Polyporous mushroom

Polyporus Mushroom (Polyporus umbellatus): A Comprehensive Reference

1. Identity and Nomenclature

Scientific and Common Names

The ingredient commonly marketed as "polyporus mushroom" is not a plant but the dried sclerotium (underground resting body) of the polypore fungus Polyporus umbellatus (Pers.) Fries, belonging to the family Polyporaceae. A widely cited synonym in the scientific literature is Grifola umbellata (Pers.) Pilát. The organism belongs to the phylum Basidiomycota and family Polyporaceae. In Traditional Chinese Medicine (TCM), it is known as Zhu Ling (猪苓), a name that translates literally as "pig fungus," referring to the appearance of its sclerotia.

Morphology and Natural Source

The sclerotium grows 10 to 15 cm below the soil surface near the roots of hardwood trees, particularly oak, birch, maple, and beech. It forms irregular, elongated, or roughly cylindrical nodules, 5 to 25 cm long and 2 to 6 cm in diameter, with a black to dark brown, wrinkled exterior resembling dried pig dung. The above-ground fruiting body is a striking rosette of numerous small, circular, umbrella-shaped caps, each only 1 to 4 cm across, light brown with a central depression, emerging from a repeatedly branching whitish stalk. The whole compound fruiting body can reach up to 40 cm in diameter and appears briefly in spring or autumn.

It is an edible species of mushroom growing on roots of old beeches or oak. Zhuling is found in deciduous woodland regions in northeastern North America, Europe, and the temperate regions of China, commonly growing on dead and fallen trees and stumps. Within China, it can be found in Shaanxi, Yunnan, Jilin, Hebei, Sichuan, Shanxi, Inner Mongolia, Hubei, Guizhou, and other places.

Importantly, the sclerotia, the medicinal part of Polyporus umbellatus, play important roles in diuresis and renal protection; the sclerotia grow and develop only after symbiosis with Armillaria sp. This biological dependency makes wild cultivation highly challenging.

Common Preparations and Commercial Forms

The sclerotium is the part used medicinally. In spring and autumn every year, people gather the sclerotium of Polyporus umbellatus, remove their impurities, wash them with water, moisturize them, dry them, cut them into slices, and make them into Chinese herbal medicines. It can be made into decoctions, pills, or powders. Currently, more and more TCM preparations containing the sclerotia or sclerotia extract of P. umbellatus have been included in the 2020 Chinese Pharmacopoeia, including Wuling powder, Zhuling tang, Zhuling wan, Fenxiao tang, Yinchen Wuling powder, among others. Modern products also include standardized polysaccharide capsules and, in a clinical context, injectable forms. Both PUPS capsule and injection are Chinese Food and Drug Administration (SFDA) approved drugs, which have been used alone or in combination with a variety of clinical drugs for treating Hepatitis B, lung and liver cancers in China since 1990.

The edible and delicious fruiting body of P. umbellatus is often termed "Zhuling flower" in Chinese, which occurs rarely in the natural environment. The mycelia, another form of P. umbellatus, have been usually obtained through liquid fermentation.

Adulteration and Identification: Zhu Ling can potentially be confused with Fu Ling (Poria cocos), as both are fungal sclerotia used as diuretics. However, Fu Ling has a brown outer skin (not black) and a white, more homogeneous cross-section without the granular quality of Zhu Ling. Authentic Zhu Ling can be verified by its characteristic black, wrinkled, pig-dung-like exterior, white to yellowish-white granular cross-section, and the fact that its powder becomes gelatinous when boiled with dilute hydrochloric acid.

2. Traditional and Historical Use

China

The use of Polyporus umbellatus in China can be traced back to the Han dynasty. It was described in a few famous Chinese medical books, like Shen Nong's Herbal Classic (Shen Nong Ben Cao Jing), Chinese Materia Medica (Zhong Hua Ben Cao), Treatise on Cold Pathogenic Diseases (Shang Han Lun), and Compendium of Materia Medica (Ben Cao Gang Mu). Various ancient books recorded Polyporus umbellatus being used for treating edema and promoting the diuretic process. Polyporus umbellatus was listed in the Chinese Pharmacopoeia (2010 edition) and applied as a traditional Chinese medicine (TCM) to treat edema, acute nephritis, and diarrhea.

