New Anti-viral Compounds from Mushrooms

by Paul Stamets

A new class of anti-viral compounds has been recently discovered in mushrooms. Frank Piraino, Ph.D., and Curtis Brandt, Ph.D., at the University of Wisconsin-Madison Medical School, found a new antiviral, RC-183, that shows in vitro activity in inhibiting the herpes simplex I and II viruses, as well as varicella zoster virus, influenza A virus, and the respiratory syncytial virus.¹ The mushroom yielding this novel antiviral is Rozites caperata, the gypsy mushroom, a mycorrhizal species associated with pines (Pinus spp., Pinaceae) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco, Pinaceae) with a wide range that includes the old growth coniferous forest in the Pacific Northwest, the East and Northern North America. This mushroom thrives in both coniferous and in hardwood forests and where huckleberry (Vaccinium ovalifolium Smith, Ericaceae) grows in the midwest.²

In a more recent article, Brandt and Piraino identified a new class of anti-viral compounds from mushrooms.³ Antivirals from other mushrooms have been identified previously from shiitake (lentinan and KS-2 from Lentinula edodes (Berk.) Singer, Polyporaceae),^4-6 turkey tail (PSP and PSK from Trametes versicolor (L.:Fr.) Pil‡t, Polyporaceae),^6-8 reishi (ganaderiol-F, ganoderic acid-§, lucidumol from Ganoderma lucidum (Fr.) Lloyd, Ganodermataceae),⁹ maitaki (3 branched §-1-6 glucans from Grifola frondosa (Dicks.:Fr.) S.F. Gray, Polyporaceae),¹⁰ and oyster mushroom (ubiquitin-like protein with anti-HIV activity from Pleurotus ostreatus (Jaqu.:Fr.) Kumm, Polyporaceae).¹¹ Other antivirals, not yet characterized, but having shown activity from hot water extracts of the fruitbodies include the ice man or tinder fungus (Fomes fomentarius (L.) Fr., Polyporaceae),¹² chaga or cinder conk (Inonotus obliquus (Pers.) Pil‡t, Hymenochaetaceae)¹³ and zhu ling (Polyporus umbellatus Fries, Polyporaceae).¹⁴

The predominant mushrooms showing promise for their anti-viral activities are polypores -- the so-called woody conks that are now believed, through ongoing DNA research, to be the ancestors of most, if not all, gilled mushrooms.¹⁵ Interestingly, no poisonous polypores are known, whereas there are more than 100 species of poisonous gilled mushrooms, of which only perhaps 20 are deadly. Most of these anti-viral compounds from mushrooms are water soluble, and relatively heat-stable. Furthermore, most of the mushrooms mentioned and/or their mycelia can be cultured to commercially significant levels. The anti-viral compounds are present both in the mycelium and in the fruiting bodies.

The current literature points to fungi, particularly those in the family Polyporaceae, as a rich frontier of new medicines. Many of these species are long-term residents of old growth forests, playing an essential role in nutrient recycling by decomposing aged trees. In a time when new anti-viral medicines are critically needed, mushrooms stand out as an untapped resource and deserve intensive studies.

Paul Stamets is the author of five books, including Growing Gourmet & Medicinal Mushrooms, a mushrooms cultivation textbook used worldwide. On the editorial boards of the International Journal of Medicinal Mushrooms and Mushroom, the Journal, he is an advisor to the Center for Integrative Medicine, Tucson, Arizona. A pioneer in the cultivation of mushrooms, especially the family Polyporaceae, he is an active adventurer into the old growth forests of the Pacific Northwest, cloning and archiving mushroom strains from these ancient woodlands. He owns Fungi Perfecti, website: <http://www.fungi.com>.

References:

1. Piraino F, Brandt CR. Isolation and partial characterization of an antiviral, RC-183, from the edible mushroom Rozites caperata. Antiviral Res 1999;43:67-8.

2. Arora M. Mushrooms Demystified. Berkeley (Calif.): Ten Speed Press; 1986.

3. Brandt CR, Piraino F. Mushroom Antivirals. Recent Research Developments in Antimicrobial Agrents & Chemotherapy 2000;4:11-26.

4. Suzuki H, Okubo A, Yamazaki S, Suzuki K, Mitsuya H, Toda S. Inhibition of the infectivity and cytopathic effect of human immunodeficiency virus by water soluble lignin in an extract of the culture medium of Lentinus edodes mycelia (LEM). Biochem Biophys Res Commun 1989;160:367-73.

5. Sarkar S, Koga J, Whitley RJ, Chatterjee S. Antiviral effect of the extract of culture medium of Lentinus edodes mycelia on the replication of herpes simplex virus. Antiviral Res. April 20, 1993; 4:293-303.

6. Tochikura TS. A biological response modifier, PSK, inhibits immunodeficiency virus infection in vitro. Biochem Biophys Res Commun 1987;148:726-33.

7. Collins RA, Ng TB. Polysaccharopeptide from Coriolus versicolor has potential for use against human immunodeficiency virus type 1 infection. Life Sciences 1997; 60(25):PL383-7. [Editor's note: Trametes versicolor, syn. Coriolus versicolor]

8. Ghoneum M. Anti-HIV activity in vitro of MGN-3, an activated
arabinoxylane from rice bran. Biochem Biophys Res Commun 1998;243:25-9.

9. Hattori M. Inhibitory effects of components from Ganoderma lucidum on the growth of human immunodeficiency virus (HIV) and the Protease Activity in Proceedings of the 1st International Symposium on Ganoderma lucidum in Tokyo, Japan, Nov. 17-18, 1997, 128-35.

10. Nanba H. Immunostimulant activity in-vivo and anti-HIV activity in-vitro of 3 branched §-1-6 glucans extracted from Maitake mushroom (Grifola frondosa) in Proceedings of the VIII International Conference on AIDS and the III STD World Congress, 1992.

11. Wang HX, Ng TB. Isolation of a novel ubiquitin-like protein from Pleurotus ostreatus mushroom with anti-human immunodeficiency virus, translation-inhibitory, and ribonuclease activities. Biochem Biophysl Res Commun 2000;276:587-93.

12. Aoki M, Tan M, Fukushima A. Antiviral Substance with systemic effects produced by Basidiomycetes such as Fomes fomentarius. Bioscience, Biotechnology, and Biochemistry 1993;57:278.

13. Kahlos K. et al. Preliminary tests of antiviral activity of two Inonotus obliquus strains. Fitoterapia 1996;6(4):344-7.

14. Yan SC. Clinical and experimental research on Polyporus umbellatus polysaccharide in the treatment of chronic viral hepatitis. Chung Kuo Chung Hsi I Chieh Ho Tsa Chih Mar 1988;8(3):141-3,131.

15. Hibbett DS, Pine EM, Langer E, Langer G, Donoghue MJ. Evolution of gilled mushrooms and puffballs inferred from ribosomal DNA sequences. Proc Natl Acad Sci USA 1997 Oct;94:12002-6.