Journal of Advanced Research (Feb 2022)

Natural triterpenoids from licorice potently inhibit SARS-CoV-2 infection

  • Yang Yi,
  • Junhua Li,
  • Xinyuan Lai,
  • Meng Zhang,
  • Yi Kuang,
  • Yang-Oujie Bao,
  • Rong Yu,
  • Wei Hong,
  • Elishiba Muturi,
  • Heng Xue,
  • Hongping Wei,
  • Tong Li,
  • Hui Zhuang,
  • Xue Qiao,
  • Kuanhui Xiang,
  • Hang Yang,
  • Min Ye

Journal volume & issue
Vol. 36
pp. 201 – 210

Abstract

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Introduction: The COVID-19 global epidemic caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2) is a great public health emergency. Discovering antiviral drug candidates is urgent for the prevention and treatment of COVID-19. Objectives: This work aims to discover natural SARS-CoV-2 inhibitors from the traditional Chinese herbal medicine licorice. Methods: We screened 125 small molecules from Glycyrrhiza uralensis Fisch. (licorice, Gan-Cao) by virtual ligand screening targeting the receptor-binding domain (RBD) of SARS-CoV-2 spike protein. Potential hit compounds were further evaluated by ELISA, SPR, luciferase assay, antiviral assay and pharmacokinetic study. Results: The triterpenoids licorice-saponin A3 (A3) and glycyrrhetinic acid (GA) could potently inhibit SARS-CoV-2 infection, with EC50 of 75 nM and 3.17 µM, respectively. Moreover, we reveal that A3 mainly targets the nsp7 protein, and GA binds to the spike protein RBD of SARS-CoV-2. Conclusion: In this work, we found GA and A3 from licorice potently inhibit SARS-CoV-2 infection by affecting entry and replication of the virus. Our findings indicate that these triterpenoids may contribute to the clinical efficacy of licorice for COVID-19 and could be promising candidates for antiviral drug development.

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