Long-Term Habitual Exercise and Combination of ß-Hydroxy-ß-Methylbutyrate plus Black Ginger Alter the Autophagy and Mitochondria Related Genes in SAMP8 Mice.

Muscle mass and strength decrease with aging; however, habitual exercise can maintain muscle health. ß-Hydroxy-ß-methyl butyrate calcium (HMB) and black ginger (BG) improve muscle protein metabolism and energy production. Combining these two molecules, which have similar effects, may have a synergistic effect. Senescence-accelerated mouse-prone 8 (SAMP8) is a useful model of muscle aging. Therefore, we explored how the combination of habitual exercise, HMB, and BG affected muscle aging. We used 28-wk-old (28w) SAMP8 mice divided into six groups: 28 wk (28w), 44 wk (44w, Con), exercise (Ex), Ex+BG, Ex+HMB, and Ex+BG+HMB (Ex+Comb). Mice were required to run on a treadmill for 16 wk for 5 d per week. In 28w and 44w mice, grip strength tests and dissection were conducted. Muscle weight was measured, and qPCR and immunoblotting were conducted. Muscle mass and strength were declined in the 44w group. Exercise with HMB or BG alone had no effect, whereas muscle mass and strength were augmented in the Ex+Comb group. Similarly, levels of mitochondrial function- and biogenesis-related genes were increased. Autophagy-related protein (Atg3, 7, 16L1 and Beclin1) were altered in the Ex+Comb group. These results suggest that Ex+Comb affects autophagy. Overall, the combination of habitual exercise and HMB+BG may enhance muscle mass and strength by affecting the mitochondrial and autophagy systems in SAMP8.

Habitual Aerobic Exercise Diminishes the Effects of Sarcopenia in Senescence-Accelerated Mice Prone8 Model.

Loss of muscle mass and strength are progressing with aging. Exercise is a beneficial method to prevent physical dysfunction, and habitual exercise can improve the muscle quality. Therefore, we evaluated the effects of long-term habitual exercise's impact on sarcopenia utilizing the senescence-accelerated mice prone8 (SAMP8) model. Notably, 27 w SAMP8 were used in this study. Mice were classified into 28 (28 w) and 44 weeks old. The 44-week group was divided into the sedentary group (44 w) and a group exercising for 16 weeks (44 w + Ex). The 44 w + Ex performed habitual exercise from 28 to 44 weeks. Additionally, grip strength tests were performed with mice aged 28 and 44 weeks. Muscles were harvested and measured muscle weight at 44 w. Gastrocnemius decreased in 44 w, but was unchanged in 44 w + Ex. There was a trend for lower muscle grip strength in the 44 w group, but there was no change in 44 w + Ex. The phosphorylation levels of Akt and p70S6K as a protein synthesis marker were decreased in 44 w. Cytochrome c oxidase subunit IV (CoxIV) mRNA and protein levels decreased in 44 w. These results suggested that long-term habitual exercise attenuates muscle mass and strength decline, possibly through maintenance of muscle protein synthesis and mitochondrial maintenance.