Abstract: AimTo investigate the regulatory effects of various anti-inflammatory drugs on both endogenous and TNFα-induced NF-κB activation as well as the relative biological activity. Methods HEK293 cells were cultured in 96-well plate and 6-well plate，treated with meloxicam, indomethacin, dexamethasone and hydrocortisone, without or with 10 ng·mL^-1 TNFα for 24 hours. Then cell proliferation was measured by MTT and cell apoptosis was analyzed by pI stain-flow cytometry. HEK293/κB-luc cells transfected stably with pElam-κB-luc vector, were cultured in 96-well plate and treated as above. Equal amounts of cell lysates were tested for luciferase activity which represents NF-κB activation. ResultsEndogenous NF-κB activation was present in HEK293 cells and its level can be increased about 2 times by 10 ng·mL^-1 TNFα-induction. Dexamethasone (1×10^-8 mol·L^-1) and meloxicam (1×10^-7-1×10^-6 mol·L^-1) can decrease both endogenous and TNFα-induced NF-κB activation. Hydrocortisone (1×10^-9 mol·L^-1) increases endogenous NF-κB activation but decreases TNFα-induced one significantly. No influence of indomethacin on endogenous NF-κB activation was observed. However, its influence on TNFα-induced NF-κB activation is needed for further study. Cell apoptosis was observed after treatment with TNFα and 1×10^-8, 1×10^-6 mol·L^-1 dexamethasone and 1×10^-7 mol·L^-1 indomethacin, or only with dexamethasone. No significant effect of these anti-inflammatory drugs on cell proliferation was observed. ConclusionVarious anti-inflammatory drugs differ in their ability to regulate NF-κB activation in HEK293 cells, which indicates that NF-κB activation might be a potential useful target to study mechanism and for drug screening.