Palmatine inhibits TRIF-dependent NF-κB pathway against inflammation induced by LPS in goat endometrial epithelial cells

Palmatine, a natural pharmaceutical drug, possesses many biological activities. But its clinical application is rarely reported in the veterinary medicine. The aim of this study was to investigate the anti-inflammatory effects of palmatine on lipopolysaccharide (LPS)-induced inflammation in goat endometrial epithelial cells (gEECs), and the possible molecular mechanisms. Palmatine cell toxicity was determined by MTT assay, and the production of inflammatory cytokine in the cultured medium was measured with ELISA, qRT-PCR and Western blotting. Our results showed that palmatine treatment inhibited the release of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, nitric oxide (NO), matrix metalloproteinase (MMP)-9 and MMP-2. Furthermore, palmatine enhanced the secretion of prostaglandins E2 (PGE2) and IL-10. Palmatine significantly down-regulated the expression of Toll-like receptor 4 (TLR4), cluster of differentiation 14 (CD14), Toll/interleukin 1 receptor (TIR)-domain-containing adaptor protein inducing interferon-β (TICAM, TRIF) and nuclear factor-κB (NF-κB) in LPS stimulated gEECs, but did not alter the production of MyD88. In conclusion, palmatine inhibits TRIF-dependent NF-κB pathway to reduce LPS-induced inflammatory responses in goat endometrial epithelial cells.