Midazolam inhibits proinflammatory mediators in the lipopolysaccharide-activated macrophage.
BACKGROUND
Midazolam, a benzodiazepine, has a hypnotic effect and is widely used as a sedative. The role of midazolam in activation of macrophages during sepsis is not known. The aim of this study was to evaluate the antiinflammatory actions of midazolam in cultured macrophages.


METHODS
Using a macrophage cell line, RAW264.7 cells, the effect of midazolam on proinflammatory mediators and activation of mitogen-activated protein kinase was measured by Western blot. Nuclear factor-kappaB (NF-kappaB) activation and translocation of p65 subunit of NF-kappaB was measured using luciferase assay and immunocytochemistry. Superoxide production was measured by lucigenin chemiluminescence.


RESULTS
Midazolam significantly inhibited lipopolysaccharide-induced up-regulation of both cyclooxygenase 2 and inducible nitric oxide synthase in a dose-dependent manner (approximately 3-30 microm). IkappaB-alpha degradation and NF-kappaB transcriptional activity induced by lipopolysaccharide were also suppressed by the midazolam. Nuclear translocation of the p65 subunit of NF-kappaB was inhibited by midazolam. Furthermore, midazolam suppressed phosphorylation of p38 mitogen-activated protein kinase and also inhibited lipopolysaccharide-induced superoxide production in macrophages.


CONCLUSIONS
These results suggest that midazolam has an antiinflammatory action by inhibiting inducible nitric oxide synthase and cyclooxygenase-2 expression, possibly through suppression of NF-kappaB and p38 mitogen-activated protein kinase activation.
Kim
Seon Nyo
SN
Department of Physiology, Chungnam National University, Daejeon, Korea.
Son
Soo Chang
SC
Lee
Sang Mook
SM
Kim
Cuk Seong
CS
Yoo
Dae Goon
DG
Lee
Sang Ki
SK
Hur
Gang Min
GM
Park
Jin Bong
JB
Jeon
Byeong Hwa
BH
D000818:Animals; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D018836:Inflammation Mediators / Q000037:antagonists & inhibitors* / Q000378:metabolism; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D008262:Macrophage Activation / Q000187:drug effects* / Q000502:physiology; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D008874:Midazolam / Q000494:pharmacology*; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism
D018836:Inflammation Mediators; D008070:Lipopolysaccharides; D016328:NF-kappa B; D020928:Mitogen-Activated Protein Kinases; D008874:Midazolam