3‑Bromo‑5‑(ethoxymethyl)‑1,2‑benzenediol inhibits LPS-induced pro-inflammatory responses by preventing ROS production and downregulating NF-κB in vitro and in a zebrafish model.

The anti-inflammatory effects of 3‑bromo‑5‑(ethoxymethyl)‑1,2‑benzenediol (BEMB) from Polysiphonia morrowii were evaluated in lipopolysaccharide (LPS)-induced RAW264.7 cells and zebrafish embryo. BEMB showed anti-inflammatory effects by inhibiting the production of nitric oxide (NO) and reactive oxygen species (ROS), and the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) in the LPS-activated RAW264.7 cells and zebrafish embryo without cytotoxicity. Moreover, BEMB suppressed the protein and mRNA expression levels of nuclear factor (NF)-κB (p65 and inhibitor of NF-κB [IκB]-A) in RAW264.7 cells and zebrafish embryo, respectively. Collectively, the results of this study indicate that BEMB suppressed the production of pro-inflammatory mediators such as NO, iNOS, and COX-2 as well as their regulation in LPS-induced RAW264.7 cells and zebrafish embryos by inhibiting ROS production and NF-κB expression. Therefore, this study suggests that BEMB could be a potential anti-inflammatory agent for the treatment of inflammatory diseases.