☯ TCM Properties

Category: clearing heat

Temperature: neutral

Taste: sweet

Meridians: lung, stomach, liver, spleen, kidney, large intestine

Functions:

Cools the Blood and stops bleeding

Traditional Chinese Uses

Hei Mu Er is the dried fruiting body of the wood-ear fungus Auricularia auricula-judae (the related A. polytricha/heimuer is used interchangeably). Sweet and neutral, entering the Lung, Stomach, Liver, Spleen and Kidney channels, it is valued in TCM to cool the Blood and stop bleeding, and as a moistening tonic that nourishes Yin, invigorates the Blood and moistens the Intestines. It is taken for reckless bleeding from Heat in the Blood, including bloody stool, hemorrhoidal bleeding, bloody dysentery, uterine bleeding and blood in the urine, and for Yin-Blood deficiency with dry constipation.

Being a food-grade substance, it is commonly cooked in congee, soups and stews as much as decocted, and pairs with other Blood-cooling or moistening herbs. Traditionally used with caution in Blood deficiency without Heat.

Western Herbalism Properties

Actions:

tonic

Relationships

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Botanical Description

Auricularia auricula-judae (and the closely related A. polytricha) is a saprotrophic jelly fungus of the Auriculariaceae family, widely distributed across temperate and subtropical forests of Asia, Europe, and the Americas, where it grows on dead or dying broadleaf wood, particularly elder, elm, and various Chinese hardwoods. The fruiting body is gelatinous when fresh and dries to a hard, brittle, dark form that rehydrates readily; individual basidiocarps are cup- to ear-shaped, two to ten centimeters across, with a smooth, finely veined or slightly wrinkled upper hymenial surface that is dark reddish-brown to nearly black, and a slightly paler, finely hairy lower surface (A. polytricha is more densely tomentose). Multiple fruit bodies often cluster together along host wood, attached by a small lateral or off-center point.

Active Constituents

Glucuronoxylomannan

Acidic heteropolysaccharide

Concentration: the principal water-soluble polysaccharide of the fruiting body, built from mannose, glucuronic acid, glucose and xylose

The immunologically active backbone polysaccharide of wood ear and the fraction carrying its anticoagulant activity. An acidic polysaccharide of this type catalyses thrombin inhibition specifically through antithrombin rather than through heparin cofactor II, which is a heparin-like but not heparin-identical mechanism.

beta-D-Glucan

Cell-wall polysaccharide

Two beta-D-glucans, one water-soluble and one alkali-insoluble, were isolated from the fruiting body. These are the fraction behind the immunostimulant and hypoglycaemic effects reported in animal work.

Adenosine

Purine nucleoside

Concentration: around 133 micrograms per gram of dry fungus reported for Auricularia auricula, and 154 micrograms per gram for A. polytricha

The small-molecule antiplatelet constituent. Adenosine at these levels inhibits ADP-induced platelet aggregation in rat models and in human platelets, and it is the most plausible explanation for the platelet inhibition seen in the classic human case of purpura after a Sichuan meal containing black tree fungus.

Melanin

Phenolic pigment polymer

The pigment that makes the fruiting body black and one of its main antioxidant constituents; it is among the compounds that differ most between the 30 varieties surveyed in a systematic mycochemical comparison.

Ergosterol

Fungal sterol

The fungal membrane sterol and the precursor of vitamin D2, into which it is converted by ultraviolet light during sun-drying. Sun-dried wood ear therefore carries appreciable vitamin D2, while artificially dried material largely does not.

Ergothioneine

Thiol-containing amino acid derivative

A fungal antioxidant amino acid present in wood ear and quantified across cultivated varieties. It is one of the constituents responsible for the antioxidant capacity of the fruiting body.

Insoluble dietary fibre

Structural cell-wall carbohydrate

Concentration: up to 70-80% of the dry weight, the highest of any edible mushroom

The bulk of the dry fruiting body. This is what accounts for the traditional use in the stool and for the food-scale effects on lipid absorption, and it is why the fungus swells so dramatically on rehydration.

⚠ Drug Interactions

Warfarin, heparin and direct oral anticoagulants

Moderate Evidence: Probable

A polysaccharide isolated from Auricularia auricula prolongs clotting through catalysis of thrombin inhibition by antithrombin, the same cofactor heparin works through, and not through heparin cofactor II. Acidic polysaccharides extracted from the fruiting body show anticoagulant activity in vitro, and in mice an Auricularia polysaccharide prolonged APTT, PT and thrombin time and reduced carrageenan-induced thrombosis. The evidence is in vitro and animal, but the mechanism overlaps directly with therapeutic anticoagulation.

