Tannins from Hamamelis virginiana bark extract: characterization and improvement of the antiviral efficacy against influenza A virus and human papillomavirus

• Published in: PloS one 2014-01, Vol.9 (1), p.e88062-e88062
• Main Authors: Theisen, Linda L, Erdelmeier, Clemens A J, Spoden, Gilles A, Boukhallouk, Fatima, Sausy, Aurélie, Florin, Luise, Muller, Claude P
• Format: Article
• Language: English
• Subjects: Acids; Amino acids; Animals; Antimicrobial agents; Antiviral activity; Antiviral agents; Antiviral Agents - chemistry; Antiviral Agents - pharmacology; Bark; Binding; Biology; Catechin; Chemistry; Dogs; Enrichment; Epigallocatechin gallate; Exo-a-sialidase; Gallic acid; Hamamelis - chemistry; Hamamelis virginiana; Health aspects; Hemagglutination; Herbal medicine; Herpes viruses; Human papillomavirus; Human papillomavirus 16 - metabolism; Humans; Hygiene; Immunology; Infections; Influenza; Influenza A; Influenza A virus - metabolism; Influenza, Human - drug therapy; Influenza, Human - metabolism; Influenza, Human - pathology; Inhibition; Life cycle engineering; Life cycles; Low molecular weights; Madin Darby Canine Kidney Cells; Medicine; Molecular weight; Papillomavirus; Papillomavirus infections; Papillomavirus Infections - drug therapy; Papillomavirus Infections - metabolism; Papillomavirus Infections - pathology; Plant Bark - chemistry; Plant extracts; Plant Extracts - chemistry; Plant Extracts - pharmacology; Polyphenols; Proteins; Studies; Tannic acid; Tannins; Tannins - chemistry; Tannins - pharmacology; Ultrafiltration; Vaccines; Viruses
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0088062

Antiviral activity has been demonstrated for different tannin-rich plant extracts. Since tannins of different classes and molecular weights are often found together in plant extracts and may differ in their antiviral activity, we have compared the effect against influenza A virus (IAV) of Hamamelis virginiana L. bark extract, fractions enriched in tannins of different molecular weights and individual tannins of defined structures, including pseudotannins. We demonstrate antiviral activity of the bark extract against different IAV strains, including the recently emerged H7N9, and show for the first time that a tannin-rich extract inhibits human papillomavirus (HPV) type 16 infection. As the best performing antiviral candidate, we identified a highly potent fraction against both IAV and HPV, enriched in high molecular weight condensed tannins by ultrafiltration, a simple, reproducible and easily upscalable method. This ultrafiltration concentrate and the bark extract inhibited early and, to a minor extent, later steps in the IAV life cycle and tannin-dependently inhibited HPV attachment. We observed interesting mechanistic differences between tannin structures: High molecular weight tannin containing extracts and tannic acid (1702 g/mol) inhibited both IAV receptor binding and neuraminidase activity. In contrast, low molecular weight compounds (