Analysis of the Antioxidant and Antimicrobial Activity, Cytotoxic, and Anti-Migratory Properties of the Essential Oils Obtained from Cultivated Medicinal Lamiaceae Species

Abstract

This study aims to highlight the therapeutic potential of some Lamiacea essential oils (EOs). For this purpose, eight EOs, including two from Lavandula angustifolia Mill. cultivated in Romania and Spain (LA1 and LA2), Salvia officinalis L. (SO), Lavandula hybrida Balb. ex Ging (LH), Salvia sclarea L. (SS), Mentha smithiana L. (MS), Perovskia atriplicifolia Benth. (PA), and Mentha x piperita L. (MP), were evaluated in vitro in terms of antioxidant, cytotoxic, antimicrobial, and anti-migratory activities. As regards the antioxidant capacity, expressed as the EO concentration that produces 50% of the maximum effect (IC₅₀ value), the EOs obtained from the cultivated plants of the Lamiaceae family are ordered as follows: LA2 ˃ LA1 ˃ LH > MP > MS > SO > SS > PA. For the determination of antimicrobial activity, the reference strains used for testing were Salmonella enterica serotype typhimurium, Shigella flexneri serotype 2b, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans, and Candida parapsilosis. The most intense inhibitory effect was observed in EOs of MS and MP on all tested microbial strains. The cytotoxic and anti-migratory activity of EOs was tested on two melanoma cell lines (A375 and B164A5) and on a healthy keratinocyte line (HaCaT). EOs LA1 and MP manifested the highest selectivity on the analysed tumoural cells, by reducing their migration in comparison with the control, proving to have therapeutic potential.

Keywords: Lamiaceae; anti-migratory activity; antimicrobial activity; antioxidant activity; cytotoxic activity; essential oil.

Figure 1

Hierarchical cluster for describing similarity in the activity of the studied plant samples (Source: authors’ own graphical representation of experimental data using PAST 4.03).

Figure 2

Boxplot distribution of measured diameter values for the analysed EO samples (Source: authors’ own graphical representation of experimental data using SAS Studio).

Figure 3

A375 human melanoma cell viability, after stimulation with the EOs (50 and 150 μg/mL—clear vs. dotted texture of the colour fill) for 24 h. Data are expressed as mean ± SD (*** p < 0.001; ** p < 0.01). The comparison between groups was performed using the One-way ANOVA test followed by Dunnett’s post-test.

Figure 4

B164A5 murine melanoma cell viability, after stimulation with the EOs (50 and 150 μg/mL—clear vs. dotted texture of the colour fill) for 24 h. Data are expressed as mean ± SD (*** p < 0.001; ** p < 0.01). The comparison between groups was performed using the One-way ANOVA test followed by Dunnett’s post-test.

Figure 5

HaCaT human keratinocyte viability after stimulation with the EOs (50 and 150 μg/mL—clear vs. dotted texture of the colour fill) for 24 h. Data are expressed as mean ± SD (*** p < 0.001; ** p < 0.01 and * p < 0.050). The comparison between groups was performed using the One-way ANOVA test followed by Dunnett’s post-test.

Figure 6

The anti-migratory effect of the tested EOs (50 μg/mL) (A—LA1; LA2; SO and LH) on human melanoma cell line A375. The images were taken at 0, 12, and 24 h after stimulation.

Figure 7

The anti-migratory effect of the tested EOs (50 μg/mL) (B—SS; MS; PA and MP) on human melanoma cell line A375. The images were taken at 0, 12, and 24 h after stimulation.

Figure 8

The anti-migratory effect of the tested EOs (50 μg/mL) (A—LA1; LA2; SO and LH) on murine melanoma cell line B164A4. The images were taken at 0, 12, and 24 h after stimulation.

Figure 9

The anti-migratory effect of the tested EOs (50 μg/mL) (B—SS; MS; PA and MP) on murine melanoma cell line B164A4. The images were taken at 0, 12, and 24 h after stimulation.

Figure 10

The anti-migratory effect of the tested EOs (50 μg/mL) (A—LA1; LA2; SO and LH) on the HaCaT cell line, keratinocytes. The images were taken at 0, 12 and 24 h after stimulation.

Figure 11

The anti-migratory effect of the tested EOs (50 μg/mL) (B—SS; MS; PA and MP) on the HaCaT keratinocyte cell line. The images were taken at 0, 12, and 24 h after stimulation.