Aromadendrin Inhibits Lipopolysaccharide-Induced Inflammation in BEAS-2B Cells and Lungs of Mice

Aromadendrin is a phenolic compound with various biological effects such as anti-inflammatory properties. However, its protective effects against acute lung injury (ALI) remain unclear. Therefore, this study aimed to explore the ameliorative effects of aromadendrin in an experimental model of lipopolysaccharide (LPS)-induced ALI. In vitro analysis revealed a notable increase in the levels of cytokine/chemokine formation, nuclear factor kappa B (NF-κB) activation, and myeloid differentiation primary response 88 (MyD88)/toll-like receptor (TLR4) expression in LPS-stimulated BEAS-2B lung epithelial cell lines that was ameliorated by aromadendrin pretreatment. In LPS-induced ALI mice, the remarkable upregulation of immune cells (ICs) and IL-1β/IL-6/TNF-α levels in the bronchoalveolar lavage fluid (BALF) and inducible nitric oxide synthase (iNOS)/cyclooxygenase-2 (COX-2)/CD68 expression in lung was decreased by the oral administration of aromadendrin. Histological analysis revealed the presence of cells in the lungs of acute lung injury (ALI) mice, which was alleviated by aromadendrin. In addition, aromadendrin ameliorated lung edema. This in vivo effect of aromadendrin was accompanied by its inhibitory effect on LPS-induced NF-κB activation, MyD88/TLR4 expression, and signal transducer and activator of transcription 3 (STAT3) activation. Furthermore, aromadendrin increased the expression of heme oxygenase-1 (HO-1)/ NAD(P)H quinone dehydrogenase 1 (NQO1) in the lungs of ALI mice. In summary, the in vitro and in vivo studies demonstrated that aromadendrin ameliorated endotoxin-induced pulmonary inflammation by suppressing cytokine formation and NF-κB activation, suggesting that aromadendrin could be a useful adjuvant in the treatment of ALI.