GC-MS-based metabolomics for the profiling of bioactive compounds in four Lamiaceae plants with multiple bioactive potentials

Lamiaceae aromatic plants are widely recognized for their diverse secondary metabolites and have promising antioxidant applications in pharmacology, medicine, food, cosmetology, and aromatherapy. This study systematically evaluated the volatile secondary metabolite compositions of essential oils (EOs) and hydrosols (HDs) from four Lamiaceae species— Lavandula angustifolia (La), Origanum vulgare (Ov), Mentha spicata (Ms), and Salvia sclarea (Ss), as well as antioxidant activities including DPPH, ABTS, FRAP, and ORAC, and tyrosinase inhibitory activity. A total of 205 volatile compounds were identified. Terpenoids dominated all EOs, while HDs were enriched in alcohols and hydrocarbons. Multivariate analyses, including principal component analysis (PCA), hierarchical cluster analysis (HCA), and orthogonal partial least square discriminant analysis (OPLS-DA), clearly separated EOs from HDs, confirming the extraction method as a key determinant. Antioxidant assays revealed that OvEO and OvHD consistently exhibited superior performance across DPPH, ABTS, FRAP, and ORAC assays. For tyrosinase inhibition, EOs were substantially more effective than HDs, with OvEO showing the strongest inhibition (82%), followed by LaEO (69.8%). Correlation analysis identified carvacrol, thymol, and γ-terpinene as key contributors to radical scavenging, while α-bourbonene, Germacrene D, and dihydrocarvone were associated with tyrosinase inhibitory activity. The broad-spectrum bioactivities of the studied Lamiaceae EOs and HDs suggest their potential as natural ingredients for further investigation in various industrial applications. Overall, these findings indicate that both EOs and HDs from Lamiaceae plants, particularly O. vulgare , warrant further exploration as potential whitening additives in cosmetic formulations or might be used as bleaching agents in food systems.