Abstract: AIM: To study the effect of crocetin on the formation of advanced glycation end products (AGEs) and receptor forAGEs (RAGE)protein expression in diabetic rats induced by streptozotocin (STZ).METHODS: Rats were injected STZ in tail vessel with a dose of 45 mg·kg ^-1.3 d later, the rats whose blood glucose were over 11.1 mmol·L ^-1 were regarded as diabetic rats, and were divided randomly into two groups:diabetic mellitus (DM)group, crocetin (50 mg·kg ^-1, po)group.At the same time, 8 normal rats were regarded as control group. After 21 d treatment, The levels of fasting blood glucose (FBG), serum fructosamine (FMN)and glycosylated hemoglobin (GHb)were measured.The contents of AGEs in aorta and mesenteric vessel were detected by fluorospectrophotometry.HE staining for mesenteric aorta was performed, and RAGE protein expression was studies with immunohistochemical method.RESULTS: Compared with DM group, crocetin did not decrease the level of FBG.However, it could decrease the levels of FMN and GHb in blood and AGEs in aorta and mesenteric vessel (P <0.01 or 0.05).HE staining demonstrated injure of mesenteric aorta attenuated and RAGE protein expression decreased after crocetin treatment.CONCLUSION: These results suggest that crocetin not only inhibit nonenzymatic glycation reaction but also reduce RAGE protein expression in diabetic rats, which may contribute to attenuate diabetic vascular complications.

Key words: crocetin, advanced glycation endoproducts, receptor for advanced glycation endoproducts, diabetic mellitus, diabetic vascular complication