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

► Eighty-four compounds were identified in the Tunisian Nigella sativa essential oil. ► The essential oil showed pronounced dose dependant antibacterial activity. ► Thymoquinone cytotoxicity on Hep-2 cells was significantly stronger than the essential oil. ► N. sativa essential oil is a good source of bioactive compounds.