Bioactive compounds and metabolites in mushrooms
Mushrooms in ancient healing
Edible mushrooms with therapeutic potency
References
Further reading
Fungi have gained significant attention in the field of phytomedicine as potential natural sources of bioactive compounds and secondary metabolites. Fungi that produce visible fruiting bodies are called macrofungi. Mushrooms are edible macrofungi mainly found in rainy and snow-melting seasons.
Mushrooms form macroscopic fruiting bodies that eventually produce and disperse spores. Mushroom spores contain all the essential components that are needed to produce a new fungus. Mushrooms can exist in nature in many forms, including leathery or woody, fleshy, or sub-fleshy forms.
Mushrooms are rich sources of dietary fibers, vitamins, minerals, trace elements, essential amino acids, complex polysaccharides, unsaturated fatty acids, and antioxidants.
Polysaccharides, alkaloids, proteins, fats, minerals, carotenoids, glycosides, terpenoids, folates, tocopherols, flavonoids, phenolics, volatile oils, ascorbic acid, lectins, enzymes, and organic acids are the main bioactive compounds present in mushrooms.
Medicinal mushrooms and fungi are believed to have around 130 therapeutic properties, including anticancer, anti-inflammatory, antioxidant, anti-diabetic, anti-microbial, immunomodulatory, and cardiovascular- and hepato-protective functions.
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Bioactive compounds and metabolites in mushrooms
Several bioactive compounds found in mushrooms, including lectins, phenolic carboxylic acids, coenzymes, and triterpenoids, have immunomodulatory properties, including activation of phagocytes, cytotoxic T cells, and antibody-mediated immune responses (humoral immunity). These compounds play vital roles in stimulating the immune system in response to infection or disease.
Mushrooms contain more than 30 polyphenolic compounds that act as potent antioxidants to scavenge free radicals and prevent oxidative damage to cellular macromolecules. Tannins, phenolic acids, oxidized polyphenols, hydroxybenzoic acids, lignans, flavonoids, stilbenes, and hydroxycinnamic acids are the major phenolic compounds found in mushrooms.
These compounds can provide protection against various health complications, including cardiovascular disease, age-related neurodegenerative diseases, and cancers.
Moreover, these compounds exhibit anti-microbial, anti-inflammatory, antiatherogenic, antithrombotic, antiallergenic, and vasodilatory activities. Some phenolic compounds derived from mushrooms can also inhibit nitric oxide production.
Terpenes and terpenoids are the most abundant organic compounds found in mushrooms. Terpenoids can prevent drug-induced kidney toxicity and inflammation. Major terpene derivatives found in mushrooms include ganoderal, ganodermic, ganoderic acids, lucidone, ganodermanondiol, and ganodermanontriol. These compounds have anticancer, anti-microbial, and immunomodulatory activities.
Polysaccharides are the most common mushroom-derived bioactive compounds with numerous therapeutic properties, including anti-inflammatory, anticancer, and immunomodulatory functions.
Mushroom polysaccharides exert these functions by activating various immune cells, including neutrophils, cytotoxic T cells, natural killer cells, monocytes, macrophages, and dendritic cells.
In the gastrointestinal (GI) tract, mushroom polysaccharides are degraded by the gut microbial populations. Some gut bacteria use polysaccharides as energy sources to produce various secondary metabolites with health-enhancing properties, including short-chain fatty acids, valerate acid, acetone, and propionate.
Mushroom polysaccharides as dietary fibers can also increase the abundance of beneficial bacteria and reduce the abundance of pathogenic bacteria.
Proteins and peptides are vital bioactive nutraceuticals found in mushrooms that play important roles in nutrient absorption, digestion, and activation of immune response against invading pathogens.
Ribonucleases, lectins, ribosome-inactivating proteins, laccases, and fungal immunomodulatory proteins are the major mushroom-derived proteins and peptides with pharmaceutical potential.
