A novel nanoparticle-based co-delivery system of Fritillaria persica L. extract and gemcitabine for inhibiting breast cancer progression.

Breast cancer remains one of the leading causes of cancer-related mortality worldwide, highlighting the urgent need for more effective and less toxic therapeutic strategies. In the present study, a novel nanotherapeutic platform composed of aqueous Fritillaria persica L. (FP) extract and gemcitabine (Gem)-loaded chitosan (CS) nanoparticles (FP/Gem/CS-NPs) was successfully developed and evaluated against MCF-7 and MDA-MB-231 breast cancer cell lines. Physicochemical characterization demonstrated the successful fabrication of spherical FP/Gem/CS-NPs with a mean hydrodynamic diameter of approximately 69 nm, a polydispersity index (PDI) of 0.500, and a zeta potential of -16.2 mV. The nanoparticles demonstrated high entrapment efficiency (78.41%) and sustained drug release behavior, with nearly 50% of Gem released over 72 h, compared with the rapid burst release of free gemcitabine. Biological evaluations revealed that FP/Gem/CS-NPs exerted significantly enhanced anticancer activity compared with free Gem or FP extract alone. MTT assays demonstrated strong dose- and time-dependent cytotoxicity, with markedly reduced IC50 values in both MCF-7 and MDA-MB-231 cells following nanoparticle treatment. Flow cytometry and caspase-3/7 analyses confirmed substantial apoptosis induction, particularly in the highly aggressive MDA-MB-231 cells. Gene expression analysis further demonstrated significant upregulation of pro-apoptotic BAX and cell cycle regulator P21, alongside downregulation of anti-apoptotic BCL-2, indicating activation of mitochondrial apoptotic pathways. Moreover, NRF2 expression was elevated, suggesting modulation of oxidative stress responses. Cell cycle analysis revealed prominent G2/M phase arrest in treated cells. Collectively, these findings indicate that FP/Gem/CS-NPs represent a promising synergistic nanotherapeutic system capable of enhancing gemcitabine efficacy while modulating apoptosis, oxidative stress, and cell cycle pathways in breast cancer cells.