Birch Mazegill

Metadata

Regulatory Status

China

• Not listed in the Chinese Pharmacopoeia as a medicinal fungus
• Used in traditional folk medicine for various ailments, though documentation is limited
• Research on bioactive polysaccharides conducted at Chinese universities including Shandong Agricultural University

United States

• Not marketed as a dietary supplement
• No FDA GRAS status
• Not assessed by the National Institutes of Health for clinical investigation
• Recognized primarily as a wood-decay fungus in mycological literature

European Union

• Not assessed under EU Novel Food Regulation (EU) 2015/2283
• No EMA/HMPC monograph
• Recognized in European mycological surveys as a common saprotrophic polypore on birch and other hardwoods

Japan

• No pharmaceutical approval
• Not included in Japanese Kampo medicine formularies
• Recognized in mycological literature as a common forest fungus

Conditions & Indications

Primary (Preclinical Evidence)

• Cervical cancer (in vitro and in vivo) — Ethanolic extracts of L. betulina demonstrated significant cytotoxicity against human cervical cancer cell lines HeLa, CaSki, and SiHa. In a HeLa-implanted mouse model, the extract showed antitumor activity with tumor growth inhibition, supporting potential anticancer applications requiring further clinical investigation (Ramamurthy et al. 2019, bioRxiv).
• Breast cancer (in vitro) — The ethyl acetate extract displayed strong anticancer activity against MDA-MB-231 triple-negative breast cancer cells, with an IC50 of 51.46 micrograms/mL and 83.15% inhibition at 200 micrograms/mL (Ren et al. 2014, Int J Med Mushrooms).
• Oxidative stress conditions — Water-soluble polysaccharides LBPs-5 and LBPs-6 demonstrated significant free radical scavenging activity against DPPH, ABTS, and hydroxyl radicals, with activity comparable to or approaching that of ascorbic acid at higher concentrations (Zhang et al. 2021, BMC Chemistry).

Secondary (Limited Preclinical Evidence)

• Hepatocellular carcinoma (in vitro) — Petroleum ether and ethyl acetate extracts showed toxicity against SMMC-7721 human hepatoma cells, comparable to the positive control quercetin (Ren et al. 2014).
• Bacterial infections — Extracts showed mild to moderate antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Candida albicans, though activity was generally weaker than standard antibiotics (Ren et al. 2014).

Emerging/Preclinical

• Immunosuppression — Ergosterol peroxide and 9(11)-dehydroergosterol peroxide isolated from L. betulina have demonstrated immunosuppressive activity, suggesting potential applications in autoimmune conditions or transplant medicine, though this remains highly speculative (Yaoita et al. 2002).
• Anti-inflammatory applications — Phenolic compounds identified via ultrasonic-assisted extraction (gallic acid, caffeic acid, catechin) possess known anti-inflammatory properties, though these have not been specifically tested in L. betulina extract form (Tung et al. 2026, Scientific Reports).
• Selenium biofortification — Selenium-enriched L. betulina mycelium showed enhanced antioxidant, antifungal, and cytostatic potential compared to non-enriched cultures, suggesting biofortification as a strategy to enhance medicinal value (Turlo et al. 2015).

Mechanism of Action

Primary Mechanisms

1. Polysaccharide-mediated antioxidant activity via free radical scavenging: The water-soluble polysaccharides LBPs-5 and LBPs-6 are beta-pyranose structures composed primarily of glucose (76-79%), glucuronic acid (15-17%), and mannose (4-5%). These polysaccharides scavenge free radicals through hydrogen atom donation from hydroxyl groups and through the chelation of transition metal ions that catalyze oxidative reactions. The glucuronic acid content is positively correlated with antioxidant potency, with LBPs-6 (higher glucuronic acid proportion) showing slightly stronger activity than LBPs-5.

