The steady-state level of Akt/mTORC1 signaling in aged skeletal muscle is not altered after 2 months of treatment with ursolic acid or tomatidine. Data are from the quadriceps muscles of 22-month-old C57BL/6 mice treated for 2 months with control diet, ursolic acid diet, or tomatidine diet as in Figs. 2 and 3. A, quadriceps protein extracts were subjected to immunoblot analysis with anti-S6K and anti-phospho-S6K antibodies. Left, representative immunoblots and Ponceau S stains. Middle, quantification of total S6K. Right, quantification of the normalized ratio of phospho-S6K to total S6K in each extract. B, quadriceps protein extracts were subjected to immunoblot analysis with anti-Akt and anti-phospho-Akt antibodies. Left, representative immunoblots and Ponceau S stains. Middle, quantification of total Akt. Right, quantification of the normalized ratio of phospho-Akt to total Akt in each extract. Horizontal bars denote means ± S.E. p values were determined with a one-way ANOVA and Dunnett's multiple comparison test. N.S. denotes p > 0.05.