IN VITRO EVALUATION OF SCHIFF BASE DECORATED PHTHALOCYANINES FOR PHOTODYNAMIC THERAPY IN PC3 PROSTATE CANCER CELLS

Abstract

Schiff base decorated non-ionic phthalocyanine compounds with different metals and metal free version were synthesized and characterized through different spectroscopic techniques.The influence of central metal on the photophysicochemical properties was systematically investigated in DMSO. Obtained results reveal that the singlet oxygen quantum yield followed the order In3b>Zn3b>3bH 2 Pc in DMSO. All synthesized non-ionic phthalocyanine compounds except metal-free phthalocyanine (0.12 for 3bH 2 Pc) have good Φ ∆ values (0.71 for Zn3b, 0.85 for In3b) compared to the unsubstituted ZnPc in DMSO (Φ ∆ = 0.67). In addition to photophysicochemical studies, in vitro PDT studies were also performed on PC3 prostate cancer cells to evaluate the biological activity of Pcs. All compounds exhibited low dark cytotoxicity at the selected concentration. Upon light irradiation, phthalocyanine-mediated PDT significantly reduced cell viability and induced apoptotic cell death. These effects were accompanied by a pronounced increase in intracellular ROS generation, particularly in cells treated with metallophthalocyanine-mediated PDT. In particular, In3b-and Zn3b-mediated PDT exhibited markedly enhanced cytotoxic and apoptotic effects compared to metal-free 3bH₂Pc. These findings demonstrate a strong correlation between improved photophysical properties, increased ROS generation, and enhanced in vitro PDT efficacy.