Methyl 3-Bromo-4,5-dihydroxybenzoate Attenuates Inflammatory Bowel Disease by Regulating TLR/NF-κB Pathways

Inflammatory bowel disease (IBD) is characterized by uncontrolled, chronic relapsing inflammation in the gastrointestinal tract and has become a global healthcare problem. Here, we aimed to illustrate the anti-inflammatory activity and the underlying mechanism of methyl 3-bromo-4,5-dihydroxybenzoate (MBD), a compound derived from marine organisms, especially in IBD, using a zebrafish model. The results indicated that MBD could inhibit the inflammatory responses induced by CuSO₄, tail amputation and LPS in zebrafish. Furthermore, MBD notably inhibited the intestinal migration of immune cells, enhanced the integrity of the gut mucosal barrier and improved intestinal peristalsis function in a zebrafish IBD model induced by trinitro-benzene-sulfonic acid (TNBS). In addition, MBD could inhibit ROS elevation induced by TNBS. Network pharmacology analysis, molecular docking, transcriptomics sequencing and RT-PCR were conducted to investigate the potential mechanism. The results showed that MBD could regulate the TLR/NF-κB pathways by inhibiting the mRNA expression of TNF-α, NF-κB, IL-1, IL-1β, IL6, AP1, IFNγ, IKKβ, MyD88, STAT3, TRAF1, TRAF6, NLRP3, NOD2, TLR3 and TLR4, and promoting the mRNA expression of IL4, IκBα and Bcl-2. In conclusion, these findings indicate that MBD could be a potential candidate for the treatment of IBD.