Phycocyanin Type 2 Diabetic Rat Pancreatic Islet Cells Of Nf-¦Êb, I¦Êb And Inos Expression

Objective:To investigate the effect of spirulina platensis extract—phycocyanin on the expression of NF-κB,IκB and iNOS in islet cells of type 2 diabetes mellitus in rats. And to explore the mechanisms of protection to islet cells by phycocyanin.Methods:32 healthy male Wistar rats were first adaptively fed for 1 week. Next, type 2 diabetes mellitus models were induced to 24 rats by high-fat diet and low dose intraperitoneal injection of streptozotocin (STZ). The 24 diabetic rats were then randomized into diabetic model group(B), phycocyanin group(C) and metformin group(D), with eight rats in each group. The other rats were normal control group(A). Group C and D were treated with phycocyanin and metformin respectively. The free blood glucose (FBG) was determined by biochemical assay. The morphology and structures of islet cells were observed by histopathological technique. The expression of nuclear factorκB (NFκB), inhibitoryKB (IκB) and inducible nitric oxide synthase (iNOS) in islet cells were detected by immunohistochemical technique.Results:1.After the injection of STZ, the weight of group B, C and D was significantly lower than that of group A (P<0.05);after treatment, the weight of group C and D was obviously higher than that of group B (P<0.05).2. After the injection of STZ, the FBG of group B, C and D was significantly higher than that of group B(P<0.05);after treatment, the FBG. of group C and D was obviously lower than that of group B(P<0.05).3.Compared with group A,there was an increase in NF-κB protein while a decrease in 1κB protein in islet cells of group B, C and D (P<0.05).There was a contrary change in NF-κB and 1κB protein in groups C and D compared with group B(P<0.05).4.Compared with group A,the expression of iNOS in islet cells of group B,C and D was increased (P<0.05);compared with group B, the expression of iNOS of group C and D was decreased (P<0.05).5.The number of islet cell masses decreased;the islet shrinked and the islet cells arranged disorderly with plasma swelling and vacular degeneration in islet cells of group B.The morphology and structure of the treatment groups improved significantly than those in model group.Conclusions:Phycocyanin can not only improve glucolipid metabolism, but also lower the expression of NF-κB and iNOS, and increase the expression of 1κB.It thus exerts the action against the inflammatoy reaction, protects islet cells in T2DM,and slows the process of T2DM.