Protection of C2C12 skeletal muscle cells toward oxidation by a polyphenol-rich plant extract

Graphical abstract Abstract Sarcopenia is a very disabling age-related disease which affects the mass and strength of skeletal muscles. This syndrome has no efficient treatment and is associated with important oxidative stress which could play important role in skeletal muscle degeneration. In this context, the cytoprotective activity and the antioxidant properties of a polyphenol-rich plant extract (PRPE) were evaluated in undifferentiated C2C12 murine skeletal muscle cells (myoblasts). PRPE is a potent antioxidant mixture as shown by its reactive oxygen species (ROS) scavenging properties by using the Kit Radicaux Libres method and the dihydroethidium (DHE) scavenging assay. In addition, PRPE has significant protecting properties in C2C12 cells toward oxidative stress triggered by 2, 2′-azobis (2-amidinopropane) dihydrochloride (AAPH) which is an ROS generator, as measured by different complementary approaches. PRPE counteracts several AAPH-induced cytotoxic effects. PRPE prevents morphological changes evaluated by phase contrast microscopy and decreases the number of dying cells determined by counting in the presence of trypan blue and the intracellular ROS overproduction evaluated by flow cytometry after staining with DHE. In addition, PRPE tends to normalize the expression of genes (peroxiredoxin 1 (Pdrx1), nuclear factor erythroid 2-related factor 2 (Nrf2), and peroxisome proliferator-activator receptor gamma coactivator 1-alpha (Pgc1α)) involved in the oxidant stress defense under ROS exposure. Altogether; our data show that PRPE has potent antioxidant properties and protects C2C12 skeletal muscle cells toward AAPH-induced oxidative stress. These cytoprotective properties of PRPE in skeletal muscle cells submitted to a pro-oxidant environment deserve further investigation in the context of sarcopenia.