Clinical note: Culinary portions are unlikely to matter, but treat concentrated polysaccharide extracts as an anticoagulant. Monitor INR if a patient on warfarin starts a wood ear supplement, and stop supplements a week before surgery or neuraxial anaesthesia.

Aspirin, clopidogrel and other antiplatelet drugs

Moderate Evidence: Probable

Wood ear inhibits ADP-induced platelet aggregation in human platelets and in rats, attributable largely to its adenosine content, and an isolated polysaccharide inhibited platelet aggregation in orally dosed rats to a degree comparable with aspirin. The interaction is documented in a human at ordinary dietary exposure: Hammerschmidt's 1980 report in the New England Journal of Medicine described platelet inhibition and purpura after meals containing black tree fungus, the case that gave the phenomenon the name Szechwan purpura.

Clinical note: Ask about frequent wood ear consumption in a patient on dual antiplatelet therapy who presents with easy bruising. Advise stopping supplements, and moderating heavy dietary intake, before surgery or dental extraction.

Wood ear rehydrated at room temperature for many hours (Burkholderia gladioli pv. cocovenenans contamination)

Major Evidence: Established

This is not a herb-drug interaction but the single most lethal hazard of this material, and it must be stated plainly. Burkholderia gladioli pathovar cocovenenans grows on soaked wood ear and produces bongkrekic acid, which irreversibly inhibits the mitochondrial adenine nucleotide translocase and shuts down cellular energy production, causing multiorgan failure. The bacterium grows best around body temperature and produces most toxin near 26 degrees Celsius, exactly the conditions of an overnight soak on a kitchen counter. Bongkrekic acid is heat-stable: cooking does not destroy it and washing does not remove it, and there is no antidote. Auricularia auricula was newly identified as a vehicle in 2018, and China's national surveillance recorded 19 bongkrekic acid outbreaks from 2010 to 2020 with 146 illnesses and 43 deaths. A 2024 case report documents severe poisoning from spoiled Auricularia auricula.

Clinical note: Rehydrate dried wood ear in the refrigerator, for no more than a few hours, and discard any that has been soaked at room temperature overnight or that smells or feels slimy. Never advise a patient to pre-soak a day ahead. Suspected poisoning is a medical emergency with no antidote: refer immediately for supportive and organ-support care rather than waiting for symptoms to declare themselves.

Auricularia cornea (A. polytricha, Mao Mu Er) and other Auricularia species sold as Hei Mu Er

Minor Evidence: Established

The identity issue here is taxonomic rather than adulteration in the fraudulent sense, and it affects how the literature should be read. The mushroom cultivated and eaten as Hei Mu Er in China is Auricularia heimuer, described as a new species in 2014 on molecular and morphological grounds; the European Auricularia auricula-judae to which it was long referred is not known to occur in East Asia. Almost all pharmacological papers on Chinese material are published under the names A. auricula or A. auricula-judae and in practice concern A. heimuer. The hairy wood ear A. cornea, formerly called A. polytricha, is a separate cultivated species also traded as wood ear and carries a comparable adenosine content of about 154 micrograms per gram.

Clinical note: Read A. auricula-judae in the Chinese literature as A. heimuer. The clinical properties described here are those of the cultivated East Asian wood ear complex; do not assume they transfer to wild-collected European Auricularia auricula-judae, which has not been studied in the same way.

Evidence Tier

Moderate evidence · 3 studies

Recorded studies by study design, strongest design at the top. This is a study-design tier only, not a GRADE rating: it does not weigh risk of bias, consistency or precision.

