Gastroprotective effect of crocin in ethanol-induced gastric injury in rats

The present study investigated the gastroprotective effect of crocin in ethanol-induced gastric injury in rats. Rats were allocated into a normal group, an ulcer group, a crocin-treated group, an ulcer group pretreated with crocin, and an ulcer group pretreated with omeprazole as a reference anti-ulcer drug. Rats were sacrificed 3h after ethanol administration. Prophylactic administration of crocin (50mg/kg/day, i.p.) for 3 consecutive days before the administration of 70% ethanol (10 ml/kg, orally) resulted in significant gastroprotection compared to ethanol-ulcerated rats as manifested by significant reduction in the gastric ulcer index. Crocin pretreatment increased ethanol-lowered levels of gastric juice mucin and mucosal prostaglandin E2 (PGE2) and interleukin-6 (IL-6). Moreover, crocin significantly decreased ethanol-elevated tumor necrosis factor-alpha (TNF-α) level, myeloperoxidase activity and heat shock protein 70 mRNA and protein levels. It also restored ethanol-altered mucosal levels of glutathione, malondialdehyde and superoxide dismutase activity. Furthermore, crocin-pretreatment alleviated ethanol-induced mucosal apoptosis as revealed by significant down-regulation of cytochrome c and caspase-3 mRNA expression, significant decrease in caspase-3 activity and mitigated DNA fragmentation as indicated by significant decrements in comet parameters. The protective efficacy of crocin was further supported by histological assessment. No significant difference was observed between crocin and omeprazole (20mg/kg orally 1h before ethanol administration) regarding their mucin-secretagogue and antioxidant effects, as well as their effects on TNF-α, IL-6 and cytochrome c. On the other hand, omeprazole was superior in enhancing PGE2 level and in alleviating neutrophil infiltration, caspase-3 activation and DNA fragmentation. Conclusively, crocin protects rat gastric mucosa against ethanol-induced injury via anti-inflammatory, anti-oxidative, anti-apoptotic and mucin-secretagogue mechanisms that are probably mediated by enhanced PGE2 release.