Effects of Sunphenon and Polyphenon 60 on proteolytic pathways, inflammatory cytokines and myogenic markers in H2O2-treated C2C12 cells.
The effect of Sunphenon and Polyphenon 60 in oxidative stress response, myogenic regulatory factors, inflammatory cytokines, apoptotic and proteolytic pathways on H2O2-induced myotube atrophy was addressed. Cellular responses of H2O2-induced C2C12 cells were examined, including mRNA expression of myogenic regulatory factors, such as MyoD and myogenin, inflammatory pathways, such as TNF-α and NF-kB, as well as proteolytic enzymes, such as μ-calpain and m-calpain. The pre-treatment of Sunphenon (50 μg/mL)/Polyphenon 60 (50 μg/mL) on H2O2-treated C2C12 cells significantly down-regulated the mRNA expression of myogenin and MyoD when compared to those treated with H2O2-induced alone. Additionally, the mRNA expression of μ-calpain and m-calpain were significantly(p<0.05) increased in H2O2-treated C2C12 cells, whereas pre-treatment with Sunphenon/Polyphenon significantly down-regulated the above genes, namely μ-calpain and m-calpain. Furthermore, the mRNA expression of TNF-α and NF-kB were significantly increased in H2O2-treated C2C12 cells, while pre-treatment with Sunphenon (50 μg/mL)/Polyphenon 60 (50 μg/mL) significantly (p<0.05) down-regulated it when compared to the untreated control group.Subsequent analysis of DNA degeneration and caspase activation revealed that Sunphenon (50 μg/mL)/Polyphenon 60 (50 μg/mL) inhibited activation of caspase-3 and showed an inhibitory effect on DNA degradation. From this result, we know that, in stress conditions, μ-calpain may be involved in the muscle atrophy through the suppression of myogenin and MyoD. Moreover, Sunphenon may regulate the skeletal muscle genes/promote skeletal muscle recovery by the up-regulation of myogenin and MyoD and suppression of μ-calpain and inflammatory pathways and may regulate the apoptosis pathways. Our findings suggest that dietary supplementation of Sunphenon might reduce inflammatory events in muscle-associated diseases, such as myotube atrophy.
Department of Animal Science and BK21 PLUS program, Chonbuk National University, Jeonju 561-756, South Korea.
Allur Subramaniyan
AS
Sivakumar
Inho
I
Hwang
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002154:Calpain / Q000235:genetics / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D002460:Cell Line; D004789:Enzyme Activation / Q000187:drug effects; D005419:Flavonoids / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007249:Inflammation / Q000188:drug therapy* / Q000276:immunology; D051379:Mice; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology; D009133:Muscular Atrophy / Q000473:pathology; D017570:MyoD Protein / Q000235:genetics / Q000378:metabolism; D018008:Myogenin / Q000235:genetics / Q000378:metabolism; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D010636:Phenols / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
D005419:Flavonoids; D017570:MyoD Protein; C057363:MyoD1 myogenic differentiation protein; D018008:Myogenin; D016328:NF-kappa B; D010636:Phenols; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; C074269:Sunphenon; D006861:Hydrogen Peroxide; D002154:Calpain; D053148:Caspase 3; C449000:m-calpain; C449002:mu-calpain