An in vitro study on the free radical scavenging capacity of ergothioneine: comparison with reduced glutathione, uric acid and trolox

Carbon Monoxide Protects Against Ischemia-reperfusion Injuryin Vitrovia Antioxidant Properties

“…Indeed, the chemical reactivity of oxyradicals such as superoxide, hydroxyl and peroxyls radicals towards biological targets is different; accordingly, the relative efficiency of an antioxidant can vary depending on the oxidant [37]. For instance, it has been demonstrated that ergothioneine, a low-molecular-mass thiol, was a protective against oxidation in tissues, scavenging singlet oxygen and hydroxyl radicals [38]. By contrast, this compound did not react with superoxide or hydrogen peroxide and it did not inhibit microsomal lipid peroxidation in the presence of iron [39].…”

The Neurospora crassa mutant NcΔEgt-1 identifies an ergothioneine biosynthetic gene and demonstrates that ergothioneine enhances conidial survival and protects against peroxide toxicity during conidial germination

“…Similarly, various effects of the addition of EGT either to cells or in vitro in the presence of peroxides have been reported. Franzoni et al (2006) concluded that EGT was the most active scavenger against three species of free radicals Fig. 9.…”

“…EGT also has peroxynitrite (ONOO À and ÁONOOH) scavenging capacity, and inhibited oxidation by ONOO À of both purified calf thymus DNA and of DNA in a neuronal hybridoma cell line (Aruoma et al, 1999). EGT provided better protection than GSH against oxidation of a-keto-c-methiolbutyric acid by ONOOH and peroxyl radical (ROOÁ) (Franzoni et al, 2006). EGT also significantly blocked the inhibitory effects of singlet oxygen ( 1 O 2 ) generation by the photosensitive dyes Rose Bengal and phenosafranin .…”

“…EGT, at the physiological concentrations of one to two mM in certain animal tissues scavenges the hydroxyl radical (HO ) more efficiently than GSH (Akanmu et al, 1991); consequently, EGT prevents the HO -mediated oxidation of a-keto-c-methiolbutyric acid (Franzoni et al, 2006). In addition, EGT can serve as an effective scavenger of hypoclorous acid (HOCl), thereby preventing the oxidation of a 1 -antiproteinase (Akanmu et al, 1991).…”

Cancer Chemoprevention

“…Consequently, ERT shows a peculiar stability and reactivity compared to other naturally occurring thiols because it does not auto-oxidize, forms disulfides with difficulty because the standard redox potential at pH 7 of the thiol-disulfide couple of ergothioneine is -0.06 V compared to -0.20 to -0.32 V for other natural thiols, requires a more severe oxidative stress to oxidize, and does not promote the classical Fenton reaction (Figure 15.4). 63 It also has chelating properties toward divalent metallic cations due to its α-amino acid moiety, activates antioxidant enzymes such as glutathione peroxidase and superoxide dismutase (SOD), inhibits superoxide-generating enzymes such as NADPH-cytochrome c reductase, and affects the oxidation of various hemoproteins such as hemoglobin and myoglobin.…”