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Effect of 20-hydroxyecdysone and its metabolites in the absence or presence of IGF-1 on regulation of skeletal muscle cell growth


Kanokwan Suhatcho
Boon-ek Yingyongnarongkul
Saowanee Kumpun
Ratchakrit Srikuea

Abstract

Purpose: To investigate the effect of 20-hydroxyecdysone (20E) and its metabolites and their synergistic effect with IGF-1 on regulation of skeletal muscle cell growth.


Methods: Mouse skeletal muscle cell line (C2C12) was solely treated with 20E and its metabolites (14- deoxy- 20-hydroxyecdysone, poststerone, and 14-deoxypoststerone) at doses of 0.1, 1, and 10 µM or co-treated with IGF-1 (10 ng/ml). Cell  viability and proliferative capacity were evaluated using MTT and BrdU incorporation assays, respectively. Myogenic differentiation  proteins [embryonic myosin heavy chain (EbMHC) and MHC], androgen receptor (AR), and IGF-1 receptor (IGF-1R) protein expression were investigated using immunocytochemistry.


Results: Treatments of 20E and its metabolites had no toxicity on skeletal muscle cells or  induced AR/IGF-1R expression. In addition, solely treatment of 20E and its metabolites or co-treatment with IGF-1 had no significant  effect on cell proliferation and myogenic differentiation capacity. In contrast, IGF-1 treatment alone significantly increased EbMHC  expression (p<0.0001), MHC expression (p<0.05), and myotube number (p<0.05).


Conclusion: These results indicate that 20E and its  metabolites have no direct or synergistic effect with IGF-1 on skeletal muscle cell growth. Nevertheless, the pharmacological effects of  20E on skeletal muscle mass and strength in vivo that raises its therapeutic potential may associate with its indirect action. 


Journal Identifiers


eISSN: 1596-9827
print ISSN: 1596-5996