Mushrooms are a diverse collection of fungi, constituting many thousands of species. Mushrooms have been consumed for medicinal purposes for countless generations, especially in Asian countries, although only a small percentage have been scientifically investigated. Mushrooms display a variety of medicinal properties including antiviral, antibacterial, antitumor, anti-allergic, anti-inflammatory, hypoglycemic and immune-stimulating behavior. On the other hand, some mushrooms are psychoactive, while others are poisonous, so caution is always advised. Consult with a practitioner of traditional Chinese medicine to better understand the properties of mushrooms.
Antiviral compounds are used to treat viral infections, however, not all antivirals are effective against all viruses. Unlike most antibiotics that kill bacteria, antiviral compounds generally do not destroy their target pathogen; rather, they inhibit the development or reproduction of the virus, according to the “Textbook for Functional Medicine.” Because viruses use the host’s cells to replicate, safe and effective antiviral compounds must be able to interfere with the virus without harming the host tissues. Natural antivirals exist in some mushrooms, plants and fruits, although man-made varieties are often used to combat herpes, HIV, influenza, hepatitis and other viruses that cause disease.
Antiviral Properties of Mushrooms
Antiviral effects have been discovered not only for whole mushrooms, but also for extracts of isolated compounds within mushrooms, according to the “Mayo Clinic Book of Alternative Medicine.” Direct antiviral effects include inhibition of viral enzymes, synthesis of viral nucleic acids and adsorption or uptake of viruses. Indirect antiviral effects are achieved by stimulating the immune response against the viral invasion and promoting biochemical factors, such as alkalinity, that discourage viral replication. Antimicrobial compounds that have been isolated from mushrooms include lentinan, ganaderiol-F, ganoderic acid-ß, lucidumol, PSP, coprinol, campestrin, sparassol, armillaric acid, cortinellin and ustilagic acid, according to a German study published in a 2005 edition of the journal “Evidence-Based Complementary and Alternative Medicine.”
The primary mushrooms showing promise for their antiviral properties are called polypores, which are considered to be the ancestors of most gilled mushrooms. A particularly powerful mushroom that has been identified as inhibiting the activity of the herpes simplex I and II viruses, varicella zoster virus, influenza-A virus and the respiratory syncytial virus is Rozites caperata or the Gypsy Mushroom, according to a study published in a 2000 edition of the journal “Recent Research Developments in Antimicrobial Agents and Chemotherapy.” Other mushrooms that demonstrate antiviral activity include Lentinula edodes or Shiitake mushroom, Grifola frondosa or Maitake mushroom, Ganoderma lucidum or Mannentake mushroom, Trametes versicolor and Reishi mushrooms.
Many of the mushroom species that display antiviral properties are long-term residents of “Old Growth” forests, such as those seen in Washington State, Oregon and Northern California in the United States. They play important roles in recycling the elements within decomposing trees. A complication of using these types of mushrooms for natural antivirals is that they are difficult or impossible to cultivate due to their complex interdependence with their host trees, according to the book “Chinese Herbal Medicine: Materia Medica.”