Essential Oil From Dittrichia viscosa L.: A Potential Source of Bioactive Substances With Antioxidant, Antimicrobial, and Antidiabetic Properties: In Vitro and In Silico Studies.

Abstract

In Morocco, Dittrichia viscosa L. has long been used to treat a variety of illnesses. The objective of this work was to comprehensively evaluate the essential oil (EO) derived from D. viscosa essential oil (DVEO) for its antibacterial, antidiabetic, and antioxidant effects and to confirm the in vitro results using in silico approaches. The chemical composition of DVEO was investigated using gas chromatography-mass spectrometry (GC-MS). The antioxidant ability was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and the β-carotene bleaching inhibitory activity. To assess the antibacterial potential, disc diffusion and in vitro microdilution were employed. The antidiabetic potential of DVEO was further investigated in this study by evaluating its inhibitory effects on α-amylase and α-glucosidase enzymes. The molecular docking was employed to support the experimental findings by modeling interactions between key DVEO compounds and relevant protein targets. Pharmacokinetics and toxicity were evaluated and predicted for these compounds. GC-MS analysis revealed that Shyobunol constituted over 40% of the DVEO composition. In the β-carotene and DPPH tests, DVEO exhibited a notable antioxidant effect, with IC₅₀ values of 28.93 ± 0.37 μg/mL and 759.44 ± 4.35 μg/mL, respectively, compared with standard antioxidant BHT (19.23 ± 0.53 μg/mL). The EO also demonstrated strong antibacterial activity, especially against Staphylococcus aureus (inhibitory zone [IZ] = 17.11 ± 1.11 mm) and Bacillus subtilis (IZ = 22.05 ± 0.98 mm). By inhibiting intestinal α-glucosidase and pancreatic α-amylase, the DVEO had IC₅₀ values of 0.341 ± 0.11 mg/mL and 0.361 ± 0.04 mg/mL. The IC₅₀ was determined to be between 0.281 and 0.401 mg/mL based on replicate experiments. Molecular docking simulations indicated that DVEO constituents interact favorably with the active sites of key enzymes, reinforcing their potential biological relevance. Several compounds also displayed favorable physicochemical, pharmacokinetic, and toxicity profiles, supporting their role as potent therapy candidates. These findings highlight DVEO as a valuable source of bioactive molecules with potential applications in drug discovery and development.