Dexmedetomidine alleviates hepatic injury via the inhibition of oxidative stress and activation of the Nrf2/HO-1 signaling pathway

Background: Dexmedetomidine (Dex), frequently used as an effective sedative, was reported to play a critical role in the protection of multiple organs. However, its underlying mechanism of a putative protective effect on ischemia/reperfusion (I/R)-induced liver injury is still unclear. Methods: A hepatocyte injury model was established by treating WRL-68 cells with oxygen and glucose deprivation/reoxygenation (OGD/R). Enzyme Linked Immunosorbent Assay (ELISA) kits were used to determine the level of inflammatory factors (IL-6, IL-1 beta, and TNF-alpha), and oxidative stress indicators (ROS, MDA, GSH-Px, and SOD). MTT assay and flow cytometry analysis were used to determine the influence of Dex on cell viability and cell apoptosis. Expression of nuclear factor erythroid-derived 2- like 2 (Nrf2), HO-1, and apoptosis-related proteins (Bax, Bcl-2, caspase3, and caspase9) were detected by qRT-PCR and western blotting. Results: Dex promoted cell viability and suppressed cell apoptosis in OGD/R-treated WRL-68 cells. Dex reduced TNF-alpha, IL-6, IL-1 beta, ROS, and MDA production, whereas it increased that of SOD and GSH-Px in OGD/R-treated WRL-68 cells. Moreover, Nrf2, HO-1, and Bcl-2 expression was upregulated, whereas, in contrast, transcripts for Bax, caspase3, and caspase9 were downregulated following Dex treatment under OGD/R. Knockdown of Nrf2 reversed the Dex effects on cell proliferation, apoptosis, and expression of TNF-alpha, IL-6, IL-1 beta, ROS, MDA, SOD, and GSH-Px. Conclusion: Dex protects WRL-68 cells against OGD/R-induced injury by inhibiting inflammation, oxidative stress, and cell apoptosis via the activation of Nrf2/HO-1 signaling pathway, suggesting that Dex may be a potential protector against hepatic injury.