2. Ergosterol peroxide-mediated cytotoxicity and immunomodulation: Ergosterol peroxide (5alpha,8alpha-epidioxyergosta-6,22-dien-3beta-ol) induces apoptosis in cancer cells through multiple pathways including inhibition of NF-kB signaling, activation of caspase cascades, and modulation of Bcl-2 family proteins. It also exhibits immunosuppressive effects by inhibiting mitogen-induced proliferation of T-lymphocytes and suppressing the mixed lymphocyte reaction, suggesting dual anticancer and immunomodulatory functionality.

3. Phenolic compound-mediated antioxidant and antimicrobial activity: The phenolic fraction, including gallic acid, protocatechuic acid, catechin, caffeic acid, and p-hydroxybenzoic acid, contributes to antioxidant capacity through both hydrogen atom transfer (HAT) and single electron transfer (SET) mechanisms. Antimicrobial effects are mediated through disruption of bacterial cell membrane integrity and inhibition of microbial enzyme activity.

Secondary Mechanisms

4. Cytotoxic selectivity through multiple extract fractions: Different solvent extracts (petroleum ether, ethyl acetate, methanol) show differential activity against various cancer cell lines, suggesting that multiple bioactive compound classes contribute to overall anticancer effects. The ethyl acetate fraction shows the strongest anticancer activity, likely due to concentration of medium-polarity compounds including ergosterol derivatives and phenolic acids.

5. Potential prebiotic effects of undigested polysaccharides: As beta-glucan structures, LBPs may resist upper gastrointestinal digestion and serve as substrates for beneficial colonic bacteria, though this has not been directly studied for L. betulina polysaccharides specifically.

Clinical Evidence Summary

No human clinical trials have been conducted with Lenzites betulina. All evidence is preclinical, consisting of in vitro cell culture studies and limited in vivo animal models.

Key Preclinical Studies

Evidence Limitations

• No human clinical trials exist for any preparation of Lenzites betulina
• In vitro anticancer results may not translate to in vivo therapeutic efficacy due to bioavailability limitations
• The HeLa-implanted mouse study (Ramamurthy et al. 2019) was posted as a bioRxiv preprint and may not have undergone full peer review
• Antimicrobial activity is generally mild compared to conventional antibiotics, limiting direct therapeutic application
• Lack of pharmacokinetic data for any bioactive compound from this species
• No standardized extract or preparation exists for comparison across studies
• The taxonomic reclassification to Trametes betulina means some older literature may be difficult to locate or attribute correctly

Safety Profile

General Assessment

Lenzites betulina has no documented history of toxicity in traditional use or preclinical studies. It is classified as non-poisonous and non-edible (due to its tough, leathery texture rather than any toxic properties). The absence of clinical trials means that formal safety evaluation in humans has not been conducted. Preclinical cytotoxicity studies suggest selective activity against cancer cells relative to normal cells, though this requires clinical confirmation.

Contraindications

• Known allergy to mushrooms (Basidiomycota): Standard precaution for all medicinal mushroom preparations
• Autoimmune conditions: The immunosuppressive compounds ergosterol peroxide and 9(11)-dehydroergosterol peroxide may theoretically affect immune regulation; use with caution
• Pregnancy and lactation: No reproductive toxicity data available; avoid until safety is established
• Concurrent immunotherapy: The immunosuppressive steroidal compounds may theoretically interfere with immunostimulatory cancer therapies

Drug Interactions

• No documented drug interactions in humans
• Theoretical interaction with immunosuppressant medications due to the presence of ergosterol peroxide (may have additive immunosuppressive effects)
• Theoretical interaction with anticoagulants based on general polypore polysaccharide properties, though not specifically demonstrated for this species

Side Effects

• No side effects documented in the literature due to absence of human clinical use
• The tough, leathery fruiting body is not consumed as food, making oral toxicity from whole mushroom ingestion unlikely

Toxicology

• No formal toxicology studies have been published
• Preclinical cell culture studies show selectivity for cancer cells over normal cells, suggesting a reasonable therapeutic index
• Selenium-enriched mycelium was evaluated for cytostatic (not cytotoxic) effects, suggesting controlled bioactivity rather than general toxicity

Clinical Dosage

No clinically validated dosage exists for Lenzites betulina due to the complete absence of human trials.

