Evaluation of the Dermatoprotective Properties of Clinopodium nepeta and Thymus vulgaris Essential Oils: Phytochemical Analysis, Anti-Elastase, Anti-Tyrosinase, Photoprotective Activities, and Antimicrobial Potential Against Dermatopathogenic Strains.

BACKGROUND

The growing demand on natural ingredients in cosmetics has immensely contributed to a renewed interest in cosmetic industry in plant derivatives, especially essential oils. The aim of this study is to examine the dermatoprotective and antifungal properties of Clinopodium nepeta (CNEO) and Thymus vulgaris (TVEO) essential oils.

MATERIALS AND

METHODS

Gas chromatography-mass spectrometry (GC-MS) analysis was performed to identify the chemical composition of the essential oils. Anti-elastase and anti-tyrosinase activities were evaluated using standard enzymatic inhibition assays, and IC50 values were calculated. Photoprotective properties were determined using in vitro sun protection factor (SPF) calculations. Antifungal and antibacterial activities were assessed using the disc diffusion method and minimum inhibitory concentration (MIC) determination against Candida albicans, Candida glabrata, Micrococcus luteus, and Staphylococcus aureus.

RESULTS

GC-MS analysis revealed the presence of 13 compounds in CNEO, mainly oxygenated monoterpenes (91.9%) with pulegone (42.3%) as the main component, and 25 compounds in TVEO, with α-terpineol (19.8%) and carvacrol (13.5%) as the dominant compounds. CNEO showed superior anti-elastase activity (IC50 = 13.55 ± 0.81 µg/mL) compared with TVEO (IC50 = 28.40 ± 2.64 µg/mL). Both oils demonstrated significant anti-tyrosinase effects, with CNEO showing greater efficacy in inhibiting monophenolase (IC50 = 36.71 ± 4.09 µg/mL) and diphenolase (IC50 = 22.77 ± 0.97 µg/mL) than TVEO. SPF calculations revealed notable photoprotective properties for both oils, with CNEO (SPF = 6.472) slightly outperforming TVEO (SPF = 5.640). Antifungal tests against C. albicans and C. glabrata, and antibacterial tests against M. luteus and S. aureus showed that both oils possess strong antifungal and antibacterial activities, with CNEO demonstrating superior efficacy (MIC = 0.50 ± 0.00% v/v for both Candida strains) compared with TVEO (MIC = 0.011 ± 0.00% v/v for both Candida strains).

CONCLUSION

This study provides the first comprehensive assessment of the dermatoprotective, antifungal, and antibacterial activities of CNEO and confirms the potential of TVEO in cosmetic, antifungal, and antibacterial applications. The results suggest that these essential oils could serve as promising natural ingredients in dermatoprotective, antifungal, and antibacterial formulations.