Comparative analysis of essential oil and different extracts of Ajuga chamaecistus ssp. scoparia on antibacterial activity

Abstract

Antibacterial activities of essential oils (EO) and different plant extracts obtained from the aerial parts of Ajuga chamaecistus ssp. scopria were investigated under in vitro condition. Minimum inhibitory concentration (MIC) assay was carried out using two-fold serial dilution method and MTT assay against grampositive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria. Antibacterial activity against both bacteria was observed for the EO, while the hexane extract exhibited antibacterial effect only against S. aureus. The EO analysis with GC and GC-MS exhibited sixty nine compounds representing 99.72 % of the total oil composition. The major constituents were β-pinene (16.08 %), α-thujene (10.66 %), α-pinene (7.43 %), linalool (7.37 %), bicyclogermacrene (6.71 %), δ-cadinene (6.40 %), limonene (4.95 %) and spathulenol (3.09 %). The antibacterial activity of EO observed in the present study could be due to the major compounds belonging to oxygenated terpenes and aromatic structures, the large monoterpenes group and potential synergistic effects between these compounds and other terpenes.

Comparative analysis of essential oil and different extracts of Ajuga chamaecistus ssp. scoparia on antibacterial activity