L-ergothioneine (ERT, 2-thiol-l-histidine-betaine) is an unusual bioactive compound found in food. The biological function of this hydrophilic low-molecular-weight thiol is not known fully even though it has widespread presence in products such as mushrooms and milk.
ERT is exclusively synthesized in a few organisms such as fungi – edible mushrooms (Paul and Snyder, 2010), mycobacteria (Ey et al., 2007), and cyanobacteria (Pfeiffer et al., 2001). In mammals, only ingestion is possible as it is not naturally synthesised. It localises in the mitochondria and cells and tissues normally exposed to oxidative stress and involved in the inflammatory response process (Paul and Snyder 2010; Gründemann 2012).
Benefits and issues are associated with L-ergothioneine in food.
The benefits: it has a wide range of physiological functions, related to its antioxidant and scavenging activities (Aruoma et al., 1999; Paul and Snyder 2010). The issues: it can impact human health at the genetic level. A few case-control studies suggest an association between gene polymorphisms in the ERT organic cation transporter gene, SLC22A4 and susceptibility to a variety of chronic inflammatory diseases (Tokuhiro et al., 2003; Peltekova et al., 2004; Waller et al., 2006; Santiago et al., 2006).
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Waller, S., Tremelling, M., Bredin, F., Godfrey, L., Howson, J., Parkes, M. (2006) Evidence for association of OCTN genes and IBD5 with ulcerative colitis. Gut 55 pp. 809–14.