Inhibitory effects of indomethacin on interleukin-1 and nitric oxide production in rat microglia in vitro.

Indomethacin, as a nonsteroidal antiinflammatory drug, is reported to be effective in some degree in the prevention and treatment of Alzheimer's disease (AD). Effects of indomethacin on proinflammatory cytokines interleukin-1 (IL-1), tumor necrosis factor alpha and nitric oxide (NO) on rat microglia in vitro were investigated. The biological activities of IL-1 were assayed by thymocyte proliferation assay and the activities of TNG-alpha, by L929 cytotoxicity assay. NO concentration was represented by nitrite and determined by Griess reaction. Indomethacin inhibited IL-1 and NO production by rat microglia stimulated at the concentration of 0.1-10 micromol/l. However, it did not show any inhibitory effect on TNF-alpha production by resting and LPS-stimulated rat microglia. The results suggest that the mechanism by which indomethacin might be beneficial in treatment of AD might be due to the inhibition IL-1 and NO production from microglia.