title: Berberine acutely inhibits the digestion of maltose in the intestine.
abstract: BACKGROUND
  The Chinese Goldthread Rhizome has been used in the Traditional Chinese Medicine as an important ingredient of many formulas for the treatment of diabetes mellitus. Berberine, the main effective composition of Chinese Goldthread Rhizome, is also effective in treating diabetes in today's clinical practice of Traditional Chinese Medicine.
  
  
  OBJECTIVE
  To evaluate the hypoglycemic activity of berberine which treats acutely on the postprandial blood glucose, and to explore the mechanism of this activity.
  
  
  METHODS
  1. One-dose preprandial intragastric administrations of berberine were given to normal animals (dogs and rats), and the postprandial blood glucose concentration curves were measured. Serum insulin enzyme linked immunosorbent assay (ELISA) was only performed in rats. 2. The euglycemic clamp test was performed to evaluate the effect of one-dose berberine intragastric administration on the blood glucose transformation and utilization rate in rats. 3. In the Caco-2 cell monolayer test, the changes of glucose concentration on the apical and basolateral sides were measured when the maltose solution containing berberine was added to the apical side. 4. The inhibition ratio of berberine against α-glucosidase was measured in vitro. 5. The effect of berberine on the fluorescence emission spectrums of α-glucosidase was studied.
  
  
  RESULTS
  One-dose preprandial intragastric administration of berberine delayed the rise of post-maltose blood glucose, did not affect postprandial blood glucose after glucose meal, and did not affect the insulin level in normal rats; reduced post-maltose blood glucose in normal dogs. 2. The result of euglycemic clamp test showed that one-dose intragastric administration of berberine had no effect on the blood glucose transformation and utilization rate in rats. 3. Berberine added to the maltose solution on the apical side of Caco-2 cell monolayer reduced the glucose concentration on the apical side. Glucose in basolateral side of all groups cannot be detected. 4. Berberine inhibited the activity of α-glucosidase in vitro. 5. Berberine significantly and concentration dependently quenched the fluorescence emission spectrum of α-glucosidase.
  
  
  CONCLUSIONS
  Our findings suggest an additional mechanism of the hypoglycemic activity of berberine by demonstrating its ability to acutely inhibit the α-glucosidase, and support the traditional use of berberine and Chinese Goldthread Rhizome for the treatment of diabetes mellitus.
authors.affiliation: Shenyang Pharmaceutical University, Department of Pharmacology, Wenhua Road, No. 103, Shenyang 110016, China.
authors.forename: Zeng-Qiang
authors.initials: ZQ
authors.lastname: Li
authors.forename: Dai-Ying
authors.initials: DY
authors.lastname: Zuo
authors.forename: Xiao-Di
authors.initials: XD
authors.lastname: Qie
authors.forename: Huan
authors.initials: H
authors.lastname: Qi
authors.forename: Ming-Qi
authors.initials: MQ
authors.lastname: Zhao
authors.forename: Ying-Liang
authors.initials: YL
authors.lastname: Wu
mesh_terms: D000818:Animals; D001599:Berberine / Q000494:pharmacology* / Q000627:therapeutic use; D001786:Blood Glucose / Q000378:metabolism*; D018938:Caco-2 Cells; D003106:Colon / Q000378:metabolism*; D039323:Coptis / Q000737:chemistry*; D003920:Diabetes Mellitus / Q000188:drug therapy; D004063:Digestion / Q000187:drug effects*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004333:Drug Administration Routes; D004365:Drugs, Chinese Herbal / Q000494:pharmacology / Q000627:therapeutic use; D004797:Enzyme-Linked Immunosorbent Assay; D005947:Glucose / Q000378:metabolism; D065089:Glycoside Hydrolase Inhibitors; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D008320:Maltose / Q000378:metabolism*; D008517:Phytotherapy; D019518:Postprandial Period; D051381:Rats; D017208:Rats, Wistar; D027343:Rhizome
chemical_list: D001786:Blood Glucose; D004365:Drugs, Chinese Herbal; D065089:Glycoside Hydrolase Inhibitors; D007004:Hypoglycemic Agents; D001599:Berberine; D008320:Maltose; D005947:Glucose