Anti‐prediabetic effect of rose hip (Rosa canina) extract in spontaneously diabetic Torii rats

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 N ϵ ‐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.