Polyporus umbellatus is an edible and medicinal mushroom recognized for its long history of use in traditional medicine systems, particularly in Asia. This fungus is also known by several common names, including Zhu Ling, Tsuchi-maitake, and Umbrella Polypore. Its earliest recorded use appears in the ancient Chinese medical text, Shen Nung Pen Tsao Ching, between A.D. 25-220. This mushroom continues to attract scientific interest for its potential applications.
Identification and Natural Habitat
Polyporus umbellatus forms a large, rounded cluster of numerous small caps. The individual caps, 1 to 5 centimeters wide, are circular, ranging in color from whitish to pale smoky brown, and often display small dark scales when young. These caps branch out from a central stalk, creating a structure that resembles a bouquet of tiny umbrellas. The entire fruiting body can reach up to 50 centimeters in diameter.
This mushroom originates from a dense, underground sclerotium, an irregular, tuber-like fungal mass that can exceed 30 centimeters across. Polyporus umbellatus is a parasitic fungus, commonly found growing at the base or on large underground roots of hardwood trees, such as oaks and maples, across temperate regions of North America, Europe, and Asia. It causes a white rot in its host trees, allowing the mushroom to reappear in the same location annually.
Key Bioactive Compounds
Polyporus umbellatus contains various chemical constituents. Among the most studied are polysaccharides, which are complex carbohydrates. Beta-glucans, a type of polysaccharide in Polyporus umbellatus, have been investigated for their potential to support the immune system. These compounds are responsible for many observed bioactivities.
The mushroom also contains various steroids, including ergosterol, a precursor to vitamin D2, and unique compounds called polyporusterones, referenced in research related to the mushroom’s diuretic effects. Diterpenoids are another class of compounds found in Polyporus umbellatus. Other compounds include triterpenoids, nucleosides, alkaloids, polypeptides, amino acids, and organic acids.
Traditional and Investigated Uses
In Traditional Chinese Medicine (TCM), Polyporus umbellatus (Zhu Ling) has been used for centuries to manage fluid balance. It was primarily employed to promote urination and address conditions related to fluid retention, often referred to as “dampness.” Traditional applications also included treating edema, scanty urine, vaginal discharge, jaundice, and diarrhea.
Modern scientific investigations have explored many of these traditional uses. Research indicates its diuretic properties, showing it helps the body expel excess fluids and toxins by promoting urine production. Studies have also focused on its potential to support kidney function and protect against renal fibrosis, with compounds like ergone, a bioactive steroid, showing promise in preventing kidney injury. Additionally, Polyporus umbellatus is studied as an immunomodulator, with polysaccharides demonstrating the ability to enhance cellular immunity and upregulate certain immune cells in research models. Research also suggests its potential in antioxidant activity and supporting liver health.
Common Forms and Preparation
When Polyporus umbellatus is used for medicinal preparations, it is typically the underground sclerotium that is utilized, rather than the visible fruiting body. This sclerotium, a dense, tuber-like fungal mass, contains the concentrated beneficial compounds. The sclerotium has been officially included in the 2020 edition of the Chinese Pharmacopoeia for its therapeutic applications.
Consumers can find Polyporus umbellatus in several forms. These include dried powder, prepared by freeze-drying and grinding the mature sclerotia. Capsules containing powdered extracts are also widely available. Liquid tinctures represent another common form for easy incorporation into wellness routines. Traditionally, the dried sclerotium is prepared as a decoction, which involves boiling the mushroom in water to extract its beneficial compounds. When using commercial products, individuals should follow the specific instructions provided on the product labels for proper usage.