Abstract: In this study,the effect of Maqian (Zanthoxylum myriacanthum var. pubescens Huang) essential oil (MQEO) on oxidative stress in lipopolysaccharide (LPS)stimulated THP-1 cells was investigated.Cells were pretreated with vehicle,Dex or different doses of MQEO,and then cultured with LPS for 24 h.The intracellular reactive oxygen species (ROS) were determined by staining the cells with 2′,7′-ichlorofluorescein diacetate (DCFH-DA) followed by flow cytometry analysis.Cells were stained with Annexin V-FITC/PI and assayed for apoptosis by flow cytometry.NO was determined by Griess reagent method.Cell lysates were prepared and assayed for the activity of intracellular superoxide dismutase (SOD) by a colorimetric method and the expression of p47 phox (the cytoplasmic subunit of NADPH oxidase) by western blotting.The results showed that,compared with cells treated with vehicles,cells treated with MQEO exhibited significantly reduced LPS stimulated ROS and NO production in a concentration-dependent manner.In addition,cells treated with MQEO showed significantly less LPS-induced decrease in SOD activity as well as the increase of expression of cytoplasmic subunit of NADPH oxidase (p47 phox). Furthermore,cells treated MQEO exhibited markedly reduced LPS-stimulated apoptosis.Collectively,these findings suggested that MQEO had the ability to suppress oxidative stress in LPS-stimulated THP-1 cells and protect cells from apoptosis.MQEO had the potential application for the prevention and treatment of various diseases related to oxidative stress.

Key words: Maqian essential oil, THP-1, oxidative stress, apoptosis