Effect of synergism between leucine and quercetin: a new strategy against metabolic disorders

The aim of this study was to investigate the effects of quercetin and/or leucine on the intestinal permeability and metabolic endotoxemia in diet-induced obese mice. C57Bl/6J mice were divided into five groups: Chow diet; high-fat high-sucrose diet (HFHS); HFHS+quercetin 83mg/kg bw/day; HFHS+leucine 1.4g/kg bw/day; or HFHS with a combination of both doses for 12 weeks. Co-administration of quercetin and leucine did not prevent weight gain or adipose tissue deposition. However, quercetin and leucine supplementation was associated with a trend towards preventing obesity-induced hyperinsulinemia during fasting and significantly prevented the increase of free 8-isoprostane fractions in plasma. Furthermore, co-administration of quercetin and leucine significantly increased the Fiaf and Muc2 genes, which have been associated with beneficial changes in the gut microbiota. Our findings indicate that quercetin and leucine exert beneficial metabolic synergistic effects that could be associated with changes in the intestinal physiology. More research is needed to evaluate the therapeutic applicability of quercetin and leucine in the treatment of insulin resistance and whether these changes are associated with functional or taxonomic changes in the gut microbiota. FAPESP2013/12366-0