8-bromo-2--deoxyguanosine and hypobromous-acid

Hypobromous acid (HOBr) is generated not only by eosinophils but also by neutrophils in the presence of Br

Topics: Bromates; Chromatography, High Pressure Liquid; Deoxycytidine; Deoxyguanosine; Halogenation; Nucleosides; Phosphates; Potassium Compounds; Spectrometry, Mass, Electrospray Ionization; Thymidine; Urea

Myeloperoxidase (MPO)-generated halogenating molecules, such as hypochlorous acid and hypobromous acid (HOBr), in inflammatory regions are postulated to contribute to disease progression. In this study, we showed that ergothioneine (EGT), derived from an edible mushroom, inhibited MPO activity as well as the formation of 8-bromo-2'-deoxyguanosine in vitro. The HOBr scavenging effect of EGT is higher than those of ascorbic acid and glutathione. We initially observed that the administration of Coprinus comatus, an edible mushroom containing a high amount of EGT, inhibited the UV-B-induced inflammatory responses and DNA halogenation, suggesting that EGT is a promising anti-inflammatory agent from mushrooms.

Topics: Agaricales; Animals; Anti-Inflammatory Agents; Ascorbic Acid; Bromates; Deoxyguanosine; DNA; Ergothioneine; Glutathione; Halogenation; Hypochlorous Acid; Inflammation; Male; Mice; Mice, Hairless; Peroxidase; Ultraviolet Rays

At the sites of inflammation, hypohalous acids, such as hypochlorous acid and hypobromous acid (HOBr), are produced by myeloperoxidase. These hypohalous acids rapidly react with the primary amino groups to produce haloamines, which are relatively stable and can diffuse long distances and cross the plasma membrane. In this study, we examined the effects of taurine, the most abundant free amino acid in the leukocyte cytosol, on the hypohalous acid-dependent formation of 8-chloro-2'-deoxyguanosine (8-CldG) and 8-bromo-2'-deoxyguanosine (8-BrdG). The reaction of taurine with HOBr yielded taurine bromamine, which is the most stable among other bromamines of amino acids. Taurine also enhanced the bromination of only dG among the four 2'-deoxynucleosides, whereas it inhibited the 8-CldG formation. The specificity of taurine for the enhanced formation of halogenated dG is completely different from that of nicotine, an enhancer of chlorination. The amount of dibrominated taurine (taurine dibromamine) closely correlated with the formation of 8-BrdG, suggesting that taurine dibromamine might be a plausible mediator for the dG bromination in vivo.

Topics: Animals; Bromates; Chromatography, High Pressure Liquid; Deoxyguanosine; Halogenation; Humans; Hypochlorous Acid; In Vitro Techniques; Inflammation; Peroxidase; Tandem Mass Spectrometry; Taurine