The effect of eicosapentaenoic and docosahexaenoic acid on protein synthesis and breakdown in murine C2C12 myotubes

Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA) have been found to stimulate protein synthesis with little information regarding the effects on protein breakdown. Furthermore whether there are distinct effects of EPA and DHA remains to be established. The aim of the current study was to determine the distinct effects of EPA and DHA on protein synthesis, protein breakdown and signalling pathways in C2C12 myotubes. Fully differentiated C2C12 cells were incubated for 24 hours with 0.1% ethanol (control), 50µM EPA or 50µM DHA prior to experimentation. After serum (4h) and amino acid (1h) starvation cells were stimulated with 2mM L-leucine and protein synthesis measured using (3)H -labelled phenylalanine. Protein breakdown was measured using (3)H-labelled phenylalanine and signalling pathways (Akt, mTOR, p70S6k, 4EBP1, rps6 and FOXO3a,) via western blots. Data revealed that after incubation with EPA protein synthesis was 25% greater (P