title: Epigallocatechin Gallate Reduces Slow-Twitch Muscle Fiber Formation and Mitochondrial Biosynthesis in C2C12 Cells by Repressing AMPK Activity and PGC-1α Expression.
abstract: Epigallocatechin gallate (EGCG) is a major active compound in green tea polyphenols. EGCG acts as an antioxidant to prevent the cell damage caused by free radicals and their derivatives. In skeletal muscle, exercise causes the accumulation of intracellular reactive oxygen species (ROS) and promotes the formation of slow-type muscle fiber. To determine whether EGCG, as a ROS scavenger, has any effect on skeletal muscle fiber type, we applied different concentrations (0, 5, 25, and 50 μM) of EGCG in the culture medium of differentiated C2C12 cells for 2 days. The fiber-type composition, mitochondrial biogenesis-related gene expression, antioxidant and glucose metabolism enzyme activity, and ROS levels in C2C12 cells were then detected. According to our results, 5 μM EGCG significantly decreased the cellular activity of SDH, 25 μM EGCG significantly downregulated the MyHC I, PGC-1α, NRF-1, and p-AMPK levels and SDH activity while enhancing the CAT and GSH-Px activity and decreasing the intracellular ROS levels, and 50 μM EGCG significantly downregulated MyHC I, PGC-1α, and NRF-1 expression and HK and SDH activity while increasing LDH activity. Furthermore, 300 μM H2O2 and 0.5 mM AMPK agonist (AICAR) improved the expression of MyHC I, PGC-1α, and p-AMPK, which were all reversed by 25 μM EGCG. In conclusion, the effect of EGCG on C2C12 cells may occur through the reduction of the ROS level, thereby decreasing both AMPK activity and PGC-1α expression and eventually reducing slow-twitch muscle fiber formation and mitochondrial biosynthesis.
authors.affiliation: College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University , Guangzhou, Guangdong 510640, People's Republic of China.
authors.forename: Lina
authors.initials: L
authors.lastname: Wang
authors.affiliation: College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University , Guangzhou, Guangdong 510640, People's Republic of China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wang
authors.affiliation: College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University , Guangzhou, Guangdong 510640, People's Republic of China.
authors.forename: Kelin
authors.initials: K
authors.lastname: Yang
authors.affiliation: College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University , Guangzhou, Guangdong 510640, People's Republic of China.
authors.forename: Gang
authors.initials: G
authors.lastname: Shu
authors.affiliation: College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University , Guangzhou, Guangdong 510640, People's Republic of China.
authors.forename: Songbo
authors.initials: S
authors.lastname: Wang
authors.affiliation: College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University , Guangzhou, Guangdong 510640, People's Republic of China.
authors.forename: Ping
authors.initials: P
authors.lastname: Gao
authors.affiliation: College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University , Guangzhou, Guangdong 510640, People's Republic of China.
authors.forename: Xiaotong
authors.initials: X
authors.lastname: Zhu
authors.affiliation: College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University , Guangzhou, Guangdong 510640, People's Republic of China.
authors.forename: Qianyun
authors.initials: Q
authors.lastname: Xi
authors.affiliation: College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University , Guangzhou, Guangdong 510640, People's Republic of China.
authors.forename: Yongliang
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University , Guangzhou, Guangdong 510640, People's Republic of China.
authors.forename: Qingyan
authors.initials: Q
authors.lastname: Jiang
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002460:Cell Line; D051379:Mice; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism; D018485:Muscle Fibers, Skeletal / Q000187:drug effects / Q000378:metabolism; D018657:Muscle Fibers, Slow-Twitch / Q000187:drug effects* / Q000378:metabolism; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha / Q000235:genetics* / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000975:Antioxidants; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; C485290:Ppargc1a protein, mouse; D017382:Reactive Oxygen Species; D002392:Catechin; C045651:epigallocatechin gallate; D055372:AMP-Activated Protein Kinases
keywords: C2C12; EGCG; mitochondria biosynthesis; muscle fiber types