Chemical composition and antibacterial activity of Kaempferia galanga essential Oil

Abstract

Kaempferia galanga L. is a traditional herbal medicine with high essential oil content. Gas chromatography-mass spectrometry (GC-MS) detected 25 different compounds in K. galanga essential oil, representing 95.98% of the total oil. The antibacterial activity of the essential oil was measured by the microtiter broth dilution method, and minimum inhibitory concentrations (MICs) against the three pathogenic bacterial strains Escherichia coli, Salmonella typhimurium and Staphylococcus aureus were 5, 1, and 2 mg/mL, respectively. The antibacterial mechanisms of K. galanga essential oil were further explored, and massive nucleotide and protein leakage demonstrated that it caused membrane disruption in the pathogens. SDS-PAGE confirmed the disruptive action of the essential oil on the cytoplasmic membrane. Moreover, the essential oil-induced cell wall and membrane damage was observed by scanning electron microscopy. These findings indicated K. galanga essential oil might constitute a candidate for developing new food preservatives and pharmaceuticals.