Investigating Phenolic Contents, Antioxidant Capacity and Enzyme Inhibition Activity of Vitex agnus-castus Vinegar

This study aims to determine phenolic contents, antioxidant capacity, and enzyme inhibition activity of Vitex agnus-castus L. extracts and three vinegars of Vitex Agnus-Castus L. (VAC Vinegar 1, 2, and 3). Quinic acid, gallic acid, protocatechuic acid, gentisic acid, chlorogenic acid, protocatechuic aldehyde, 4-OH benzoic acid, caffeic acid, salicylic acid, cyranoside, luteolin, and apigenin were detected in VAC Vinegar 1. VAC Vinegar 1 exhibited the highest phenolic (219.95 ± 4.57 µg PEs/mg) and flavonoid (121.71 ± 2.43 µg QEs/mg) contents. VAC Vinegar 3 demonstrated exceptional radical scavenging (ABTS IC₅₀: 3.20 ± 0.01 µg/mL). VAC Vinegar 1 and 3 exhibited potent α-glucosidase inhibition and strong α-amylase inhibition. VAC vinegar 1 achieved the highest cholinesterase (93.12% AChE; 84.18% BChE), and urease (98.67%) inhibition, and all vinegars showed superior elastase and tyrosinase inhibition. Results highlight the functional potential of Vitex agnus-castus L. vinegars with potential applications related to anti-aging, neuroprotective, and glycemic regulatory effects.