title: Antidiabetic mechanism of Coptis chinensis polysaccharide through its antioxidant property involving the JNK pathway.
abstract: BACKGROUND
  Antidiabetic activity of Coptis chinensis Franch (Ranunculaceae) polysaccharide (CCPW) has been reported. However, its molecular mechanism remains unclear.
  
  
  OBJECTIVE
  An attempt was made to further verify the antidiabetic activity of CCPW on type 2 diabetes mellitus (T2DM) and elucidate the mechanism of antidiabetic activity.
  
  
  METHODS
  Male Wistar rats were fed with high-fat diet (HFD) and injected with streptozotocin (STZ) to generate a T2DM model. Effects of CCPW on fasting blood glucose (FBG), triglyceride (TG), total cholesterol (TC), glutathione (GSH), glutathione peroxidases (GSH-Px), superoxide dismutases (SOD), catalase (CAT), malondialdehyde (MDA), c-jun n-terminal kinase (JNK), phosphorylated insulin receptor substrate 1 (phospho-IRS1), phosphorylated phosphatidylinositol 3 kinase (phospho-PI3Kp85) and glucose transporter 4 (Glut4) were investigated.
  
  
  RESULTS
  FBG level of diabetic rats could be significantly inhibited by 51.2, 42.7, and 23.3% through administration of CCPW at doses of 200, 100, and 50 mg/kg b.w., respectively (p < 0.01). CCPW also could significantly reduce TG by 19.2, 12.1, and 7.4%, and TC by 24.2, 20.9, and 18.7%, respectively (p < 0.05 or p < 0.01). CCPW showed an obvious antioxidant effect through increasing GSH-Px, SOD, and CAT activities, and decreasing GSH and MDA contents (p < 0.05 or p < 0.01). Furthermore, CCPW could inhibit JNK and phospho-IRS1 expression and promote the expression of phospho-PI3Kp85 and Glut4 compared with those in the DM group (p < 0.05 or p < 0.01).
  
  
  CONCLUSIONS
  CCPW can produce antidiabetic activity in rats with T2DM through its antioxidative effect, which is closely related to the JNK/IRS1/PI3K pathway.
authors: College of Basic Medical Sciences, Changchun University of Chinese Medicine , Changchun, Jilin , PR China .
authors: Shuang
authors: S
authors: Jiang
authors: Yahong
authors: Y
authors: Wang
authors: Dayong
authors: D
authors: Ren
authors: Jianrui
authors: J
authors: Li
authors: Guangxin
authors: G
authors: Yuan
authors: Liping
authors: L
authors: An
authors: Peige
authors: P
authors: Du
authors: Jie
authors: J
authors: Ma
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D039323:Coptis; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy* / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D020935:MAP Kinase Signaling System / Q000187:drug effects* / Q000502:physiology; D008297:Male; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use; D011134:Polysaccharides / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000975:Antioxidants; D007004:Hypoglycemic Agents; D010936:Plant Extracts; D011134:Polysaccharides
keywords: Hyperglycemic; hypolipidemic; oxidative stress; type 2 diabetes