Evaluation of the Antibacterial Activity and Efflux Pump Reversal of Thymol and Carvacrol against <i>Staphylococcus aureus</i> and Their Toxicity in <i>Drosophila melanogaster</i>
Zildene de Sousa Silveira,
Nair Silva Macêdo,
Joycy Francely Sampaio dos Santos,
Thiago Sampaio de Freitas,
Cristina Rodrigues dos Santos Barbosa,
Dárcio Luiz de Sousa Júnior,
Débora Feitosa Muniz,
Lígia Claudia Castro de Oliveira,
José Pinto Siqueira Júnior,
Francisco Assis Bezerra da Cunha,
Henrique Douglas Melo Coutinho,
Valdir Queiroz Balbino,
Natália Martins
Affiliations
Zildene de Sousa Silveira
Laboratory of Semi-Arid Bioprospecting (LABSEMA), Regional University of Cariri-URCA, Crato 63105-000, CE, Brazil
Nair Silva Macêdo
Laboratory of Semi-Arid Bioprospecting (LABSEMA), Regional University of Cariri-URCA, Crato 63105-000, CE, Brazil
Joycy Francely Sampaio dos Santos
Laboratory of Semi-Arid Bioprospecting (LABSEMA), Regional University of Cariri-URCA, Crato 63105-000, CE, Brazil
Thiago Sampaio de Freitas
Laboratory of Microbiology and Molecular Biology (LMBM), Regional University of Cariri-URCA, Crato 63105-000, CE, Brazil
Cristina Rodrigues dos Santos Barbosa
Laboratory of Microbiology and Molecular Biology (LMBM), Regional University of Cariri-URCA, Crato 63105-000, CE, Brazil
Dárcio Luiz de Sousa Júnior
Laboratory of Semi-Arid Bioprospecting (LABSEMA), Regional University of Cariri-URCA, Crato 63105-000, CE, Brazil
Débora Feitosa Muniz
Laboratory of Microbiology and Molecular Biology (LMBM), Regional University of Cariri-URCA, Crato 63105-000, CE, Brazil
Lígia Claudia Castro de Oliveira
Laboratory of Semi-Arid Bioprospecting (LABSEMA), Regional University of Cariri-URCA, Crato 63105-000, CE, Brazil
José Pinto Siqueira Júnior
Laboratory of Microorganism Genetics (LGM), Federal University of Paraiba-UFPB, João Pessoa 58051-900, PB, Brazil
Francisco Assis Bezerra da Cunha
Laboratory of Semi-Arid Bioprospecting (LABSEMA), Regional University of Cariri-URCA, Crato 63105-000, CE, Brazil
Henrique Douglas Melo Coutinho
Laboratory of Microbiology and Molecular Biology (LMBM), Regional University of Cariri-URCA, Crato 63105-000, CE, Brazil
Valdir Queiroz Balbino
Graduate Program in Biological Sciences-PPGCB, Federal University of Pernambuco-UFPE, Recife 50670-901, PE, Brazil
Natália Martins
Faculty of Medicine, University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal
The antibacterial activity and efflux pump reversal of thymol and carvacrol were investigated against the Staphylococcus aureus IS-58 strain in this study, as well as their toxicity against Drosophila melanogaster. The minimum inhibitory concentration (MIC) was determined using the broth microdilution method, while efflux pump inhibition was assessed by reduction of the antibiotic and ethidium bromide (EtBr) MICs. D. melanogaster toxicity was tested using the fumigation method. Both thymol and carvacrol presented antibacterial activities with MICs of 72 and 256 µg/mL, respectively. The association between thymol and tetracycline demonstrated synergism, while the association between carvacrol and tetracycline presented antagonism. The compound and EtBr combinations did not differ from controls. Thymol and carvacrol toxicity against D. melanogaster were evidenced with EC50 values of 17.96 and 16.97 µg/mL, respectively, with 48 h of exposure. In conclusion, the compounds presented promising antibacterial activity against the tested strain, although no efficacy was observed in terms of efflux pump inhibition.
