L-Arginine protects ovine intestinal epithelial cells from lipopolysaccharide-induced intestinal barrier injury

This research aims to explore the effect of L-arginine (Arg) on ovine intestinal epithelial cells (IOECs) from lipopolysaccharide (LPS)-induced intestinal barrier injury. IOECs were incubated for 16 h and classified as 4 groups with the replacement of various mediums, including (1) control (Con), Arg-free Dulbecco's modified Eagle's F12 Ham medium (DMEM); (2) Arg treatment, Arg-free DMEM supplemented with 100 μM Arg; (3) LPS treatment, Arg-free DMEM supplemented with 10 μg/mL LPS; (4) LPS with Arg treatment, Arg-free DMEM supplemented with both 10 μg/mL LPS and 100 μM Arg. Arg supplementation to LPS-treated IOECs resulted in lower (P < 0.05) relative Toll-like receptor 4 (TLR4) protein level. Arg supplementation to LPS-treated IOECs resulted in up-regulated (P < 0.05) zonula occludens-1 (ZO-1), peptide transporter 1 (PEPT1) protein levels, and the ratio of phosphorylated mechanistic target of rapamycin (phospho-mTOR)-to-mTOR. The results show that Arg protects IOECs from LPS induced intestinal barrier injury.