Background: Saffron is the dried stigmata of the flowers of saffron (Crocus sativus L., Iridaceae). Saffron is well known for the treatment of gastric disorders in traditional medicine.

Objectives: In the search for new potential antiulcer agents, the effects of the ethanol extract of saffron and its active constituents crocin and safranal as compared with omeprazole against gastric ulcer induced by indomethacin in non-diabetic and streptozocin diabetic rats were studied.

Methods: The effects of pretreatment with saffron extract ( 25, 100 or 250 mg/kg, p.o.) , crocin ( 2.5, 5 or 10 mg/kg, p.o.) and safranal ( 0.25, 2, 5 ml/kg, p.o.) and omeprazole (30 mg/kg, p.o.) 30 min before administration of indomethacin (40 mg/kg, p.o. in non-diabetic rats and 15 mg/kg, p.o. in diabetic rats) on gastric lesions, increase of lipid peroxidation and decrease of glutathione levels induced by indomethacin in non-diabetic and diabetic rats were evaluated.

Results: Saffron extract, crocin, safranal and omeprazol prevented the gastric lesions, increase of lipid peroxidation and decrease of glutathione levels induced by indomethacin in non-diabetic and diabetic rats as compared with the control group (P < 0.01). The effects of saffron extract, crocin and safranal on the gastric ulcer index, lipid peroxidation and glutathione levels were comparable to omeprazole.