Organ-specific antioxidant capacities and cytotoxic effects of Thermopsis turcica extracts in breast cancer.

Background and Aims: Thermopsis turcica is an endemic species present in Türkiye and it is seen as a source of functional compounds such as antioxidant phenolics. Even though some biological activities of the aerial parts of T. turcica have been determined, knowledge regarding the organ-specific chemical composition and effects on human breast cancer is still scarce. Therefore, the present study aims to evaluate the antioxidant capacities, phenolic acid profiles, and potential biological activities of methanol extracts obtained from the leaf, flower, and stem tissues of T. turcica. Methods: The antioxidant capacities of methanol extracts of T. turcica was tested with complementary methods (TAC, CUPRAC, FRAP, and DPPH). While the total phenol (TPC) and flavonoid contents (TFC) of the extracts were determined spectrophotometrically, their phenolic acid profiles were determined by high-performance liquid chromatography (HPLC). The cytotoxic effects of extracts on the human normal breast cell line (MCF-10A cells) and the breast tumor cell lines (MCF7, MDA-MB-231, and SKBR3) were also analyzed after 24 h treatment. Results: The leaf extracts were found to have higher antioxidant capacity, which was associated with the presence of higher amounts of TPC and TFC. The HPLC analysis revealed the presence of quercetin, hesperidin, and rosmarinic acid as the main compounds in the leaf extracts, while a high amount of benzoic acid was found in the flower extract. Leaf and flower extracts also showed stronger cytotoxic activity against MCF-7 cells (IC50 values were 0.65 mg/mL and 0.55 mg/mL, respectively) as compared to stem extract (IC50 value was 1.10 mg/mL). Leaf extracts were the most active extract against SKBR3 cells with IC50 of 0.75 mg/mL. All extracts exhibited weak cytotoxic effects against MDA-MB-231 cells and IC50 values (1.53-1.75 mg/mL) were similar to the MCF-10A cells (IC50 values: 1.59-1.69 mg/mL). Conclusion: In conclusion, extracts derived from T. turcica have the potential to serve as a valuable source of bioactive metabolites with antioxidant and antiproliferative properties. [ABSTRACT FROM AUTHOR]