Universally available herbal teas based on sage and perilla elicit potent antiviral activity against SARS-CoV-2 in vitro

Abstract

The current SARS-CoV-2/COVID-19 pandemic represents an unprecedented medical and socioeconomic crisis. Highly efficient treatment options preventing morbidity and mortality are not broadly available and approved drugs are hardly affordable in developing countries. Even after vaccine approvals, it will take several months until the vaccinated and convalescent individuals establish herd immunity. Meanwhile, non-pharmaceutical interventions and antiviral treatments are indispensable to curb the death toll of the pandemic. To identify cost-effective and ubiquitously available options, we tested common herbs consumed worldwide as herbal teas. We found that aqueous infusions prepared by boiling leaves of the Lamiaceae plants perilla and sage elicit potent antiviral activity against SARS-CoV-2 in human cells. Sustained antiviral activity was evident even when cells were treated for only half an hour, and in therapeutic as well as prophylactic regimens. Given the urgency, such inexpensive and broadly available substances might provide help during the pandemic - especially in low-income regions.