Antiviral activity of hop constituents against a series of DNA and RNA viruses

• Published in: Antiviral research 2004, Vol.61 (1), p.57-62
• Main Authors: Buckwold, Victor E, Wilson, Richard J.H, Nalca, Aysegul, Beer, Brigitte B, Voss, Thomas G, Turpin, Jim A, Buckheit, Robert W, Wei, Jiayi, Wenzel-Mathers, Michelle, Walton, Eve M, Smith, Robert J, Pallansch, Melanie, Ward, Priscilla, Wells, Jay, Chuvala, Lara, Sloane, Sandra, Paulman, Robin, Russell, Julie, Hartman, Tracy, Ptak, Roger
• Format: Article
• Language: English
• Subjects: Animals; Antibiotics. Antiinfectious agents. Antiparasitic agents; Antiviral; Antiviral agents; Antiviral Agents - pharmacology; Biological and medical sciences; Bovine viral diarrhea virus; Cell Line; Cytomegalovirus; Cytomegalovirus - drug effects; Cytomegalovirus - growth & development; Diarrhea Viruses, Bovine Viral - drug effects; Diarrhea Viruses, Bovine Viral - growth & development; DNA Viruses - drug effects; DNA Viruses - growth & development; Flavonoids; Hepatitis B virus; Hepatitis C virus; Herpes simplex virus; Herpesvirus 1, Human - drug effects; Herpesvirus 1, Human - growth & development; Herpesvirus 2, Human - drug effects; Herpesvirus 2, Human - growth & development; Hops; Human immunodeficiency virus; Humans; Humulus - chemistry; Influenza A virus; Influenza B virus; iso-Xanthohumol; iso-α-Acid; Lead compounds; Medical sciences; Pharmacology. Drug treatments; Plant Extracts - pharmacology; Propiophenones - pharmacology; Respiratory syncytial virus; Rhinovirus; RNA Viruses - drug effects; RNA Viruses - growth & development; Virus Replication - drug effects; Xanthohumol; Yellow fever virus
• ISSN: 0166-3542; 1872-9096
• DOI: 10.1016/S0166-3542(03)00155-4

We investigated whether crude hop extracts and purified hop components representing every major chemical class of hop compound have antiviral activity. These hop constituents were tested for antiviral activity against bovine viral diarrhea virus (BVDV) as a surrogate model of hepatitis C virus (HCV), human immunodeficiency virus (HIV), influenza A virus (FLU-A), influenza B virus (FLU-B), rhinovirus (Rhino), respiratory syncytial virus (RSV), yellow fever virus (YFV), cytomegalovirus (CMV), hepatitis B virus (HBV), and herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2). The extracts all failed to prevent the replication of HIV, FLU-A, FLU-B, RSV and YFV. A xanthohumol-enriched hop extract displayed a weak to moderate antiviral activity against BVDV (therapeutic index (TI)=6.0), HSV-2 (TI = >5.3), Rhino (TI=4.0) and HSV-1 (TI = >1.9) with IC 50 values in the low μg/ml range. Pure iso-α-acids demonstrated low to moderate antiviral activity against both BVDV (TI=9.1) and CMV (TI=4.2) with IC 50 values in the low μg/ml range. No antiviral activity was detected using β-acids or a hop oil extract. Ultra-pure preparations (>99% pure) were used to show that xanthohumol accounted for the antiviral activity observed in the xanthohumol-enriched hop extract against BVDV, HSV-1 and HSV-2. Xanthohumol was found to be a more potent antiviral agent against these viruses than the isomer iso-xanthohumol. With Rhino, the opposite trend was observed with iso-xanthohumol showing superior antiviral activity to that observed with xanthohumol. Xanthohumol also showed antiviral activity against CMV, suggesting that it might have a generalized anti-herpesvirus antiviral activity. Again, superior antiviral activity was observed with the xanthohumol isomer against CMV. In summary, iso-α-acids and xanthohumol were shown to have a low-to-moderate antiviral activity against several viruses. These hop constituents might serve as interesting lead compounds from which more active anti-HCV, anti-Rhino and anti-herpesvirus antiviral agents could be synthesized.