Enhanced Cytotoxicity of Liposomal Daunorubicin in HCT116 Colorectal Cancer Cells: Modulation of Oxidative Stress and ERK1/2 gene expression

Purpose Colorectal cancer (CRC) is a leading global health challenge with high morbidity and mortality. Daunorubicin (DNR), an anthracycline, induces cytotoxicity via DNA damage and reactive oxygen species (ROS) generation but is limited by systemic toxicity and drug resistance. Liposomal encapsulation enhances DNR's delivery and efficacy, potentially overcoming these limitations. This study aimed to compare the effects of free DNR and liposomal DNR (LDNR) on HCT116 CRC cells, evaluating cytotoxicity, oxidative stress, total antioxidant capacity (TAC), extracellular signal-regulated kinase 1/2 (ERK1/2) gene expression, and cell morphology. Methods LDNR was synthesized via the thin-layer hydration method. HCT116 cells were treated with free DNR (0.5 µM) or LDNR (0.125–2 µM) for 72 hours. Cytotoxicity was assessed by MTT assay; IC50 values were calculated. Intracellular ROS was measured by flow cytometry using DCFH-DA probe. TAC was measured using a FRAP-based commercial kit. ERK1/2 gene expression was quantified by real-time PCR. Morphological changes were examined by inverted light microscopy. Results LDNR exhibited a zeta potential of -50.7 mV and a mean particle size of 118.3 nm (PDI = 0.21). The IC50 of LDNR was 0.18 µM. At an equimolar concentration of 0.5 µM, LDNR caused 70.8% cell death versus 60.4% for free DNR (p < 0.0001). ERK1/2 gene expression decreased to 0.08-fold (LDNR) and 0.28-fold (free DNR) of controls (p < 0.001). Oxidative stress increased to 36.8% (LDNR) and 22.3% (free DNR) from 1.7% in controls (p < 0.001). TAC decreased by 0.39 U/mL (LDNR) and 0.33 U/mL (free DNR) (p < 0.001). Microscopic analysis showed apoptotic morphology (spherical shapes, dense nuclei) in LDNR-treated cells. Conclusion LDNR demonstrates superior cytotoxicity, ROS generation, and ERK1/2 gene suppression compared to free DNR in HCT116 CRC cells, with morphological evidence of apoptosis. These findings support further investigation of LDNR as a potential CRC therapeutic, though in vivo validation and mechanistic studies are required.