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

Abstract

Sarcopenia is a very disabling age-related disease which affects the mass and the strenght of skelettal muscles. This syndrome has no efficient treatment and is associated with an important oxidative stress which could play important roles in skelettal muscle degeneration. In this context, the cytoprotective activity and the antioxidant properties of a polyphenol-rich plant extract (PRPE) was 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 KRL (Kit Radicaux Libres) method and the dihydroethidium (DHE) scavening assay. In addition, PRPE has significant protecting properties in C2C12 cells towards oxidative stress triggered by 2, 2′-azobis (2-amidinopropane) dihydrochloride (AAPH) which is a ROS generator, as measured by different complementary approaches. PRPE counteracts several AAPH-induced cytotoxic effects. PRPE prevents morphological changes evaluated by phase contrast microscopy, 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 dihydroethidium (DHE). In addition, PRPE tends to normalize the expression of genes (peroxiredoxin 1 (Pdrx1), nuclear factor erythroid 2-related factor 2 (Nrf2), 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 towards 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.