The free radical mechanisms in beta-carotene induced gastric cytoprotection in HCl model.

The aims of our experiments were to clear up the possible correlations between the free radical mechanisms and the gastric cytoprotection of beta-carotene on HCl-induced gastric mucosal lesions. The beta-carotene was intragastrically given in doses of 1 and 10 mg/kg and 30 min. later 1 ml 0.6 N HCl was given to provoke the mucosal damage. After 1, 5, 15, 30 and 60 min. the animals were sacrificed. The number and severity of gastric mucosal lesions were calculated. The superoxide dismutase (SOD), glutathion peroxidase (GPX), catalase (CAT) activity and the malondialdehyde (MDA) and reduced glutathion (GSH) contents were determined from the gastric mucosa of rats. It was found that 1. beta-carotene was able to reduce the number and severity of ulcers only after 30 min.; 2. the CAT activity was decreased at 60 min. by carotene; 3. the GPX activity became dissimilar in the different groups after 15 min; 4. the changes of GSH were found to be similar ones; 5. the SOD activity was lower during the cyto-protection; 6. the MDA level remained practically unchanged. It has been concluded that 1. the free radicals are the consequences of the development of gastric ulcer and cytoprotection; 2. the scavenger character of beta-carotene is involved in its cytoprotective effect.