Effects Of Purendan Superfine Powder On The Expression Of Ang-2and TNF-α In Retinal Of Diabetes Rats

PURPOSEThroughing investigating the effect of purendan superfine powder onthe expression of angiopoietin-2(Ang-2) and tumor necrosis factor-α(TNF-α) in retinal with diabetes rats, to discuss the protect effective of PRDon the diabetes rats’ retinal capillary pathological changes.METHODSThirty six male Wistar rats were divided into3groups randomly:normal control group, diabetic model group and the PRD treatment group,each group includes12rats. Use the intraperitoneal injection of2%Streptozotocin (25mg/kg·d) on the PRD treatment group and diabetics modelrats for3days continually, to establish type Ⅱ diabetes rats model. Theblood glucose≥16.7mmol/L was taken as a standard. After establishing themodel successfully, the diabetes model group was intragastric administrationwith solvents without PRD; and the rats in PRD treatment group wereintragastric administration with PRD (1.8g/kg/d) for12weeks. The rats innormal control group were bred as normal. ONE TOUCH blood glucosemeter was used to detect the blood glucose of rats in each group; thehematoxylin-eosin (HE) staining was used to observe histopathologicalchange in retina of rats in each group; the SP immunohistochemical stainingand Western blotting were used to assess the expression of Ang-2protein inretina of rats in each group; the Western blotting was used to examine theexpression of TNF-α protein in retina of rats in each group; and the RT-PCRwas used to examine the expression of TNF-α mRNA in retina of rats in eachgroup. RESULTS1. The blood glucose of rats in each groupThe blood glucose of rats in diabetic model group was21.63±1.01mmol/L,compared with the normal control group’s, which date displayed as4.57±0.42mmol/L, was obviously higher (P＜0.01). The date of bloodglucose of rats in PRD treatment group was14.60±0.95mmol/L, whichwas obviously lower than that of rats in diabetic model group (P＜0.01).2. The histopathological changes of the rats retinal in each groupIn the normal control group, the layer of retinal was clear, the structurewas integrity, the surface of internal limiting membrane was smooth andthe nerve cells of all levels were orderly and uniform. In diabetic modelgroup, the surface of internal limiting membrane was rough andintumesces obviously; part of the internal limiting membrane wasruptured. Capillary endothelial cell was heaved in the internal limitingmembrane occasionally. The layer of retinal was less clear, gangliocytewas disordered and the quality was decrease. There appears vacuole-liketransformed, karyopycnosis, and so on. Compared with diabetic modelgroup’s, the PRD treatment group’s histopathological expression wasimproved.3. The Ang-2expression in retinal of rats from each group3.1. The results of SP immunohistochemistryThe positive expression of Ang-2protein was shown as buffy granulesand located at cytoplasm. The cells with positive expression of Ang-2were distributed in retinal ganglion cell layer and inner nuclear layermainly. Compared with normal control group, the positive expression ofAng-2was darker buffy in diabetic model group. The positiveexpression of the PRD treatment group was lighter than that in diabeticmodel group.3.2. The research result about area of Ang-2positive expression in each groupby immunohistochemical staining analysis by MiVnt image analysissystem Compared with normal control group, the area of Ang-2positiveexpression in diabetic model group was increased obviously (P＜0.01).Compared with diabetic model group, the area of PRD treatment groupwas decreased obviously (P＜0.01).3.3. The result about Ang-2protein expression in retina of rats by Westernblot methodCompared with normal control group, the expression of Ang-2proteinin diabetic model group was increased obviously (P＜0.01). Theexpression of Ang-2protein in PRD treatment group was decreased thanthat in diabetic model group (P＜0.01).4. The TNF-α expression in retinal of rats from each group4.1. The result about expression of TNF-α protein in retina of rats by Westernblot method:Compared with normal control group, the expression of TNF-α protein indiabetic model group was increased obviously (P＜0.01). The expressionof TNF-α protein in PRD treatment group was decreased than that indiabetic model group (P＜0.01).4.2. The result about expression of TNF-α mRNA in retina of rats byRT-PCR:The expression of TNF-α mRNA in retina was obviously increased indiabetic model group rats than that in normal control group (P<0.01).Compared with diabetic model group, the expression of TNF-α mRNA inPRD treatment group was decreased obviously (P＜0.01).CONCLUSIONPRD could change the diabetic retinopathy of the diabetic rats，whichmight through down regulating the expression of Ang-2and TNF-α of thediabetic rats’ retinal, to reduce the leakage of retinal capillary and thepathology angiogenesis, so that, it could protect the diabetic rats’ retinalcapillary avoiding the damage of diabetes.