Investigation of the anticancer of photodynamic therapy effects by using the novel Schiff base ligand palladium complexes on human breast cancer cell line

Chemotherapy plays a role in many cancer therapies, including breast cancer, but due to its significant side effects, alternate treatment approaches have been investigated. One such alternative is photodynamic therapy (PDT), which employs a combination of oxygen, a photosensitizer (PS), and light of a specific wavelength. Transition metal complexes and SBL have gained interest in PDT. In this study aimed to assess the potential antitumor activity and underlying mechanism of a newly synthesized Schiff base ligand (SBL)-mediated PDT on MCF-7 cells, comparing its efficacy to cisplatin. We synthesized and characterized two novel Pd-conjugated SBL compounds (complex-1 and 2). Following the treatment of MCF-7 cells with these compounds, a light-emitting diode (LED) was utilized to deliver a light dose of 14.8 J/cm². In MCF-7 cells, we also looked at cytotoxicity, cell death rates, and ROS levels. Results indicated a significant increase in cytotoxicity (IC₅₀:12.5 µM) (p < 0.05) and ROS levels (258.33%) (p < 0.05) in the group treated with complex-1-mediated PDT compared to control. The late apoptotic (29.78%) (p < 0.05) and necrotic (24.23%) (p < 0.05) cell death also increased significantly compared to the control group (1.86 ± 0.92, 1.89 ± 0.32, respectively). In conclusion, our study suggests that the complex-1 compound may serve as a promising candidate for anticancer agents in PDT for MCF-7 cells. In contrast, complex-2-mediated PDT did not demonstrate any observable anticancer activity.