Comparative evaluation of bioactive properties of Philadelphus coronarius leaf and flower extracts: Antioxidant and enzyme inhibitory activities

This study comparatively evaluated the bioactive properties of Philadelphus coronarius leaf and flower extracts, focusing on phenolic composition, antioxidant capacity, and enzyme inhibitory activities. Plant materials were collected, dried, powdered, and extracted using 80% ethanol via ultrasound-assisted extraction. Total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activities (ABTS, DPPH, and FRAP assays) were determined, along with α-glucosidase and acetylcholinesterase inhibitory activities. The leaf extract exhibited significantly higher phenolic and flavonoid contents (4082.81 mg GAE/100 g DW and 3444.17 mg CE/100 g DW, respectively) compared to the flower extract (1864.06 mg GAE/100 g DW and 869.17 mg CE/100 g DW). Similarly, the antioxidant capacities (DPPH, ABTS, and FRAP values) of the leaf extract were found to be significantly higher than those of the flower extract. In enzyme inhibition studies, the leaf extract demonstrated stronger α-glucosidase inhibitory activity (IC50: 0.0211 mg/mL) than the flower extract (IC50: 0.0523 mg/mL). In contrast, acetylcholinesterase inhibition was similar for both extracts. Overall, the findings indicate that P. coronarius leaves possess a strong bioactive potential, particularly in terms of phenolic compounds, antioxidant capacity, and α-glucosidase inhibitory activity. Therefore, the leaf part of this species may be considered a promising natural source of antioxidants and functional bioactive compounds.