Comparative metabolomic profiling and chemometric correlation of Salvia rosmarinus Spenn. and Origanum vulgare L. with antibacterial, antioxidant and anti-inflammatory activities

The Lamiaceae plants are recognized in folk medicine for their antibacterial and anti-inflammatory properties. This study reports the first MS-based metabolomics analysis, integrating with chemometrics to explore metabolome heterogeneity in Salvia rosmarinus Spenn. (rosemary) and Origanum vulgare L. (oregano), and to pinpoint the key metabolites driving their antibacterial, antioxidant, and anti-inflammatory activities. UPLC–QTOF–MS/MS facilitated the identification of 164 metabolites, including flavonoids and hydroxycinnamic acids, which were reported for the first time in these species. For instance, salvianolic acid D and quercetin coumaroylhexoside were detected in rosemary, while salvianolic acid K, cleroden J, and flavonoids like nepitrin were newly reported in oregano. In biological evaluation, rosemary strongly inhibited methicillin-resistant Staphylococcus aureus and Escherichia coli, exhibited the highest radical scavenging capacity in DPPH assay, and showed superior anti-inflammatory effects through COX-II inhibition and TNF-α and NF-κB suppression. In contrast, oregano displayed the strongest reducing power in FRAP assay. Chemometric analyses revealed that flavonoids, hydroxycinnamic acids, and terpenes were the principal discriminating classes. Partial least squares analysis correlated rosemary’s antibacterial and radical scavenging activity with hydroxycinnamic acids, flavonoids, and terpenes, while its anti-inflammatory effects were linked to flavonoids and diterpenes. In oregano, FRAP reducing power correlated with benzyl derivatives, organic acids, and hydroxycinnamic acids.