Systematic review / meta-analysis

0

Randomized controlled trial

0

Other clinical trial

0

Observational / case report

0

In vitro / animal

3

1 verified · 2 unverified

Show 3 studies

The nontoxic mushroom Auricularia auricula contains a polysaccharide with anticoagulant activity mediated by antithrombin
Extraction Optimization, Structural Characterization, and Anticoagulant Activity of Acidic Polysaccharides from Auricularia auricula-judae
A systematic study on mycochemical profiles, antioxidant, and anti-inflammatory activities of 30 varieties of Jew's ear (Auricularia auricula-judae)

Other / unclassified

0

Verified: design read from PubMed for a DOI that resolves to the cited paper Unverified: taken from the study's recorded description

Clinical Studies

The nontoxic mushroom Auricularia auricula contains a polysaccharide with anticoagulant activity mediated by antithrombin

Seon-Joo Yoon, Myeong-Ae Yu, Yu-Ryang Pyun, Jae-Kwan Hwang, Djong-Chi Chu, Lekh Raj Juneja, Paulo A. S. Mourão (2003) Thrombosis Research in vitro Verified: In vitro / animal

A polysaccharide from the fruiting body prolonged clotting assays, and the mechanism was traced specifically to catalysis of thrombin inhibition by antithrombin rather than by heparin cofactor II. This is the primary mechanistic basis for treating wood ear as an anticoagulant-interacting food.

DOI: 10.1016/j.thromres.2003.10.022 Link

Extraction Optimization, Structural Characterization, and Anticoagulant Activity of Acidic Polysaccharides from Auricularia auricula-judae

Chun Bian, Zhenyu Wang, John Shi (2020) Molecules in vitro

Acidic polysaccharides were extracted and structurally characterised from the fruiting body and shown to have anticoagulant activity, confirming that the effect belongs to the acidic polysaccharide fraction rather than to the neutral glucans.

DOI: 10.3390/molecules25030710 Link

A systematic study on mycochemical profiles, antioxidant, and anti-inflammatory activities of 30 varieties of Jew's ear (Auricularia auricula-judae)

Tahidul Islam, Fangjie Yao, Wenyi Kang, Lixin Lu, Baojun Xu (2022) Food Science and Human Wellness in vitro

Thirty cultivated varieties were compared for total carbohydrate, beta-glucan, reducing sugar, melanin, pectin, vitamin D2, ergosterol and ergothioneine and for antioxidant and anti-inflammatory activity. Content varied widely between varieties, which is why single figures for wood ear composition should be read as ranges rather than constants.

DOI: 10.1016/j.fshw.2022.03.005 Link

Historical Texts

Shen Nong Ben Cao Jing

Han dynasty

The earliest record, where the wood ears are entered under the name nou and grouped as the five wood ears. The stated action is to boost qi so that one does not hunger, to lighten the body and to strengthen the will, a tonic rather than a blood-cooling reading.

Xin Xiu Ben Cao (Tang Ben Cao)

Tang dynasty (659)

Defines the five wood ears by the tree they grow on: mulberry, sophora, paper mulberry, elm and willow. Classical practice treated the host tree as part of the drug's identity, so the classical entries do not correspond cleanly to a single modern fungal species.

Ben Cao Gang Mu

Ming dynasty (1596)

Li Shizhen notes that wood ear grows on rotting wood, without branch or leaf, engendered by the residual qi of damp-heat. The cooling of blood and stopping of bleeding for which it is used today belongs to this later tradition rather than to the Han-dynasty tonic entry.

References

Dale E. Hammerschmidt. Szechwan Purpura . New England Journal of Medicine (1980) [DOI]
Mengdi Shi, Mei Zeng, Aerbusili Genjiafu, Xiangxing Zhang, Lanlan Guo, Ruikai Shang, Zhiqiang Zhou, Xiangdong Jian, Lingjia Yu. Severe bongkrekic acid poisoning caused by eating spoiled Auricularia auricula: a case report . BMC Complementary Medicine and Therapies (2024) [DOI]
Hexiang Zhang, Yunchang Guo, Lili Chen, Zhitao Liu, Junhua Liang, Mengmeng Shi, Fei Gao, Yunqi Song, Jiang Chen, Ping Fu. Epidemiology of foodborne bongkrekic acid poisoning outbreaks in China, 2010 to 2020 . PLOS ONE (2023) [DOI]
Fang Wu, Yuan Yuan, Shuang-Hui He, Asanka R. Bandara, Kevin D. Hyde, Vera F. Malysheva, De-Wei Li, Yu-Cheng Dai. Global diversity and taxonomy of the Auricularia auricula-judae complex (Auriculariales, Basidiomycota) . Mycological Progress (2015) [DOI]
Tahidul Islam, Kumar Ganesan, Baojun Xu. Insights into health-promoting effects of Jew's ear (Auricularia auricula-judae) . Trends in Food Science & Technology (2021) [DOI]

Hei Mu Er

Traditionally used for

Cautions & contraindications