Comparative Analysis of GC-MS Chemical Profiles and Multidimensional Biological Activities of Essential Oils from Thirteen Lamiaceae Plants

Lamiaceae plants produce essential oils (EOs) with diverse chemical compositions and biological activities. This study investigated the volatile composition and multiple biological activities of EOs from 13 Lamiaceae species. EOs were obtained by hydrodistillation and characterized by gas chromatography–mass spectrometry (GC-MS), followed by hierarchical clustering and principal component analysis. Antioxidant, antibacterial, cytotoxic, and anti-inflammatory activities were evaluated using in vitro and murine models. GC-MS analysis revealed substantial interspecific variation in volatile composition, with Origanum vulgare characterized by carvacrol and limonene, Thymus spp. by thymol, Rosmarinus officinalis by eucalyptol and α-pinene, Mentha canadensis by L-menthol, and Perilla frutescens by perillaldehyde. Scutellaria baicalensis, Elsholtzia ciliata, Phlomis mongolica, and Schizonepeta tenuifolia showed distinctive profiles associated with limonene and isopulegone, nepetalactone, pulegone, and anethole and anisaldehyde, respectively. Multivariate analysis further separated the 13 oils into three chemotype groups: a carvacrol-rich Origanum group, a Scutellaria and Thymus group enriched in sesquiterpenes or thymol, and a group comprising the remaining six genera dominated by shared monoterpene hydrocarbons. Most EOs exhibited substantial 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity, with Rosmarinus officinalis and Perilla frutescens showing the strongest activity, with IC50 values of 2.14 and 2.08 μg/mL, respectively. Origanum vulgare, Thymus citriodorus, Thymus vulgaris, and Thymus mongolicus displayed strong antibacterial activity against five pathogens, with minimum inhibitory concentration (MIC) values ranging from 2 to 8 μg/mL. Cytotoxicity assays showed potent activity against HepG2 and LNCaP cells, with IC50 values ranging from 0.31 to 0.95 μg/mL. Elsholtzia ciliata and Perilla frutescens exhibited particularly strong potency, with IC50 values ranging from 0.31 to 0.40 μg/mL. In a murine skin inflammation model, selected EOs significantly reduced inflammation-related markers, including COX-2, TNF-α, NF-κB, IKK, Akt, and PKC. Correlation analysis identified significant associations of carvacrol, thymol, and β-linalool with antibacterial activity, whereas no significant associations were observed between individual major constituents and antioxidant or cytotoxic activity after false discovery rate (FDR) correction. Overall, the 13 Lamiaceae EOs displayed distinct chemical profiles and activity patterns, providing a basis for further investigation of their bioactive constituents and potential applications.