Polyphenol supplementation ameliorates PUFA benefits in metabolic and oxidative status in dogs

Abstract

The effect of PUFA on obesity‐associated oxidant stress could be explained by the stimulation of endogenous antioxidant processes, or by their own ability to be oxidized. The adjunction of antioxidant to PUFA could help to elucidate their mechanism of action.Our aim was to check the effects of PUFA supplementation w/wo curcumin polyphenols on metabolic status, plasma lipids, and antioxidant status in dogs.Obese dogs were given for 2 consecutive periods of 6 w hyperenergetic diet supplemented with either n‐3 PUFA (Diet1) then n‐3 PUFA plus curcumin (Diet2). Before (T0) and at the end of each 6‐wk period, body composition, insulin sensitivity (IS), plasma lipid and oxidative status markers (total antioxidant status, TAS and glutathione peroxidise, GPx) were determined.At the end of both periods, body composition and IS were did not differ from T0 values. At the end of Diet1, plasma NEFA were lower and total cholesterol was higher than at T0; at the end of Diet2, TG levels were lower. The TAS was higher than at T0 at the end of Diet1, and even more at the end of Diet2. Compared to T0 GPx activity was unchanged at the end of each period.Our results show that polyphenols could have synergistic effects with PUFA. This suggests that PUFA would not act as oxidation substrates. Indeed their protection against oxidation would account for their action. Further experiments could be helpful for a better understanding of the mechanism of action.