ABSTRACT
BACKGROUND: Prediabetes, a high-risk state for developing diabetes showing impaired glucose tolerance but a normal fasting blood glucose level, has an increasing prevalence worldwide. However, no study investigating the prevention of impaired glucose tolerance at the prediabetic stage by anti-diabetic functional foods has been reported. Thus, the present study aimed to evaluate the anti-prediabetic effect of rose hip in a prediabetic rat model. RESULTS: Spontaneously diabetic Torii (SDT) rats were supplemented with hot-water extract of rose hip at a dose of 100 mg kg-1 body weight day-1 for 12 weeks. The results obtained showed that the supplementation of rose hip extract improved impaired glucose tolerance, promoted insulin secretion, preserved pancreatic beta-cell function and suppressed plasma advanced glycation end-products formation of methylglyoxal-derived hydroimidazolone (MG-H1) residue and Nϵ -carboxymethyl-lysine residues (e.g. MG-H1, control: 465.5 ± 43.8 versus rose hip: 59.1 ± 13.0 pmol mg protein-1 , P < 0.05) in SDT rats at the prediabetic stage (12-20 weeks old). CONCLUSION: The present study provides the first evidence showing that a hot-water extract of rose hip could exert an anti-prediabetic effect in a rat model. © 2017 Society of Chemical Industry.
Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/administration & dosage , Plant Extracts/administration & dosage , Rosa/chemistry , Animals , Blood Glucose/metabolism , Diabetes Mellitus, Type 2/metabolism , Glycation End Products, Advanced/metabolism , Humans , Insulin/metabolism , Male , Pancreas/metabolism , Rats , Rats, Sprague-DawleyABSTRACT
Prediabetes, typically defined as impaired glucose tolerance and/or impaired fasting blood glucose, is a high-risk state of developing diabetes. The association of diabetes-related metabolites with prediabetes has not been investigated intensively. This study aimed to get insights into the metabolic behaviors of some typical diabetes-related metabolites in plasma of male Spontaneously Diabetic Torii (SDT) rats during pathogenic progress of diabetes and to assess in vivo if the variation in these metabolites related to the progression of prediabetic stage. To address this question, SDT rats and Sprague Dawley (SD) rats as control were maintained from the age of 7 to 25 weeks. Five typical advanced glycation end products (AGEs) residue of plasma protein and their free adducts were determined by liquid chromatography with tandem mass detection over the duration of the investigation. The SDT rats exhibited impaired glucose tolerance since the age of 12 weeks and developed diabetes with significantly elevated fasting glucose levels after 22 weeks. At the prediabetic stage (12-21 weeks), no significant differences were observed on AGE-free adducts levels of SDT rats compared with SD rats. However, methylglyoxal-derived hydroimidazolone (MG-H1) residue contents of plasma protein were significantly elevated in SDT rats at the age of 16 weeks, whereas other AGE residues of plasma protein did not show marked difference. The present study has revealed significant increase in MG-H1 residue content of plasma protein at the prediabetic stage of a spontaneously diabetic rat model, irrespective of unaltered fasting blood glucose and constant plasma levels of other AGEs.
ABSTRACT
The purpose of this study was to gain insight into the production behavior of free adducts of advanced glycation end-products (AGEs) in Wistar rats under acute hyperglycemic conditions. Five AGE-free adducts as well as their precursors (i.e., highly reactive carbonyl intermediates of methylglyoxal and glyoxal) in rat plasma were quantitatively determined at greater than nanomolar levels using the liquid chromatography/tandem mass spectrometry method coupled with 2,4,6-trinitrobenzene sulfonate and 2,3-diaminonaphthalene derivatization techniques. An oral glucose (2 g/kg dose) tolerance test to 10-week-old Wistar rats provided evidence that the plasma levels of diabetes-related metabolites did not change acutely within 120 min, irrespective of increasing blood glucose levels.
