Selective Effects of Curcumin on CdSe/ZnS Quantum Dots induced Phototoxicity Using UVA Irradiation in Normal Human Lymphocytes and HL-60 cells

Abstract

Quantum dots have received considerable attention due to their potential role in photosensitization during photodynamic therapy. Although Quantum dots are attractive nanomaterials due to their novel and unique physicochemical properties, concerns about their toxicity remain. This study suggests a combination strategy, CdSe/ZnS Quantum dots together with curcumin, a natural yellow pigment from turmeric, to reduce Quantum dot-induced cytotoxicity. The aim of this study was to explore a potentially effective cancer treatment: co-exposure of HL-60 cells and human normal lymphocytes to CdSe/ZnS Quantum dots and curcumin. Cell viability, apoptosis, reactive oxygen species (ROS) generation, and DNA damage induced by CdSe/ZnS Quantum dots and/or curcumin with or without ultraviolet A (UVA) irradiation were evaluated in both HL-60 cells and normal lymphocytes. In HL-60 cells, cell death, apoptosis, ROS generation, and single/double DNA strand breaks induced by CdSe/ZnS Quantum dots were enhanced by treatment with curcumin and UVA irradiation. The protective effects of curcumin on cell viability, apoptosis, and ROS generation were observed in normal lymphocytes, but not leukemia cells. These results demonstrated that treatment with CdSe/ZnS Quantum dots combined with curcumin increased cell death in HL-60 cells, which was mediated by ROS generation. However, curcumin acted as an antioxidant in cultured human normal lymphocytes.