Shenling Baizhu Powder and Betulin attenuate sepsis-induced intestinal injury by targeting GADD45B/TAOK1/p38 MAPK pathway.

ETHNOPHARMACOLOGICAL RELEVANCE

Enhanced apoptosis of intestinal epithelial cells during sepsis results in impaired barrier function, facilitating the influx of bacteria and endotoxins into the bloodstream, which worsens the organism's damage. Therefore, addressing intestinal injury in sepsis may represent a novel approach to treatment. Shenling Baizhu Powder (SLBZP), a classical traditional Chinese medicine formula, has been widely used for the treatment of Inflammatory diseases including sepsis. However, its potential mechanisms of action in sepsis-induced intestinal injury remain unclear.

AIM OF THE STUDY

This study aimed to investigate whether SLBZP and its betulin ameliorate intestinal barrier function and cellular death in sepsis mice and LPS-induced IEC-6 cells through GADD45B/TAOK1/p38 MAPK pathway.

MATERIALS AND METHODS

Network pharmacology and Gene Expression Omnibus (GEO) database were used to identify the potential active ingredients and epigenetic regulators of SLBZP. High-performance liquid chromatography coupled with mass spectrometry (HPLC/MS) was used to measure the betulin present in SLBZP. Besides, the animal model of sepsis was developed by using a cecal ligation and puncture (CLP) to investigate the protective roles of SLBZP and betulin on intestinal injury in sepsis. Furthermore, the determination of cell viability, inflammation, and apoptosis of LPS-induced IEC-6 cells treated by betulin was performed by Cell counting Kit-8 (CCK-8), ELISA, Tunel staining, and flow cytometry assays. Meanwhile, the underlying mechanism was investigated through IHC, qMSP, and Western blot assays, respectively.

RESULTS

Through network and GSE202261 analysis, three epigenetic regulators including GADD45B, MAP3K7, and PRKAA1 were screened from the "drug-component-target" network. The betulin and the GADD45B had a good binding ability in molecular docking. Animal experiments indicated that SLBZP and betulin could inhibit inflammation, ameliorate intestinal injury, and reduce cell apoptosis in mice. Moreover, the intestinal cytotoxicity of LPS-treated IEC-6 cells was significantly inhibited after betulin treatment, as accompanied by an increase in DNA methylation level in the TAOK1 promoter. Importantly, we found that the overexpression of GADD45B and TAOK1, or p38 MAPK inhibitor reversed the anti-apoptosis effect induced by the betulin.

CONCLUSIONS

SLBZP and betulin may exert anti-inflammatory and anti-apoptosis effects against sepsis-associated intestinal barrier injury, possibly via the GADD45B/TAOK1/p38 MAPK pathway.