Rutin alleviated lipopolysaccharide-induced damage in goat rumen epithelial cells.

Objective: Rutin, also called vitamin P, is a flavonoids from plants. Previous studies have indicated that rutin can alleviate the injury of tissues and cells by inhibiting oxidative stress and ameliorating inflammation. There is no report on the protective effects of rutin on goat rumen epithelial cells (GRECs) at present. Hence, we investigated whether rutin can alleviate lipopolysaccharide (LPS)-induced damage in GRECs.

Methods: GRECs were cultured in basal medium or basal medium containing 1 μg/mL LPS, or 1 μg/mL LPS and 20 μg/mL rutin. Six replicates were performed for each group. After 3-h culture, the GRECs were harvested to detect the relevant parameters.

Results: Rutin significantly enhanced the cell activity (p<0.05) and transepithelial electrical resistance (TEER) (p<0.01) and significantly reduced the apoptosis rate (p<0.05) of LPSinduced GRECs. Rutin significantly increased superoxide dismutase, glutathione peroxidase, and catalase activity (p<0.01) and significantly decreased lactate dehydrogenase activity and reactive oxygen species and malondialdehyde (MDA) levels in LPS-induced GRECs (p<0.01). The mRNA and protein levels of interleukin 6 (IL-6), IL-1β, and C-X-C motif chemokine ligand 8 (CXCL8) and the mRNA level of tumor necrosis factor-α (TNF-α) and chemokine C-C motif ligand 5 (CCL5) were significantly increased in LPS-induced GRECs (p<0.05 or p<0.01), while rutin supplementation significantly decreased the mRNA and protein levels of IL-6, TNF-α, and CXCL8 in LPS-induced GRECs (p<0.05 or p<0.01). The mRNA level of toll-like receptor 2 (TLR2), and the mRNA and protein levels of TLR4 and nuclear factor κB (NF-κB) was significantly improved in LPS-induced GRECs (p<0.05 or p<0.01), whereas rutin supplementation could significantly reduce the mRNA and protein levels of TLR4 (p<0.05 or p<0.01). In addition, rutin had a tendency of decreasing the protein levels of CXCL6, NF-κB, and inhibitor of nuclear factor kappa-B alpha (0.05< p<0.10). Rutin could significantly decreased interferon regulatory factor 3 mRNA expression in LPS-induced GRECs (p<0.05), whereas interferon induced protein with tetratricopeptide repeats 3 (IFIT3) and toll-interacting protein (TOLLIP) mRNA expression was not significantly different between the groups. LPS reduced the tight junction protein zonula occludin 1 (ZO-1) level in GRECs whereas rutin enhanced it. Rutin significantly improved tight junction protein Claudin-1 mRNA expression in LPS-induced GRECs (p<0.01), but could not affect tight junction protein Occludin mRNA expression.

Conclusion: Rutin alleviated LPS-induced barrier damage in GRECs by improving oxidation resistance and anti-inflammatory activity, which may be related to TLR/NF-κB signaling pathway inhibition.