Chemical Composition and Antibacterial Activity of Three Volatile Oils Extracted from Nigella sativa L. Seeds

Nigella sativa L. (Ranunculaceae) and its volatiles have a wide range of benefits. The aim of this study was to investigate the chemical composition and in vitro antibacterial activity of three volatile oils from Erzincan (Local market/Provincial Agriculture and Forestry Office in Erzincan) and Konya. These three samples were grown under different edaphic and climatic conditions. The disc diffusion method was used to test the antibacterial activity against ten standard bacterial strains (Staphylococcus aureus, Clostridium perfringens, Enterococcus faecium, Pseudomonas fluorescens, Pseudomonas aeruginosa, Salmonella enterica, Salmonella enteritidis, Bacillus cereus, Listeria monocytogenes, and Escherichia coli). Monoterpenes were abundant in the chemical composition of all volatile oils tested. The seeds of Erzincan (from local market), Erzincan (from Erzincan Provincial Authority of Agriculture and Forestry) and Konya were characterized by the presence of p-cymene (41.74%-51.98%), α-thujene (16.02%-16.49) and nerol (7.91%-8.50%). Clostridium perfringens (inhibition zone: 35 to 39.3 mm) and Pseudomonas aeruginosa (inhibition zone: 29.7 to 38.7 mm) were found to be particularly sensitive to all volatile oils tested. The results of this study show that the volatile oil of the seeds of N. sativa has remarkable antibacterial activity, which may be due to the presence of various secondary metabolites. In view of the uncontrolled development of antibiotic resistance, these compounds can be used for prophylactic or curative purposes.