Blushing Bracket

Metadata

Regulatory Status

Korea

• Traditional Use: Wild specimens have been subject to bioactivity-guided fractionation studies at Korean research institutions, identifying antibacterial sterols.
• Commercial Status: Not commercially marketed as a standalone medicinal product or food supplement.

United States

• FDA Status: No GRAS determination. Not marketed as a dietary supplement.
• Research Status: Known in natural products and pharmaceutical chemistry literature.

European Union

• Status: Not authorized as a food or food supplement under Novel Food Regulation.
• Mycological Status: Common and widely distributed bracket fungus across European deciduous forests, particularly on willow (Salix) and birch (Betula).

China

• Status: Not listed in the Chinese Pharmacopoeia. Available in traditional herbal markets in some regions.

Conditions & Indications

Primary Indications (Animal / In Vitro Evidence)

• Cancer (antitumor activity) — Polysaccharides extracted from mycelial culture of D. confragosa inhibited the growth of Sarcoma 180 and Ehrlich solid tumors by 90% when administered intraperitoneally at 300 mg/kg in mouse models. Seven steroidal compounds were identified, with four endoperoxide-bridge-containing steroids showing strong cytotoxicity against HCT116 (colon), A549 (lung), MDA-MB-231 (breast), and A375SM (melanoma) cancer cell lines. These endoperoxide steroids induce ferroptosis via NOS2 targeting, representing a novel anticancer mechanism.
• Antimicrobial infections — The triterpenoid 20(29)-lupen-3-one shows antifungal activity against Saccharomyces cerevisiae and Microsporum gypseum, and antibacterial activity against Escherichia coli, Proteus vulgaris, Pseudomonas pyocyanea, Bacillus subtilis, and Staphylococcus aureus. Aqueous extract inhibits P. aeruginosa and E. coli (inhibition zones 12 mm), while petroleum ether extract inhibits S. aureus (19 mm) and E. coli (13 mm). Demethylincisterol A3 demonstrates anti-Helicobacter pylori activity with 33.9% inhibition, more potent than the positive control quercetin.
• Oxidative stress and antioxidant defense — Exceptional antioxidant capacity with DPPH radical scavenging IC50 of 8.53 micrograms/mL. High total phenol content (54.17 mg GAE/g) and flavonoid content (48.46 mg CE/g) contribute to robust free radical neutralization.

Secondary Indications (In Vitro / Preliminary Evidence)

• Anti-atherosclerotic and cardiovascular protection — Antioxidant and anti-inflammatory properties suggest cardiovascular protective potential through reduction of oxidative stress, LDL oxidation, and vascular inflammation.
• Anti-diabetic activity — Polar solvent extracts demonstrate antidiabetic activity through alpha-amylase and alpha-glucosidase enzyme inhibition in vitro, suggesting potential for blood glucose management.
• Genoprotective effects — Extracts show DNA-protective properties in the comet assay against oxidative genotoxic damage, indicating potential chemopreventive value.

Emerging/Preclinical Indications

• Ferroptosis-based cancer therapy — Endoperoxide-containing steroids from D. confragosa represent a new class of ferroptosis inducers via NOS2 (nitric oxide synthase 2) targeting. Ferroptosis is a recently characterized form of regulated cell death driven by iron-dependent lipid peroxidation, and its induction represents a promising cancer therapeutic strategy, particularly for therapy-resistant cancers.
• Women’s reproductive health — Recent bioactivity profiling has identified implications for possible application in enhancing women’s reproductive health, though specific mechanisms and compounds responsible require further characterization.
• Anti-Helicobacter pylori therapy — Demethylincisterol A3’s anti-H. pylori activity suggests potential application in gastric health, possibly as a complement to conventional triple therapy.

Mechanism of Action

Primary Mechanisms

1. Polysaccharide-mediated antitumor immunomodulation Polysaccharides from D. confragosa mycelial culture activate innate immune cells and enhance tumor surveillance. The 90% inhibition of Sarcoma 180 and Ehrlich solid tumors at 300 mg/kg (intraperitoneal) suggests potent immunostimulatory activity, likely mediated through beta-glucan activation of Dectin-1 and complement receptor 3 on macrophages and NK cells, consistent with the polysaccharide antitumor mechanisms well-characterized in other medicinal polypore fungi. The intraperitoneal route of administration in these studies suggests a direct immune cell-activating mechanism rather than a cytotoxic one.

