Abstract

Osteosarcoma (OS) is an aggressive primary bone malignancy characterized by limited therapeutic options and poor prognosis in advanced stages. Guggulsterone (GS), a naturally occurring plant-derived sterol, has recently been reported to suppress OS progression by inhibiting glycolysis via the MAPK signaling pathway. Although these findings underscore the therapeutic potential of GS in OS, the contribution of mitochondrial quality control to its antitumor activity remains unclear. Here, we report that GS disrupts mitochondrial integrity, elevates oxidative stress, and drives enhanced mitophagy in OS cells. RNA sequencing combined with functional assays revealed significant enrichment of mitophagy-related pathways, while rescue experiments confirmed that blocking mitophagy or SIRT3 activity markedly alleviated GS-induced mitochondrial damage, apoptosis, and growth inhibition. Mechanistically, GS activated the SIRT3-dependent PINK1/Parkin axis in a time-dependent manner, providing compelling evidence for its involvement in mitophagy regulation. Importantly, GS markedly inhibited OS tumor growth in vivo without causing detectable systemic toxicity. Collectively, our findings identify a mechanism distinct from the previously reported glycolysis/MAPK pathway, thereby broadening the mechanistic understanding of GS and underscoring its potential as a mitochondria-targeted therapeutic strategy for OS.