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Chemopreventive Agents
Published in David E. Thurston, Ilona Pysz, Chemistry and Pharmacology of Anticancer Drugs, 2021
Ergothioneine (Figure 12.35) is an unusual naturally occurring amino acid with significant antioxidant activity. Structurally, it is identical to the amino acid histidine (in the betaine or zwitterion form) except for the addition of a thiol group at the C2-position of the 5-membered imidazole ring. It was discovered in 1909 in the sclerotia of Claviceps purpurea (the ergot fungus) which gave rise to its name, and was subsequently found in semen, blood, and various mammalian tissues such as the kidneys and liver. Its structure was determined much later in 1911, and it was not synthesized until 1951. It is claimed to be an “antioxidant vitamin” with cancer chemopreventive and cardiovascular properties, and is available worldwide as a dietary supplement. Structures of the two canonical forms of ergothioneine, the thione and thiol species. The thione form is the most stable species in solution, which means that the C2-sulfur atom of ergothioneine is less nucleophilic compared to other cellular thiols such as glutathione.
Role of Diet in Vitiligo
Published in Vineet Relhan, Vijay Kumar Garg, Sneha Ghunawat, Khushbu Mahajan, Comprehensive Textbook on Vitiligo, 2020
Rachita Misri, Khushbu Mahajan
Mushrooms also seem to have a beneficial effect in vitiligo. Cremini mushrooms and brown mushrooms are excellent sources of selenium, riboflavin, pantothenic acid, niacin, and copper, which act as free-radical scavengers [31]. Mushrooms also contain a powerful antioxidant L-ergothioneine (a sulfur-containing amino acid, synthesized by soil bacteria in fungal substrates) which scavenges superoxide and singlet oxygen and suppresses TNF-α [32]. L-ergothioneine is not destroyed when mushrooms are cooked.
Ergothioneine Mitigates Telomere Shortening under Oxidative Stress Conditions
Published in Journal of Dietary Supplements, 2022
Priscilla Samuel, Menelaos Tsapekos, Nuria de Pedro, Ann G. Liu, J. Casey Lippmeier, Steven Chen
Ergothioneine is a naturally occurring amino acid with potent antioxidant properties. It is synthesized exclusively by fungi, cyanobacteria, and mycobacteria. In mammals, ergothioneine is obtained through the diet and accumulates in most tissues (up to millimolar levels) via the action of an integral membrane protein, organic cation transporter (OCTN1) (Cheah and Halliwell 2012). Ergothioneine can be found in trace amounts in a wide variety of foods, though higher levels can be found in certain species of mushrooms, black and red beans, organ meats, and oat bran (Ey et al. 2007). Ergothioneine produced via fermentation technology has United States Generally Recognized as Safe status (United States Food and Drug Administration 2018). The safety of ergothioneine has also been evaluated by the European Food Safety Authority, and a synthetic form has novel food status in Europe (Turck et al. 2016). Ergothioneine is readily absorbed and retained in plasma and whole blood in response to oral supplementation (Cheah et al. 2017). In cell culture, knockdown of OCTN1 results in oxidative damage to proteins, lipids, and DNA (Paul and Snyder 2010). Similarly, OCTN1 knockout mice are completely deficient of ergothioneine and are more susceptible to oxidative stress and inflammation (Kato et al. 2010). The presence of ergothioneine in human tissues, the specialized nature of its transport system, and its antioxidant and cytoprotective properties all suggest that ergothioneine is involved in healthy aging (Ames 2018). The objective of this study was to determine if ergothioneine can reduce telomere shortening in vitro using cultured primary human fibroblasts. Because ergothioneine has well-known antioxidant properties, and oxidative stress is known to accelerate telomere shortening, testing was conducted under both standard and oxidative conditions.