Increased anticancer activity in cancer cells after photodynamic therapy with <i>Aristolochia samsunensis</i> : phytochemical characterization, antioxidant activity and molecular docking approaches

This study investigates the antioxidant activity, the phytochemical compounds, the total phenolic and flavonoid contents, anticancer potential, and photodynamic therapy (PDT) effectiveness of Aristolochia samsunensis methanol extract. The IC50 value of the methanol extract from A. samsunensis was measured as 189.64 ± 20.33 µg/mL using the DPPH radical scavenging assay, while the IC50 value of BHT, used as a positive control, was found to be 230.00 ± 10.00 µg/mL. These results indicate that the extract of A. samsunensis has a higher antioxidant capacity than BHT. The total phenolic content of the extract was determined as 12.80 ± 0.80 mg GAE/g, the total flavonoid content as 37.77 ± 0.53 mg QE/g, flavanol content as 92.58 ± 8.68 mg QE/g, and proanthocyanidin content as 69.00 ± 4.46 mg CAE/g. These findings suggest that A. samsunensis could be a rich source of bioactive compounds with potential biological activity. HPLC analysis identified key components, including caffeic acid (478.11 mg/L), ascorbic acid (338.01 mg/L), and catechin (159.07 mg/L). Anticancer and PDT activities were evaluated in HEK293 and MKN28 cell lines. Although the extract did not exhibit direct anticancer activity, it showed significant PDT activity, particularly at lower concentrations and under green light exposure. Molecular docking analyses demonstrated that compounds such as catechin and caffeic acid interact strongly with the target protein 1EDH, with catechin showing the highest binding affinity. This suggests that catechin could be a promising compound for further research as a photosensitizer agent. These results indicate that A. samsunensis may be a valuable candidate for PDT-based therapies and offer an innovative approach for anticancer treatment.