title: Antihyperglycemic effect of the traditional Chinese scutellaria-coptis herb couple and its main components in streptozotocin-induced diabetic rats.
abstract: BACKGROUND
  Scutellaria-coptis herb couple (SC) is the main herb couple in many traditional Chinese compound formulas used for the treatment of diabetes mellitus, which has been used to treat diabetes mellitus for thousands of years in China. In this study we provide experimental evidence for the clinical use of SC in the treatment of diabetes mellitus.
  
  
  OBJECTIVE
  To confirm the anti-diabetic effect of SC extract and its main components, and to explore its mechanism from the effect on intestinal disaccharidases by in vivo and in vitro experiment.
  
  
  METHODS
  SC extract was prepared and the main components (namely berberine and baicalin) contained in the extract were assayed with high performance liquid chromatography (HPLC). And diabetic model rats were induced by intraperitoneal injection of streptozotocin (STZ). After grouped randomly, diabetic rats were administered SC extract, berberine, baicalin, berberine+baicalin, acarbose and vehicle for 33d, respectively. Body weight, food intake, urine volume, urine sugars, fasting plasma glucose and fasting plasma insulin were monitored to evaluate the antidiabetic effects on diabetic rats. Intestinal mucosa homogenate was prepared and the activities of intestinal disaccharidases were assayed. Moreover, oral sucrose tolerance test (OSTT) was performed and the inhibitory effects of SC extract and its main components (berberine and baicalin) on the maltase and sucrase in vitro was evaluated.
  
  
  RESULTS
  After the treatment of SC extract and its main components, the body weight and the fasting plasma insulin level were found to be increased while food intake, urine volume, urine sugars and fasting plasma were decreased. OSTT showed that SC extract and its main components could lower the postprandial plasma glucose level of diabetic rats. Furthermore, SC extract and its main components could inhibit the activities of intestinal disaccharidases in diabetic rats, whereas only SC extract and berberine could inhibit the activity of maltase in vitro.
  
  
  CONCLUSIONS
  According to our present findings, scutellaria-coptis herb couple (SC) possessed potent anti-hyperglycemic effect on STZ-induced diabetic rats. And SC extract and its main components exerted anti-hyperglycemic effect partly via inhibiting the increased activities of intestinal disaccharidases and elevating the level of plasma insulin in diabetic rats induced by STZ.
authors.affiliation: Department of Pharmaceutical Science, Medical College of Hunan Normal University, Changsha 410013, PR China.
authors.forename: Sheng-Zi
authors.initials: SZ
authors.lastname: Liu
authors.forename: Yuan-Xiong
authors.initials: YX
authors.lastname: Deng
authors.forename: Bo
authors.initials: B
authors.lastname: Chen
authors.forename: Xiao-Jie
authors.initials: XJ
authors.lastname: Zhang
authors.forename: Qun-Zhi
authors.initials: QZ
authors.lastname: Shi
authors.forename: Xi-Min
authors.initials: XM
authors.lastname: Qiu
mesh_terms: D000818:Animals; D039323:Coptis; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy* / Q000378:metabolism; D004365:Drugs, Chinese Herbal / Q000494:pharmacology / Q000627:therapeutic use*; D005947:Glucose / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D007328:Insulin / Q000097:blood; D007413:Intestinal Mucosa / Q000201:enzymology; D008297:Male; D008517:Phytotherapy; D051381:Rats; D017207:Rats, Sprague-Dawley; D027343:Rhizome; D031364:Scutellaria baicalensis
chemical_list: D004365:Drugs, Chinese Herbal; D007004:Hypoglycemic Agents; D007328:Insulin; D006026:Glycoside Hydrolases; D005947:Glucose