Protective effects of betulinic acid on oxidative stress-induced apoptosis and DNA damage in C2C12 myoblasts

Purpose: Betulinic acid, a naturally occurring pentacyclic triterpenoid, has various pharmacological properties, including antioxidant, anti-inflammatory, and antitumor activities.On the other hand, its protective effects against oxidative injury in skeletal muscle cells are poorly understood.This study examined whether betulinic acid can attenuate oxidative stress-induced cytotoxicity in immortalized mouse myoblast C2C12 cells.Methods: C2C12 cells were treated with hydrogen peroxide (H 2 O 2 ) to mimic an oxidative environment.The protective effects of betulinic acid against H 2 O 2 -induced cytotoxicity were investigated to determine if they were related to inhibition of apoptosis, DNA damage, and autophagy.The antioxidant activity of betulinic acid was assessed by examining its inhibitory effects on H 2 O 2 -induced reactive oxygen species (ROS) production.Results: Betulinic acid significantly attenuated H 2 O 2 -induced cytotoxicity in C2C12 cells, primarily by suppressing apoptosis.Betulinic acid also prevented the H 2 O 2 -induced increase in the Bax/Bcl-2 ratio, inhibited cytochrome c release into the cytoplasm, and suppressed caspase activation accompanied by fragmentation of poly (ADP-ribose) polymerase.In addition, betulinic acid markedly reduced H 2 O 2 -induced DNA damage, including the levels of DNA damage markers and oxidized nucleosides, and downregulated autophagy-related markers, inhibiting H 2 O 2 -induced autophagy.Betulinic acid effectively blocked H 2 O 2 -induced ROS generation, including mitochondrial superoxide, suggesting a role in maintaining mitochondrial homeostasis and preventing apoptotic signaling.Conclusion: Butulinic acid is a promising protective agent against oxidative damage in skeletal muscle cells.