title: Antidiabetic effects of flavonoids from Sophora flavescens EtOAc extract in type 2 diabetic KK-ay mice.
abstract: BACKGROUND
  Bitter and cold Chinese medicines have been long used for the treatment for diabetes mellitus (DM) for thousands of years in China. The roots of Sophora flavescens Ait., one of bitter and cold Chinese medicines commonly used to remove lung heat have been used to counteract DM and exerted good clinical effects for diabetic patients in some folk hospitals in Fujian province, PR China. However, the corresponding active principles and antidiabetic mechanism of this Traditional Chinese Medicine remain unclear. Therefore, in this study, we aim at chemical profiling of the active principles, validating the potential antidiabetic effects of the active EtOAc extract (SF-EtOAc) in vitro and in vivo, and elucidating its probable antidiabetic mechanism as well as evaluating its acute oral toxicity.
  
  
  METHODS
  An off-line semi-preparative LC-NMR and LC-UV-ESI MS protocol was developed to determine the chemical principles of the active EtOAc extract rapidly and unambiguously. The effect of SF-EtOAc on the glucose transporter type 4 (GLUT4) translocation in L6 myotubes was examined. T2DM KK-Ay mice were induced by high-fat diet. SF-EtOAc was orally administration at the dose of 30, 60 and 120 mg/kg/d, for 21 days. Metformin was used as positive control. Body weight, plasma glucose, oral glucose tolerance test, serum insulin and blood-lipid indexes were measured. Phosphorylation of the AMP-activated protein kinase (AMPK) expression in liver was measured.
  
  
  RESULTS
  We found that SF-EtOAc significantly improved oral glucose tolerance, increased serum high density lipoprotein cholesterol (HDL-C) and reduced body weight, blood glucose levels and other related blood-lipid indexes. Mechanistically, SF-EtOAc elevated phosphorylation of AMP-activated protein kinase (AMPK) and stimulated membrane translocation of GLUT4. Moreover, it was unveiled that oral median lethal dose (LD50) of SF-EtOAc was more than 7500 mg/kg, suggesting that SF-EtOAc was practically non-toxic for mice.
  
  
  CONCLUSIONS
  SF-EtOAc improves glucose tolerance, reduces hyperglycemia and resumes insulin levels, at least in part, by activating GLUT4 translocation which may be modulated by AMPK pathway. According to the results of the present study, SF-EtOAc possesses a potent antidiabetic activity and could be used as a safe remedy for the treatment of diabetes.
authors.affiliation: College of Pharmacy, South-Central University for Nationalities, 182 Min-Zu Road, Wuhan 430074, PR China; State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu-Chong-Zhi Road, Shanghai 201201, PR China.
authors.forename: Xinzhou
authors.initials: X
authors.lastname: Yang
authors.affiliation: College of Pharmacy, South-Central University for Nationalities, 182 Min-Zu Road, Wuhan 430074, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.affiliation: College of Pharmacy, South-Central University for Nationalities, 182 Min-Zu Road, Wuhan 430074, PR China.
authors.forename: Chan
authors.initials: C
authors.lastname: Xu
authors.affiliation: College of Pharmacy, South-Central University for Nationalities, 182 Min-Zu Road, Wuhan 430074, PR China.
authors.forename: Mi
authors.initials: M
authors.lastname: Huang
authors.affiliation: College of Pharmacy, South-Central University for Nationalities, 182 Min-Zu Road, Wuhan 430074, PR China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: College of Pharmacy, South-Central University for Nationalities, 182 Min-Zu Road, Wuhan 430074, PR China.
authors.forename: Jingnan
authors.initials: J
authors.lastname: Lv
authors.affiliation: College of Pharmacy, South-Central University for Nationalities, 182 Min-Zu Road, Wuhan 430074, PR China.
authors.forename: Xinhua
authors.initials: X
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu-Chong-Zhi Road, Shanghai 201201, PR China.
authors.forename: Changqiang
authors.initials: C
authors.lastname: Ke
authors.affiliation: State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu-Chong-Zhi Road, Shanghai 201201, PR China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Ye
authors.affiliation: College of Pharmacy, South-Central University for Nationalities, 182 Min-Zu Road, Wuhan 430074, PR China. Electronic address: shuguangwen@whu.edu.cn.
authors.forename: Guangwen
authors.initials: G
authors.lastname: Shu
authors.affiliation: College of Pharmacy, South-Central University for Nationalities, 182 Min-Zu Road, Wuhan 430074, PR China. Electronic address: zping0124@163.com.
authors.forename: Ping
authors.initials: P
authors.lastname: Zhao
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D002460:Cell Line; D002784:Cholesterol / Q000097:blood / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D059305:Diet, High-Fat; D005230:Fatty Acids, Nonesterified / Q000097:blood / Q000378:metabolism; D005260:Female; D005419:Flavonoids / Q000494:pharmacology / Q000627:therapeutic use* / Q000633:toxicity; D005947:Glucose / Q000378:metabolism; D005951:Glucose Tolerance Test; D007004:Hypoglycemic Agents / Q000494:pharmacology / Q000627:therapeutic use* / Q000633:toxicity; D007328:Insulin / Q000097:blood / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism; D010179:Pancreas / Q000187:drug effects / Q000473:pathology; D008517:Phytotherapy; D018517:Plant Roots; D051381:Rats; D029909:Sophora; D014280:Triglycerides / Q000097:blood / Q000378:metabolism
chemical_list: D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D005419:Flavonoids; D007004:Hypoglycemic Agents; D007328:Insulin; D014280:Triglycerides; D002784:Cholesterol; D005947:Glucose
keywords: AMPK; Antidiabetic; GLUT4; KKAy mice; Off-line HPLC-NMR; Sophora flavescens