# Mushrooms as Functional Foods for Meniere's Disease
###### Abstract
Mushrooms contain bioactive proteins and peptides known to have antihypertensive, immunomodulatory, antifungal, antibiotic, antibacterial activities, anticancer, antiviral, and antioxidant properties [14; 15]. Bioactive components reported in different edible mushrooms include \(\beta\)-glucans, lentinan, peptidoglycan, ergosterol, cordycepin, tocopherols, quercetin, catechin, lovastatin, eritadenine, hericcones, erinacines, among many others [16]. Furthermore, mushroom bioactive elements include ribosome incativating proteins, proteases, antifungal proteins, and lectins, present namely in _Gandorma lucidum_, _Agaricus bisporus_, and _Boletus satanus_[17; 18]. Protein from mushrooms contrasts from animal, vegetable, and microbial proteins, usually forming cytotoxic enzymes (efficient tools to combat cancer), and include fungal immunomodulatory proteins (FIPs), Ribosome Inactivating Proteins (RIPs), nucleases, ubiquitin-like proteins, and proteins possessing enzymatic activity such as ribonucleases and lacases [19; 20; 21]. Mushrooms contain ergothioneine, which humans are unable to synthesize, a unique sulfur-containing amino acid, an antioxidant, cytoprotective, and anti-inflammatory element with therapeutic potential, approved by world food agencies. The novel food, synthetic L-ergothioneine, has also been approved by the FDA and EFSA at a recommended dosage of 30 mg/day for adults [22; 23; 24]. Ergothioneine is a thiourea derivative of histidine synthesized by few bacteria and fungi and exclusively acquired by animals and plants from exogenous sources, representing a rich source of nutrients for microbiota in the host environment. Ergothioneine is a natural powerful antioxidant activity, derived from microorganisms, especially in edible mushrooms, and a close relationship with various oxidative stress-related diseases. Besides the antioxidant properties, it has a powerful cytoprotective role in some important cells and tissues [25; 26]. Mushrooms have been proven to be the highest dietary source of ergothioneine, accounting for about 95% of dietary intake [27]. Ergothioneine has a protective role in chronic inflammatory disorders. The organic cation transporter OCTN1 has been presumed to carry organic cations across the plasma membrane, but the key substrate of this transporter is in fact ergothioneine [28]. The antioxidant activity of ergothioneine has many advantages over other antioxidants such as glutathione and ascorbic acid due to its specific transportation of OCTN1. The molecular and genetic defects and the pathophysiology behind [PERSON]'s disease, as well as the dysregulation of these ion transporters, can result in severe defects in hearing or even deafness, enhancing the dietary role of ergothioneine from mushrooms [29]. Ergothioneine is a chief amino acid but an under-recognized dietary nutrient known to avert several inflammatory and cardiovascular diseases, diabetes, and liver and neurodegenerative diseases and has been suggested as a \"vitamin\" and to have nutraceutical uses [26] (Figure 1). It is also considered that ergothioneine deficiency may be related to neuropathy and aging, which may increase the risk of aging-related oxidative stress diseases in the elderly. Ergothioneine ameliorates the deterioration of sleep quality caused by psychological stress, possibly through anti-inflammatory and antioxidant mechanisms in the central and peripheral nervous system (Figure 1) [30]. Ergothioneine extracted from _Pleurotus ostreatus_, the second most cultivated edible mushroom worldwide, was shown to exhibit strong antioxidant activity; hence, it could be a functional food for the prevention and treatment of ulcerative colitis [31]. The _Pleurotus ostreatus_ (oyster) and _Ganoderma lucidum_ (reishi) bioactive compounds have antimicrobial and prebiotic properties which are distributed in the mushroom mycelium and fruiting body.