Abstract

The aim of the current study was to investigate the possible protective effect of sildenafil (SIL) on cysteamine induced peptic ulcer in Wistar rats. Rats were randomly divided into five groups; six animals each. Normal control group; in which animals received an aqueous solution of Tween 80 (1 ml/kg) as a vehicle, two doses orally at an interval of 4 h. SIL group, in which animals received 25 mg/kg SIL orally 30 min before vehicle administration. Cysteamine group; in which duodenal ulceration was induced by two oral doses of cysteamine-HCl (450 mg/kg in 10% aqueous solution) at an interval of 4 h. Cysteamine+omepeazole group; in which animals were pretreated with 20 mg/kg omeprazole orally 30 min before cysteamine. Cysteamine+SIL group; in which animals were pretreated with 25 mg/kg SIL orally, 30 min before cysteamine. Twenty-four hours after the last dose of vehicle or cysteamine, rats were euthanized and the duodena were removed to determine the number of ulcers, ulcer surface area, ulcer score and ulcer index as well as superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), myeloperoxidase (MPO), thiobarbituric acid reactive substances (TBARS) in tissue homogenates referring to the malondialdehyde, reduced glutathione (GSH) and oxidized glutathione (GSSG). The results of the present study showed that SIL treatment decreased the number of ulcers, the ulcer surface area, the ulcer score and the ulcer index in the cysteamine induced duodenal ulcer. Moreover, SIL ameliorated the biochemical changes that were induced by cysteamine. In conclusion, SIL attenuates experimentally induced peptic ulceration using cysteamine partially through induction of nitrogen oxide (NO) and antioxidant effect which may be useful in the treatment of cystinosis.

Key words: Cysteamine, cystinosis, sildenafil, duodenal ulcer, rats.