In TCM theory, Polyporus umbellatus mushroom is sweet, bland, and neutral in nature, entering the kidney and bladder meridians. In TCM practice, Polyporus umbellatus has been used as a diuretic for the treatment of various kidney diseases associated with edema, scanty urine, vaginal discharge, cloudy painful urinary dysfunction, and diarrhea.

A central classical formula featuring this fungus is Wu Ling San (Five-Ingredient Powder with Poria). In this formula it is combined with Fu Ling, Ze Xie, Bai Zhu, and Gui Zhi, as prescribed in the Shang Han Lun. Another key classical prescription is Zhu Ling Tang (Polyporus Decoction), also drawn from the Shang Han Lun, used for damp-heat urinary dysfunction including dysuria and blood in the urine.

Japan and Other Asian Traditions

In addition to its centuries-long use in China, Polyporus umbellatus has also been used as a traditional medicine in Japan, India, and other countries for centuries for curing edema and as a diuretic.

3. Key Constituents and Active Compounds

Principal Chemical Classes

P. umbellatus is a species of mushroom that possesses a wide range of bioactive compounds including polysaccharides, terpenes, nucleosides, sterols, alkaloids, and several others. The fungus contains two principal groups of chemicals: the steroid fraction and the polysaccharide fraction. Other minor compounds have also been described, including anthraquinones, triterpenoids, nucleosides, alkaloids, ceramides, amino acids, vitamins, and potassium salts.

Polysaccharides (PUPs)

Polysaccharides are the predominant bioactive compounds in P. umbellatus, and have been widely used due to their abundant nutritional and medicinal benefits. Since the first unrefined P. umbellatus polysaccharides (PUPs) were obtained in 1973, they have been studied for half a century and are currently gaining increasing attention. Accumulating evidence has demonstrated that PUPs are the main and representative pharmacologically active ingredients, displaying multiple bioactivities both in vivo and in vitro, such as antioxidant, immunomodulatory, antitumor, anti-proliferative, and hepatoprotective activities. PUPs have been isolated from different sources of P. umbellatus, including sclerotia, fruiting body, mycelia, and fermentation liquid.

Steroidal Compounds: Ergone, Ergosterol, and Polyporusterones

P. umbellatus has yielded twenty-five types of steroidal substances, including ergosterol, ergocalciferone, polypore steroid, acetosyringone, and more. Ergone and ergosterol are among the main components of Polyporus umbellatus.

Ergosta-4,6,8(14),22-tetraen-3-one (ergone) is the primary diuretic component of P. umbellatus, and is particularly considered an important source of targeted drugs for the treatment of kidney disease. Ergasta-4,6,8,22-tetraen-3-one, the main source of diuretic effects, relies on the regulation of Na⁺/K⁺ ion balance in the body to exert its diuretic effects. In addition to ergone, the ergosterol and D-mannitol components included in P. umbellatus also facilitate the diuretic process.

Ohsawa et al. identified seven polyporusterones from the fruiting bodies of P. umbellatus and named them polyporusterone A, B, C, D, E, F, and G. The cytotoxic activities of polyporusterone A, B, C, D, E, F, and G were tested against leukemia 1210 cells; polyporusterone A to G inhibited the proliferation of leukemia 1210 cells in a concentration-dependent manner.

Ergosterol is widely found in nature and is a common component of fungi; it is also an important raw material for synthesizing vitamin D. Pharmacokinetic studies demonstrated that ergosterol and ergone had high distribution and absorption in the plasma, and the two main components of Polyporus umbellatus were mainly excreted by faeces.

Other Bioactive Constituents

The pharmaceutical components in Polyporus umbellatus include polysaccharides, ergosterols, biotin, proteins, and other molecules. Two triterpenes — polyporusterones A and B — present in an aqueous extract of P. umbellatus exhibit inhibitory activities against free radical-induced hemolysis of red blood cells in vitro. The fungus also contains biotin (vitamin B7), D-mannitol, and significant potassium content, compounds that have been proposed to contribute to its water-regulating activity.

