Inhibition of LPS-induced NO production by plant essential oils.

Essential oils (EOs), derived from medicinal plants, has been reported to possess various bioactivities to treat inflammatory diseases. Therefore, it is urgent to investigate the effect and the mechanism of EOs essential oils as naturally anti-inflammatory agents. The present study indicated thirty-one EOs had different inhibition on lipopolysaccharide (LPS)-induced nitric oxide (NO) production. Moreover, the most potent EOs against NO production in BV2 cells were chuan-xiong, schizonepeta tenuifolia, lemongrass and zedoary turmeric with IC(50) values of 12.59, 23.12, 22.76 and 21.88 μg/mL, respectively. The further studies revealed that ligustilide, tributyl citrate and longifolene, the main constituents of chuan-xiong EO, schizonepeta tenuifolia EO and zedoary turmeric EO, were responsible for their activities against NO production with IC(50) values of 8.75, 6.05 and 20.32 μg/mL. Above all, theses EOs were confirmed to be promising anti-inflammatory agents.