Dietary Dunaliella bardawil, a beta-carotene-rich alga, protects against acetic acid-induced small bowel inflammation in rats

Background: Reactive oxygen species mediate tissue injury in inflammatory bowel disease. beta-Carotene is known as a potent free radical quencher and antioxidant. Aim: The authors evaluated the efficacy of prefeeding Dunaliella bardawil, rich in beta-carotene, to ameliorate acid-induced enteritis in a rat model. Methods: Enteritis was induced in female Sprague-Dawley rats by injection of 2 mL acetic acid (0.67 mol/L) to a ligated duodenal loop following 10 weeks of feeding diets containing beta-carotene and compared with various controls. The effects of beta-carotene were evaluated by changes in myeloperoxidase activity, histology, and histomorphometry. Results: Feeding beta-carotene resulted in suppressed mucosal myeloperoxidase activity, both basal and that induced by acetic acid injection. Acetic acid treatment induced major histopathologic changes in the duodenal mucosa, including small, irregular, and distorted villi; damage to the epithelium; edema of the lamina propria; accumulation of inflammatory cells; and hemorrhage. beta-Carotene treatment prevented these acid-induced histopathologic changes, and this was confirmed by histomorphometry of the villi. Conclusions: These results demonstrate the effectiveness of beta-carotene in a rat model as a prophylactic dietary measure in reducing the effects of acidinduced enteritis and raise the possibility that patients with Crohn's disease may benefit from the consumption of natural beta-carotene.