Ugur, Ayse RuveydaDagi, Hatice TurkOzturk, BahadirTekin, GulsumFindik, Duygu2020-03-262020-03-2620160973-12960976-4062https://dx.doi.org/10.4103/0973-1296.191459https://hdl.handle.net/20.500.12395/33283Background: Methicillin resistance is a serious health concern since it has spread among Staphylococcus aureus and coagulase-negative Staphylococci (CoNS) that are frequent community and nosocomial pathogens worldwide. Methicillin-resistant strains are often resistant to other classes of antibiotics, making their treatment difficult. Nigella sativa oil is known to be active against Gram-positive cocci, yet its in vitro cytotoxicity is rarely investigated, is a proper and powerful candidate for treatment of methicillin-resistant isolates. Objectives: The aim of this study is to evaluate the in vitro antibacterial activity and cytotoxicity effect of N. sativa oil. Materials and Methods: The minimal inhibitory concentrations (MICs) of N. sativa oil were determined by broth microdilution method against four different American Type Culture Collection strains, 45 clinical isolates of methicillin-resistant S. aureus (MRSA), and 77 methicillin-resistant CoNS (MRCoNS). The effects of different dilutions (0.25 mu g/mL, 0.5 mu g/mL, and 1 mu g/mL) of N. sativa oil on the proliferation of gingival fibroblasts were evaluated. Results: The MIC values of N. sativa oil against clinical isolates of Staphylococci were between < 0.25 mu g/mL and 1.0 mu g/mL. Compared to the control group, there was no cytotoxic effect on the proliferation of the gingival fibroblasts. Conclusion: In the present study, the oil of N. sativa was very active against MRSA and MRCoNS and had no in vitro cytotoxicity at relevant concentrations. These findings emphasize that there is a requirement for further clinical trials on N. sativa oil for "safe" medical management of infections caused by methicillin-resistant Staphylococci.en10.4103/0973-1296.191459info:eu-repo/semantics/openAccessCytotoxic effectmethicillin-resistant StaphylococcimicrodilutionNigella sativaArticle1247S471S47427761077N/AWOS:000391129400014Q4