Water Soluble Ppropolis (Greit120) and Human Interferon – α (HuIFN-AlfaN3) shows Anti – Influenza virus activity in vitro

Influenza virus infects the respiratory tract in humans and animals causing a variety of different symptoms, including fever, nasal secretions, cough, headache, muscle pain and pneumonia which often could become severe. It was found that Influenza A viruses remained resistant to amantadine and rimantadine with high level of osletamvir resistance. The chemical composition of propolis is complex and more than 180 compounds have been identified. HuIFN-αN3 is a multi-subtype protein also showing antiviral activity against Influenza virus. The aim of the present research is to elucidate the anti-influenza activity of a characterized highly water-soluble propolis sample (Greit120 produced by B Natural, Corbetta, Milano, Italy) in combination with HuIFN-αN3 at different ratios (1:1, 1:2 and 2:1). Greit120 propolis polyphenols, total phenolic acids and bioflavonoids, were qualitatively and quantitatively characterized by HPLC-UV-ESI-MS at the University of Modena and Reggio Emilia, Modena, Italy. The Influenza A and separately Influenza B viruses were added to the cells treated with B Natural Greit120 sample and HuIFN-αN3 at different ratios and after an incubation period, plaques assay was performing to measure the virus titer. Best results (ID50) were obtained with 10% Greit120 and HuIFN-αN3 in a combination of 1:2 (ID50 12±2 µg/ml for Influenza A and 19±6 µg/ml for Influenza B). ID50 index was also calculated to compare the ID50 (AV) activity of Greit120 propolis:HuIFN-αN3 in comparison with Ribavirin. Anyway, 1:2 was found the best ratio for Greit120 combined with HuIFN-αN3 (0.5 for Influenza B and 0.6 for Influenza A). Propolis is known to possess antibacterial, antifungal and antiviral activities [Kujumgiev A. Antibacterial, antifungal and antiviral activity of propolis of different geographic origin. J Ethnopharmacol. 64, 235, 199], also against anti-influenza virus [Shimizu T. Anti-influenza virus activity of propolis in vitro and its efficacy against influenza infection in mice. Antivir Chem Chemother. 19, 7, 2008]. In this study, we confirm the capacity of the highly water-soluble propolis sample (Greit120 from B Natural) to inhibit the influenza A and B viruses growth in vitro also in combination of HuIFN-αN3. This activity may be related to greit120 water solubility, high polyphenols content and to its complex composition made of different phenolic acids and bioflavonoids.