Urolithin A ameliorates experimental autoimmune encephalomyelitis by targeting aryl hydrocarbon receptor

Background: Urolithin A (URA) is an intestinal microbiota metabolic product from ellagitannin-containing foods with multiple biological activities. However, its role in autoimmune diseases is largely unknown. Here, for first time, we demonstrate the therapeutic effect of URA in an experimental autoimmune encephalomyelitis (EAE) animal model. Methods: Therapeutic effect was evaluated via an active and passive EAE animal model in vivo. The function of URA on bone marrow-derived dendritic cells (BM-DCs), T cells, and microglia were tested in vitro. Findings: Oral URA (25 mg/kg/d) suppressed disease progression at prevention, induction, and effector phases of preclinical EAE. Histological evaluation showed that significantly fewer inflammatory cells, decreased demyelination, lower numbers of M1-type microglia and activated DCs, as well as reduced infiltrating Th1/Th17 cells were present in the central nervous system (CNS) of the URA-treated group. URA treatment at 25 mu M inhibited the activation of BM-DCs in vitro, restrained Th17 cell differentiation in T cell polarization conditions, and in a DC-CD4(+) T cell co-culture system. Moreover, we confirmed URA inhibited pathogenicity of Th17 cells in adoptive EAE. Mechanism of URA action was directly targeting Aryl Hydrocarbon Receptor (AhR) and modulating the signaling pathways. Interpretation: Collectively, our study offers new evidence that URA, as a human microbial metabolite, is valuable to use as a prospective therapeutic candidate for autoimmune diseases. (C) 2021 The Authors. Published by Elsevier B.V.

Automated summary

This study demonstrates the therapeutic effect of Urolithin A in an experimental autoimmune encephalomyelitis (EAE) animal model, with potential as a prospective therapeutic candidate for autoimmune diseases. The mechanism involves targeting the Aryl Hydrocarbon Receptor (AhR) and modulating signaling pathways to suppress inflammation and regulate immune cell functions at different stages of disease progression.