Photodynamic therapy with curcumin and near-infrared radiation as an antitumor strategy to glioblastoma cells.

Glioblastoma is a malignant neoplasm that develops in the central nervous system and is characterized by high rates of cell proliferation and invasion, presenting resistance to treatments and a poor prognosis. Photodynamic therapy (PDT) is a therapeutic modality that can be applied in oncological cases and stands out for being less invasive. Photosensitizers (PS) of natural origin gained prominence in PDT. Curcumin (CUR) is a natural compound that has been used in PDT, considered a promising PS. In this work, we evaluated the effects of PDT-mediated CUR and near-infrared radiation (NIR) in glioblastoma cells. Through trypan blue exclusion analysis, we chose the concentration of 5 μM of CUR and the dose of 2 J/cm 2 of NIR that showed better responses in reducing the viable cell number in the C6 cell line and did not show cytotoxic/cytostatic effects in the HaCat cell line. Our results show that there is a positive interaction between CUR and NIR as a PDT model since there was an increase in ROS levels, a decrease in cell proliferation, increase in cytotoxicity with cell death by autophagy and necrosis, in addition to the presence of oxidative damage to proteins. These results suggest that the use of CUR and NIR is a promising strategy for the antitumor application of PDT.