Antiviral Activity of Sambucus FormosanaNakai against Human Coronavirus NL63

by | May 27, 2020 | 2019, Botanicals, Lung Health

Written by Joyce Smith, BS. In vitro assays of Sambucus FormosanaNakai ethanol extract validate its effectiveness as an antiviral agent against human coronavirus HCoV-NL63.

The human coronavirus (HCoV-NL63) is one of a number of common human coronaviruses belonging to the genus coronavirus in the Coronaviridae family 1. HCoV-NL63 circulates worldwide during winter months and usually causes mild upper respiratory tract symptoms including runny noses, sore throats and coughs in both children and adults 2. It may also cause lower respiratory tract illnesses such as pneumonia and bronchiolitis in young children and elderly 3. Sambucus FormosanaNakai, (Sambucus FM), a species of elderberry, is a traditional medicinal herb with anti-inflammatory and antiviral potential. In Taiwan, this popular herb treats many health concerns from inflammation, circulation problems, rheumatoid arthritic and back pain, neuritis, dermatitis to many infectious diseases. 4. The active phenolic components of the herb include caffeic acid, caffeotannic acid, chlorogenic acid, coumaric acid, ferulic acid, and gallic acid, which have all demonstrated anti-inflammatory, anti-tumor and anti-hepatotoxic activities 5.

The study objective 6 was to explore the antiviral activity of Sambucus FN extract and its phenolic acid components against HCoVNL63. Using appropriate controls, the researchers tested the in vitro effects of HCoVNL63 on cultured LLC-MK2 cells that were treated with varying concentrations of Sambucus FN, to determine cell viability, cytopathic effect (CPE) (changes in host cells that are caused by viral invasion), cell cycle and virus yield, plaque formation, virucidal activity (the ability to inactivate viruses), and the ability of the virus to attach to cells and replicate.

Researchers found that Sambucus FN extract had many anti-HCoV-NL63 activities:

  • Of the five active polyphenols tested, only caffeic acid, chlorogenic acid, and gallic acid diminished the ability of the virus to damage infected cells.
  • SambucusFM reduced viral replication which researchers attributed to its caffeic, chlorogenic and gallic acids, with caffeic acid demonstrating the highest viral yield reduction at a concentration of IC50=3.54 μM,  followed by chlorogenic acid (IC50=43.45 μM) and coumaric acid (IC50=71.48 μM).
  • Caffeic acid showed stronger inhibitory activity on plaque formation than chlorogenic acid (IC50=5.4uM vs. IC50=44.38 μM).
  • Caffeic acid also was an important player in antiviral activity, potentially influencing the binding of HCoVNL63 to the co-receptors heparin sulfate proteoglycans and receptor ACE2.
  • In addition, caffeic acid was the only polyphenol that was able to inactivate the HCoV-NL63 virus, which it did at IC50=91.3μM and to reduce its ability attach to cell surfaces (IC50 of 8.1 μM).

Further studies are necessary to determine the antiviral capability of Sambucus FK against the broad spectrum of human respiratory coronaviruses.

Source: Weng, Jing-Ru, Chen-Sheng Lin, Hsueh-Chou Lai, Yu-Ping Lin, Ching-Ying Wang, Yu-Chi Tsai, Kun-Chang Wu, Su-Hua Huang, and Cheng-Wen Lin. “Antiviral activity of Sambucus FormosanaNakai ethanol extract and related phenolic acid constituents against human coronavirus NL63.” Virus Research 273 (2019): 197767.

© 2019 Elsevier B.V. All rights reserved.

Posted May 27, 2020.

Joyce Smith, BS, is a degreed laboratory technologist. She received her bachelor of arts with a major in Chemistry and a minor in Biology from  the University of Saskatchewan and her internship through the University of Saskatchewan College of Medicine and the Royal University Hospital in Saskatoon, Saskatchewan. She currently resides in Bloomingdale, IL.

References:

  1. Li X, Liu Y, Hou X, et al. Chlorogenic acid inhibits the replication and viability of enterovirus 71 in vitro. PLoS One. 2013;8(9):e76007.
  2. Cui LJ, Zhang C, Zhang T, et al. Human Coronaviruses HCoV-NL63 and HCoV-HKU1 in Hospitalized Children with Acute Respiratory Infections in Beijing, China. Advances in virology. 2011;2011:129134.
  3. Huang SH, Su MC, Tien N, et al. Epidemiology of human coronavirus NL63 infection among hospitalized patients with pneumonia in Taiwan. Journal of microbiology, immunology, and infection = Wei mian yu gan ran za zhi. 2017;50(6):763-770.
  4. Yang KC, Chiu, S.T et al. Flora of Taiwan. 2nd edition 2003.
  5. Zhang T, Zhu M, Chen X, Bi K. Simultaneous analysis of seven bioactive compounds in Sambucus Chinensis Lindl by HPLC. Analytical letters. 2010;43(16):2525-2533.
  6. Weng JR, Lin CS, Lai HC, et al. Antiviral activity of Sambucus FormosanaNakai ethanol extract and related phenolic acid constituents against human coronavirus NL63. Virus research. 2019;273:197767.