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

Abstract

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.

Conclusion

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.

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Acknowledgments

This work is supported by grants from the National Natural Science Foundation of China (No.81173604), the Specialized Research Program of “Twelfth Five-Year Plan” of China (No.2011ZX09307-303-03), and the Fundamental Research Funds for the Central Universities (No.21612411).

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Correspondence to Xian-hui He.

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Responsible Editor: Liwu Li.

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Qiao, J., Xu, Lh., He, J. et al. Cucurbitacin E exhibits anti-inflammatory effect in RAW 264.7 cells via suppression of NF-κB nuclear translocation. Inflamm. Res. 62, 461–469 (2013). https://doi.org/10.1007/s00011-013-0598-z

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  • DOI: https://doi.org/10.1007/s00011-013-0598-z

Keywords

  • Cucurbitacin E
  • RAW 264.7 cells
  • Lipopolysaccharides
  • Actin cytoskeleton
  • NF-κB