4. Mechanisms of Action

Diuretic Mechanism

The primary diuretic component, ergasta-4,6,8,22-tetraen-3-one (ergone), relies on the regulation of Na⁺/K⁺ ion balance in the body to exert its diuretic effects. Research has additionally implicated modulation of aquaporin (water channel) expression in renal medullary tissue as a contributing mechanism, as shown in animal studies examining the effects of aqueous sclerotia extract on kidney AQP1, AQP2, AQP3, and V2R expression in normal rats.

Immunomodulatory Mechanisms

PPS extracted from P. umbellatus sclerotia significantly stimulated the proliferation of splenocytes and peritoneal macrophages, increasing the production of inflammatory mediators (nitric oxide) and cytokines (IL-1β and TNF-α) in C3H/HeN mice. Combined FCM and confocal laser-scanning microscopy analyses showed that PPS promoted the activation and maturation of macrophages via the TLR4-modulated nuclear factor kappa B (NF-κB) pathway.

PPS promotes the activation and maturation of murine bone marrow-derived dendritic cells (BMDCs) via TLR4, contributing to the understanding of fungi-mediated immunomodulatory activity. Research demonstrated that P. umbellatus extract produces inflammatory mediators and IL-1 through a pathway involving TLR4 and NF-κB activation. TLR activation induces immune factors that interfere with the immune response by directly promoting NO release from macrophages, and indirectly by increasing MHC class II molecules and costimulatory molecules on the surface of stimulated cells, as well as secretion of IL-12 to promote the growth and differentiation of T lymphocytes.

Crude polyporus polysaccharide has been shown to suppress the growth of tumor cells via the TLR4/NF-κB pathway and to greatly induce the transformation of M2 subtype macrophages to the M1 subtype in vitro. A specific water-soluble polysaccharide (HPP) isolated from P. umbellatus was shown to increase the secretion of immune factors by IFN-γ-stimulated macrophages, including nitric oxide (NO), interleukin-6 (IL-6), interleukin-1β (IL-1β), RANTES, and interleukin-23 (IL-23), and the expression of the cell membrane molecule CD80.

Antitumor Mechanisms

Some polysaccharides exert direct antitumor effects by inducing cell cycle arrest and apoptosis, while the majority of polysaccharides can regulate the host immune system and indirectly inhibit tumors by activating either non-specific or specific immune responses. The pharmacological activities of Polyporus umbellatus can be linked to the steroids (diuretic, nephroprotective, anti-inflammatory, and antioxidative activities) and polysaccharides (anticancer, immuno-enhancing, and hepatoprotective activities).

Nephroprotective Mechanism

P. umbellatus has been shown to prevent kidney injury and subsequent kidney fibrosis. Lipidomic analysis was performed to explore the intrarenal profile of lipid metabolites and to investigate the effect of PPU and its main bioactive component, ergone, on disorders of lipid metabolism in rats with chronic renal failure induced by adenine. Ergone ketone has a renal protective effect on rat renal intestinal fibrosis induced by aristolochic acid or adenine.

5. Scientific Evidence by Area of Use

5.1 Diuretic and Renal Function

Modern in vitro or in vivo pharmacological studies have demonstrated that Polyporus umbellatus possesses diuretic, nephroprotective, anticancer, immuno-enhancing, hepatoprotective, anti-inflammatory, and antioxidative activities. It is particularly noteworthy that pharmacological studies and clinical practice provide strong evidence for diuretic and treatment of various kidney diseases.

Most of the pharmacological studies were conducted using crude and poorly characterized extracts of Polyporus umbellatus in animals, especially in the case of diuretic activities and the treatment of kidney diseases. Animal models have repeatedly shown increases in urine output following administration of aqueous extracts or ergone specifically. The precise mechanism, as noted above, involves Na⁺/K⁺ ion regulation and aquaporin modulation. The pharmacological studies so far have mostly been performed in vitro and in vivo in animals; hence, the evidence is limited and clinical studies in humans are needed in order to assess the therapeutic potential of Polyporus umbellatus.

Evidence strength: Substantial preclinical evidence; limited direct high-quality human clinical trials specifically for this isolated compound as a diuretic.

