Magnolol Potentiates Sorafenib-induced Apoptosis and Inhibits Metastatic Signaling in Renal Carcinoma

Sorafenib is a standard targeted therapy for renal cell carcinoma; however, resistance and limited efficacy remain clinical challenges. Magnolol, a bioactive compound derived from Magnolia officinalis, exhibits anti-cancer properties, and may enhance therapeutic responses. This study investigated whether magnolol potentiates the anti-tumor effects of sorafenib in murine renal carcinoma (Renca) cells and explored the underlying molecular mechanisms.

Cell viability was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and drug interactions were analyzed using the Chou-Talalay method. Apoptosis was evaluated by Annexin V/propidium iodide (PI) staining, cell-cycle analysis, and caspase activation. Western blotting and flow cytometry were performed to examine apoptotic pathways and epidermal growth factor receptor (EGFR)/SRC proto-oncogene, non-receptor tyrosine kinase (SRC)/nuclear factor kappa B (NF-κB) signaling. Transwell assays and protein expression profiling were used to analyze migration, invasion, and epithelial-mesenchymal transition (EMT) markers.

Combination treatment synergistically reduced cell viability, with a combination index (CI) <1, and significantly enhanced apoptosis via activation of intrinsic and extrinsic pathways. Co-treatment suppressed EGFR/SRC proto-oncogene, SRC/ NF-κB signaling and reduced migration, invasion, and EMT-associated markers.

Magnolol enhances sorafenib efficacy by promoting apoptosis and inhibiting survival and metastatic signaling pathways in renal carcinoma cells.