Mastitis, defined as
inflammation of the mammary gland, is an
infectious disease with a major economic influence on dairy industry. Staphylococcus aureus is a common gram-positive pathogen that frequently causes subclinical,
chronic infection of the mammary gland in dairy cows.
Farrerol, a
traditional Chinese medicine isolated from rhododendron, has been shown to have anti-bacterial activity. However, the effect of
farrerol on S. aureus
infection in mammary epithelium has not been studied in detail. The aim of this study was to investigate the effect of
farrerol on the invasion of bovine mammary epithelial cells (bMEC) by S. aureus. The expression of
antimicrobial peptide genes by bMEC were assessed in the presence or absence of S. aureus
infection. Our results demonstrated that
farrerol (4-16 μg/ml) reduced > 55% the internalization of S. aureus into bMEC. We also found that
farrerol was able to down-regulate the
mRNA expression of tracheal
antimicrobial peptide (TAP) and bovine neutrophil β-
defensin 5 (BNBD5) in bMEC infected with S. aureus. The
Nitric oxide (NO) production of bMEC after S. aureus stimulation was decreased by
farrerol treatment. Furthermore,
farrerol treatment suppressed S. aureus-induced NF-κB activation in bMEC. These results demonstrated that
farrerol modulated TAP and BNBD5 gene expression in mammary gland, enhances bMEC defense against S. aureus
infection and could be useful in protection against
bovine mastitis.