Phenolic profile, in vitro bioactivities, and in silico inhibition of α-amylase and trypsin by Thymelaea hirsuta (L.) Endl.

Abstract

Research on plants like Thymelaea hirsuta (L.) Endl. is increasingly crucial for identifying alternative therapies for chronic diseases. This study investigated the n-butanol leaf fraction (NBF) of T. hirsuta for its antioxidant, anti-diabetic, and anti-inflammatory properties through in vitro experiments, including 2,2-diphenyl-1-picrylhydrazyl (DPPH^•), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS^•+), Ferric Reducing Antioxidant Power (FRAP), Ferrous Ion Chelating (FIC), α-amylase inhibition, and anti-inflammatory assays. In silico study was also conducted against α-amylase and trypsin enzymes. Eighteen (18) compounds, including various phenolic acids and flavonoids, were identified by HPLC-PDA-MS/MS. The NBF demonstrated potent antioxidant activity, exhibiting 99.60% inhibition against ABTS^•+, 92.85% against DPPH^•, and 88.05% for FIC. It also showed significant α-amylase inhibition (85.40% at 5 mg/mL; IC₅₀: 0.37 ± 0.08 mg/mL). Furthermore, the NBF displayed notable anti-inflammatory activities, with 95.37% inhibition of protein denaturation (IC₅₀: 1.83 ± 0.06 mg/mL), 79.14% inhibition of heat-induced haemolysis (IC₅₀: 0.026 mg/mL), and 77.72% inhibition of proteinase (IC₅₀: 0.81 ± 0.95 mg/mL). In silico molecular docking studies against α-amylase and trypsin enzymes revealed feruloyl apigenin as a promising dual inhibitor. This novel compound exhibited a binding affinity comparable to acarbose and diclofenac sodium. These findings highlight the NBF of T. hirsuta as a potential source of bioactive compounds for future anti-inflammatory and anti-diabetic pharmaceutical development.