Thymol improves barrier function and attenuates inflammatory responses in porcine intestinal epithelial cells during lipopolysaccharide (LPS)-induced inflammation

It is well known that essential oil thymol exhibits antibacterial activity. The protective effects of thymol on pig intestine during inflammation is yet to be investigated. In this study, an in vitro lipopolysaccharide (LPS)-induced inflammation model using IPEC-J2 cells was established. Cells were pre-treated with thymol for 1 h and then exposed to LPS for various assays. Interleukin 8 (IL-8) secretion, the mRNA abundance of cytokines, reactive oxygen species (ROS), nutrient transporters, and tight junction proteins was measured. The results showed that LPS stimulation increased IL-8 secretion, ROS production, and tumor necrosis factor alpha (TNF-α) mRNA abundance (P < 0.05), but the mRNA abundance of sodium-dependent glucose transporter 1 (SGLT1), excitatory amino acid transporter 1 (EAAC1) and H+/peptide cotransporter 1 (PepT1) were decreased (P < 0.05). Thymol blocked ROS production (P < 0.05) and tended to decrease the production of LPS-induced IL-8 secretion (P = 0.0766). The mRNA abundance of IL-8 ...