1,8-Cineol Attenuates LPS-Induced Acute Pulmonary Inflammation in Mice

Eucalyptol, also known as 1,8-cineol, is a monoterpene and has been shown to exert anti-inflammatory and antioxidant effect. It is traditionally used to treat respiratory disorders due to its secretolytic properties. In the present study, we evaluated the effect of 1,8-cineol on pulmonary inflammation in a mouse model of acute lung injury. We found that 1,8-cineol significantly decreased the level of TNF-α and IL-1β, and increased the level of IL-10 in lung tissues after acute lung injury induced by lipopolysaccharide (LPS). It also reduced the expression of nuclear factor kappa B (NF-κB) p65 and toll-like receptor 4 (TLR4), and myeloperoxidase activity in lung tissues. In addition, 1,8-cineol reduced the amounts of inflammatory cells in bronchoalveolar lavage fluid (BALF), including neutrophils and macrophages, and significantly decreased the protein content in BALF and the lung wet/dry weight (W/D) ratio. Its effect on LPS-induced pulmonary inflammation was associated with suppression of TLR4 and NF-κB expressions. Our results provide evidence that 1,8-cineol inhibits acute pulmonary inflammation, indicating its potential for the treatment of acute lung injury.