Synergistic effects of curcumin and gamma-oryzanol solid dispersions ameliorate muscle atrophy by upregulating Nrf2 and IGF1/Insulin-Akt-mTOR activities in middle-aged rats

•Curcumin mixed with gamma-oryzanol solid dispersions (GO-CURSD) on middle-aged rat’s muscles were tested.•Supplementation with GO-CURSD for 6 weeks ameliorated muscle atrophy.•GO-CURSD promoted anti-inflammatory and antioxidant activities through the Nrf2 pathway resulting in less muscle damage.•GO-CURSD ameliorated muscle atrophy by activating IGF1/Insulin-Akt-mTOR activity and down-regulating Atrogin-1 and MuRF-1 genes.