Antifungal activity and chemical composition of Iranian medicinal herbs against fish pathogenic fungus, Saprolegnia parasitica

This study aimed to identify the chemical composition of essential oil of some Iranian medicinal plants and their antifungal activity against Saprolegnia parasitica in comparison to formalin as positive control under in vitro conditions. The essential oils of Eryngium campestre, Pimpinella affinis, Mentha piperita, Achillea wilhelmsii and Cuminum cyminum were analyzed for their activity by disk diffusion, Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC) methods. Also, the oil constituents of investigated plants were analyzed by gas chromatography/mass spectrometry (GC/MS). The major constituent of the surveyed essential oils was bornyl acetate (17.9%) in E. campestre, Pregeijene (27.3%) in P. affinis, menthol (48.5%) in M. piperita, 1,8-cineol (25.2%) in A. wilhelmsii, and α- Pinene (29.1%) in C. cyminum. The MIC values for the surveyed essential oil were was 0.5 μg ml-1 for C. cyminum followed by M piperita and E. campestre both having 1 μg ml-1, for P. affinis 2 μg ml-1 and was 4 μg/mL for A. wilhelmsii. The MFC for the mentioned essential oil were with 0.5 μg ml-1 again lowest for C. cyminum, followed by M. piperita and E. campestre with 2 μg ml-1, for P. affinis MFC was 4 μg ml-1 while it was with 8 μg ml-1 highest for essential oils from A. wilhelmsii. The results indicate that the essential oils of C. cyminun, E. campestre and M. piperita could be potential candidates for new plant based antifungal components in aquaculture against S. parasitica.