Fig 2: Western blot analysis in beta-hydroxy-beta-methylbutyrate (HMB) supplemented rats in different exercise protocols. Protein levels of myogenin (A), TGF-ß (B), IGF-1 (C), p-Akt (D), p-mTOR/t-mTOR (E), p70S6K (F), GDF8 (G), FoxO3a (H), MAFbx (I), and MuRF1 (J); n=6 rats in each group. HT3, HT3L: injured, supplemented, and 3 sessions per week of no-load or load training; HT5, HT5L: injured, supplemented, and 5 sessions per week of no-load or load training. Data are reported as means±SD. *P<0.05, **P<0.01 (one-way ANOVA and Tukey’s test).

Fig 3: Neurodegeneration, MAPK, and ubiquitin-proteasome signaling pathways were upregulated in skeletal muscles of chronic obstructive pulmonary disease mice. (A) heatmap showing the enrichment of genes in gastrocnemius muscle by RNA sequencing. (B,C) histogram and upset plot showing the enrichment results of KEGG. (D) GO treeplot showing the different signaling pathways using average expression of differential genes in the gastrocnemius muscle. (E) KEGG treeplot showing the different signaling pathways using average expression of differential genes in the gastrocnemius muscle. (F) gene expression of MuRF1 and Atrogin1 in RNA-seq. n = 5, *p < 0.05, **p < 0.01.

Fig 4: MON improved DEX-treated muscle atrophy in mice. The expression of MyHC, Atrogin1, MuRF1, and Myostatin was determined in gastrocnemius tissues of mice by Western blot (A). Relative expression of each protein was normalized to ß-actin (B–E). Each value is the mean ± SD of three independent experiments. # p < 0.05, ### p < 0.001 vs. Nor; * p < 0.05, ** p < 0.01 and *** p < 0.001 vs. DEX. Nor, normal group; DEX, dexamethasone-treated group; and MON, monotropein-administrated group.

Fig 5: Western blot analysis of sedentary non-injured (SED-Ct), sedentary non-injured supplemented with HMB (SED-Ct-HMB), sedentary injured (SED), sedentary injured with HMB (SED-HMB) rats. Protein levels of myogenin (A), TGF-ß (B), IGF-1 (C), phospho-Akt (D), p-mTOR/t-mTOR (E), p70S6K (F), GDF8 (G), FoxO3a (H), MAFbx (I), and MuRF1 (J); n=6 rats in each group. Data are reported as means±SD. *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001 (one-way ANOVA and Tukey’s test).