Chemical Composition, Antibacterial Properties, and Anti-Enzymatic Effects of Essential Oils Sourced from Tunisia.

This study was conducted to examine the chemical composition of the essential oils (EOs) from six Tunisian species and to evaluate their anti-enzymatic and antibiofilm activities. The EOs were obtained through hydro-distillation of dried leaves and subsequently analyzed using GC/MS. The main class of compounds was constituted by oxygenated monoterpenes, particularly prominent in (75.7%), (72.8%), and (67%). Anti-enzymatic activities against cholinesterases, α-amylase, and α-glucosidase were evaluated using spectrophotometric methods. Notably, the , and EOs displayed potent acetylcholinesterase (AChE) inhibition (IC: 0.25-0.60 mg/mL), with exhibiting lower activity (IC: 1.2 mg/mL). and showed remarkable α-amylase inhibition (IC: 0.88 mg/mL), while and significantly hindered α-glucosidase (IC < 30 mg/mL), distinguishing them from other EOs with limited effects. Additionally, the EOs were assessed for their anti-biofilm properties of Gram-positive ( and ) and Gram-negative (, and ) bacterial strains. The EO demonstrated the main antibiofilm effect against and with an inhibition > 80% at 10 mg/mL. These findings could represent a basis for possible further use of EOs in the treatment of human microbial infections and/or as a coadjutant in preventing and treating Alzheimer's disease and/or diabetes mellitus.