Constituents, Antibacterial Effect, and Cytotoxicity of Essential Oil from Aerial Parts of Notopterygium incisum.

ABSTRACT

Notopterygium incisum Ting ex H. T. Chang (N. incisum) is a precious Chinese traditional medicine distributed in high-altitude regions of southwest China. The aim of this study was to investigate the composition, antibacterial activity, and cytotoxicity of essential oil from aerial parts of N. incisum. N. incisum essential oil (NI-EO) was extracted by hydro-distillation, and gas chromatography/mass spectrometry (GC-MS) analysis showed that the major components of NI-EO were D-limonene (18.42%) and γ-terpinene (15.03%). The antibacterial activity and mechanism study showed that the diameters of inhibition zone (DIZs) of NI-EO against E. coli and S. aureus were 14.63 and 11.25 mm and the minimum inhibitory concentrations were 3.75 and 7.5 µL/mL, respectively. NI-EO not only caused intracellular biomacromolecule leakage and cell deformation by destroying bacterial cell wall integrity and cell membrane permeability, but also degraded the mature biofilm. The low toxicity of NI-EO was demonstrated in an assay on bovine mammary epithelial cells. These results implied that NI-EO was mainly composed of monoterpenes and sesquiterpenes and had excellent antibacterial activity and showed low levels of cytotoxicity. It is expected to be applied as a natural antibacterial agent in the future.