Dandelion polysaccharide treatment protects against dextran sodium sulfate‐induced colitis by suppressing NF‐κB/NLRP3 inflammasome‐mediated inflammation and activating Nrf2 in mouse colon

Abstract

The treatment of ulcerative colitis (UC) is still an intractable medical problem. Polysaccharides are promising candidates for the treatment of UC and have received widespread attention in recent years. The objective of this study was to explore the protective effect and underlying mechanism of dandelion polysaccharide (DP) on dextran sulfate sodium (DSS)‐induced colitis in mice. Our results showed that oral administration of DP could dramatically alleviate colonic lesions, as evidenced by reduced DAI scores, shortening of colon length, and ameliorating pathologic abnormalities in colons. Additionally, the expressions of pro‐inflammatory factors (TNF‐α, IL‐1β, and IL‐6) and the infiltration of inflammation‐regulation cells, marked by myeloperoxidase and F4/80, were also inhibited after DP treatment. Moreover, DP treatment also markedly suppressed the nuclear translocation of NF‐κB‐p65 and the activation of the NLRP3 inflammasome. Furthermore, DP also activated the Nrf2/HO‐1 pathway and reduced the oxidative stress induced by DSS. Overall, these results suggest that DP could be a promising novel therapeutic approach for the treatment of UC.

Levosimendan and Dobutamin Attenuate LPS-Induced Inflammation in Microglia by Inhibiting the NF-κB Pathway and NLRP3 Inflammasome Activation via Nrf2/HO-1 Signalling

“…In contrast, the treatment with levosimendan or dobutamine significantly downregulated p-NF-κB levels, hindering NLRP3 expression and its downstream signal. Moreover, previous evidence suggested that NF-κB inhibition might be the key to blunt NLRP3 signalling by activating the Nrf2/HO-1 signal pathway [74,75]; therefore, we speculated that the inhibition of oxidative stress and the activation of the Nrf2/HO-1 pathway mediated by levosimendan and dobutamine are involved in NLRP3 inflammasome inhibition during neuroinflammation, although these effects were investigated for the first time in the present study. Moreover, it is well known that LPS activates TLR4/NF-κB signalling, thus stimulating the transcription of the pro-inflammatory cytokines IL-6 and TNFα [76].…”