Antioxidant balance after long-term consumption of standard diets including bread crust glycated compounds by adult rats.

The objective of the present study was to evaluate the in vivo uptake of antioxidant capacity (AC) in rats fed on diets containing commonly consumed MRPs obtained from bread crust (BC) at long-term. Additionally we focused on understanding the effects of those compounds on the oxidative status of these animals. The global antioxidant response of the diets was measured. During 88 days, rats were fed control diet or diets containing BC or its soluble high molecular weight, soluble low molecular weight or insoluble fractions (BC, HMW, LMW and insoluble diets, respectively). In the final week, faeces from different dietary treatments were collected to determine the AC still retained in it and then calculate the uptake efficiency of AC. Animals were sacrificed and the liver and biceps brachii muscle were removed to investigate catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and reduced glutathione (GSH) levels. The addition of BC or its derivatives in the diet led to a significantly higher AC excreted with the faeces and to a lower uptake rate (around 90% in these groups vs. 98% in the control group). The muscle and liver showed different oxidative status after consumption of experimental diets. The muscle evidenced certain oxidative damage due to the BC consumption, more pronounced when the isolated fractions were ingested. However, the BC diet, but not the rest, induced a positive effect on the antioxidant defence in the liver, the key organ for xenobiotic metabolism, with increases in the CAT and GPx activities as well as the GSH stock (56, 20 and 14% with respect to the control group, respectively). The discordance found between the antioxidant status of muscle and antioxidant status of liver highlights the importance of considering several tissues to establish the effect of glycated compounds on the redox balance in an organism.