5.2 Renal Fibrosis and Nephroprotection

A 2021 study published in Frontiers in Pharmacology (PMC7934088) used lipidomic analysis in a rat model of adenine-induced chronic renal failure to investigate the protective effects of Polyporus umbellatus. Results showed decreased creatinine clearance rate indicating declining kidney function in the CRF group, and lipidomics identified 65 lipid species that showed significant differences between CRF and control groups. The study demonstrated that both whole PPU extract and isolated ergone were able to partially normalize aberrant intrarenal fatty acyl metabolites, suggesting a role in protecting against lipid-metabolic disruption associated with renal fibrosis.

Active compounds in P. umbellatus contribute to diuretic activity, antitumor effects, liver protection, immune modulation, antiaging properties, protection against DNA damage, antimutagenic effects, improvement of renal function, and amelioration of renal collagen deposition and subsequent fibrosis.

Evidence strength: Preclinical only (animal models); no robust human clinical data specifically for renal fibrosis.

5.3 Antitumor and Cancer-Adjunct Activity

Some studies have shown that the crude polysaccharide extract plays a role in inhibiting breast cancer, bladder cancer, lung cancer, and colon cancer.

In vitro cytotoxicity studies have examined several isolated sterols. Methanol extracts of sclerotium of P. umbellatus exhibited a cytotoxic effect against human gastric cancer cells, and ergone inhibited the growth of cancer cell lines in colon, cervix, liver, and stomach. The cytotoxic effects were stronger against cancerous cells in liver and colon than the cervix and stomach cancer cells.

P. umbellatus polysaccharides were shown to inhibit the cachexia induced by toxohormone-L in animal studies. Polyporus umbellatus polysaccharide enhances cytotoxic activity mediated by natural killer cells against target cells of YAC-1 cells and P-815 cells of mice.

With respect to bladder cancer, Chinese medicine polyporus has shown efficacy in treating bladder cancer with minimal side effects in clinical applications, though its material basis and mechanism of action remain not fully clarified. Clinical studies conducted in China during the 1990s examined Zhu Ling preparations as adjuncts to conventional bladder cancer therapy, observing reductions in postoperative recurrence rates, though these studies were limited in design and reporting quality.

Evidence strength: Mostly in vitro and animal data. Some clinical application in China as adjunct therapy (SFDA-approved in China for hepatitis B and cancer), but large-scale, double-blind, placebo-controlled human RCTs are lacking in the international literature.

5.4 Viral Hepatitis B (Hepatoprotective and Antiviral)

This is the area for which the most organized clinical data exists. PUPS has been identified as the major bioactive component that has immuno-enhancing, anti-tumor, anti-inflammatory, and hepatoprotective activities. Both PUPS capsule and injection are SFDA-approved drugs, which have been used alone or in combination with a variety of clinical drugs for treating Hepatitis B, lung, and liver cancers in China since 1990.

A systematic review examined nine randomized trials involving 936 patients with chronic hepatitis B assessing Chinese herbal interventions. Polyporus umbellatus polysaccharide showed a positive effect on HBeAg clearance compared to placebo (RR 3.06, 95% CI 1.13–8.29) and on HBV DNA clearance compared to non-specific treatment (RR 4.14, 95% CI 1.00–17.19). However, overall evidence quality was low, and the authors concluded that rigorous, double-blind, placebo-controlled trials are still needed.

One randomized trial of 90 patients with chronic hepatitis B examined combination and monotherapy approaches. Group I received Dan Shen plus PUPS, Group II Dan Shen alone, and Group III PUPS alone. At 3 months, ALT normalization rates were 80.0%, 40.0%, and 53.3%, and HBeAg negative conversion rates were 56.7%, 50.0%, and 16.7%, respectively. These results suggest PUPS alone or in combination may contribute to viral clearance markers, though they are drawn from a single, older Chinese trial.

Evidence strength: Weak to moderate; some positive signals from small, methodologically limited RCTs conducted primarily in China, with low overall evidence quality by systematic review standards.

5.5 Immunomodulation

Polyporus polysaccharide has multiple pharmacological functions, including anticancer, immunoenhancing, radioprotective, and antioxidative activities. Preclinical evidence consistently demonstrates that PUPs stimulate macrophages, dendritic cells, and NK cells through TLR4/NF-κB signaling. PPS treatment of murine BMDCs resulted in a dose-dependent upregulation of interleukin-12 p40, IL-10, and CD86 expression on the cell surface of BMDCs. Furthermore, PPS treatment enhanced T-cell activation while reducing phagocytosis in BMDCs.

