Chemical composition and antidermatophytic activity of Nigella sativa essential oil

The essential oil of Nigella sativa extracted by standard hydrodistillation method from Cleavenger’s apparatus was done for Gas Chromatography (GC) and Gas Chromatography-Magnetic Separation (GC-MS) analysis. The oil yield was 0.35% (v/w) and had the presence of 17 volatile components representing 97.54% of the total oil which were identified. The major components of essential oil were para-cymene (54.13%), alpha-thujene (10.43%), hydrocarveol (10.40%), longifolene (6.97%), beta-pinene (3.10%), and other components were present in trace amounts. The in vitro antimicrobial activity against five pathogenic fungi was done by disc diffusion method and microdilution method. The oil represents the strong antimicrobial activity against Microsporum gypseum, Trichophyton rubrum and Trichophyton simii with diameter of inhibition zone and activity index 38 mm (AI: 1.90), 20 mm (AI: 1.33) and 35 mm (AI: 1.09), respectively as compared with Chrysosporium tropicum with diameter of inhibition zone 26 mm (AI: 0.86) and Chrysosporium evolceanui with diameter of inhibition zone 25 mm (AI: 0.71).   Key words: Essential oil, antimicrobial, microdilution, dermatophytes.