Phytochemical Composition, Antioxidant, Anti-inflammatory and Antimicrobial Activity of Nigella sativa L. Essential Oil

The present study reports the chemical composition, antimicrobial activity, antioxidant and anti-inflammatory properties of Nigella sativa essential oil and its main compounds. The essential oil was obtained from the seeds of the Nigella sativa by hydrodistillation and analysed by GC-MS. The major components were p-cymene (32.05 %), alpha-thujene (6.0 %), alpha-pinene (1.11 %), camphene (11.0 %), sabinene (1.0 %), beta- pinene (7.0 %), beta-myrcene (0.21 %), alpha-phellandrene (0.45 %), limonene (0.13 %), gamma-terpinene (5.12 %), terpinolene (0.23 %), camphor (1.0 %), carvone (0.32 %), thymoquinone (20.32 %), thymol (10.12 %), carvacrol (1.0 %), Longicyclene (0.9) % and borneol (0.43 %). Antioxidant, anti-inflammatory and antibacterial activities of the essential oil from Iranian Nigella sativa seeds and its main terpenes (p-cymene, gamma-terpinene, thymoquinone, beta-pinene, thymol and alpha-thujene) were determined. The thymoquinone exhibited strong antioxidant activity (14.0 +/- 0.7 mu g/ml) and high anti-inflammatory activity (90.21 +/- 0.2 %). Thymoquinone was found to be the most active to decrease oxidation and NO excretion. The essential oil was also subjected to antifungal and antibacterial tests, using the minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal (MBC/MFC) method. The essential oil was particularly active against Candida albicans and Escherichia coli, with the lowest MIC and MBC/MFC value. In conclusion, these results support the use of the essential oil and its main compounds for their anti-inflammatory properties and antimicrobial activity.