow fever viruses, Sindbis virus, human cytomegalovirus, Rift valley fever virus, feline herpesvirus, lumpy skin disease virus, and canine distemper virus. Medicinal plants are known to be a reservoir of bioactive compounds with useful pharmacological actives. This revision has identified one hundred and twelve (112) plants found with various antiviral activities. These plants cut across different families. An intriguing observation is the reported presence of antiviral in different classes of phytochemicals like alkaloids, flavonoids, tannins, anthraquinones, glucosides, polyphenols, saponins, essential oils, peptides and polysaccharides. There is the need for concerted paradigm shift to natural products of plant origin towards developing novel antiviral agents against COVID-19 especially with the reported safety challenge of adverse events and serious adverse events associated with already developed vaccines and pills.