Antiviral activity of Sambucus FormosanaNakai ethanol extract and related phenolic acid constituents against human coronavirus NL63

Virus Res. 2019 Nov;273:197767. doi: 10.1016/j.virusres.2019.197767. Epub 2019 Sep 24.

Abstract

Human coronavirus NL63 (HCoV-NL63), one of the main circulating HCoVs worldwide, causes respiratory tract illnesses like runny nose, cough, bronchiolitis and pneumonia. Recently, a severe respiratory illness outbreak of HCoV-NL63 has been reported in a long-term care facility. Sambucus FormosanaNakai, a species of elderberry, is a traditional medicinal herb with anti-inflammatory and antiviral potential. The study investigated the antiviral activity of Sambucus FormosanaNakai stem ethanol extract and some phenolic acid constituents against HCoV-NL63. The extract was less cytotoxic and concentration-dependently increased anti-HCoV-NL63 activities, including cytopathicity, sub-G1 fraction, virus yield (IC50 = 1.17 μg/ml), plaque formation (IC50 = 4.67 μg/ml) and virus attachment (IC50 = 15.75 μg/ml). Among the phenolic acid constituents in Sambucus FormosanaNakai extract, caffeic acid, chlorogenic acid and gallic acid sustained the anti-HCoV-NL63 activity that was ranked in the following order of virus yield reduction: caffeic acid (IC50 = 3.54 μM) > chlorogenic acid (IC50 = 43.45 μM) > coumaric acid (IC50 = 71.48 μM). Caffeic acid significantly inhibited the replication of HCoV-NL63 in a cell-type independent manner, and specifically blocked virus attachment (IC50 = 8.1 μM). Therefore, the results revealed that Sambucus Formosana Nakai stem ethanol extract displayed the strong anti-HCoV-NL63 potential; caffeic acid could be the vital component with anti-HCoV-NL63 activity. The finding could be helpful for developing antivirals against HCoV-NL63.

Keywords: Antiviral; Attachment inhibition; Caffeic acid; Human coronavirus NL63; Sambucus FormosanaNakai; Virus yield.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antiviral Agents / pharmacology*
  • Cell Line
  • Cell Survival / drug effects
  • Coronavirus Infections
  • Coronavirus NL63, Human / drug effects*
  • Epithelial Cells / drug effects*
  • Epithelial Cells / virology
  • Humans
  • Hydroxybenzoates / chemistry
  • Hydroxybenzoates / pharmacology*
  • Inhibitory Concentration 50
  • Kidney / cytology
  • Kidney / virology
  • Macaca mulatta
  • Plant Extracts / chemistry
  • Plant Extracts / pharmacology*
  • Plant Stems / chemistry
  • Respiratory System / cytology
  • Respiratory System / virology
  • Sambucus / chemistry*
  • Virus Attachment / drug effects

Substances

  • Antiviral Agents
  • Hydroxybenzoates
  • Plant Extracts
  • phenolic acid