In vitro assessment of the combined effect of eicosapentaenoic acid, green tea extract and curcumin C3 on protein loss in C2C12 myotubes

Abstract

EPA has been clinically shown to reduce muscle wasting during cancer cachexia. This study investigates whether curcumin or green tea extract (GTE) enhances the ability of low doses of eicosapentaenoic acid (EPA) to reduce loss of muscle protein in an in vitro model. A low dose of EPA with minimal anti-cachectic activity was chosen to evaluate any potential synergistic effect with curcumin or GTE. Depression of protein synthesis and increase in degradation was determined in C2C12 myotubes in response to tumour necrosis factor-α (TNF-α) and proteolysis-inducing factor (PIF). EPA (50 μM) or curcumin (10 μg ml(-1)) alone had little effect on protein degradation caused by PIF but the combination produced complete inhibition, as did the combination with GTE (10 μg ml(-1)). In response to TNF-α (25 ng ml(-1))-induced protein degradation, EPA had a small, but not significant effect on protein degradation; however, when curcumin and GTE were combined with EPA, the effect was enhanced. EPA completely attenuated the depression of protein synthesis caused by TNF-α, but not that caused by PIF. The combination of EPA with curcumin produced a significant increase in protein synthesis to both agents. GTE alone or in combination with EPA had no effect on the depression of protein synthesis by TNF-α, but did significantly increase protein synthesis in PIF-treated cells. Both TNF-α and PIF significantly reduced myotube diameter from 17 to 13 μm for TNF-α (23.5%) and 15 μm (11.8%) for PIF However the triple combination of EPA, curcumin and GTE returned diameters to values not significantly different from the control. These results suggest that either curcumin or GTE or the combination could enhance the anti-catabolic effect of EPA on lean body mass.

Antidiabetic Properties of Curcumin I: Evidence from In Vitro Studies

“…In addition, curcumin and EPA significantly increased protein synthesis. PIF and TNF-α reduced myotube diameter (13 µm) and was attenuated with EPA and curcumin co-treatment (17 µm) to levels similar to control myotubes [100].…”

“…Combined treatment of C2C12 myotubes with curcumin (10 µM) and eicosapentaenoic acid (EPA; 50 µM) for 24 h resulted in significantly reduced proteolysis-inducing factor (PIF)-and TNF-α-induced protein degradation (Table 3) [100]. The activity of chymotrypsin-like enzyme, as an indicator of proteasome activity, was significantly increased by TNF-α and PIF, and was attenuated with curcumin and EPA co-treatment.…”

Could Omega 3 Fatty Acids Preserve Muscle Health in Rheumatoid Arthritis?

“…The degradation of muscle protein is increased by inflammation and could be regulated by treatment with omega 3 FA (Table 1). In myotubes, EPA inhibited the effect of TNF-α on muscle proteolysis [124]. DHA was also found to inhibit muscle protein degradation in C 2 C 12 [125] .…”

Plant Extracts as Possible Agents for Sequela of Cancer Therapies and Cachexia

“…Also, it alleviated the CT-26-mediated C2C12 myotube wasting and changed myosin heavy chain (MyH), Akt phosphorylation and p65 phosphorylation. Curcumin and green tea extract, extracted from Curcuma longa and Camellia sinensis respectively, ameliorated weight loss and muscle wasting [ 128 ]. This treatment was implemented on C2C12 myotubes for 24 h as its dosage of 10 μg/mL.…”