Water Extract of the Chaga Medicinal Mushroom, Inonotus obliquus (Agaricomycetes), Inhibits SARS-CoV-2 Replication in Vero E6 and Vero Cell Culture Experiments.

The antiviral properties of water extracts from pharmaceutical raw materials of the chaga mushroom, Inonotus obliquus, were studied against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). All studies with infectious materials were carried out in an isolated virological laboratory of the State Research Center of Virology and Biotechnology Vector of Rospotrebnadzor, which has a sanitary and epidemiological conclusion for the right to work with pathogenic biological agents of I-II pathogenicity groups. Antiviral activity was determined by the ability of I. obliquus water extracts to inhibit the replication of SARS-CoV-2 (nCoV/Victoria /1/2020 strain) in Vero E6 and Vero cell cultures. The results of these studies showed that water extracts of I. obliquus are characterized by low toxicity in Vero and Vero E6 cell cultures and have antiviral activity against SARS-CoV-2. The 50% inhibitory concentration ranged from 0.75 to 11.6 µg/mL. A patent for the invention was received (Patent RU, 2741714 C 1, 2021).

Medicinal Mushrooms against Influenza Viruses.

This review provides results obtained by scientists from different countries on the antiviral activity of medicinal mushrooms against influenza viruses that can cause pandemics. Currently, the search for antiviral compounds is relevant in connection with the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Medicinal mushrooms contain biologically active compounds (polysaccharides, proteins, terpenes, melanins, etc.) that exhibit an antiviral effect. The authors present the work carried out at the State Research Center of Virology and Biotechnology Vector in Russia, whose mission is to protect the population from biological threats. The research center possesses a collection of numerous pathogenic viruses, which allowed screening of water extracts, polysaccharides, and melanins from fruit bodies and fungal cultures. The results of investigations on different subtypes of influenza virus are presented, and special attention is paid to Inonotus obliquus (chaga mushroom). Compounds produced from this mushroom are characterized by the widest range of antiviral activity. Comparative data are presented on the antiviral activity of melanin from natural I. obliquus and submerged biomass of an effective strain isolated in culture against the pandemic strain of influenza virus A/California/07/09 (H1N1 pdm09).

Antiviral Effect of Agaricomycetes Mushrooms (Review).

This review presents data on the studied antiviral activities of Agaricomycetes mushrooms against the herpes, West Nile, influenza, human immunodeficiency, and hepatitis viruses, as well as orthopoxviruses, including the variola virus. Polysaccharides and other compounds (e.g., proteins, glycoproteins, terpenoids, melanins, nucleosides) exhibit antiviral activity against many viruses that are pathogenic in humans. Effective strains isolated from wild mushrooms in culture represent promising objects for the development of biotechnological drugs, including ones possessing antiviral activity. The data on antitumor and antiviral activities of compounds from the same mushroom species indicate the correlation of these properties. With regard to this connection, preparations of Basidiomycetes may have prophylactic value in preventing cancers with a viral etiology.

Antiviral activity of polyporoid mushrooms (higher Basidiomycetes) from Altai Mountains (Russia).

Antiviral activity against type A influenza virus of birds A/chicken/Kurgan/05/2005 (H5N1) and humans A/Aichi/2/68 (H3N2) was investigated for aqueous extracts from mycelium of 11 basidial fungi species collected in the Altai Mountains (Altai Republic, Russia). The most perspective strains for producing antiviral medicines are studied strains Daedaleopsis confragosa, Datronia mollis, Ischnoderma benzoinum, Trametes gibbosa, T. versicolor, Laricifomes officinalis, and Lenzites betulina.