RRC ID 50419
Author Tanaka Y, Takahashi K, Kato JI, Sawazaki A, Akasaka T, Fujita N, Kumamaru T, Saito Y, Shirouchi B, Sato M.
Title Starch synthase IIIa and starch branching enzyme IIb-deficient mutant rice line ameliorates pancreatic insulin secretion in rats: screening and evaluating mutant rice lines with antidiabetic functionalities.
Journal Br J Nutr
Abstract Diabetes mellitus is a metabolic disease spreading worldwide that has been reported to worsen the development and progression of other diseases (cancer, vascular diseases and dementia). To establish functional rice lines with anti-postprandial hyperglycaemic effects, we developed mutant rice lines, which lack one or two gene(s) related to starch synthesis, and evaluated their effects. Powder of mutant rice lines or other grains was loaded to rats fasted overnight (oral grain powder loading test). Incremental area under time-concentration curves (iAUC) were calculated with monitored blood glucose levels. Rice lines with anti-postprandial hyperglycaemic effects were separated by cluster analysis with calculated iAUC. A double mutant rice #4019 (starch synthase IIIa (ss3a)/branching enzyme IIb (be2b)), one of the screened mutant rice lines, was fed to Goto-Kakizaki (GK) rats, an animal model for type 2 diabetes, for 5 weeks. Plasma levels of C-peptide, a marker of pancreatic insulin secretion, were measured with ELISA. For in vitro study, a rat pancreatic cell line was cultured with a medium containing rat serum which was sampled from rats fed #4019 diet for 2 d. After 24-h of incubation, an insulin secretion test was performed. Through the oral rice powder loading test, seven rice lines were identified as antidiabetic rice lines. The intake of #4019 diet increased plasma C-peptide levels of GK rats. This result was also observed in vitro. In rat serum added to cell medium, ornithine was significantly increased by the intake of #4019. In conclusion, the mutant rice #4019 promoted pancreatic insulin secretion via elevation of serum ornithine levels.
Volume 119(9)
Pages 970-980
Published 2018-5-1
DOI 10.1017/S0007114518000314
PII S0007114518000314
PMID 29532765
MeSH 1,4-alpha-Glucan Branching Enzyme / deficiency 1,4-alpha-Glucan Branching Enzyme / genetics* 1,4-alpha-Glucan Branching Enzyme / metabolism Animal Feed Animals Area Under Curve Blood Glucose Cluster Analysis Diabetes Mellitus, Type 2 / metabolism Diabetes Mellitus, Type 2 / prevention & control* Gene Expression Regulation, Enzymologic Gene Expression Regulation, Plant Glucose Tolerance Test Glycylglycine / blood Hypoglycemic Agents / pharmacology* Insulin / metabolism Insulin Secretion / drug effects Insulin Secretion / genetics* Male Mutation Ornithine / blood Oryza / classification Oryza / enzymology Oryza / genetics* Oryza / metabolism Pancreas / metabolism Rats Rats, Sprague-Dawley Starch Synthase / deficiency Starch Synthase / genetics* Starch Synthase / metabolism
IF 3.334
Times Cited 4
Rice Induced mutation lines