High-content screening of Thai medicinal plants reveals Boesenbergia rotunda extract and its component Panduratin A as anti-SARS-CoV-2 agents

Abstract

Since December 2019, the emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has caused severe pneumonia, a disease named COVID-19, that became pandemic and created an acute threat to public health. The effective therapeutics are in urgent need. Here, we developed a high-content screening for the antiviral candidates using fluorescence-based SARS-CoV-2 nucleoprotein detection in Vero E6 cells coupled with plaque reduction assay. Among 122 Thai natural products, we found that Boesenbergia rotunda extract and its phytochemical compound, panduratin A, exhibited the potent anti-SARS-CoV-2 activity. Treatment with B. rotunda extract and panduratin A after viral infection drastically suppressed SARS-CoV-2 infectivity in Vero E6 cells with IC50 of 3.62 μg/mL (CC50 = 28.06 µg/mL) and 0.81 μΜ (CC50 = 14.71 µM), respectively. Also, the treatment of panduratin A at the pre-entry phase inhibited SARS-CoV-2 infection with IC50 of 5.30 µM (CC50 = 43.47 µM). Our study demonstrated, for the first time, that panduratin A exerts the inhibitory effect against SARS-CoV-2 infection at both pre-entry and post-infection phases. Apart from Vero E6 cells, treatment with this compound was able to suppress viral infectivity in human airway epithelial cells. This result confirmed the potential of panduratin A as the anti-SARS-CoV-2 agent in the major target cells in human. Since B. rotunda is a culinary herb generally grown in China and Southeast Asia, its extract and the purified panduratin A may serve as the promising candidates for therapeutic purposes with economic advantage during COVID-19 situation.

The SARS-CoV-2-Inactivating Activity of Hydroxytyrosol-Rich Aqueous Olive Pulp Extract (HIDROX®) and Its Use as a Virucidal Cream for Topical Application

“…The use of natural compounds from plants with proven activity against pathogenic viruses is one such strategy. Exploratory research of natural components that show anti-SARS-CoV-2 activity is being actively conducted and some candidate components have been reported by us and other groups in vitro [ 11 , 12 , 13 ]. Plant polyphenols are naturally-derived compounds that show antiviral activity against various pathogenic viruses [ 14 ].…”

The Role of Diet and Supplementation of Natural Products in COVID-19 Prevention

“…Natural products acting, for example, on such mechanisms exacerbated during COVID-19, such as pulmonary hypertension, notoriously borne by Glycyrrhiza glabra extracts, should be further examined in docking research to gather those compounds able to provide benefits in COVID-19 patients [ 16 ]. Important clinical trials are also planned to highlight which type of herbal extracts can address COVID-19 [ 17 , 18 ]. The issue of using folk medicine is fundamental for at least two reasons.…”

Screening of potent phytochemical inhibitors against SARS-CoV-2 protease and its two Asian mutants

“…Kanjanasirirat et al , [ 26 ] tested 122 Thai natural products and found panduratin A from Boesenbergia rotunda as potent anti-SARS-CoV-2 inhibitor. Treatment of Vero E6 cells with B. rotunda extract and panduratin An upon viral infection drastically suppressed SARS-CoV-2 infectivity with IC 50 values of 3.62 μg/mL (CC 50 = 28.06 μg/mL) and 0.81 μΜ (CC 50 = 14.71 μM), respectively.…”