Phytochemical profiling and biocidal activity of four Iranian Mentha (Lamiaceae) species.

• The most abundant compounds found in the mentha species were D-carvone, menthofurane, and linalyl acetate, respectively. • The mentha species show antimicrobial activity. • The mentha species exhibit anticancer properties against different tumor cell lines. The objective of this study was to evaluate the antibacterial and antifungal activities, and cytotoxic effects of the essential oils (EOs) from Mentha spicata, M. aquatica, M. longifolia , and M. × piperita collected at three developmental stages. According to principal component analysis, carvone, menthofuran, and linalyl acetate were the distinctive major components of M. spicata (57.7–65.6%) and M. longifolia (64.7–72%), M. aquatica (23–52.4%), and M. × piperita (50.6–70.2%) EOs, respectively. Zone of inhibition (ZI) around EOs for bacterial strains ranged from 9 mm (against Klebsiella pneumonia) to 26 mm (against Staphylococcus aureus). For fungal strains, EOs were highly active towards Aspergillus niger showing ZI ranging from 23 mm (M. × piperita) to 28 mm (M. aquatica), while Candida albicans was markedly more resistant, giving ZI ranging from 11 mm (M. × piperita) to 14 mm (M. aquatica). Essential oils were active toward both Gram-positive and Gram-negative bacterial pathogens, with a MIC range from 20 µg mL−1 (in M. aquatica and M. longifolia against S. aureus) to 70 µg mL−1 (in M. × piperita against K. pneumonia). The lowest and highest MIC of the oils against fungal strains were recorded on A. niger (30.0 µg mL−1) and C. albicans (80.0 µg mL−1), respectively. Essential oils exhibited strong cytotoxicity to the cancer cell lines while being almost nontoxic toward normal cells. The most and the least active Mentha species were M. aquatica against MCF-7 (IC 50 : 36±1.9 μg/mL) and M. × piperita against A549 (IC 50 : 68±1.8 μg/mL), respectively. Overall, M. aquatica could be a good candidate for future supplementary studies. [ABSTRACT FROM AUTHOR]