Remimazolam reduces sepsis-associated acute liver injury by activation of peripheral benzodiazepine receptors and p38 inhibition of macrophages

Remimazolam is a novel ester-type benzodiazepine with ultrafast onset of sedation effect and fast recovery of consciousness. It has potential advantages in the sedation of sepsis-associated acute liver injury (SALI) patients. However, the effect and mechanism of remimazo lam on inflammation in the liver have not yet been elucidated. This study investigated the anti-inflammatory effects and mechanisms of remimazolam on SALI both in vivo and in vitro.Lipopolysaccharide (LPS) plus galactosamine treated rat model and LPS-challenged RAW264.7 cells model were constructed to simulate SALI. Next, the models were used to explore the efficacy of remimazolam treatment on SALI. Benzodiazepine receptor inhibitor, PK11195, was also employed. Hepatic injury was assessed by quantifying levels of transaminases, examining liver pathology, and calculating the number of inflammatory cells in the liver. Inflammatory response was evaluated by determining levels of pro-inflammatory cytokines and chemokines in blood, as well as p38 phosphorylation (p-p38) in the liver.SALIrat models showed significant liver damage as manifested by increased levels of transaminases, proinflammatory cytokines, chemokines, and p-38. Remimazolam treatment reduced the liver injury and pathological changes, suppressed pro-inflammatory reactions, and elevated p-p38. The protective effect of remimazolam on liver injury was significantly blocked by PK11195. In LPS-stimulated RAW264.7 cells, it was found that treatment with remimazolam reduced the inflammatory response in LPS-treated cells in a time-dependent manner and decreased the level of p-p38. These results suggest that PK11195 can block remimazolam-induced inhibition of proinflammatory cytokine release and p-38 phosphorylation.This study shows that remimazolam can attenuate inflammatory response in SALI, which may be associated with activation of peripheral benzodiazepine receptors and inhibition of p38 phosphorylation in macrophages.