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The genus Mentha (Lamiaceae), comprising aromatic perennial plants widely distributed in temperate regions, holds significant medicinal and commercial value. This study aimed to investigate the chemical profile and bioactivities of hydroalcoholic extracts from Mentha longifolia (L.) L., Mentha pulegium L., and Mentha spicata L. harvested from the Campania region, Southern Italy. Chemical analysis using LC-HRESIMS/MS identified a total of 21 compounds. The extracts, particularly M. pulegium , exhibited notable antioxidant activity, evaluated through DPPH and FRAP assays, probably related to their chemical composition. Both M. pulegium and M. longifolia demonstrated a higher phenolic content, with M. pulegium also containing the highest levels of flavonoids. In addition, the extract's ability to inhibit biofilm formation was evaluated against several pathogenic strains, including Gram-positive bacteria ( Listeria monocytogenes and Staphylococcus aureus ) and Gram-negative bacteria ( Acinetobacter baumannii , Pseudomonas aeruginosa , and Escherichia coli ) using crystal violet and MTT assays. All extracts effectively inhibited biofilm formation in A. baumannii and P. aeruginosa , with M. pulegium also showing moderate activity against the metabolism of L. monocytogenes . The pronounced antibacterial and biofilm-inhibitory properties of M. pulegium highlight its potential for pharmaceutical applications.

Many studies have demonstrated the herbicidal effects of several essential oils and their possible use as substitutes for chemical herbicides. Several enzymes play a very significant role in seed germination: among these, α-amylase could be involved in essential oil phytotoxic processes. The aims of this study were to compare the chemical composition of the essential oils of two ecotypes of O. heracleoticum growing in Cilento (Southern Italy) and to study their possible use as natural herbicide using Raphanus sativus , Sinapis arvensis and Lolium multiflorum seeds. Moreover, a possible inhibitory activity on the α-amylase enzyme extracted from germinating seeds was evaluated as a possible mechanism of action. Both oils, characterized by GC-MS, belonged to a carvacrol chemotype. The alpha-amylase activity was determined using DNSA (dinitrosalicylic acid) assay quantifying the reducing sugar produced. Furthermore, the essential oils demonstrated phytotoxicity at the highest dose tested, and an inhibitory effect on α-amylase, probably correlated with the phytotoxic effects, was registered. The oils showed interesting phytotoxic and alpha-amylase inhibitory activities, which deserve to be further investigated.