Synergistic chemo-photodynamic therapy using Verteporfin and Paclitaxel for enhanced antitumor efficacy against BT-474 cells

Breast cancer (BC) is the most diagnosed malignancy among women. Hormone receptor and HER2-positive BC is one of the major subtypes of BC that affect millions of lives globally. Chemotherapy is the first-line therapeutic approach for this subtype of BC but multiple side effects are associated with it. Photodynamic therapy is a light-based therapy that can be used as a complementary treatment in combination with chemotherapy to reduce its side effects and improve the therapeutic outcomes. In the present study, verteporfin a second-generation photosensitizer was used in combination with paclitaxel to investigate the effect of combination therapy on BC cells. The internalization of both drugs was recorded using UV–vis spectroscopy. BT-474 BC cells were treated with both drugs individually and in various combinational ratios (1:1,1:2, 2:1). Cytotoxic effects of both drugs were evaluated using an thiazolyl blue tetrazolium bromide assay. A reactive oxygen species (ROS) assay was performed to evaluate the underlying mechanism of cell death. The combination therapy showed a significant increase in ROS production which induces oxidative stress that causes cell death. Results indicate an enhanced therapeutic efficiency of drugs in combination therapy compared to mono-therapy against BC.