Dexmedetomidine attenuates lipopolysaccharide-induced proinflammatory response in primary microglia

BackgroundNeuroinflammation mediated by microglia has been implicated in delirium. Suppression of microglial activation may therefore contribute to alleviate delirium. It has been reported that dexmedetomidine (DEX) has a potent anti-inflammatory property. In the present study, we investigated the effects of DEX on the production of proinflammatory mediators in lipopolysaccharide-stimulated microglia.Materials and methodsThe concentrations of DEX were chosen to correspond to 1, 10, and 100 times of clinically relevant concentration (i.e., 1, 10, and 100 ng/mL). The levels of proinflammatory mediators, such as inducible nitric oxide synthase or nitric oxide, prostaglandin E2, interleukin 1β, and tumor necrosis factor α, were measured.ResultsDEX at 1 ng/mL did not affect the production of proinflammatory mediators. DEX at 10 and 100 ng/mL significantly inhibited the release of nitric oxide, prostaglandin E2, interleukin 1β, and tumor necrosis factor α and the expression of inducible nitric oxide synthase messenger RNA.ConclusionsThese results suggest that DEX is a potent suppressor of lipopolysaccharide-induced inflammation in activated microglia and may be a potential therapeutic agent for the treatment of intensive care unit delirium.