Poster Presentation Joint Annual Scientific Meeting of the Nutrition Society of NZ and the Nutrition Society of Australia

Potential of dietary propolis in protecting bovine mammary epithelial cells against mastitis pathogens using in vitro models (#P46)

Kai Wang 1 , Xiao-Lu Jin 1 , Jian-xin Liu 1 , Fuliang Hu 1
  1. College of Animal Sciences, Zhejiang University, Hangzhou, China

Background/Aims: Inflammation of the mammary gland (mastitis) caused by invading pathogens is common among lactating dairy cows and causes great economic losses. We recently demonstrated that Chinese propolis (CP), a resinous substance collected by honeybees, can positively influence anti-inflammatory processes and antioxidant defense systems in vivo but little is known about how propolis treatment of mastitis in dairy cows may influence these activities.

Methods: We investigated the potentially protective effects of CP on aspects of mastitis by usingan in vitro model ofmastitis-induced cell damage involving cultured bovine mammary epithelial cells (MAC-T) which received a range of mastitis pathogen-related insults. Cell viability was measured by cell counting kit (CCK)-8 cell viability assay and expression of inflammatory/antioxidant genes were measured by qPCR. Using a cell-based reporter assay system, we evaluated CP and its main constituents’ on NF-κB and Nrf2-ARE transcription activity.

Results: Treatment of cells withcell wall components lipopolysaccharide (LPS), heat inactivated E. coli and S. aureus, but not TNF-α or lipoteichoic acid (LTA), significantly decreased cell viability (p<0.01). CP pretreatment (15μg/ml) significantly (p<0.05) protected cell viability losses CP pretreatment of MAC-T cells resulted in less impact on IL-6 and TNF-α mRNA expressions but increased expression of antioxidant genes HO-1, Txnrd-1 and GCLM. CP and its polyphenolic active components (mainly CAPE and quercetin) had strong inhibitive effects against NF-κB and increased the transcriptional activation of the Nrf2-ARE pathway.

Conclusions: Our findings support the usage of dietary propolis for the treatment of bovine mastitis.

Funding source: NSFC