Lectins bind with cell surface carbohydrates and trigger anti-microbial and immunomodulatory functions. Fungal immunomodulatory proteins can suppress tumor cell migration and invasion, and thus, are used as adjuvants in cancer therapies. Ribosome-inactivating proteins exhibit anti-viral activities by inhibiting the reverse transcriptase activity of human immunodeficiency virus 1 (HIV-1).
Polyunsaturated fatty acids derived from mushrooms are capable of reducing blood cholesterol level. The lipidic fraction of mushrooms contains tocopherols that act as natural antioxidants. Linoleic acid derived from mushrooms can reduce inflammation by inhibiting the production of nitric oxide and pro-inflammatory cytokines.
Linoleic acid can also inhibit acetylcholinesterase and butyrylcholinesterase and reduce the risk of Alzheimer’s disease. Anticancer polysaccharides derived from mushrooms can reduce tumor size and increase the survival rate of tumor-bearing mice. Glucans derived from mushrooms have antioxidant, anticholesterolemic, anticancer, neuroprotective, and immunomodulating activities.
Mushrooms: Medicine or myth? ⏲️ 6 Minute English
Mushrooms in ancient healing
Humans consume wild mushrooms since ancient times. China was the first country to cultivate mushrooms and currently has the highest total production of these edible macro fungi. Edible mushrooms were also found in Chile almost 13,000 years back. Therapeutic use of mushrooms was evidenced in Mexican, the ancient Greek, Chinese, Roman, and Egyptian societies since a very long time.
Mushrooms were used as anti-microbial agents more than 4,000 years back. In Egyptian hieroglyphs, mushrooms are pictured as immortality plants (sons of the gods). Ancient literature also mentioned using mushrooms as anti-inflammatory agents for wound healing.
Edible mushrooms with therapeutic potency
Mushrooms are regarded as powerful immune-enhancing superfoods. Bioactive compounds produced by mushrooms are mainly associated with their therapeutic potential.
Agaricus subgrufescens farmed in the United States produces a variety of bioactive compounds and is used as medicinal food for cancer, diabetes, hyperlipidemia, hepatitis, and arteriosclerosis. This mushroom is a rich source of many polysaccharides, including riboglucans, β-glucans, and glucomannans.
Chaga fungus produced in cold climatic conditions is mainly used in Russia to restore vitality and maintain health. This mushroom contains a wide range of antioxidants, including superoxide dismutase, melanin, and triterpenes like lupeol, inotodiol, and botulin. In addition, it contains polyphenols, sterols, and polysaccharides.
Cordyceps sinensis is a medicinal mushroom commonly used to maintain lung, kidney, and adrenal functions. Cordycepin is a chemical found specifically in this mushroom. In addition, it contains beta-glucan and CO-1. As a sport medicine, it improves physical strength and performance.
Trametes versicolor is a well-known mushroom typically produced in temperate climates. It contains polysaccharides, proteins, amino acids, and many bioactive compounds. Two main polysaccharides (PSP and PSK) isolated from this mushroom are used as adjuvant cancer therapy. In addition, this mushroom has immune-stimulating activity.
Ganoderma lingzhi is regarded as a powerful “Shen” tonic because of its nerve- and kidney-relaxing properties. Ganoderma lucidum is another type of mushroom commonly used to treat insomnia.
Lentinula edodes is a well-known mushroom that contains a wide variety of polysaccharides with therapeutic benefits, including beta-glucan, lentinan, emitanin, and KS-2. Lion’s mane is another well-known mushroom with nootropic and neurotrophic activities. Hericenones and erinacines are the two main nootropic compounds in this mushroom that are used as cognitive enhancers.
A wide variety of edible mushrooms have also been tested as therapeutic natural products to treat coronavirus disease 2019 (COVID-19). Anti-viral, anti-inflammatory, anti-thrombotic, and immunomodulatory properties make mushrooms a potential natural medicine to treat microbial infections.
References
Further Reading