Esculin Inhibits the Inflammation of LPS-Induced Acute Lung Injury in Mice Via Regulation of TLR/NF-κB Pathways

In this study, we investigated anti-inflammatory effects of esculin (ESC) on lipopolysaccharide (LPS)-induced acute lung injury (ALI). ALI was induced in mice by intratracheal instillation of LPS, and ESC (20 and 40 mg/kg) was given orally 1 h prior to LPS administration. After 6 h, bronchoalveolar lavage fluid (BALF) and lung tissue were collected. ESC pretreatment decreased LPS-induced evident lung histopathological changes, lung wet-to-dry weight ratio, and lung myeloperoxidase activity. In addition, pretreatment with ESC inhibited inflammatory cells and proinflammatory cytokines including tumor necrosis factor-α (TNF-α), interleukin-1β, and interleukin-6 in BALF. Furthermore, we demonstrated that ESC inhibited the Toll-like receptor-2 (TLR2), Toll-like receptor-4 (TLR4), myeloid differentiation primary response gene-88 (MyD88), and nuclear factor-κB (NF-κB) p65 in LPS-induced ALI. The results indicated that the ESC had a protective effect on LPS-induced ALI in mice.