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


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Department of Immunobiology, Institute of Tissue Transplantation and Immunology, Jinan University, 601 Huangpu Dadao West, Guangzhou 510630, China. qiaojingbaobao@163.com
Jing
J
Qiao
Li-hui
LH
Xu
Jian
J
He
Dong-yun
DY
Ouyang
Xian-hui
XH
He
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D053583:Interleukin-1beta / Q000378:metabolism; D008070:Lipopolysaccharides; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism*; D014315:Triterpenes / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D000893:Anti-Inflammatory Agents; D053583:Interleukin-1beta; D008070:Lipopolysaccharides; D016328:NF-kappa B; D014315:Triterpenes; D014409:Tumor Necrosis Factor-alpha; C102326:cucurbitacin E