Xianglian Pill attenuates ulcerative colitis through TLR4/MyD88/NF-κB signaling pathway

J Ethnopharmacol. 2023 Jan 10:300:115690. doi: 10.1016/j.jep.2022.115690. Epub 2022 Sep 6.

Abstract

Ethnopharmacological relevance: Xianglian Pill (XLP) is a classical Chinese medicine prescription applied for controlling ulcerative colitis (UC). Whereas, the underlying mechanism remains unclear.

Aim of the study: The present work was aimed to investigate the mechanism of XLP in dextran sulfate sodium (DSS)-induced UC via the Toll Like Receptor 4 (TLR4)/Myeloid Differentiation factor 88 (MyD88)/Nuclear Factor kappa-B (NF-κB) signaling in mice.

Materials and methods: The major components of XLP were detected by high-performance liquid chromatography-diode array detection (HPLC-DAD). The ulcerative colitis model was induced by DSS in mice. 5-Amino Salicylic Acid (5-ASA) group and XLP group were intragastrically treated. Disease activity index (DAI) and colon length were monitored and hematoxylin-eosin (HE) staining was conducted. Gasdermin D (GSDMD)-N and TLR4 expressions in colon tissues were visualized by immunofluorescence. TLR4 mRNA was measured by Real Time Quantitative PCR (RT-qPCR). The expressions of NOD-like receptor thermal protein domain associated protein 3 (NLRP3), active-caspase-1, GSDMD-N, TLR4, MYD88, NF-κB, p-NF-κB, and the ubiquitination of TLR4 in colon tissues were detected by Western blot. Myeloperoxidase (MPO) enzyme activity was examined and serum inflammatory factors Interleukin (IL)-1β, IL-6, Tumor Necrosis Factor-α (TNF-α), and IL-18 were determined by Enzyme-linked Immunosorbent Assay (ELISA). TLR4-/- mice were applied for verifying the mechanism of XLP attenuated DSS symptoms.

Results: The XLP treatment extended colon length, reduced DAI, and attenuated histopathological alteration in DSS-induced mice. XLP administration suppressed MPO activity and reduced the content of IL-1β, IL-6, TNF-α and IL-18 in serum. XLP also inhibited the expression levels of GSDMD-N, TLR4, NLRP3, active-caspase-1, MyD88, p-NF-κB/NF-κB in colon tissues of DSS-induced mice. TLR4-/- mice proved that TLR4 was involved in XLP-mediated beneficial effect on DSS-induced ulcerative colitis.

Conclusions: XLP might treat ulcerative colitis by regulating the TLR4/MyD88/NF-κB signaling pathway.

Keywords: Gene knockout; Inflammation; Pyroptosis; Ulcerative colitis (UC); Xianglian pill (XLP).

MeSH terms

  • Animals
  • Caspases / metabolism
  • Colitis, Ulcerative* / chemically induced
  • Colitis, Ulcerative* / drug therapy
  • Colitis, Ulcerative* / pathology
  • Colon
  • Dextran Sulfate / toxicity
  • Disease Models, Animal
  • Drugs, Chinese Herbal
  • Eosine Yellowish-(YS) / metabolism
  • Eosine Yellowish-(YS) / pharmacology
  • Eosine Yellowish-(YS) / therapeutic use
  • Hematoxylin / metabolism
  • Hematoxylin / pharmacology
  • Hematoxylin / therapeutic use
  • Interleukin-18 / metabolism
  • Interleukin-18 / pharmacology
  • Interleukin-18 / therapeutic use
  • Interleukin-6 / metabolism
  • Mice
  • Myeloid Differentiation Factor 88* / metabolism
  • NF-kappa B / metabolism
  • NLR Family, Pyrin Domain-Containing 3 Protein / metabolism
  • Peroxidase / metabolism
  • RNA, Messenger / metabolism
  • Signal Transduction
  • Toll-Like Receptor 4 / metabolism
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • Drugs, Chinese Herbal
  • Interleukin-18
  • Interleukin-6
  • Myd88 protein, mouse
  • Myeloid Differentiation Factor 88
  • NF-kappa B
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • RNA, Messenger
  • Tlr4 protein, mouse
  • Toll-Like Receptor 4
  • Tumor Necrosis Factor-alpha
  • xianglian pill
  • Dextran Sulfate
  • Peroxidase
  • Caspases
  • Eosine Yellowish-(YS)
  • Hematoxylin