Eremostachys molucelloides Bunge'nin Antimikrobiyal Etkileri Üzerine Bir Araştırma

Abstract

Overuse and misuse of antibiotics have caused the spread of antibiotic resistance among bacteria. The insufficiency of existing antibiotics in the combat against these resistant bacteria has necessitated the discovery of new and effective antimicrobial drugs. The discovery that bacteria synthesize various virulence factors by the quorum sensing (QS) system has suggested that QS inhibitors may be used in the fight against infectious diseases. This study aimed to determine the antibacterial and anti-QS activities of methanol and water extracts of aerial and root parts of Eremostachys moluccelloides Bunge. The minimum inhibitory concentration (MIC) values of the extracts were investigated against reference bacterial strains using the broth microdilution method. Anti-QS activities were examined by violacein and pyocyanin pigments inhibition and swarming motility inhibition assays against Chromobacterium violaceum ATCC 12472 and Pseudomonas aeruginosa PAO1 bioreporter strains. The anti-biofilm activities of the extracts were tested against P. aeruginosa PAO1 using the crystal violet staining method. The MIC value (> 2000 µg/mL) of the extracts against the tested strains could not be determined. All extracts partially inhibited the swarming motility of P. aeruginosa. Methanol extract of the aerial part inhibited pyocyanin production by 81.7% without interfering with P. aeruginosa growth. The extracts had no significant inhibitory activity on biofilm formation and violacein pigment production. These results showed that the extracts of E. moluccelloides may be good anti-QS agents. Further research can be done to elucidate the mechanisms underlying these biological activities.