title: Regulation of signaling molecules associated with insulin action, insulin secretion and pancreatic β-cell mass in the hypoglycemic effects of Korean red ginseng in Goto-Kakizaki rats.
abstract: BACKGROUND
  Korean red ginseng (KRG) has long history as herbal remedy for antidiabetic effect.
  
  
  OBJECTIVE
  To study molecular mechanisms by which KRG ameliorates diabetes mellitus, we investigated whether the supplementation with the aqueous extract of KRG as a dietary admixture (1%, w/w) regulates the expressions of signaling molecules that are associated with insulin action, insulin secretion and pancreatic β-cell mass in spontaneously diabetic Goto-Kakizaki (GK) rats.
  
  
  METHODS
  An aqueous extract of KRG was supplemented for the estimated dosage to be 0.2 g/kg rat/day beginning at 5 weeks of age for 12 weeks in male GK rats. Plasma glucose levels were measured every 4 weeks. The expressions of signaling molecules that are associated with insulin action, insulin secretion and β-cell mass in tissues were determined by Western blotting.
  
  
  RESULTS
  The 12-week supplementation with KRG significantly (P<0.05) decreased blood glucose compared to control. It up-regulated the expression of glucose transporter (GLUT) 4 in adipose tissue, and down-regulated the expression of protein tyrosine phosphatases (PTP)-1B in adipose tissue and skeletal muscle. It also up-regulated the expression of insulin and down-regulated the expression of uncoupling protein (UCP) 2, Bax and poly (ADP-ribose) polymerase (PARP) in pancreas.
  
  
  CONCLUSIONS
  These results suggest that GLUT4, PTP-1B, insulin, UCP2, Bax and PARP may be the primary targets of KRG that result in increase in insulin action and in insulin secretion, and decrease in β-cell mass, and that cause the normalization in glucose homeostasis.
authors.affiliation: Division for Metabolism and Functionality Research, Korea Food Research Institute, 516 Baekhyun-dong, Bundang-gu, Songnam-si, Kyonggi-do 463-746, Republic of Korea. khyey@kfri.re.kr
authors.forename: Hye Young
authors.initials: HY
authors.lastname: Kim
authors.forename: Kyong
authors.initials: K
authors.lastname: Kim
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D051275:Glucose Transporter Type 4 / Q000378:metabolism; D006943:Hyperglycemia / Q000188:drug therapy* / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D007328:Insulin / Q000378:metabolism; D050417:Insulin-Secreting Cells; D007473:Ion Channels / Q000378:metabolism; D008297:Male; D055670:Medicine, Korean Traditional; D024101:Mitochondrial Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism; D005894:Panax; D010179:Pancreas / Q000187:drug effects / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use*; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1 / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D000071246:Uncoupling Protein 2; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: C494828:Bax protein, rat; D001786:Blood Glucose; D051275:Glucose Transporter Type 4; D007004:Hypoglycemic Agents; D007328:Insulin; D007473:Ion Channels; D024101:Mitochondrial Proteins; D010936:Plant Extracts; C495694:Slc2a4 protein, rat; C000604391:Ucp2 protein, rat; D000071246:Uncoupling Protein 2; D051028:bcl-2-Associated X Protein; C499322:Parp1 protein, rat; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; C516610:Ptpn1 protein, rat