The increasedexpression of PDX-1 may improve insulin resis tance in T2DM rats / 中国医师杂志

ABSTRACT

Objective Pancreatic duodenal homeobox-1 ( PDX-1) plays an important role in the occurrence and development of diabetes.More importantly,its potential application in insulin resistance (IR) improvement is attracting further attention .Berberine has been shown to improve glucose metabolism and insulin resistance .In this study,rat models of type 2 diabetes mellitus ( T2DM) were established by combination of intraperitoneal injection of low -dose streptozotocin and highg-lucose-high-fat diet induction .The effect of berberine on fasting glucose , fasting serum insulin , homeostasis model assessment of insulin resistance ( HOMAI-R) , and ex-pression of PDX -1 of islet in T2DM rats were analyzed .The present study aimed to evaluate the anti-diabetic efficacy of berberine and study the mechanism of its preliminary therapeutic effects .Methods Twenty healthy adult male Sprague Dawley ( SD) rats were di-vided by random number table into the normal control group ( n =6) feeding with a standard diet ,and the experimental group ( n =14 ) given an intraperitoneal injection of streptozotocin .The rats with fasting blood glucose ( FBG) greater than 13.8 mmol/L were ran-domly divided into diabetes mellitus group feeding high sugar high fat diet for two weeks and then continuing with a standard diet , and the berberine group given berberine [180 mg /(kg· d)] every day.The normal control group and diabetes mellitus group were given physiological saline for every day 6 weeks.At the end of 6th week, the rats were executed , and the levels of fasting glucose, fasting se-rum insulin, HOMA-IR, and expression of PDX-1 in pancreas islet of each group were detected .The expression of PDX1-in pancreas islet was examined by immunohistochemistry .The image pro plus 6.0software was used to calculate the integrated optical density ( IOD) of positive expression .Results Compared with the normal control group , FBG, fasting insulin levels ( FINS) , and HOMA-IR of the diabetes mellitus group and berberine group were significantly increased ( P <0.05 ) .Compared with the diabetes mellitus group, FBG, FINS, and HOMA-IR of the berberine group were statistically significantly decreased [ ( 13.11 ±6.87 ) mmol/L vs (18.45 ±4.69) mmol L/, (2.58 ±0.34) μIU/ml vs (2.98 ±0.40) μIU/ml, 1.60 ±0.91 vs 2.75 ±0.28, P <0.05].Compared with the normal control group , the expression of PDX-1 of the islet in the diabetes mellitus group and berberine group was statistically significantly decreased ( P <0.05).After treatment with berberine, FBG, FINS, HOMA-IR, and IOD of PDX-1 in pancreas islet of berberine treatment rats were significantly increased compared with the diabetes mellitus group ( 9.14 ±1.51 vs 6.79 ±0.98 , P <0.01 ) .Conclusions The increases of PDX-1 in islet may be one of the mechanism in the improvement of hyperglycemia .