title: Bismuth increases hydroxyl radical-scavenging activity of histamine H2-receptor antagonists.
abstract: The effects of histamine H2-receptor antagonists, alone or in a combination with bismuth, on *OH-provoked degradation of deoxyribose were studied. The histamine H2-receptor antagonists (cimetidine, ranitidine and roxatidine), themselves decreased the deoxyribose damage in Fenton-type systems. In combinations with bismuth, their inhibitory effect in Fenton system (Fe(III)/ascorbic acid + H2O2 was stronger. Moreover, unlike F(III) and Cu(II), which in the presence of ascorbic acid + H2O2 led to an increase in the *OH formation (deoxyribose damage), Bi(III) showed an opposite effect. The present results are interpreted in view of a better ( )OH scavenging activity of bismuth complexes of histamine H2-receptor antagonists as compared to that of the corresponding drugs. These findings might be one more explanation why bismuth salts, in combination with acid-reducing agents, are more effective anti-ulcer agents.
authors.affiliation: Institute of Physiology, Bulgarian Academy of Sciences, Acad. G.Bonchev Str., Bild. 23, 1113 Sofia, Bulgaria.
authors.forename: Margarita
authors.initials: M
authors.lastname: Kirkova
authors.forename: Albena
authors.initials: A
authors.lastname: Alexandrova
authors.forename: Neli
authors.initials: N
authors.lastname: Yordanova
mesh_terms: D000975:Antioxidants / Q000494:pharmacology; D001205:Ascorbic Acid / Q000494:pharmacology; D001729:Bismuth / Q000494:pharmacology*; D002927:Cimetidine / Q000494:pharmacology; D003300:Copper / Q000494:pharmacology; D003855:Deoxyribose / Q000378:metabolism; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006635:Histamine H2 Antagonists / Q000494:pharmacology*; D017665:Hydroxyl Radical / Q000378:metabolism*; D007501:Iron / Q000378:metabolism; D008353:Mannitol / Q000494:pharmacology; D016877:Oxidants / Q000378:metabolism*; D010880:Piperidines / Q000494:pharmacology; D011899:Ranitidine / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D006635:Histamine H2 Antagonists; D016877:Oxidants; D010880:Piperidines; D017665:Hydroxyl Radical; D008353:Mannitol; D003855:Deoxyribose; D003300:Copper; D002927:Cimetidine; D011899:Ranitidine; D007501:Iron; D001205:Ascorbic Acid; D001729:Bismuth; C053742:roxatidine acetate