Journal of medicinal food - ۲۰۱۳

Abstract In this study, a most consumer-acceptable rye bread (RB) containing saffron (S) powder (RB+S) was designed to verify its anti-diabetic properties, and to compare these effects with those of RB and S separately, matched to a similar dose of bioactive components, used in the high-fat (HF) diet in streptozotocin (STZ)-induced Wistar rats. After baking, beneficial antioxidant and sensory properties for RB enriched with ۰.۱۲% S were achieved. Twenty-four severely diabetic rats (fasting blood glucose (FBG) ≥۳۵۰ mg·dL(-۱)) were randomized to incorporate either ۰.۰۸% of pure S, or RB enriched with ۰.۱۲% S (the diet provided ۰.۰۸% of S), or RB alone into their diet for ۵ weeks. As controls, nontreated, HF-feeding STZ-induced rats (positive control-HF/STZ) and rats receiving normal laboratory diet (negative control-C) were used. A significant FBG-lowering effect was observed (۴۷%, ۵۳%, and ۵۴% reduction vs. HF/STZ; P<.۰۵) after S, RB, and RB+S treatment. Improvements in the rats' glycemia were achieved by β-cell regeneration and increases in insulin secretion. Only in the S and RB+S group of rats, a significant (P<.۰۵) increase in relative pancreas (vs. HF/STZ) was noted. A significant (P<.۰۵) reduction in the concentration of thiobarbituric acid-reactive substances (TBARS) was achieved, whereas the ferric-reducing ability of plasma (FRAP) was not changed after S, RB and RB+S treatment (vs. HF/STZ). Triglyceride (TG) concentrations after S, RB, and RB+S treatment were significantly decreased (P<.۰۵) versus HF/STZ. Both S and RB can be used in diabetic therapy, but no additional metabolic effect was achieved after consumption of RB+S.