PEGylated liposomal delivery of a tagitinin C-rich supercritical CO2 extract from Tithonia diversifolia induces antitumor effects via dual activation of mitochondrial apoptosis and ferroptosis

The therapeutic potential of tagitinin C, a potent sesquiterpene lactone from Tithonia diversifolia , is limited by its poor solubility and non-selective toxicity. This study aimed to evaluate the antitumor efficacy and safety of a tagitinin C-rich extract encapsulated in PEGylated liposomes (LPEG-ESTD), hypothesizing that this delivery system would enhance therapeutic outcomes by simultaneously activating mitochondrial apoptosis and ferroptosis pathways. The tagitinin C-rich supercritical co 2 extract was characterized (HPLC, FTIR) and encapsulated into PEGylated liposomes via thin-film hydration. The nanoformulation was thoroughly characterized (size, zeta potential, encapsulation efficiency, release profile and structural morphology by electronic microscopy). Efficacy was evaluated through cytotoxicity on B16F10 cells and an in vivo Sarcoma 180 model. Mechanistic pathways and safety were assessed via histopathological and immunohistochemical analyses (Ki-67, TUNEL, caspase-3, Bcl-2, Bax, NF-κB, NRF2). The optimized LPEG-ESTD formulation exhibited a nanometric size (∼120 nm), high encapsulation efficiency (>90%), and sustained release. It significantly enhanced cytotoxicity in vitro and potently inhibited tumor growth in vivo . Mechanistic studies revealed the nanoformulation activated mitochondrial apoptosis (increased TUNEL, caspase-3, Bax; suppressed Ki-67 and NF-κB) and induced ferroptosis (upregulated NRF2). Crucially, the liposomal system effectively mitigated the systemic toxicity of the free extract. This study demonstrates that PEGylated liposomes are a highly effective delivery system for a supercritical CO 2 -extracted phytotherapeutic. The LPEG-ESTD nanoformulation represents a promising strategy for cancer treatment by concurrently inducing apoptosis and ferroptosis, underscoring the value of advanced delivery systems in enhancing the efficacy and safety of natural anticancer compounds.