2. Endoperoxide steroid ferroptosis induction via NOS2 Four endoperoxide-containing steroids isolated from D. confragosa induce ferroptosis in cancer cells by targeting NOS2 (nitric oxide synthase 2). Ferroptosis is an iron-dependent form of regulated cell death characterized by accumulation of lipid peroxides on cellular membranes. NOS2 modulation by these compounds leads to altered nitric oxide metabolism, iron dysregulation, and lethal lipid peroxidation in susceptible cancer cells. This mechanism is particularly significant because ferroptosis can overcome resistance to apoptosis-inducing therapies, offering a potential strategy for therapy-resistant tumors in HCT116 (colon), A549 (lung), MDA-MB-231 (triple-negative breast), and A375SM (melanoma) lines.

3. Ergosterol peroxide anti-inflammatory and anticancer activity Ergosterol peroxide (5alpha,8alpha-epidioxyergosta-6,22-dien-3beta-ol), present at 188.75 mg/100g dry weight, suppresses inflammatory responses through inhibition of NF-kB signaling pathway in macrophages and reduces growth of cancer cells. This compound also inhibits iNOS and COX-2 expression, reducing nitric oxide and prostaglandin E2 production, and contributes to both the anti-inflammatory and anticancer profiles of D. confragosa extracts.

Secondary Mechanisms

• Triterpenoid antimicrobial activity: 20(29)-lupen-3-one disrupts microbial cell membrane integrity through interaction with membrane lipids, demonstrating broad-spectrum activity against both Gram-positive and Gram-negative bacteria as well as pathogenic fungi.
• Phenolic antioxidant mechanisms: High phenolic content (54.17 mg GAE/g) provides free radical scavenging through hydrogen atom donation and electron transfer, metal ion chelation (Fe2+, Cu2+), and inhibition of lipid peroxidation chain reactions. The resulting DPPH IC50 of 8.53 micrograms/mL indicates potent antioxidant capacity.
• Alpha-glucosidase and alpha-amylase inhibition: Polar solvent extracts inhibit carbohydrate-digesting enzymes, reducing postprandial glucose absorption and providing a mechanism for antidiabetic activity similar to the pharmaceutical drug acarbose.
• Demethylincisterol A3 anti-H. pylori activity: This sterol compound demonstrates selective anti-Helicobacter pylori activity (33.9% inhibition), possibly through disruption of bacterial membrane function or interference with urease activity.

Clinical Evidence Summary

No human clinical trials have been published for Daedaleopsis confragosa. All pharmacological evidence derives from in vitro studies, compound isolation and characterization, and animal models.

Key Research Studies

Evidence Limitations

• No human clinical trials for any indication.
• The landmark 90% antitumor inhibition study used intraperitoneal polysaccharide administration in mice, a route not directly translatable to oral supplementation in humans.
• Most studies use different extraction methods and solvents, making cross-study comparison difficult.
• Ergosterol peroxide is common across many fungal species and is not unique to D. confragosa; the specific therapeutic advantage of this species over other ergosterol peroxide-containing fungi is not established.
• The ferroptosis mechanism, while novel and scientifically significant, has been demonstrated only in vitro in cancer cell lines and requires animal model and eventual clinical validation.
• Traditional use documentation is sparse compared to species in the Ganoderma, Trametes, or Cordyceps genera.
• Standardization of extracts and quality control for potential therapeutic applications has not been established.

Safety Profile

General Assessment

Limited formal safety data exist for D. confragosa. The species is not traditionally consumed as food due to its tough, woody fruiting body. No systematic toxicological assessment has been published. The presence of cytotoxic endoperoxide steroids and ergosterol peroxide warrants caution, particularly with concentrated or extracted preparations.

Contraindications

• Pregnancy and lactation: No safety data available. The presence of cytotoxic steroids and ferroptosis-inducing compounds creates theoretical risk. Avoid during pregnancy and lactation.
• Bleeding disorders: Ergosterol peroxide and related compounds may have effects on coagulation pathways. Caution advised.
• Not established for direct consumption: The tough, leathery fruiting body is not suitable for eating; this species is primarily of pharmacognostic interest.

Drug Interactions

No clinical drug interactions documented. Theoretical interactions include:

• Anticancer drugs: Endoperoxide steroids may interact with ferroptosis-targeting or NOS2-modulating cancer therapies. Severity: Theoretical.
• Antidiabetic agents: Alpha-glucosidase and alpha-amylase inhibitory activity may produce additive hypoglycemic effects when combined with acarbose, miglitol, or other oral antidiabetic agents. Severity: Theoretical.
• Anticoagulants: Ergosterol peroxide content may affect coagulation parameters. Severity: Theoretical.

