Antimicrobial and Antibiofilm Potential of Thymus vulgaris and Cymbopogon flexuosus Essential Oils against Pure and Mixed Cultures of Foodborne Bacteria

Tetraclinis articulata (Vahl) Mast.: Volatile constituents, antioxidant, antidiabetic and wound healing activities of its essential oil

Type 2 diabetes mellitus (T2DM) is a metabolic syndrome known to contribute to impaired wound healing. This condition can be further worsened by excessive melanin production, elastin degradation, and chronic infections at the wound site, potentially leading to melasma and diabetic dermopathy. The purpose of this study was to investigate the phytochemical profile and inhibitory effects of Tetraclinis articulata essential oil (TAEO) on target enzymes involved in diabetes pathogenesis and chronic wound remodeling, namely α-amylase, α-glucosidase, tyrosinase, and elastase, as well as its in vitro antibacterial activity. Gas chromatography and mass spectrometry (GC-MS) analysis of TAEO led to the identification of 46 volatile compounds, representing 96.61 % of TAEO. The major metabolites were bornyl acetate (29.48 %), α-pinene (8.96 %), germacrene D (7.70 %), and d-limonene (5.90 %). TAEO exhibited limited scavenging activity against DPPH free radicals, whereas the FRAP and ABTS assays indicated a relatively higher antioxidant activity. Remarkably, TAEO disclosed a promising in vitro antidiabetic activity against α-glucosidase with an IC50 value of 178 ± 1.6 μg/mL, which is comparable to the standard inhibitor acarbose (IC50 = 143 ± 1.1 μg/mL). In silico, molecular docking analysis against α-glucosidase identified 15 compounds that interacted with the enzyme's active site, whereas skin permeability and sensitization assessments indicated that 26 out of the 44 identified volatile compounds were predicted to be free from any skin sensitivity risk. On the other hand, moderate inhibitory activity was recorded against α-amylase, tyrosinase, and elastase. Notably, TAEO at 5 % significantly suppressed biofilm formation by P. aeruginosa, S. aureus, and E. faecalis, common skin pathogens associated with wound infections, and reduced their swarming motility. Our findings suggest that TAEO may hold the potential as a natural remedy for type 2 diabetes and its associated co-morbidities, especially chronic wounds.