Mossy Maze Polypore

Metadata

Regulatory Status

Poland / European Union

• Not assessed under EU Novel Food Regulation (EU) 2015/2283
• No EMA/HMPC monograph
• Extensively studied at Maria Curie-Sklodowska University in Lublin, Poland, which has produced the majority of published research on the medicinal properties of C. unicolor
• The Department of Biochemistry and Biotechnology at UMCS has established C. unicolor as a model organism for medicinal polypore research in Europe
• Not commercially available as a medicinal product in any EU member state

United States

• Not marketed as a dietary supplement
• No FDA GRAS status
• Not assessed by NIH for clinical investigation
• Recognized in North American mycological literature as a common saprotrophic polypore on hardwoods

China and Japan

• Not listed in the Chinese Pharmacopoeia or Japanese Pharmacopoeia
• Some Chinese research on Cerrena species exists but the primary research base is European
• No traditional use documented in East Asian medicine systems

Conditions & Indications

Primary (Preclinical Evidence)

• Ovarian cancer (in vitro) — Laccase from C. unicolor exhibited cytotoxic and antiproliferative effects on ovarian cancer cells from the Caov-3 and NIH:OVCAR-3 cell lines. Caov-3 cells (platinum-resistant ovarian cancer) demonstrated higher sensitivity to the laccase preparation than NIH:OVCAR-3 cells, suggesting potential activity in treatment-resistant ovarian malignancies (Kaczmarek et al. 2024, Ann Agric Environ Med).
• Colon cancer (in vitro) — Laccase preparation showed antiproliferative effects on CT-26 colon cancer cells with an IC50 of 3.849 micrograms/mL, while normal L929 fibroblasts were significantly less affected (IC50 of 5.857 micrograms/mL), demonstrating selective cytotoxicity (Wlizlo et al. 2025, PLoS ONE). Low molecular weight subfractions also inhibited HT-29 human colon cancer cells at concentrations of 25-200 micrograms/mL (Jaszek et al. 2019, Scientific Reports).
• Breast cancer (in vitro) — Low molecular weight subfraction III showed the strongest inhibitory activity against MDA-MB-231 triple-negative breast cancer cells and MCF7 breast cancer cells among the bioactive subfractions tested (Jaszek et al. 2018, PLoS ONE).
• Immune stimulation (in vitro) — Endopolysaccharide fraction (c-EPL) stimulated the production and secretion of TNF-alpha (up to 2000 pg/mL) and IL-6 (up to 400 pg/mL) by THP-1-derived macrophages, indicating potent immunostimulatory activity (Jaszek et al. 2015, Int J Biol Macromol).

Secondary (Preclinical Evidence)

• Herpes simplex virus infection (in vitro) — Laccase was the most active fraction against herpes simplex virus (HSV) at an early stage of viral replication, suggesting interference with viral entry or early gene expression. Activity against encephalomyocarditis virus (EMCV) was observed when virus was pre-incubated with laccase both before and after the adsorption step (Jaszek et al. 2015).
• Prostate cancer (in vitro) — Low molecular weight subfractions demonstrated inhibitory activity against PC3 prostatic carcinoma cells (Jaszek et al. 2018).
• Bacterial infections (in vitro) — Low molecular weight secondary metabolites from idiophasic cultures showed antimicrobial activity against multiple bacterial strains, with the ex-LMS fraction exhibiting the strongest antibacterial effects (Jaszek et al. 2013, BioMed Research International).

Emerging/Preclinical

• Nematode control — Low molecular weight secondary metabolites (ex-LMS) from C. unicolor idiophasic cultures demonstrated efficacy against Rhabditis nematodes, expanding the bioactive profile beyond human medicine applications (Jaszek et al. 2022, Molecules).
• Chemopreventive applications — Bioactive fractions isolated from milk-supplemented cultures of C. unicolor demonstrated chemopreventive activity on colon cancer cells, with the milk supplementation strategy enhancing bioactive compound production (Osinska-Jaroszuk et al. 2021).
• Oxidative damage protection — The ex-LMS fraction demonstrated potent antioxidant activity (39-90% by chemiluminometric measurement, 20-90% ABTS scavenging, 10-59% DPPH reduction), suggesting applications in oxidative stress-related conditions (Jaszek et al. 2013).

