Chemical composition,antimicrobial potential against cariogenic bacteria and cytotoxic activity of Tunisian Nigella sativa essential oil and thymoquinone

We investigate in this work the chemical composition by GC–EIMS, the antibacterial and the cytotoxic activities of Tunisian Nigella sativa essential oil and its bioactive compound, thymoquinone, were tested against various clinical cariogenic bacteria (n = 30). Eighty-four compounds were identified in the essential oil. The major one was p-cymene (49.48%) whereas thymoquinone represented only 0.79%. The essential oil (2.43 mg/disc) containing only 3.35 μg of thymoquinone showed pronounced dose dependant antibacterial activity against Streptococcus mitis, Streptococcus mutans, Streptococcus constellatus and Gemella haemolysans (15.5 ± 0.707 mm). However, pure thymoquinone compound (150 μg/disk) was active against all the studied strains especially S. mutans and S. mitis (24.5 ± 0.71 and 22 ± 1.41 mm inhibition zones, respectively).     

Fatty acid and essential oil composition of three Tunisian caraway (Carum carvi L.) seed ecotypes

BACKGROUND: The essential oil and fatty acid composition of Tunisian annual caraway (Carum carvi L.) seeds from three ecotypes was investigated by gas chromatography and gas chromatography–mass spectrometry analyses. RESULTS: Total fatty acid (TFA) proportion of caraway seeds varied from 2.95% to 5.68% (w/w). The fatty acid composition revealed that Tunisian caraway seed oil is rich in an unusual fatty acid—petroselinic acid—the proportion of which varied from 31.53% and 38.36% of TFA. Essential oil yields were relatively low and ranged from 0.86% to 1.20% (w/w). Forty‐one volatile compounds were identified, the main ones being carvone (76.78–80.53%) and limonene (13.05–20.29%). CONCLUSION: Tunisian caraway seed oil is rich in an unusual fatty acid—petroselinic acid—which is of potential industrial significance. In addition, Tunisian caraway essential oil is carvone chemotype. This fact is of great economic interest due to the several applications of carvone in the alimentary and medicinal industries. Copyright © 2009 Society of Chemical Industry