In vitro antimicrobial activity of essential oils and their acetylenic constituents

Abstract

The emergence of new infections and increase of bacterial drug resistance has prompted interest for the development of new antibacterial agents from natural sources.This study is an attempt to assess the therapeutic potential of plant constituents as new antimicrobial drugs. The essential oils from six Asteraceae species belonging to the genus Erigeron, Aster, and Senecio were evaluated for their antibacterial activity against six bacteria namely Pseudomonas aeruginosa, Bacillus subtilis, Escherichia coli, Aeromonas hydrophilla, Klebsiella pneumonia, and Streptomyces candidus using agar well diffusion method. The results revealed (Z)-lachnophyllum (<68 %) and 2(E), 8(Z)-matricaria esters (<62 %) as the major acetylenic constituents in four Erigeron species. E. mucronatus showed the highest activity against Gram-positive bacteria S. candidus (8.3 mm, MIC 5 µL/mL) and B. subtilis (11.0 mm, MIC 10 µL/mL). (Z)-Lachnophyllum and 2(E), 8(Z)-matricaria esters showed maximum activity against S. candidus (MICs 5 µL/mL). The results showed that the oils containing acetylenic constituents have potential as natural agents for treatment of infections caused by these bacteria.