Evidence strength: Strong in animal and in vitro models; no well-powered human immunological clinical trials.

5.6 Antioxidant Activity

Studies signal that the antioxidant activity of P. umbellatus polysaccharides may have the potential to treat oxidative stress. The two triterpenes, polyporusterones A and B present in an aqueous extract, exhibit inhibitory activities against free radical-induced hemolysis of red blood cells in vitro. The antioxidative effect was dose-dependent, and P. umbellatus strengthens the antioxidative effect of plasma in vivo.

Evidence strength: Preliminary; in vitro and animal data only.

5.7 Hair Growth Promotion

A study isolated three hair-regrowth substances from P. umbellatus: acetosyringe and polyporusterone A and B. The latter two compounds have been isolated and characterized. One study investigated the effect of various Chinese herbs, including P. umbellatus, on human scalp hair growth in vitro, using organ culture of human scalp hair follicles. Low doses of extracts (1.28 and 6.4 µg/ml) markedly enhanced hair growth and lengthened the period of hair growth, while high doses of mixture extracts (4 and 20 mg/ml) sharply inhibited hair growth and shortened the period of hair growth.

Evidence strength: Preliminary in vitro data only; the dose-dependent biphasic response warrants further investigation. No human clinical trials.

5.8 Antiviral Activity (Broader)

PPS exhibited significant antiviral activity against various viruses, including SARS-CoV-2 and COVID-19 in vitro, particularly evident in polysaccharides with sulfate functional groups. The development of sulfated polysaccharides has been proposed as a potential avenue for use as adjuvants in vaccine preparation and as components in functional foods.

Evidence strength: Very preliminary; in vitro only.

5.9 Antimicrobial Activity

Salmonella typhimurium can be effectively inhibited by the protein polysaccharides from P. umbellatus at a concentration of 2.5%–10.0%.

Evidence strength: In vitro only; no clinical data.

6. Body Systems and Health Areas

• Urinary/Renal System: Due to its diuretic properties, P. umbellatus is considered an important source of targeted drugs for the treatment of kidney disease. Applications include edema, acute nephritis, chronic renal failure, and urinary tract infections.
• Hepatic System: It is a traditional Chinese medicinal herb possessing multiple biological functions, such as anti-cancer, immune-regulating, and hepatoprotective activities. PUPS has been investigated for chronic viral hepatitis B.
• Immune System: PUPs modulate innate and adaptive immunity via TLR4/NF-κB pathways, promoting macrophage M1 polarization, NK cell activation, and T-lymphocyte differentiation.
• Oncology (Adjunct): SFDA-approved in China as an adjunct in hepatitis B-associated liver cancer and bladder cancer; activity demonstrated in breast, colon, lung, gastric, and cervical cancer cell lines.
• Antioxidant / Cardiovascular: Ergosterol-derived compounds show platelet and free-radical inhibitory activity; antioxidant capacity demonstrated in plasma in vivo (animal models).
• Dermatology / Hair Follicle: Polyporusterone A and B and acetosyringe have been studied for hair follicle stimulation in vitro.

7. Dosage and Preparation Forms Reported in Sources

Dosages reported reflect different preparation traditions and research contexts:

• TCM Decoction (dried sclerotia): Decoct 6–12 g. Other TCM sources report a standard dose of 10–15 g, decocted in water, 1 dose per day, divided into 2 servings. For severe edema: up to 20–30 g short-term.
• Powder form: Ground into fine powder, taken as 3–6 g with warm water.
• Polysaccharide extract (for cancer-care contexts): While the sclerotium has traditionally been prescribed as a diuretic in formulae at a dose of 6–15 g/day, polysaccharide extracts are preferred for cancer care at 3–6 g/day polysaccharide extract.
• Injectable PUPS (hospital-administered): Polyporus polysaccharide injection (hospital-administered) is used for immune modulation and adjunctive cancer therapy.

It must be noted that rigorous standardized human clinical dosing outside of the TCM pharmacopoeia context has not been established in high-quality international trials. The doses above reflect traditional practice and the Chinese clinical literature.

