title: Effects of Grifola frondosa non-polar bioactive components on high-fat diet fed and streptozotocin-induced hyperglycemic mice.
abstract: BACKGROUND
  Consumption of medicinal mushrooms for disease prevention and maintaining health has a very long history in Asia. Grifola frondosa (Fr) S.F. Gray (GF) (Meripilaceae) is a medicinal fungus popularly used for enhancing immune systems, lowering blood glucose, and improving spleen, stomach, and nerve functions.
  
  
  OBJECTIVE
  This study examines the hypoglycemic effects of GF in vitro and in vivo, and analyzes the chemical profiles of its bioactive components.
  
  
  METHODS
  In vitro hypoglycemic effects of GF was evaluated enzymatically using α-amylase and α-glucosidase inhibition assays, whereas in vivo study was conducted on high-fat diet fed and streptozotocin (HFD + STZ)-induced hyperglycemic mice. GC-MS was used to determine the chemical profiles of bioactive components.
  
  
  RESULTS
  The non-polar fraction of GF exhibited a stronger anti-α-glucosidase activity (IC50: 0.0332 mg/ml) than acarbose, but its anti-α-amylase activity (IC50: 0.671 mg/ml) was weaker. Oral administration of GF at 600 mg/kg (GF600) significantly lowered the blood glucose, HbA1c, average blood glucose, and serum total cholesterol levels in hyperglycemic mice. Although GF was found to contain mainly oleic acid and linoleic acid, their levels in the fungus were low, suggesting that the effects of GF on HFD + STZ-induced hyperglycemic mice could be due to factors other than these fatty acids.
  
  
  CONCLUSIONS
  These results conclude that GF possesses anti-α-glucosidase activity, and hypoglycemic effect in HFD + STZ-induced hyperglycemic mice.
authors.affiliation: Department of Nursing, Meiho University , Pingtung , Taiwan .
authors.forename: Kuo-Ping
authors.initials: KP
authors.lastname: Shen
authors.forename: Chun-Han
authors.initials: CH
authors.lastname: Su
authors.forename: Tzy-Ming
authors.initials: TM
authors.lastname: Lu
authors.forename: Min-Nan
authors.initials: MN
authors.lastname: Lai
authors.forename: Lean-Teik
authors.initials: LT
authors.lastname: Ng
mesh_terms: D000818:Animals; D001685:Biological Factors / Q000302:isolation & purification / Q000627:therapeutic use*; D059305:Diet, High-Fat / Q000009:adverse effects*; D048691:Grifola; D006943:Hyperglycemia / Q000097:blood / Q000139:chemically induced / Q000188:drug therapy*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D013311:Streptozocin / Q000633:toxicity*; D016896:Treatment Outcome
chemical_list: D001685:Biological Factors; D013311:Streptozocin
keywords: Maitake; diabetes; fatty acids; hypoglycemic activity; medicinal fungus; mushroom; α-Glucosidase