title: Guava leaf extracts promote glucose metabolism in SHRSP.Z-Leprfa/Izm rats by improving insulin resistance in skeletal muscle.
abstract: BACKGROUND
  Metabolic syndrome (MS) and type 2 diabetes mellitus (T2DM) have been associated with insulin-resistance; however, the effective therapies in improving insulin sensitivity are limited. This study is aimed at investigating the effect of Guava Leaf (GL) extracts on glucose tolerance and insulin resistance in SHRSP.Z-Leprfa/Izm rats (SHRSP/ZF), a model of spontaneously metabolic syndrome.
  
  
  METHODS
  Male rats at 7 weeks of age were administered with vehicle water or treated by gavage with 2 g/kg GL extracts daily for six weeks, and their body weights, water and food consumption, glucose tolerance, and insulin resistance were measured.
  
  
  RESULTS
  Compared with the controls, treatment with GL extracts did not modulate the amounts of water and food consumption, but significantly reduced the body weights at six weeks post treatment. Treatment with GL extracts did not alter the levels of fasting plasma glucose and insulin, but significantly reduced the levels of plasma glucose at 60 and 120 min post glucose challenge, also reduced the values of AUC and quantitative insulin sensitivity check index (QUICKI) at 42 days post treatment. Furthermore, treatment with GL extracts promoted IRS-1, AKT, PI3Kp85 expression, then IRS-1, AMKP, and AKT308, but not AKT473, phosphorylation, accompanied by increasing the ratios of membrane to total Glut 4 expression and adiponectin receptor 1 transcription in the skeletal muscles.
  
  
  CONCLUSIONS
  These data indicated that GL extracts improved glucose metabolism and insulin sensitivity in the skeletal muscles of rats by modulating the insulin-related signaling.
authors: Department of Endocrinology, Dongfang Hospital of Beijing University of Chinese Medicine, No.6, 1st Area Fangxing Yuan, Fangzhuang Fengtai District, Beijing 100078, China.
authors: Xiangyu
authors: X
authors: Guo
authors: Hisae
authors: H
authors: Yoshitomi
authors: Ming
authors: M
authors: Gao
authors: Lingling
authors: L
authors: Qin
authors: Ying
authors: Y
authors: Duan
authors: Wen
authors: W
authors: Sun
authors: Tunhai
authors: T
authors: Xu
authors: Peifeng
authors: P
authors: Xie
authors: Jingxin
authors: J
authors: Zhou
authors: Liansha
authors: L
authors: Huang
authors: Tonghua
authors: T
authors: Liu
mesh_terms: D000818:Animals; D019540:Area Under Curve; D001786:Blood Glucose / Q000378:metabolism*; D001835:Body Weight / Q000187:drug effects*; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D004195:Disease Models, Animal; D051275:Glucose Transporter Type 4 / Q000378:metabolism; D007333:Insulin Resistance; D008297:Male; D024821:Metabolic Syndrome / Q000188:drug therapy* / Q000378:metabolism; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism; D010766:Phosphorylation; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use*; D018515:Plant Leaves; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D031647:Psidium; D051381:Rats; D011919:Rats, Inbred Strains; D015398:Signal Transduction
chemical_list: D001786:Blood Glucose; D051275:Glucose Transporter Type 4; D010936:Plant Extracts; D051057:Proto-Oncogene Proteins c-akt