Side Effects

No systematically documented side effects due to absence of human consumption data. Based on the metabolite profile, potential concerns include gastrointestinal irritation and theoretical risk of iron dysregulation from ferroptosis-inducing compounds at high doses.

Clinical Dosage

Traditional/Folk Use

• No standardized traditional dosing protocols documented in the available literature.
• The tough, woody fruiting body is not typically consumed directly.

Research Context

• Polysaccharide antitumor study: 300 mg/kg intraperitoneally in mice (not directly translatable to human oral dosing).
• Antioxidant extracts: Various concentrations used in vitro; human-equivalent doses not established.
• Dosing guidelines for human use cannot be provided due to the complete absence of human clinical trials.
• Any therapeutic application should be considered strictly experimental and conducted under qualified professional supervision.

Sources

• Ohtsuka S, Ueno S, Yoshikumi C, et al. Polysaccharides having an anticarcinogenic effect and a method of producing them from species of Basidiomycetes. UK Patent GB 1331513. 1973
• Ruiz-Herrera J, Leon-Ramirez CG, Cabrera-Ponce JL. Constituents of the fungi Daedalea quercina and Daedaleopsis confragosa var. tricolor. Phytochemistry. 2001;56(1):89-91
• Gursoy N, Sarikurkcu C, Cengiz M, Solak MH. The antioxidant properties of polypore mushroom Daedaleopsis confragosa. Cent Eur J Biol. 2009;4(4):508-519
• Kolundzic M, Grozdanic N, Stanojkovic T, et al. Antifungal, antioxidative, and genoprotective properties of extracts from the Blushing Bracket mushroom, Daedaleopsis confragosa (Agaricomycetes). Int J Med Mushrooms. 2017;19(9):803-815
• Sahin E, Dabiri S, Bolukbasi A, et al. Determination of antioxidant and antidiabetic activities of polar solvent extracts of Daedaleopsis confragosa (Bolton) J. Schrot. Not Sci Biol. 2019;11(1):111-117
• Kim JH, Lee JS, Lee KR, et al. Identification of antibacterial sterols from Korean wild mushroom Daedaleopsis confragosa via bioactivity- and LC-MS/MS profile-guided fractionation. Molecules. 2022;27(6):1865
• Kocabas YZ, Dundar A, Acay H, et al. Bioactivity profiling of Daedaleopsis confragosa (Bolton) J. Schrot. 1888: implications for its possible application in enhancing women’s reproductive health. J Fungi. 2024;10(6):381
• Kim J, Park S, Kim H, et al. Ferroptosis-mediated anticancer activity of endoperoxide-containing steroids derived from Daedaleopsis confragosa via targeting NOS2. Anim Cells Syst (Seoul). 2025;29(1):1-14
• Alves MJ, Ferreira ICFR, Dias J, Teixeira V, Martins A, Pintado M. A review on antimicrobial activity of mushroom (Basidiomycetes) extracts and isolated compounds. Planta Med. 2012;78(16):1707-1718
• Wasser SP. Medicinal mushrooms as a source of antitumor and immunomodulating polysaccharides. Appl Microbiol Biotechnol. 2002;60(3):258-274

Connections

• Compare with Turkey Tail (Trametes versicolor) — both are polypore bracket fungi with polysaccharide-mediated antitumor activity, but Turkey Tail has far stronger clinical evidence through PSK/PSP clinical trials in Japan; D. confragosa’s unique endoperoxide steroids represent a distinct anticancer mechanism (ferroptosis vs. immune modulation)
• Compare with Fomes fomentarius (Tinder Fungus) — another traditional medicinal bracket fungus with anti-inflammatory and anticancer preclinical activities; both share the woody bracket morphology and ergosterol peroxide content
• Compare with Fomitopsis pinicola (Red-Belted Conk) — another polypore with documented triterpenoid and sterol bioactivities; both represent under-studied polypore genera with rich secondary metabolite chemistry
• The ferroptosis-inducing endoperoxide steroids from D. confragosa represent a frontier mechanism in cancer research; ferroptosis induction is an area of intense pharmaceutical interest for overcoming apoptosis-resistant tumors
• The ergosterol peroxide content (188.75 mg/100g d.w.) provides a quantitative benchmark for comparison with other ergosterol peroxide-rich medicinal fungi
• The anti-H. pylori activity of demethylincisterol A3 positions D. confragosa alongside Trametes hirsuta in the emerging area of fungal-derived gastroprotective agents
• Reishi shares the polysaccharide-mediated antitumor immunomodulation mechanism, though the specific polysaccharide structures and potencies differ between species