Influence of harvest season on the chemical composition and antifungal activity of Citrus limon essential oil

Abstract

The use of Essential Oil (EO) as an antimicrobial agent has been widely used since antiquity, and interest has grown due to the resistance of microorganisms to drugs. This study aims to evaluate the chemical composition of Algerian Citrus limon peel EO and its antifungal activity against dermatophyte strains, according to the harvest period. EO from C. limon peel harvested during four different periods (Winter, Spring, Summer, and Autumn) was extracted by hydrodistillation Clevenger type and analyzed by GC/MS. Antifungal activity was evaluated against four dermatophyte strains (Trichophyton rubrum, Microsporum canis, Trichophyton mentagrophytes, and Microsporum gypseum) using the disc diffusion and agar dilution methods. The yield of EO from C. limon peel varied from 1.54 to 2.43% (w/w), the highest yield was obtained in Autumn and the lowest in Summer, the EOs were mainly composed of limonene (43.45–58.75%) followed by β-pinene (4.73–13.23%) and γ-terpinene (8.06–11.04%). The assessment of the antifungal activity showed that C. limon peel EO has a strong antifungal activity against the tested strains, with inhibition zones ranging from 16.63 ± 0,38 to 90.00 ± 00 mm, and Minimal Inhibitory Concentration (MIC) from 0.6 to 5 mg/mL and Minimal Fungicidal Concentration (MFC) from 1.25 to 10 mg/mL. Spring harvest EO was relatively more effective in terms of MIC (0.6–2.5 mg/mL) and MFC (1.25–2.5 mg/mL). The EO of C. limon peel showed a seasonal change in the chemical composition and the antifungal activity, also revealed a high antifungal potential, and can be used for the treatment of fungal infections caused by dermatophytes.