Cucurbitacin E exhibits anti-inflammatory effect in RAW 264.7 cells via suppression of NF-κB nuclear translocation

• DOI: 10.1007/s00011-013-0598-z
• Publication Date: 2013-01-29T11:01:29Z
• Authors: Jing Qiao; Li-hui Xu; Jian He; Dong-yun Ouyang; Xian-hui He
• Keywords: Propidium iodide

Cucurbitacin E (CuE), a triterpenoid compound isolated from Cucurbitaceae plants, possesses a wide range of biological activities including anti-inflammatory properties. The present study aimed to investigate the anti-inflammatory effect of CuE and the underlying mechanism of action.The anti-inflammatory effect of CuE was evaluated in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Cell proliferation was assessed using a modified MTT assay. Cell cycle distribution was analyzed by propidium iodide staining. The actin cytoskeleton was examined by immunofluorescent staining. The expression of tumor necrosis factor (TNF)-α and interleukin (IL)-1β was determined by intracellular cytokine staining. G-actin level and nuclear factor (NF)-κB nuclear translocation were detected by immunoblotting.CuE inhibited cell proliferation and induced cell cycle arrest at G2/M phase in RAW 264.7 cells. CuE also suppressed LPS-induced cell spreading and pseudopodia formation. These effects were associated with decreased G-actin level and severe actin aggregation. Moreover, CuE significantly inhibited both TNF-α and IL-1β production in LPS-stimulated RAW 264.7 cells. This was likely mediated by suppressing LPS-induced nuclear translocation of NF-κB, a critical transcription factor responsible for pro-inflammatory cytokine expression.CuE displayed anti-inflammatory effects through suppression of NF-κB nuclear translocation leading to a decreased expression of TNF-α and IL-1β in LPS-stimulated RAW 264.7 cells.