title: Emodin attenuates TNF-α-induced apoptosis and autophagy in mouse C2C12 myoblasts though the phosphorylation of Akt.
abstract: Emodin, a major component of Rheum palmatum, has been reported to significantly protect neural tissue against apoptosis and autophagy. However, the effects and underlying mechanisms of action of emodin in muscle atrophy are still poorly defined. In this study, we investigated the protective effects and the underlying mechanisms by which emodin acts on tumor necrosis factor alpha (TNF-α)-induced apoptosis and autophagy in mouse C2C12 myoblasts. Emodin, at various concentrations, decreased TNF-α-induced apoptosis in C2C12 myoblasts, which were analyzed by Hoechst 33342 staining and annexin V/PI analysis. Emodin also inhibited the collapse of the mitochondrial membrane potential and the generation of reactive oxygen species in TNF-α-stimulated C2C12 myoblasts. Consistent with these results, the expression of Bcl-2 was increased, whereas the expression of Bax, cleaved-caspase 3 and cleaved-PARP was decreased after emodin treatment. These data demonstrate that emodin attenuated apoptosis in TNF-α-stimulated C2C12 myoblasts through mitochondrial signaling pathways. In addition, emodin inhibited autophagy in TNF-α-stimulated C2C12 myoblasts by suppressing the expression of LC3-II, Beclin-1 and Atg7. Emodin also resulted in the upregulation of the phosphorylated forms of Akt. Taken together, these results suggest that emodin inhibited apoptosis and autophagy in TNF-α-induced C2C12 myoblasts, possibly through the activation of phosphorylated Akt. Our findings suggest that emodin could be a potential therapeutic agent in the treatment of muscle atrophy.
authors.affiliation: Department of Traditional Chinese Medicine, ZhuJiang Hospital, Southern Medical University, Guangzhou, Guangdong, 510280, PR China; School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, 510515, PR China.
authors.forename: Dexiu
authors.initials: D
authors.lastname: Chen
authors.affiliation: School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, 510515, PR China.
authors.forename: Junshan
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Traditional Chinese Medicine, ZhuJiang Hospital, Southern Medical University, Guangzhou, Guangdong, 510280, PR China; School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, 510515, PR China.
authors.forename: Lu
authors.initials: L
authors.lastname: Lu
authors.affiliation: Department of Traditional Chinese Medicine, ZhuJiang Hospital, Southern Medical University, Guangzhou, Guangdong, 510280, PR China; School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, 510515, PR China.
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Department of Traditional Chinese Medicine, ZhuJiang Hospital, Southern Medical University, Guangzhou, Guangdong, 510280, PR China; School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, 510515, PR China.
authors.forename: Yanjing
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Traditional Chinese Medicine, ZhuJiang Hospital, Southern Medical University, Guangzhou, Guangdong, 510280, PR China; School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, 510515, PR China.
authors.forename: Mingqing
authors.initials: M
authors.lastname: Wang
authors.affiliation: Department of Traditional Chinese Medicine, ZhuJiang Hospital, Southern Medical University, Guangzhou, Guangdong, 510280, PR China; School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, 510515, PR China.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Traditional Chinese Medicine, ZhuJiang Hospital, Southern Medical University, Guangzhou, Guangdong, 510280, PR China; School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, 510515, PR China.
authors.forename: Dandan
authors.initials: D
authors.lastname: Xie
authors.affiliation: Department of Traditional Chinese Medicine, ZhuJiang Hospital, Southern Medical University, Guangzhou, Guangdong, 510280, PR China; School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, 510515, PR China.
authors.forename: Jiebing
authors.initials: J
authors.lastname: Chen
authors.affiliation: School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, 510515, PR China.
authors.forename: Jianxin
authors.initials: J
authors.lastname: Diao
authors.affiliation: Department of Traditional Chinese Medicine, ZhuJiang Hospital, Southern Medical University, Guangzhou, Guangdong, 510280, PR China; School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, 510515, PR China. Electronic address: 54140527@qq.com.
authors.forename: Lianbo
authors.initials: L
authors.lastname: Wei
authors.affiliation: Department of Traditional Chinese Medicine, ZhuJiang Hospital, Southern Medical University, Guangzhou, Guangdong, 510280, PR China; School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, 510515, PR China. Electronic address: Youxin624113@163.com.
authors.forename: Ming
authors.initials: M
authors.lastname: Wang
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001343:Autophagy / Q000187:drug effects; D002460:Cell Line; D004642:Emodin / Q000494:pharmacology*; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051379:Mice; D009133:Muscular Atrophy / Q000188:drug therapy*; D032446:Myoblasts / Q000187:drug effects* / Q000276:immunology; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D012250:Rheum / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
chemical_list: D000893:Anti-Inflammatory Agents; D019253:Proto-Oncogene Proteins c-bcl-2; D014409:Tumor Necrosis Factor-alpha; D051057:Proto-Oncogene Proteins c-akt; D004642:Emodin
keywords: Apoptosis; Autophagy; C2C12 myoblasts; Emodin; Tumor necrosis factor alpha