Grape seed proanthocyanidin extract alleviates inflammation in experimental colitis mice by inhibiting NF-B signaling pathway

Ulcerative colitis (UC) is a complex inflammatory disease of colorectum that induces abnormal immune responses and severely affects the quality of life of the patients. Grape seed proanthocyanidin extract (GSPE) exerts anti-inflammatory and antioxidant functions in many inflammatory diseases. The objective of this study was to investigate the potential therapeutic effects and underlying mechanisms of GSPE in UC using a dextran sodium sulfate (DSS)-induced mouse UC model and a lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage model. In this study, we found that the GSPE markedly prevented DSS-induced weight loss and colon length shortening in UC mice. Further investigations showed that GSPE significantly attenuated the expression of pro-inflammatory cytokines TNF-alpha, IL-6, and IL-1 beta, and elevated the expression of anti-inflammatory cytokine IL-10 in the colon tissues and serum of DSS-induced colitis mice by suppressing NF-kappa B signaling pathway. Furthermore, LPS-induced inflammation in RAW264.7 cells was also reversed by GSPE. Taken together, our results confirm that GSPE can ameliorate inflammatory response in experimental colitis via inhibiting NF-kappa B signaling pathway. This study advances the research progress on a potentially effective therapeutic strategy for inflammatory bowel diseases.