Skeletal muscle protein degradation induced by high‐fat diet is decreased by macadamia oil supplementation: Role of E3 ubiquitin enzyme ligase MuRF‐1 and atrogin‐1

This study aimed to assess the effect of macadamia oil (MO) on expression of genes involved in proteolytic pathways (Murf‐1 and Atrogin‐1) in diet‐induced obese C57/BL6J mice. Mice were fed a control or a high‐fat diet (HFD) and supplemented or not with MO (2.5 mg/kg) for eight weeks. mRNA levels of MuRF‐1 and atrogin‐1/MAFbx were evaluated in EDL muscle by real‐time PCR. Mice fed a HDF presented decreased EDL weight when compared to control diet (0.28 vs 0.39, respectively), suggesting muscle atrophy. MO supplementation decreased this effect (0.28 vs control 0.34; p<0.05). A significant two‐fold increase in mRNA levels of MuRF‐1 and atrogin‐1/ MAFbx, in EDL muscle, was found in mice fed a HFD. On the other hand, MO supplementation restored mRNA levels of Murf‐1 and Atrogin‐1 in mice fed a HFD to control levels, suggesting a protective effect on the pathways involved in the HFD‐induced proteolysis. Our data suggest that the increased skeletal muscle degradation induced by HDF is decreased by MO supplementation by a mechanism that involves reduced RNAm expression of Murf‐1 and Atrogin‐1. Support: FAPESP, CNPq, CAPES, Dean's Office for Research/USP, Clear, INOD, and NEL.