Ultrasound-assisted extraction and HPLC-PDA/ESI-MS profiling of Teucrium gypsophilum: Antioxidant and enzyme inhibitory activities

Teucrium gypsophilum, an endemic Moroccan species traditionally used for medicinal purposes, was investigated for the first time for its phenolic profile and biological activities. Ethanolic, aqueous, and methanolic leaf extracts were prepared via ultrasound-assisted extraction and analyzed using HPLC-PDA/ESI-MS. The main phenolic chemicals found in the methanolic extract were leonoside A/alyssonoside isomer (96.37 ± 0.361 mg/g), caffeoylquinic acid (75.66 ± 0.218 mg/g), and verbascoside (14.14 ± 0.130 mg/g). Regarding the ethanolic extract, chemical analysis identified the leonoside A/alyssonoside isomer as the most abundant (59.52 ± 0.154 mg/g), followed by the verbascoside isomer and the dihexoside isomer of apigenin with 8.89 ± 0.102 and 5.39 ± 0.005 mg/g, respectively. For aqueous extract, the main compound was caffeic acid 12.65 ± 0.105 mg/g, followed by echinacoside isomer with 6.89 ± 0.006 mg/g. The extracts demonstrated significant antioxidant activity, with the methanolic extract exhibiting the highest DPPH scavenging effect (IC50 = 2.64 ± 0.52 μg/mL) and reducing power (15.66 ± 0.11 mg AAE/g). In vitro enzyme assays revealed dose-dependent inhibitory effects against elastase (IC50: 9.09 ± 0.003 μg/mL), phospholipase A2 (IC50: 31.75 ± 0.0005 μg/mL, α-amylase (IC50: 0.45 ± 0.004 μg/mL), anti-urease, and anti- α -glucosidase effect which IC50 values equal 0.602 ± 0.049 and 0.604 ± 0.084 mg/mL and 0.38 ± 0.005 μg/mL, respectively. These findings highlight the pharmaceutical and nutraceutical potential of T. gypsophilum as a rich source of bioactive phenolic compounds.