Mechanism of Action

Primary Mechanisms

1. Laccase-mediated selective cytotoxicity against cancer cells: Laccase from C. unicolor (a multi-copper oxidase) demonstrates selective antiproliferative and cytotoxic effects on cancer cells while largely sparing normal cells. The proposed mechanism involves laccase-catalyzed generation of reactive oxygen species (ROS) at the cancer cell surface through oxidation of phenolic substrates in the culture medium. Cancer cells, which typically operate at elevated baseline ROS levels and have compromised antioxidant defenses, are more susceptible to this additional oxidative stress. The selectivity (IC50 of 3.849 micrograms/mL for CT-26 cancer cells versus 5.857 micrograms/mL for L929 normal cells) suggests a therapeutic window for laccase-based anticancer approaches.

2. Endopolysaccharide-mediated macrophage activation and cytokine production: The c-EPL fraction, rich in beta-glucans, activates THP-1-derived macrophages through pattern recognition receptors (likely Dectin-1 and TLR2/4). This activation results in dose-dependent secretion of pro-inflammatory cytokines TNF-alpha (up to 2000 pg/mL) and IL-6 (up to 400 pg/mL). TNF-alpha is a key mediator of antitumor immunity through direct tumor cell killing and promotion of adaptive immune responses. IL-6 has dual roles in immune regulation, supporting acute inflammatory responses and B-cell differentiation. This immunostimulatory profile is consistent with the general mechanism of fungal polysaccharide immunomodulation observed across the Polyporaceae family.

3. Low molecular weight secondary metabolite-mediated multi-target anticancer activity: The ex-LMS fraction contains a complex mixture of phenolic compounds (15 micromolar total phenolics), sugars (780 micrograms/mL total carbohydrates, 507 micrograms/mL reducing sugars), and proteins (189 micrograms/mL). This fraction shows the strongest anticancer activity of the three bioactive fractions, with highest potency against MDA-MB-231 breast cancer and PC3 prostate cancer cells. The mechanism likely involves multiple targets including induction of apoptosis, cell cycle arrest, and inhibition of pro-survival signaling pathways, mediated by the synergistic action of diverse low molecular weight phenolic and polyketide metabolites.

Secondary Mechanisms

4. Laccase-mediated antiviral activity: Laccase inhibits HSV replication at an early stage, possibly through oxidative modification of viral envelope glycoproteins required for cell entry. Against EMCV, laccase shows activity both pre- and post-adsorption, suggesting both direct virucidal effects and interference with intracellular viral replication. This dual-stage antiviral activity distinguishes laccase from many conventional antivirals that target a single stage of the viral life cycle.

5. Antioxidant activity through multiple mechanisms: The ex-LMS fraction demonstrates antioxidant activity through at least three mechanisms: direct free radical scavenging (DPPH and ABTS assays), metal ion chelation (reducing chemiluminescent signal from metal-catalyzed oxidation), and hydrogen atom donation (reducing power assays). The c-EPL fraction also shows significant antioxidant activity (36-70% by chemiluminometry, 2-60% ABTS scavenging, 28-32% DPPH reduction), with the polysaccharide backbone providing additional hydroxyl groups for radical scavenging.

6. Milk-medium enhancement of bioactive compound production: When C. unicolor is cultured on milk-supplemented media, the production of bioactive compounds is enhanced, possibly through the provision of casein-derived peptides and lactose as additional carbon and nitrogen sources. This finding suggests that the medicinal potential of C. unicolor may be optimized through culture condition manipulation, a relevant consideration for any future standardized extract production.

Clinical Evidence Summary

No human clinical trials have been conducted with Cerrena unicolor. All evidence is preclinical, derived from a substantial body of in vitro and limited in vivo research conducted primarily at Maria Curie-Sklodowska University in Lublin, Poland.

