title: Slow acting protein extract from fruit pulp of Momordica charantia with insulin secretagogue and insulinomimetic activities.
abstract: The protein from Thai bitter gourd (Momordica charantia) fruit pulp was extracted and studied for its hypoglycemic effect. Subcutaneous administration of the protein extract (5, 10 mg/kg) significantly and markedly decreased plasma glucose concentrations in both normal and streptozotocin-induced diabetic rats in a dose-dependent manner. The onset of the protein extract-induced antihyperglycemia/hypoglycemia was observed at 4 and 6 h in diabetic and normal rats, respectively. This protein extract also raised plasma insulin concentrations by 2 fold 4 h following subcutaneous administration. In perfused rat pancreas, the protein extract (10 microg/ml) increased insulin secretion, but not glucagon secretion. The increase in insulin secretion was apparent within 5 min of administration and was persistent during 30 min of administration. Furthermore, the protein extract enhanced glucose uptake into C2C12 myocytes and 3T3-L1 adipocytes. Time course experiments performed in rat adipocytes revealed that M. charantia protein extract significantly increased glucose uptake after 4 and 6 h of incubation. Thus, the M. charantia protein extract, a slow acting chemical, exerted both insulin secretagogue and insulinomimetic activities to lower blood glucose concentrations in vivo.
authors.affiliation: Department of Pharmacology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand. sirintorn.y@chula.ac.th
authors.forename: Sirintorn
authors.initials: S
authors.lastname: Yibchok-anun
authors.forename: Sirichai
authors.initials: S
authors.lastname: Adisakwattana
authors.forename: Cheng Yu
authors.initials: CY
authors.lastname: Yao
authors.forename: Polkit
authors.initials: P
authors.lastname: Sangvanich
authors.forename: Sophon
authors.initials: S
authors.lastname: Roengsumran
authors.forename: Walter Haw
authors.initials: WH
authors.lastname: Hsu
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D018929:Cell Culture Techniques; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000188:drug therapy*; D005638:Fruit / Q000737:chemistry; D005934:Glucagon / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000302:isolation & purification / Q000494:pharmacology* / Q000627:therapeutic use; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D000078790:Insulin Secretion; D008297:Male; D051379:Mice; D029777:Momordica charantia / Q000737:chemistry*; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism; D010179:Pancreas / Q000187:drug effects / Q000378:metabolism; D010477:Perfusion; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology; D010940:Plant Proteins / Q000302:isolation & purification / Q000494:pharmacology* / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar; D013311:Streptozocin
chemical_list: D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin; D010936:Plant Extracts; D010940:Plant Proteins; D013311:Streptozocin; D005934:Glucagon; D005947:Glucose