Ultraviolet radiation, environmental pollution, and irregular lifestyle are the main causes of inducing excessive production of reactive oxygen radicals in the skin. In the long run, it will cause the collagen and elastic fibers in the skin tissue to be relaxed and brittle, and reduce the efficiency of epidermal cell metabolism, thus accelerating the aging process. At present, natural antioxidants are dominating the market, and some raw materials including ergothioneine, such as vitamin C, coenzyme Q10 and glutathione, have been added to anti-aging cosmetics as high-quality antioxidant ingredients.
Ergothioneine, like glutathione, is a thiol, but glutathione is very unstable. In contrast, ergothioneine generally exists as thione in neutral and alkaline aqueous solutions and is able to resist its own oxidation. It is only oxidized to disulfide compounds under conditions such as H2O2, Cu2+, and low pH. Since ergothioneine contains imidazole group and also sulfhydryl group, it naturally has good antioxidant effect as well as glutathione.
Glutathione is a small molecule active oligopeptide whose antioxidant effect depends on the GSH-peroxidase-reductase (GSH-Px-Rx) system, which can scavenge harmful free radicals and lipid peroxides in the body, thus preventing skin aging and pigment accumulation, thus brightening the skin and giving it a glowing feel.
Unlike glutathione, the main form of lysergic acid is thione, which is thought to act as a supplement to glutathione in the body (of course, so can ferulic acid). Because glutathione is a polypeptide, its products may have problems of not being able to exist stably during transportation and storage. In contrast, ergothioneine has good stability, which can ensure the stable existence of ergothioneine in cosmetic system without affecting the stability of the system and the quality of the product, and also can overcome the disadvantage that glutathione may not have stable existence during transportation and storage.
In addition, ergothioneine does not oxidize spontaneously under physiological pH conditions. Normal human skin fibroblasts treated with ergothioneine exhibit low peroxide levels after simulated solar UV irradiation, and the ability of cells to absorb, accumulate and utilize ergothioneine makes this natural amino acid and its receptors/transporters an integral part of the skin's antioxidant defense system. It inhibits the expression of tumor necrosis factor-α (TNF-α) and MMP-1 and reduces the level of ROS, which play an important role in UV-induced skin aging, especially wrinkle formation.
Ergothioneine is a sulfur-containing imidazole amino acid. The human body cannot synthesize ergothioneine itself, but can only take it up from the diet through its transporter protein OCTN1, and it is enriched in specific human tissues and cells. In terms of biological function, ergothioneine is considered to be a natural intracellular antioxidant similar to cytoplasmic alcohols and glutathione. Glutathione also acts as an antioxidant and detoxifier, which means it helps to eliminate potentially harmful substances on one side of the body. At the same time, ergothioneine protects DNA from oxidative damage.