Key Preclinical Studies

Key Research Insight: Selective Cytotoxicity

A central finding across multiple C. unicolor studies is the selective toxicity of laccase and low molecular weight metabolites toward cancer cells while sparing normal cells. This selectivity, observed consistently across different cancer types (colon, ovarian, breast, prostate) and normal cell lines (L929 fibroblasts), suggests that C. unicolor-derived compounds may have a genuine therapeutic window. The researchers have explicitly concluded that “extracts obtained from this fungus can be safely used in anticancer therapy or chemoprevention with no significant harmful effects on normal cells.”

Evidence Limitations

• All studies are preclinical; no human clinical trials have been conducted
• The research originates predominantly from a single institution (Maria Curie-Sklodowska University, Lublin, Poland), which limits independent replication
• In vitro cytotoxicity may not translate to in vivo antitumor efficacy due to bioavailability, metabolism, and pharmacokinetic considerations
• Laccase is a large protein enzyme that would likely be degraded by gastrointestinal proteases; oral bioavailability is uncertain and may require parenteral administration
• The low molecular weight secondary metabolites are complex mixtures that have not been fully characterized or resolved into individual active compounds
• No dose-response studies in whole animal cancer models (the research is primarily cell culture-based)
• Standardization of bioactive fractions for potential clinical use has not been established
• The endopolysaccharide fraction has been tested for immunostimulatory activity but not directly for antitumor effects in animal models

Safety Profile

General Assessment

Cerrena unicolor is not known to be toxic. It is a common wood-decay fungus found throughout temperate forests of Europe and North America. The fruiting body is not consumed as food due to its tough, leathery texture. Preclinical research consistently demonstrates selective toxicity toward cancer cells while sparing normal cells, suggesting a favorable safety profile for the bioactive fractions. However, formal toxicology studies in animals or humans have not been conducted.

Contraindications

• Known allergy to mushrooms (Basidiomycota): Standard precaution for all medicinal mushroom preparations
• Active autoimmune disease: The endopolysaccharide fraction is a potent immunostimulator (TNF-alpha up to 2000 pg/mL); immune activation could theoretically exacerbate autoimmune conditions
• Organ transplant recipients: Immunostimulatory polysaccharides may counteract immunosuppressive therapy
• Pregnancy and lactation: No reproductive safety data available; avoid until safety is established

Drug Interactions

• No documented drug interactions in humans
• Theoretical interaction with immunosuppressant medications due to potent immunostimulatory effects of endopolysaccharides
• Theoretical interaction with cytotoxic chemotherapy agents — the selective cytotoxicity profile suggests potential for synergistic or antagonistic effects that would need to be evaluated preclinically before any combination use

Side Effects

• No side effects documented in the literature due to absence of human clinical use
• The in vitro research consistently shows that normal cell viability is preserved at concentrations that are cytotoxic to cancer cells, suggesting a favorable side effect profile if this selectivity translates in vivo

Toxicology

• No formal toxicology studies published
• The selectivity ratio between cancer cell and normal cell cytotoxicity provides preliminary evidence of a therapeutic window
• Laccase enzyme preparations used in research are of high purity; commercial or crude preparations may have different safety profiles

Clinical Dosage

No clinically validated dosage exists for Cerrena unicolor due to the complete absence of human trials.

Experimental Dosages (Preclinical Research)

• Laccase preparation: IC50 of 3.849 micrograms/mL against CT-26 colon cancer cells (in vitro); IC50 values against ovarian cancer cells varied by cell line
• Low molecular weight subfractions: Active against cancer cells at concentrations of 10-200 micrograms/mL (in vitro); subfraction III most potent at lower concentrations
• Endopolysaccharides: Immunostimulatory activity observed at concentrations of 6.25-800 micrograms/mL in macrophage assays
• Antioxidant activity: ex-LMS fraction active at concentrations of 6.25-800 micrograms/mL

