ε-Viniferin Attenuates LPS-Induced Inflammatory Activation in Canine Macrophages by Regulating NF-κB and MAPK Pathways

Abstract

Chronic inflammation is a key pathogenic factor contributing to multiple canine diseases, including dermatitis, arthritis, and enteritis. This study investigated the anti-inflammatory effects of ε-viniferin, a resveratrol dimer, in lipopolysaccharide (LPS)-stimulated DH82 canine macrophages. The anti-inflammatory effects of ε-viniferin were evaluated using western blot analysis, quantitative real-time polymerase chain reaction, and enzyme-linked immunosorbent assay. DH82 canine macrophages were pretreated with ε-viniferin (0.2, 0.5, and 1 µM) prior to exposure to LPS (0.1 µg/mL), with no cytotoxic effects observed at these concentrations. ε-Viniferin markedly suppressed the phosphorylation of inhibitor of κB α, nuclear factor-κB (NF-κB), extracellular signal-regulated kinase, and c-Jun N-terminal kinase, indicating concurrent suppression of the NF-κB and mitogen-activated protein kinase (MAPK) signaling pathways. In addition, ε-viniferin reduced the mRNA expression and secretion of tumor necrosis factor-α (Tnf-α), interleukin-6 (Il-6), and interleukin-1β (Il-1β), while maintaining or enhancing interleukin-10 (Il-10) levels. The observed cytokine pattern decreased the TNF-α/IL-10 ratio and induced a shift toward an anti-inflammatory cytokine-dominant profile. BAY 11-7082, a pharmacological inhibitor of NF-κB activation, produced similar effects, suggesting that ε-viniferin exerts its anti-inflammatory action partly through the inhibition of the NF-κB pathway. Collectively, these findings demonstrated that ε-viniferin attenuates LPS-induced inflammatory responses in canine macrophages via the suppression of the NF-κB and MAPK signaling pathways, highlighting its potential as a nutraceutical for the management of chronic inflammatory conditions in companion animals.