title: Thymol inhibits Staphylococcus aureus internalization into bovine mammary epithelial cells by inhibiting NF-κB activation.
abstract: Bovine mastitis is one of the most costly and prevalent diseases in the dairy industry and is characterised by inflammatory and infectious processes. Staphylococcus aureus (S. aureus), a Gram-positive organism, is a frequent cause of subclinical, chronic mastitis. Thymol, a monocyclic monoterpene compound isolated from Thymus vulgaris, has been reported to have antibacterial properties. However, the effect of thymol on S. aureus internalization into bovine mammary epithelial cells (bMEC) has not been investigated. In this study, we evaluated the effect of thymol on S. aureus internalization into bMEC, the expression of tracheal antimicrobial peptide (TAP) and β-defensin (BNBD5), and the inhibition of NF-κB activation in bMEC infected with S. aureus. Our results showed that thymol (16-64 μg/ml) could reduce the internalization of S. aureus into bMEC and down-regulate the mRNA expression of TAP and BNBD5 in bMEC infected with S. aureus. In addition, thymol was found to inhibit S. aureus-induced nitric oxide (NO) production in bMEC and suppress S. aureus-induced NF-κB activation in a dose-dependent manner. In conclusion, these results indicated that thymol inhibits S. aureus internalization into bMEC by inhibiting NF-κB activation.
authors.affiliation: College of Veterinary Medicine, Jilin University, Jilin, Changchun 130062, People's Republic of China.
authors.forename: Zhengkai
authors.initials: Z
authors.lastname: Wei
authors.affiliation: College of Veterinary Medicine, Jilin University, Jilin, Changchun 130062, People's Republic of China.
authors.forename: Ershun
authors.initials: E
authors.lastname: Zhou
authors.affiliation: College of Veterinary Medicine, Jilin University, Jilin, Changchun 130062, People's Republic of China.
authors.forename: Changming
authors.initials: C
authors.lastname: Guo
authors.affiliation: College of Veterinary Medicine, Jilin University, Jilin, Changchun 130062, People's Republic of China.
authors.forename: Yunhe
authors.initials: Y
authors.lastname: Fu
authors.affiliation: College of Veterinary Medicine, Jilin University, Jilin, Changchun 130062, People's Republic of China.
authors.forename: Yuqiang
authors.initials: Y
authors.lastname: Yu
authors.affiliation: College of Veterinary Medicine, Jilin University, Jilin, Changchun 130062, People's Republic of China.
authors.forename: Yimeng
authors.initials: Y
authors.lastname: Li
authors.affiliation: College of Veterinary Medicine, Jilin University, Jilin, Changchun 130062, People's Republic of China.
authors.forename: Minjun
authors.initials: M
authors.lastname: Yao
authors.affiliation: College of Veterinary Medicine, Jilin University, Jilin, Changchun 130062, People's Republic of China.
authors.forename: Naisheng
authors.initials: N
authors.lastname: Zhang
authors.affiliation: College of Veterinary Medicine, Jilin University, Jilin, Changchun 130062, People's Republic of China. Electronic address: yangzhengtao01@sina.com.
authors.forename: Zhengtao
authors.initials: Z
authors.lastname: Yang
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002417:Cattle; D004705:Endocytosis; D004847:Epithelial Cells / Q000187:drug effects* / Q000382:microbiology*; D020869:Gene Expression Profiling; D007155:Immunologic Factors / Q000378:metabolism*; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D013211:Staphylococcus aureus / Q000254:growth & development* / Q000276:immunology; D013943:Thymol / Q000378:metabolism*
chemical_list: D007155:Immunologic Factors; D016328:NF-kappa B; D013943:Thymol
keywords: Antimicrobial peptides; Bovine mammary epithelial cell; Bovine mastitis; NF-κB; Staphylococcus aureus; Thymol