Modulation of inflammatory and cuproptotic crosstalk by Ethyl and propyl gallate: a multi-targeted strategy against experimental colitis.

BACKGROUND AND

OBJECTIVE

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) characterized by oxidative stress, immune dysregulation, and epithelial barrier dysfunction. This study investigated the protective effects of two phenolic antioxidants derived from food sources, ethyl gallate (EG) and propyl gallate (PG), in conjunction with copper-enriched water, against dextran sulfate sodium (DSS)-induced colonic injury in mice. The focus was on the modulation of inflammation, oxidative stress, apoptosis, and the novel regulatory pathway of cuproptosis.

METHOD: The experimental protocol entailed the induction of colitis through the administration of 2.5% DSS in drinking water over a period of seven days, along with oral administration of EG, PG, or their combination at a dosage of 50 mg/kg for 21 days. Cytokine levels were quantified using ELISA, while qPCR and western blotting were employed to analyze inflammatory markers (NF-κB, JAK2-STAT3), oxidative markers (Nrf2/HO-1), apoptotic markers (Bcl2/Bax), and cuproptotic markers (FDX1/DLAT). The TUNEL assay was used to evaluate apoptotic cell death.

RESULTS

EG and PG significantly reduced the levels of TNF-α, IL-1β, and IL-6 by inhibiting the NF-κB and JAK-STAT signalling pathways while concurrently increasing the levels of IL-37. Oxidative stress is alleviated through activation of the Nrf2/HO-1 pathway. Apoptosis was suppressed via upregulation of Bcl-2/Bcl-XL and downregulation of BAX, as corroborated by the TUNEL assay results. Additionally, EG and PG mitigated cuproptosis by decreasing the expression of FDX1, DLAT, and LIAS, thereby maintaining intestinal barrier integrity.

CONCLUSION

The observations presented herein offer significant mechanistic insights into the role of ethyl gallate (EG) and propyl gallate (PG), in conjunction with copper-enriched water, in the management of ulcerative colitis through the modulation of inflammatory, oxidative, apoptotic, and cuproptotic pathways. Notably, this study is the first to document the effects of EG and PG on cuproptosis-related proteins and their potential role in alleviating DSS-induced colonic toxicity, thereby supporting further investigation of their application as food-based therapeutic agents for intestinal disorders.