Experimental Dosages (Preclinical Research)

• Polysaccharide extracts: In vitro studies used concentrations of 0.1-2.0 mg/mL for antioxidant assays
• Ethyl acetate extract: IC50 of 51.46 micrograms/mL against MDA-MB-231 cells (in vitro)
• Ethanolic extract (animal model): Specific dosages used in the HeLa-implanted mouse model were not standardized for human translation

Traditional Preparation

• Not traditionally consumed as a tea or decoction due to the tough, leathery texture of the fruiting body
• Some folk medicine traditions used decoctions of tough polypores by extended simmering (2-4 hours), though specific documentation for L. betulina is limited

Product Quality Considerations

• No commercial supplements of Lenzites betulina are widely available
• Research-grade extracts vary by solvent system (petroleum ether, ethyl acetate, methanol, hot water) and yield different bioactive profiles
• Polysaccharide content and composition depend on extraction method; cellulase-ultrasonic synergistic extraction has been demonstrated to improve yield
• Any future supplementation should be guided by clinical trial results that do not yet exist

Sources

• Ren G, Liu XY, Zhu HK, Yang SZ, Fu CX. Evaluation of cytotoxic activities of some medicinal polypore fungi from China. Fitoterapia. 2006;77(5):408-410
• Ren L, Visentin S, Bhatt M, et al. Anticancer and antimicrobial activities and chemical composition of the birch mazegill mushroom Lenzites betulina (higher Basidiomycetes). Int J Med Mushrooms. 2014;16(4):327-335
• Zhang Y, Sun L, Zhao X, et al. Isolation, structure characteristics and antioxidant activity of two water-soluble polysaccharides from Lenzites betulina. BMC Chemistry. 2021;15(1):18
• Ramamurthy D, Kumari A, Ramteke PW. Anti-cancer property of Lenzites betulina (L) Fr. on cervical cancer cell lines and its anti-tumor effect on HeLa-implanted mice. bioRxiv. 2019;540567
• Tung NT, et al. Phenolic content and biological activities of Lenzites betulina extracts obtained by ultrasonic-assisted optimization approaches. Scientific Reports. 2026;16:34988
• Turlo J, Gutkowska B, Herold F. Effect of selenium enrichment on antioxidant activities and chemical composition of Lenzites betulina and Trametes hirsuta. Food Chem Toxicol. 2015;78:112-119
• Yaoita Y, Yoshihara Y, Kakuda R, Machida K, Kikuchi M. New sterols from two edible mushrooms. Chem Pharm Bull. 2002;50(5):551-553
• Grzywacz A, Gdula-Argasinska J, Muszynska B, Tyszka-Czochara M, Librowski T, Opoka W. Medicinal properties of fungi occurring on Betula sp. trees — A review. Int J Med Mushrooms. 2015;17(12):1153-1163
• Glamoclija J, Ciric A, Nikolic M, et al. Chemical characterization and biological activity of Chaga (Inonotus obliquus), a medicinal “mushroom.” J Ethnopharmacol. 2015;162:323-332

Connections

• Closely related to Turkey Tail (Trametes versicolor) within the Polyporaceae family; shares beta-glucan polysaccharide production and has been reclassified by some taxonomists into the genus Trametes as Trametes betulina
• Compare with Trametes hirsuta, another Trametes species with overlapping polysaccharide and phenolic bioactive profiles; selenium enrichment studies have compared L. betulina and T. hirsuta directly
• The ergosterol peroxide content links to steroidal compounds found across many Polyporaceae species including Fomitopsis betulina (Birch Polypore), which also grows on birch trees and contains ergosterol derivatives
• The polysaccharide-based immune mechanisms are shared with Schizophyllum commune, which produces the clinically studied beta-glucan schizophyllan
• Unlike Turkey Tail (which has pharmaceutical-grade PSK with extensive clinical data), L. betulina remains at the preclinical stage, highlighting the significant gap between in vitro promise and clinical validation in medicinal mycology