Edited By: Dr. Asha Jyoti Bharati
Name -Wood ear mushroom
Scientific name– Auricularia auricula-judae of family Heterobasidiae
Common name- Black ear mushroom, black fungus, jelly ear mushroom, Huaier, wood ear(English), mu er (Chinese), kikurage (Japanese), Jew’s ear and Judas’ Ear
Cultivated in – China, Japan, Taiwan, Thailand, Indonesia, Korea, and Vietnam
Wood ear mushrooms are consumed especially as a traditional Chinese Medicine for more than 1000 years. The main medicinal benefits of this mushrooms are for treating jaundice and sore throats, sore eyes and as an astringent (1).
Wood ear mushrooms are non-toxic edible mushroom and the fourth most important cultivated mushrooms, Agaricus spp., Pleurotus spp., and Lentinus spp. These mushrooms are reddish-brown with soft, gelatinous texture having bell-shaped and ear-like shape without distinctive smell. It can be eaten as a fresh whole fruit body or readily rehydrate from a dried state in soups, pickles, and sauces, imparting meals consumed in the form of fast food, instant food, and processing to convert them into delicious products but should be thoroughly washed before cooking. (2).
Wood ear mushroom grows on dead wood, especially coniferous and deciduous wood of Sambucus nigra in clusters form and classified as a wood-decaying fungus (3).
Nutritional value of Wood ear mushroom
Wood ear mushrooms are medicinal mushroom with a large number of functional nutrients such as fresh fruiting bodies contain about 90 % moisture, high amount of carbohydrates (approximately 630 g kg−1 in dried fruit bodies), protein (18.3 g), dietary fibre (50 g) which are higher than those in tremella (commonly called white fungus). It also contains polysaccharides, melanin, polyphenols, abundant alkaloid, thiamin, riboflavin, ascorbic acid, vitamin D2and minerals (Ca, P, and Fe) (4).
Health benefits of Wood ear mushroom
Wood ear mushrooms have biological activities such as anti-cancer properties, antiviral properties, antioxidant, immunomodulatory, anti-inflammatory, anti-cholesterol, antidiabetic and anticoagulant activity.
1. Antibacterial properties of Wood ear mushrooms
Polysaccharides of Wood ear mushrooms helps in protection against different bacteria such as Escherichia coli and Staphylococcus aureus has a great potential as antimicrobial properties and it can be a supplementary food for human health (5).
2. Manage diabetes
Wood ear mushrooms are rich in dietary fiber (71%) mainly insoluble dietary fiber (IDF) which is beneficial for lowering the glycemic index. Therefore incorporation of Wood ear mushroom powder into the extruded snack reduced the glycemic level after ingestion (6). Moreover, this mushroom also contains polysaccharide which reduces food intake slightly lowered the plasma and urinary glucose levels (7).
3. Active component diazane in Wood ear mushrooms possess antitumor properties
Presence of antitumor active component (diazane) in wood ear mushroom act as a cytotoxic agent which possesses potent antitumor activity against bronchoalveolar cancer, sarcoma and gastric cancer cells, inhibit the proliferation of the tumor cells, induce apoptosis and may be used as a functional additive for enhancing antioxidant activities and suppressing tumor growth in the body (8). Moreover, polysaccharides from wood ear mushroom increase treatment response rate and survival rate and improved immune function without increasing the incidence of adverse effects in patients with gastrointestinal cancers (9).
4. Wood ear mushrooms lower the cholesterol level
Polyphenolic compounds (more than 16%) found in Wood ear mushrooms possesses potent hypocholesterolemic effects by improving antioxidant status, decreasing the level of total cholesterol and atherosclerosis index, increasing the level of high-density lipoprotein cholesterol and fecal excretion of bile acids (10). Furthermore, Wood ear mushrooms contain polysaccharides which significantly lowered the concentrations of serum total cholesterol and low-density lipoprotein. Therefore Wood ear mushrooms possess preventive actions against hypercholesterolemia (11).
