Unveiling antibacterial and α-amylase inhibitory potentials of Opuntia ficus-indica aqueous extract through LC–ESI–MS/MS-guided in vitro and in silico investigation

This study evaluated the bioactive potential of the aqueous extract of Opuntia ficus-indica (L.) Mill. aerial parts using combined phytochemical, biological, and computational approaches. The extraction yield was 10.82 ± 0.31%, with high total phenolic (94.36 ± 0.58 μg GAE/mg extract) and flavonoid contents (38.12 ± 0.47 μg QE/mg extract). LC–ESI–MS/MS analysis identified seventeen phenolic compounds, mainly phenolic acids and flavonoids, including ferulic acid, salicylic acid, quercetin, and catechin. The extract showed moderate antibacterial activity, with greater efficacy against Gram-positive bacteria. The lowest minimum inhibitory concentration was recorded for Staphylococcus aureus (MIC = 6.25 mg/mL). In addition, the extract exhibited dose-dependent inhibition of pancreatic α-amylase, with an IC₅₀ of 261.47 ± 1.18 μg/mL. Molecular docking revealed favourable binding affinities of major flavonoids toward antibacterial enzymes and human pancreatic α-amylase, with binding energies reaching −7.4 kcal·mol −1 . Molecular dynamics simulations over 300 ns confirmed the stability of selected protein–ligand complexes. Overall, the results indicate that O. ficus-indica aqueous extract is a phenolic-rich matrix with biologically relevant antibacterial and α-amylase inhibitory properties, supporting its potential use in nutraceutical and complementary applications. • LC–ESI–MS/MS analysis established phenolic acids and flavonoids as the core chemical drivers of the extract. • The aqueous extract demonstrated biologically relevant antioxidant and anti-inflammatory potential through complementary in vitro models. • Phenolic acids and flavonoids acted as the main contributors to protein stabilization and redox modulation. • Molecular docking linked the major phenolics to functionally relevant antioxidant and inflammatory targets. • Molecular dynamics simulations confirmed the persistence and stability of key protein–ligand interactions.