Evaluation of Antioxidant and Enzyme Inhibition Properties of Siran Propolis: Correlations With Phenolic Content...

This study evaluates the antioxidant activity, enzyme inhibition potential, and phenolic composition of ethanolic Siran propolis extract. Antioxidant capacity was measured using reducing power (CUPRAC, FRAP, and Fe³⁺-reducing) and radical scavenging (DPPH·, ABTS·⁺, and DMPD·⁺) assays. The extract showed strong reducing ability, surpassing standard antioxidants in CUPRAC and FRAP assays, correlating with high ferulic acid (40.40 mg/g) and p-coumaric acid (88.60 mg/g) levels identified by LC-MS/MS. While it demonstrated notable DPPH· scavenging (IC₅₀: 30.14 μg/mL), ABTS^·+ activity was weaker (IC₅₀: 272.44 μg/mL). Enzyme inhibition assays indicated effective inhibition of α-glycosidase, AChE (IC₅₀: 2.15 μg/mL), hCA I, and hCA II. Notably, AChE inhibition was stronger than the standard tacrine inhibitor (IC₅₀: 8.82 μg/mL), suggesting neuroprotective potential. The observed bioactivities are attributed to synergistic effects of phenolic acids and flavonoids, including quercetin, luteolin, taxifolin, and resveratrol. These findings highlight Siran propolis as a promising natural antioxidant and enzyme inhibitor source with potential therapeutic applications and food formulations.