title: Gastroprotective and antioxidant effects of usnic acid on indomethacin-induced gastric ulcer in rats.
abstract: Usnea longissima, a medicinal lichen of Anatolia (Turkey), is used in the treatment of gastric ulcer in local folk medicine. In this paper, the gastroprotective effect of usnic acid (UA) isolated from Usnea longissima was investigated in the indomethacin-induced gastric ulcers in rats at doses of 25, 50, 100 and 200 mg/kg body weight. The gastric lesions were significantly reduced by all doses of UA as compared with the indomethacin (25 mg/kg body weight) treated group. In the stomach tissues of treated animals, the in vivo antioxidant levels were evaluated. The administration of indomethacin caused a significant decrease in the levels of superoxide dismutase (SOD), glutathione peroxidase (GPx) and reduced glutathione (GSH), and an increase in the lipid peroxidation (LPO) level (p < 0.05). The administration of all doses of UA reversed the trend, inducing a significant increase of SOD, GSH and GPx levels and a reduction in LPO level in tissues. However, catalase (CAT), glutathione reductase (GR) and myeloperoxidase (MPx) activities, increased by indomethacin, were found to be lower in the UA- and ranitidine-treated groups. The gastric mucosal constitutive NO synthase (cNOS) and inducible NO synthase (iNOS) activities were also investigated in tissues of UA- (100 mg/kg), ranitidine- (50 mg/kg) and indomethacin-treated rat groups. The administration of UA and ranitidine increased the cNOS activity and lowered the iNOS activity as compared with indomethacin-treated group. These results suggest that the gastroprotective effect of UA can be attributed to its reducing effect on the oxidative damage and neutrophil infiltration in tissues.
authors.affiliation: Ataturk University, Faculty of Pharmacy, Department of Biochemistry, Erzurum, Turkey. fodabasoglu@yahoo.com
authors.forename: Fehmi
authors.initials: F
authors.lastname: Odabasoglu
authors.forename: Ahmet
authors.initials: A
authors.lastname: Cakir
authors.forename: Halis
authors.initials: H
authors.lastname: Suleyman
authors.forename: Ali
authors.initials: A
authors.lastname: Aslan
authors.forename: Yasin
authors.initials: Y
authors.lastname: Bayir
authors.forename: Mesut
authors.initials: M
authors.lastname: Halici
authors.forename: Cavit
authors.initials: C
authors.lastname: Kazaz
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001572:Benzofurans / Q000494:pharmacology*; D019610:Cytoprotection; D005753:Gastric Mucosa / Q000187:drug effects* / Q000201:enzymology; D005979:Glutathione Peroxidase / Q000378:metabolism; D007213:Indomethacin / Q000633:toxicity*; D008297:Male; D020556:Neutrophil Infiltration / Q000187:drug effects; D009569:Nitric Oxide / Q000096:biosynthesis; D009195:Peroxidase / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013276:Stomach Ulcer / Q000139:chemically induced / Q000188:drug therapy*; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D001572:Benzofurans; C073339:usnic acid; D009569:Nitric Oxide; D009195:Peroxidase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D007213:Indomethacin