Interaction of indomethacin with cytokine production in whole blood. Potential mechanism for a brain-protective effect

Both Alzheimer's disease and vascular dementia are featured by inflammatory responses and it is known that non-steroidal anti-inflammatory drugs (NSAI Ds) decrease the risk and severity of these diseases. To study the effect of NSAIDs on PGE2 levels and pro- and anti-inflammatory cytokine levels in the whole blood assay, blood samples from 23 elderly pe rsons aged 85 years were stimulated with thrombin or LPS as primary stimulu s. Indomethacin was added in concentrations ranging from 0.4 to 16 mug/ml and acetylsalicylic acid was added to in concentrations ranging from 0.5 to 8.0 mug/ml. Indomethacin abrogated thrombin- and LPS-induced PGE2 production a t all concentrations tested. In addition, indomethacin reduced the producti on of thrombin-induced IL-6 and IL-10 (p < 0.05) at physiological concentra tions. Indomethacin reduced the production of LPS-induced IL-6, IL-1<beta> and IL-10 (p < 0.05) at the highest indomethacin concentration tested. Simi lar results were obtained upon incubation with acetylsalicylic acid. It is concluded that indomethacin may reduce the thrombin-induced inflammat ory reaction by decreasing IL-6 through inhibition of PGE2 synthesis. This IL-6 reduction may be relevant for the ability of indomethacin to reduce th e risk of Alzheimer's disease. However, the decrease in IL-10 production du eto indomethacin suggests a more inflammatory state. (C) 2000 Elsevier Scie nce Inc. All rights reserved.