Gambogenic Acid Enhances Oxidative Stress and Apoptosis by Suppressing CanineOsteosarcoma Cell Growth Via Autophagy Overactivation

Canine osteosarcoma is a highly aggressive bone malignancy characterized by rapid progression and a propensity for early metastasis.Gambogenic acid (GNA), derived from Fructus garcinia, possesses a broad spectrum of bioactive effects, including anticancer, antimicrobial, antiviral, anti-inflammatory, and antioxidant properties.In this research, the canine osteosarcoma cell line McKinley was chosen to investigate the mechanisms of GNA through autophagy, thereby offering a theoretical foundation for GNA in the treatment of canine osteosarcoma.Various concentrations of GNA were utilized to assess malignant biological characteristics, including proliferation, migration, and invasion in McKinley.Furthermore, we measured the levels of oxidative stress, mitochondrial dynamics, autophagy-related indicators, and apoptosis-related indicators.The results showed that GNA demonstrated an inhibitory effect on McKinley cells, with an IC50 value of 0.28M, confirming a dosedependent reduction in cell proliferation, migration, and invasion.McKinley cells exhibited increased oxidative stress levels, reduced mitochondrial membrane potential, and impaired mitochondrial functionality.Moreover, there was a substantial increase in the number of autophagosomes and elevated expression levels of autophagy-related protein and mRNA, and autophagy flow proceeded smoothly.Additionally, the apoptosis rate increased, accompanied by elevated levels of the proapoptotic proteins.Notably, 3-Methyladenine was found to counteract the inhibitory effects of GNA on the proliferation, invasion, and migration of McKinley cells, as well as to alleviate the oxidative stress and apoptotic effects induced by GNA.In conclusion, this study demonstrated the mechanism of action of GNA in the treatment of canine osteosarcoma.