5. Anticoagulation properties
Polyphenolic compounds mainly mannose, glucose, glucuronic acid and xylose present in wood ear mushroom act as a novel alternative agent which catalyzes thrombin inhibition by antithrombin, inhibits platelet aggregation and blood clotting. Thus polysaccharides from these mushrooms may constitute a new source of compounds with action on coagulation, platelet aggregation and, perhaps, on thrombosis (12).
6. Antioxidant properties
A research study suggested that wood ear mushroom possess high antioxidant activities, which significantly inhibit lipid peroxidation, oxidative damage and potent hydroxyl radical scavenging activity than catechin (standard drug). Thus wood ear mushroom may be helpful in potential therapeutic use (13).
7. Radioprotective properties due to melanin pigments
Wood ear mushrooms are a good source of melanin pigment which may against ionizing radiation. Thus Wood ear mushroom melanins possess the ability to mediate local shielding against external radiation (14).
8. Anti-quorum-sensing properties
Wood ear mushrooms contain a bioactive pigment which may interfere with the bacterial quorum-sensing system, regulate its associated functions and prevent bacterial pathogenesis. Therefore, wood ear mushroom pigments or specific compounds may be used in humans as a novel quorum-sensing inhibitor to control and handle detrimental infections (15).
9. Immunomodulatory properties
β-glucan exopolysaccharides obtained from Wood ear mushrooms act as antifungal drugs to treat or prevent invasive mycosis infected with Cryptococcus neoformans.
Therefore, Wood ear mushrooms enhance the survival, immunostimulatory activity in phagocytes and induce host protection against C. neoformans, may be beneficial as an adjuvant for vaccines or antifungal therapy (16).
10. Polysaccharide Herein of Wood ear mushrooms can be used as an oral drug delivery
Wood ear mushrooms polysaccharide known as herein has several advantages like biodegradability, biocompatibility, low expense and ease of production which can be used as an innovative biomaterial of oral protein drug delivery system. Thus herein of wood ear mushroom-based hydrogel may be beneficial as an effective polymeric carrier for oral protein drug (17).
11. Antiviral properties of Wood ear mushrooms due to sulfated polysaccharide
Sulfated polysaccharides of mushrooms combined with virus or cells thus prohibit virus adsorption or inhibit some step of virus replication after entering the cell. Therefore these mushroom polysaccharides emerge as a new antiviral drug which attaches the HIV-1 protein so that the virus could not combine with polysaccharide further prevent progression (18).
12. Treats anemia
Wood ear mushroom polysaccharide iron complex possesses high antioxidant activity which binds to the iron to promote digestion and absorption and helpful for the treatment of iron deficiency anemia, it also reduces oxidative stress caused by the overload of iron improved the blood parameters and body weights of iron deficiency anemia patient (19).
13. Prevents obesity
Wood ear mushrooms contain a natural bioactive substance which results in reducing the body weight and adipose tissue mass by suppressing the expression of adipogenic/lipogenic genes and reduce the risk of hepatic steatosis by modulating plasma lipids and liver enzymes (20).
14. Healthy heart
Age is a major risk factor for cardiovascular disease including heart disease. However, intake of Wood ear mushrooms acts as a natural antioxidant that allows improvement of heart function through restoration of the redox balance of these organs. Therefore Wood ear mushroom polysaccharides may improve heart function especially in aging animals and retard the aging process (21).
15. Anti-inflammatory properties
Wood ear mushrooms are a good source of polysaccharides which prevent inflammation and may be helpful for the treatment of different kinds of acute and chronic inflammatory diseases like wound healing, edema and rheumatoid arthritis (22).
Side effect of Wood ear mushroom
1. Risk of anaphylaxis
Anaphylaxis is a serious, life-threatening allergic reaction which is caused by alpha-mannosidase protein from Wood ear mushroom. People who experienced anaphylaxis (severe hypotension) after the ingestion of wood ear mushroom should avoid its consumption (23).