Preparation Considerations

• The bioactive fractions (laccase, endopolysaccharides, low molecular weight metabolites) are produced through controlled mycelial fermentation in liquid culture, not from wild-harvested fruiting bodies
• Idiophasic cultures (late growth phase cultures where secondary metabolite production is maximized) yield the most bioactive preparations
• Milk-supplemented media can enhance bioactive compound production
• No commercial supplements or standardized extracts of C. unicolor are currently available
• Any future therapeutic development would likely require fermentation-based production with standardized extraction protocols

Sources

• Wlizlo K, Jaszek M, Kapusta C, et al. Is laccase from medicinal mushroom Cerrena unicolor cytotoxic to colon cancer cell line CT-26? PLoS ONE. 2025;20(5):e0322211
• Kaczmarek A, Jaszek M, Grzywnowicz K, et al. The anticancer activity of laccase from white rot fungus Cerrena unicolor on the example of its action on Caov-3 and NIH:OVCAR-3 ovarian cancer cells. Ann Agric Environ Med. 2024;31(4):555-561
• Jaszek M, Osinska-Jaroszuk M, Janusz G, et al. Antitumor potential of new low molecular weight antioxidative preparations from the white rot fungus Cerrena unicolor against human colon cancer cells. Sci Rep. 2019;9:1975
• Jaszek M, Kos K, Matuszewska A, et al. Anticancer, antioxidant, and antibacterial activities of low molecular weight bioactive subfractions isolated from cultures of wood degrading fungus Cerrena unicolor. PLoS ONE. 2018;13(6):e0197044
• Jaszek M, Osinska-Jaroszuk M, Janusz G, et al. Fungus Cerrena unicolor as an effective source of new antiviral, immunomodulatory, and anticancer compounds. Int J Biol Macromol. 2015;79:459-468
• Jaszek M, Osinska-Jaroszuk M, Janusz G, et al. New bioactive fungal molecules with high antioxidant and antimicrobial capacity isolated from Cerrena unicolor idiophasic cultures. BioMed Res Int. 2013;2013:497492
• Osinska-Jaroszuk M, Jaszek M, Starosielec M, et al. Chemopreventive activity of bioactive fungal fractions isolated from milk-supplemented cultures of Cerrena unicolor and Pycnoporus sanguineus on colon cancer cells. Int J Med Mushrooms. 2021;23(2):25-38
• Jaszek M, Matuszewska A, Pecio L, et al. Low-molecular-weight secondary metabolites from fungi: Cerrena unicolor as a new proposal of an effective preparation against Rhabditis nematodes. Molecules. 2022;27(5):1660
• Pawlik A, Janusz G, Debska I, Siwulski M, Fraczek-Szczypta A, Rogalski J. Modern pro-health applications of medicinal mushrooms: insights into the Polyporaceae family, with a focus on Cerrena unicolor. Molecules. 2025;30(20):4089

Connections

• Closely related to Turkey Tail (Trametes versicolor) within the Polyporaceae family; both produce laccase enzymes and immunostimulatory polysaccharides, though C. unicolor research focuses more on laccase as a direct anticancer agent rather than polysaccharide-based immunotherapy
• The selective cytotoxicity of C. unicolor laccase against cancer cells while sparing normal cells is a distinguishing feature not extensively documented for other medicinal polypores; this selective profile is more reminiscent of targeted cancer therapies than the broad immunostimulation seen with Reishi or Maitake polysaccharides
• The endopolysaccharide immunostimulatory mechanism (macrophage TNF-alpha and IL-6 induction) parallels the cytokine responses observed with beta-glucans from Schizophyllum commune (schizophyllan) and Turkey Tail (PSK/PSP)
• The antiviral activity of C. unicolor laccase against HSV adds a dimension not commonly explored in other medicinal polypores, potentially complementing the antiviral polysaccharide research in species like Fomes fomentarius
• Compare with Trametes hirsuta for another laccase-producing Polyporaceae species with overlapping biotechnological applications
• The Polish research program on C. unicolor represents one of the most comprehensive systematic investigations of a single medicinal polypore species in European mycological research, providing a model for evidence-based development of other understudied species