8. Safety Considerations and Interactions

Reported Safety Profile

Clinical applications have confirmed satisfactory efficacy in treating kidney diseases and bladder cancer. Additionally, no side effects or toxicity have been reported for this fungus. However, the formal toxicological evidence base is thin. Few studies have specifically mentioned its toxicity, and the long-term safety and correct evaluation of its toxicity are crucial for future application.

Based on published research through the time of several major reviews, there is no systematic information on side effects or toxicity reports (acute toxicity, sub-acute toxicity, chronic toxicity, etc.) from many years of research on Polyporus umbellatus. More experiments including in vitro, in vivo, and clinical studies should be encouraged to identify any side effects or toxicity.

Traditional TCM texts report that overdose may cause skin allergies, tinnitus, thirst, irritability, or excessive urine output.

Traditional Contraindications (TCM)

TCM practice identifies several populations in which caution is advised:

• Yin deficiency with fluid depletion (dry mouth, scanty urine): use cautiously as Polyporus may exacerbate fluid loss.
• Avoid long-term use in non-dampness patterns.
• People who are allergic to Zhu Ling should not take it. People with cold and thin semen should not take it. Patients with no water-dampness should not take it.

Drug Interactions

Caution is advised for patients on prescription diuretics due to the potential for additive diuretic effects leading to electrolyte imbalance. No controlled human drug-interaction studies have been published in the international scientific literature at the time of major reviews. Given that PUPs modulate NF-κB and TLR4-mediated immune pathways, theoretical interactions with immunosuppressive drugs warrant attention, though this has not been studied in human trials.

In a rat model of bladder cancer, the mortality of the BCG-treated group was higher than that of the group treated with PPS combined with BCG, indicating that PPS can reduce the toxicity of BCG. This interaction finding, while preclinical, may be relevant in oncological settings.

Overall Evidence Limitations

The pharmacological studies so far have mostly been performed in vitro and in vivo in animals. Hence, the evidence is limited, and clinical studies in humans are needed in order to assess the therapeutic potential of Polyporus umbellatus. The complex active substances of this fungus also hinder the research of P. umbellatus to some extent, and the mechanism of action and potential synergistic or antagonistic effects of the mixture of various active ingredients have not been clearly analyzed.

References

• Ren et al. (2025). "Polyporus umbellatus, A Precious Rare Fungus With Good Pharmaceutical and Food Value." Engineering in Life Sciences / PMC.
• Zhao YY. (2013). "Traditional uses, phytochemistry, pharmacology, pharmacokinetics and quality control of Polyporus umbellatus (Pers.) Fries: a review." Journal of Ethnopharmacology. PubMed PMID 23811047.
• ScienceDirect Topics: Polyporus umbellatus — overview (citing Zhao 2013 and related reviews).
• He et al. (2022). "Phytochemistry and bioactivities of the main constituents of Polyporus umbellatus (Pers.) Fries." ScienceDirect. PubMed PMID 35667259.
• PubMed (2021). "Polysaccharides from Polyporus umbellatus: A review on their extraction, modification, structure, and bioactivities." PMID 34419536.
• PMC (2025). "A systematic review of advances in preparation, structures, bioactivities, structural-property relationships, and applications of Polyporus umbellatus polysaccharides." PMC11780138.
• Guo Z, Zang Y, Zhang L. (2019). "The efficacy of Polyporus umbellatus polysaccharide in treating hepatitis B in China." Progress in Molecular Biology and Translational Science. PubMed PMID 31030753.
• PMC (2020). "Mechanisms of Macrophage Immunomodulatory Activity Induced by a New Polysaccharide Isolated From Polyporus umbellatus (Pers.) Fries." Frontiers in Chemistry. PMC7399574.
• Wang et al. (2021). "Polyporus umbellatus Protects Against Renal Fibrosis by Regulating Intrarenal Fatty Acyl Metabolites." Frontiers in Pharmacology. PMC7934088.
• Bandara AR et al. (2015). "Polyporus umbellatus, an Edible-Medicinal Cultivated Mushroom with Multiple Developed Health-Care Products as Food, Medicine and Cosmetics: a review." Cryptogamie, Mycologie 36(1): 3–42.
• Me & Qi Herb Database: Zhu Ling (Polyporus mushroom) — TCM Herb.
• Mushroom Nutrition: Polyporus umbellatus — Zhu Ling. (Citing primary literature including Zhao 2013 and Yuan 2004.)