Gancao Xiexin decoction attenuated experimental colitis through suppressing ACSL4-mediated ferroptosis

The Gancao Xiexin decoction (GCXXD), comprising Glycyrrhiza glabra L., Pinellia ternata (Thunb.) Makino, Scutellaria baicalensis Georgi, Zingiber officinale Roscoe, Panax ginseng C.A.Mey. , Coptis chinensis Franch. , Ziziphus jujuba Mill. , represents a traditional Chinese medicinal formulation utilized for the treatment of ulcerative colitis (UC). Nevertheless, the potential mechanism behind GCXXD treatment for UC is not yet fully elucidated.

Ulcerative colitis is a chronic inflammatory disorder of the gastrointestinal system distinguished by intestinal barrier destruction. Previous studies have indicated that excessive ferroptosis activation in intestinal epithelial cells (IECs) can worsen damage and focal permeability abnormalities in the colon. One of the main mechanisms of ferroptosis is lipid peroxides, which are dependent on long-chain acyl-CoA synthetase 4 (ACSL4) for the synthesis of membrane phospholipids. Recent research findings have provided evidence that GCXXD significantly reduces the symptoms of ulcerative colitis (UC) by preserving the intestinal mucosal barrier. So, we aim to demonstrate that the pharmacological mechanism of GCXXD is related to ferroptosis mediated by ACSL4 in this research.

In this investigation, we evaluated the GSE134025 datasets and established an experimental colitis model caused by DSS and treated with a 20 mg/kg ACSL4 inhibitor (rosiglitazone). Colon pathological alterations and Alcian blue staining were used to confirm ACSL4 inhibition as a possible therapy for UC. We then examined illness symptoms, intestinal mucosa repair, and ferroptosis markers in UC mice after treated with GCXXD (9,12,15 g/kg). Transcriptome study of colon tissues revealed more about the underlying mechanism of GCXXD in the treatment of UC. Finally, we co-administered the ACSL4 upstream agonist with GCXXD in the treatment of UC to show that GCXXD reduced inflammation in UC by modifying ACSL4-induced ferroptosis.

Through GSE134025 dataset analysis, we discovered that ACSL4 was substantially expressed in UC patients and that its inhibitors successfully reduced the clinical signs and symptoms of UC colon. Furthermore, we found that GCXXD improved colon length and body weight while increasing the expression of mucin, occuldin, and Claudin-1. It also lowered colon inflammatory cell infiltration and levels of IL-1β and TNF-α. In the meantime, GCXXD efficiently decreased ferroptosis-related indicators in colitis mice, such as MDA, Fe²⁺, COX2, and ACSL4, while also upregulated GPX4 expression. Using KEGG analysis of the genes that were differently expressed between the 3% DSS and GCXXD treatment group, we were able to discover important connections between the hippo signaling pathway, Arachidonic acid metabolism with GCXXD treatment. Due to the fact that TEAD4 functions as an upstream transcription factor for ACSL4, we combined GCXXD and Py-60, a YAP agonist in the treatment of UC. It was worth noting that GCXXD's inhibitory effect of on intestinal mucosa damage and ferroptosis was lessened when the ACSL4 upstream pathway was activated.

Gancao Xiexin decoction attenuated ferroptosis in UC which might through TEAD4/ACSL4 pathway.