This study investigated inhibiting mechanisms of Urolithin B (Uro B) on macrophage M1 polarization. Uro B (50 μM) could inhibit the PGE2, COX-2, NO, iNOS, TNF-α, IL-1β and IL-6 levels compared with model group (P < 0.05) as well as the CD86 and F4/80 expression. The miR155-5p overexpression could increase the p38 MAPK, JNK, ERK mRNA activities (P < 0.05), Uro B (50 μM) could reverse changes in these indicators (P < 0.05). Moreover, Uro B (50 μM) could inhibit the TLR4, Src, IκBα, NF-κBp65 and their phosphorylated protein expression (P < 0.05). Therefore, Uro B may inhibit macrophage M1 polarization via miR155-5p mediated MAPK/NF-кB pathway.
Keywords: NF-κB/MAPK pathway; TLR4/Src; Urolithin B; anti-inflammatory effect; macrophage M1 polarization; microRNA155.