Phytochemical profiling and molecular docking analysis of Micromeria aybalae essential oil: In vitro and in silico evaluations

Abstract

The increasing consumer preference for natural and organic products, coupled with growing concerns over the side effects and resistance associated with synthetic chemicals, has significantly increased the demand for essential oils for their potential pharmacological applications. However, many species remain unexplored. This study presents the first comprehensive analysis of Micromeria aybalae essential oil, including its phytochemical composition, antioxidant and enzyme inhibitory activities, and molecular docking results. The essential oil, obtained by hydrodistillation of aerial parts, exhibited a 0.10% (v/w) yield, relatively low among Micromeria species. The essential oil of M. aybalae was analyzed by GC-MS, identifying 91.6% of its constituents. Major compounds included caryophyllene oxide (38.5%), beta-caryophyllene (6.5%), and alpha-pinene (6.3%). Antioxidant activity was moderate, with IC50 values of 11.56 mg/mL (DPPH) and 5.09 mg/mL (ABTS), compared to trolox (IC50 = 0.22 and 0.32 mg/mL). Metal chelating activity was weak (IC50 = 1.86 mg/mL vs. EDTA at 0.09 mg/mL). The oil showed moderate reducing power (EC50 = 4.38 mg/mL for CUPRAC, 3.95 mg/mL for FRAP), while trolox had stronger activity. Enzyme inhibition was observed for tyrosinase (IC50 = 1.59 mg/mL) and alpha-amylase (IC50 = 12.74 mg/mL), though less potent than standards kojic acid and acarbose. In silico docking revealed that major constituents, especially caryophyllene oxide, interacted with alpha-amylase and tyrosinase active sites through hydrogen bonding (e.g., Asp197) and hydrophobic interactions (e.g., His61). This study presents the first detailed analysis of M. aybalae essential oil, demonstrating its moderate bioactivity and suggesting potential for further investigation of its active compounds and synergistic effects.