<i>Panax notoginseng</i> Saponins Modulate the Inflammatory Response and Improve IBD-Like Symptoms via TLR/NF-κB and MAPK Signaling Pathways

Abstract

<i>Panax notoginseng</i> saponins (PNS) are the main active ingredients of <i>Panax notoginseng</i> (Burk) F. H. Chen, which are used as traditional Chinese medicine for thousands of years and have various clinical effects, including anti-inflammation, anti-oxidation, and cardiovascular protection. Inflammatory bowel disease (IBD) is a complex gastrointestinal inflammatory disease that cannot be cured completely nowadays. The anti-inflammatory and protective effects of PNS were analyzed <i>in vitro</i> and in dextran sulfate sodium (DSS)-induced colitis mouse model. PNS inhibited the release of nitric oxide (NO), tumor necrosis factor-[Formula: see text] (TNF-[Formula: see text], interleukin-6 (IL-6), and monocyte chemoattractant protein-1 (MCP-1) in Pam3CSK4-induced RAW 264.7 macrophages. In the animal study, compared with DSS-induced mice, PNS reduced the expression of pro-inflammatory cytokines (TNF-[Formula: see text], IL-6, and MCP-1) in the colon tissues. Furthermore, PNS treatment led to a remarkable reduction in the activation of the inhibitor of nuclear factor kappa-B kinase [Formula: see text]/[Formula: see text] (IKK[Formula: see text]/[Formula: see text], I[Formula: see text]B[Formula: see text] and p65 induced by DSS. On the other hand, PNS inhibited the phosphorylation of c-Jun N-terminal kinase (JNK), p38, and extracellular regulated protein kinase 1/2 (ERK1/2). Taken together, our results suggested that PNS conferred profound protection for colitis mice through the downregulation of mitogen-activated protein kinase (MAPK) and NF-[Formula: see text]B signaling pathways, which were associated with reducing inflammatory responses, alleviating tissue damage, and maintaining of intestinal integrity and functionality.