Göksel ŞENER*,?, Kübra PASKALOĞLU*, Gülli ESER*, F. Gül AYANOĞLU-DÜLGER*

*Marmara University, Faculty of Pharmacy, Department of Pharmacology, 81010 Haydarpaşa, İstanbul, TURKEY.
oCorresponding Author

Summary:
Omeprazole and lansoprazole have been reported to be protective against acetylsalicylic acid (ASA) induced gastric mucosal injury due to their proton pump (K+/H+-ATPase) inhibitor properties. The aim of this study was to investigate the antisecretory, and the antioxidant effects of increasing doses of lansoprazole and also compare them with those of omeprazole against ASA-induced gastric damage in rats. Gastric lesions were induced by administration of ASA (200mg/kg) to fasted rats. Studies were performed on five groups of animals; control, starvation, ASA, Omeprazole (20, 40, 80 mol/kg) + ASA and Lansoprazole (1, 5, 10 mg/kg) + ASA groups. Mucosal damage, gastric acidity, as well as lipid peroxidation (LPO), glutathione (GSH) levels and myeloperoxidase (MPO) activity were determined. Both drugs significantly prevented the gastric ulcerogenesis induced by ASA, decreased the ulcer index, and the gastric acidity dose dependently. LPO, and MPO activities, which were increased by ASA, were decreased, and the GSH levels, which were decreased, were increased significantly. According to these findings, as well as the increased acidity, active oxygen species and LPO also play an important role in the pathogenesis of ASA-induced gastric damage. The drugs studied may be protective against this damage due to their antioxidant properties, and also by inhibition of acid secretion.