Novel Synergistic Radiosensitization in Breast Cancer by Gold Nanoparticles and Curcumin: An In-Vitro Study

Gold Nanoparticles and Curcumin Radiosensitize Breast Cancer

Abstract

Background: Radiotherapy is a cornerstone of breast cancer (BC) treatment, but its efficacy is often limited by radioresistance and toxicity to adjacent healthy tissues. This study aimed to investigate, the novel synergistic radiosensitizing effects of combining gold nanoparticles (GNPs) and curcumin (CUR) with ionizing radiation on MCF-7 breast cancer cells.

Materials and Methods: MCF-7 (breast cancer) and L929 (healthy murine fibroblast) cells were treated with various concentrations of CUR and GNPs, alone and in combination, with and without radiation. Cytotoxicity was evaluated using the MTT assay, and dose-response curves were generated. The half-maximal inhibitory concentration (IC₅₀) of CUR was calculated via the median-effect equation using CompuSyn software. Lactate levels were measured using a Lactic Acid Assay Kit, and superoxide dismutase (SOD) enzyme activity was assessed by colorimetric method.

Results: CUR and GNPs both reduced cell viability in a dose-dependent manner, with MCF-7 cells showing significantly higher sensitivity than L929 cells. The combined treatment of CUR + GNPs + radiation exhibited a marked synergistic cytotoxic effect, significantly greater than any single or dual treatment (p < 0.05). This combination also induced apoptosis, substantially decreased lactate levels (indicating metabolic disruption), and reduced SOD activity in cancer cells.

Conclusion: The triple combination of gold nanoparticles, curcumin, and radiation demonstrates a novel and selective synergistic radiosensitizing effect against breast cancer cells while sparing normal cells.