Effects of the low carbohydrate diet and curcumin on testosterone biosynthesis regulators (a) protein expressions in each group, (b) StAR, (c) CYP11A1, (d) 3β-HSD, (e) CYP17A1, (f) 17 β-HSD relative density analysis of the protein bands in male mice. Data are expressed as means ± SD. n = 6–9 per group. Bars (a, b, c) with different letters indicate that values are significantly different. (One-way ANOVA, Duncan’s test, p < 0.05). AIN-93M: AIN-93M diet; LC: low carbohydrate diet; LC/AIN-93M: low carbohydrate diet changed to AIN-93M diet; LC/KD: low carbohydrate diet changed to ketogenic diet; LC/KDCu: low carbohydrate diet changed to ketogenic diet and curcumin.