Trapa japonica pericarp extract reduces LPS-induced inflammation in macrophages and acute lung injury in mice

Abstract

In this study, we found that chloroform fraction (CF) from TJP ethanolic extract inhibited lipopolysaccharide (LPS)-induced production of nitric oxide (NO) and intracellular ROS in RAW264.7 cells. In addition, expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) genes was reduced, as evidenced by western blot. Our results indicate that CF exerts anti-inflammatory effects by down-regulating expression of iNOS and COX-2 genes through inhibition of MAPK (ERK, JNK and p38) and NF-κB signaling. Similarly we also evaluated the effects of CF on LPS-induced acute lung injury. Male Balb/c mice were pretreated with dexamethasone or CF 1 h before intranasal instillation of LPS. Eight hours after LPS administration, the inflammatory cells in the bronchoalveolar lavage fluid (BALF) were determined. The results indicated that CF inhibited LPS-induced TNF-α and IL-6 production in a dose dependent manner. It was also observed that CF attenuated LPS-induced lung histopathologic changes. In conclusion, these data demonstrate that the protective effect of CF on LPS-induced acute lung injury (ALI) in mice might relate to the suppression of excessive inflammatory responses in lung tissue. Thus, it can be suggested that CF might be a potential therapeutic agent for ALI.