A review of the world's response to COVID-19 and the potential of medicinal plants for future pandemics

Abstract

Coronavirus pandemics such as Spanish influenza, severe acute respiratory syndrome-coronavirus (SARS-CoV), middle east respiratory syndrome-coronavirus (MERS-CoV) and severe acute respiratory syndrome-coronavirus (SARS-CoV-2) have displayed high incidence and mortality rates prompting the need for repurposing of drugs, vaccine development and the investigation of medicinal plants. Research on previous coronaviruses has served as the foundation for COVID-19 (arising from SARS-CoV-2) research. Various medicinal plants such as Glycyrrhiza glabra, Ginkgo biloba, Curcuma longa and Artemisia annua have displayed favorable results against SARS-CoV-2. Medicinal plants as well as bioactive compounds derived from medicinal plants have been investigated in clinical trials to elucidate the effect on SARS-CoV-2. Several clinical trials evaluate the effect of the medicinal plant and bioactive compounds derived thereof on symptoms arising due to SARS-CoV-2 thus, the main aim of this review article is to highlight the gap in the investigation of the effect of medicinal plants and bioactive compounds on the specific mechanisms of COVID-19 in clinical trials. The review also highlights challenges pertaining to the standardization and quality control of medicinal plants as well as bioactive compounds derived from medicinal plants which may impede the feasibility of using medicinal plants in the clinical regimen for COVID-19 or future coronavirus pandemics.

HIGHLIGHTS • SARS-CoV-2 is a highly infectious virus with high incidence and mortality rates. • Medicinal plants and bioactive compounds derived thereof are still relevant despite the use of repurposed antivirals (remdesivir) and vaccines. • Thorough clinical trials need to be conducted to elucidate the mechanism of action of medicinal plants and bioactive compounds derived thereof on COVID-19. • Gap in clinical trials leads to the use of unapproved medicinal plants and compounds which is a major health risk.