title: Comparative study of the quercetin, ascorbic acid, glutathione and superoxide dismutase for nitric oxide protecting effects in mouse gastric fundus.
abstract: The aim of this work was to compare the preventing capacity of quercetin with Cu/Zn superoxide dismutase (Cu/Zn SOD), ascorbic acid and glutathione on nitric oxide (NO)-induced relaxation in mouse gastric fundus. Furthermore, the effects of the quercetin on the tissue level of total oxidant and antioxidant was investigated. Nitrergic stimulation (4Hz, 25V, 0.1 ms, 10s-train) and exogenous NO (10 μM) induced relaxation. Pyrogallol (10 μM), hydroquinone (100 μM) and LY83583 (6-Anilino-quinolin-5,8-quinone, 5 μM) inhibited nitrergic relaxations. The inhibition observed with pyrogallol, hydroquinone and LY83583 was prevented by quercetin (0.1 μM). Also, ascorbic acid (500 μM), glutathione (100 μM) and Cu/Zn SOD (100 U/ml) prevented the inhibitory effect of superoxide anion generators on the relaxation to nitrergic stimulation and NO. Diethyldithiocarbamic acid (DETCA; 8mM) inhibited nitrergic relaxations. DETCA-induced inhibition on nitrergic stimulation and NO-induced relaxation was prevented by quercetin, ascorbic acid, glutathione or Cu/Zn SOD. DETCA plus pyrogallol, hydroquinone or LY83583 strengthened the inhibition on the relaxations. Also, pre-treatment with quercetin, ascorbic acid and glutathione prevented the inhibitory effect of DETCA plus LY-83583 on the relaxation to nitrergic stimulation and NO but Cu/Zn SOD did not prevent this inhibition. Also, quercetin increased tissue total antioxidant capacity and decreased tissue oxidant level and oxidative stress index in DETCA-treatment group. These results indicate that quercetin has antioxidant effect and protects NO from endogenous superoxide anion-driven inactivation and enhances its biological activity, suggesting that quercetin may scavenge superoxide anion in a Cu/Zn SOD, glutathione or ascorbic acid-inhibitable manner.
authors.affiliation: Department of Pharmacology, Faculty of Medicine, Cukurova University, 01330 Adana, Turkey.
authors.forename: Peyman U
authors.initials: PU
authors.lastname: Ertuğ
authors.forename: Fatma
authors.initials: F
authors.lastname: Aydinoglu
authors.forename: Ozlem
authors.initials: O
authors.lastname: Goruroglu Ozturk
authors.forename: Ergin
authors.initials: E
authors.lastname: Singirik
authors.forename: Nuran
authors.initials: N
authors.lastname: Ögülener
mesh_terms: D000634:Aminoquinolines / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology*; D004050:Ditiocarb / Q000494:pharmacology; D005260:Female; D005748:Gastric Fundus / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D005978:Glutathione / Q000494:pharmacology*; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D051379:Mice; D009126:Muscle Relaxation / Q000187:drug effects; D009569:Nitric Oxide / Q000494:pharmacology*; D016877:Oxidants / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D011748:Pyrogallol / Q000494:pharmacology; D011794:Quercetin / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000037:antagonists & inhibitors / Q000494:pharmacology*
chemical_list: D000634:Aminoquinolines; D000975:Antioxidants; D016877:Oxidants; D011748:Pyrogallol; D009569:Nitric Oxide; C041715:6-anilino-5,8-quinolinedione; D004050:Ditiocarb; D011794:Quercetin; D013482:Superoxide Dismutase; D005978:Glutathione; D007545:Isoproterenol; D001205:Ascorbic Acid