Revitalizing Muscle Regeneration: Cocoa Polyphenols Shield Mitochondrial Integrity and Boost Myogenesis Under Oxidative Stress

Abstract

In this study, we describe the effect of cocoa polyphenol extract (CPE, from flavanols-rich cocoa) on myogenic differentiation in murine myoblasts (C2C12 cells) exposed to H2O2. The myogenic program was monitored using morphological, ultrastructural, and molecular approaches. Treatment with 100 μM of H2O2 for 1 h decreased cell viability. C2C12 (D1) exposed to H2O2 shows more apoptotic and necrotic cells, and mitochondria appear emptied, with cristae heavily damaged. To evaluate the effect of CPE on myoblast viability and myotube formation, 10 μg/mL of CPE were added 24 h prior to H2O2 treatment and cells were supplemented with fresh CPE every 24 h during differentiation. Supplementation with CPE protected C2C12 myoblasts from H2O2-induced oxidative damage both at early (D1) and late (D6) phases of differentiation, preventing cell death and mitochondrial damage. The number of mitochondria (per area of cell surface) increased 2-fold in both control and in CPE-supplemented and mitochondria in myotubes D6 showed a greater extension of mitochondrial cristae than mitochondria in D1.