Planta Med 2013; 79 - PJ7
DOI: 10.1055/s-0033-1352211

Cinnamaldehyde, carvacrol and selected organic acids affect expression of immune related genes in IPEC-J2 cells exposed to Salmonella enterica serotype Typhimurium or Escherichia coli K88

SA Burt 1, D Ahad 1, M Kinjet 2, RR Santos 3
  • 1Utrecht University, Faculty of Veterinary Medicine, IRAS-Veterinary Public Health Division, PO Box 80175, 3508TD Utrecht, The Netherlands.
  • 2Perstorp Waspik b.v., Waspik, The Netherlands.
  • 3Utrecht University, Faculty of Veterinary Medicine, IRAS-Veterinary Pharmacy, Pharmacotherapy & Toxicology Division, PO Box 80177, 3508TD Utrecht, The Netherlands.

In animal feeds, concentrations of phytochemicals and organic acids are probably not lethal to pathogens. However, previous studies have shown that sub-lethal concentrations of cinnamaldehyde, carvacrol and certain acids inhibit attachment and invasion of bacterial pathogens into IPEC-J2 cells. The aim of this study was to investigate the effects of cinnamaldehyde and organic acids on selected immune related genes in porcine jejunum epithelial (IPEC-J2) cells when exposed to S. Typhimurium or E. coli K88 to find out whether such effects could contribute to the previously observed reduction of virulence.

IPEC-J2 cells were grown to confluence and exposed to E. coli O149:K91:K88 strain 498 or S. Typhimurium ATCC 14028 for 1h in the presence and absence of cinnamaldehyde, cinnamic, lactic or propionic acid. qRT-PCR analysis was carried out using primers for immune related genes: IkBa (a marker for the crucial inflammatory mediator NFkB), Heat shock proteins Hsp70, Hsp70.2, Hsp27, hypoxia inducible factor HIF-1a and Nrf2. Expression levels were normalized to untreated control cells.

Results showed fold changes in gene expression levels in the presence/absence of phytochemicals and/or organic acids and after bacterial exposure. (e.g. Figure 1 shows expression levels of IkBa).

Bacterial attack induces IL-8 and IkBa but in the presence of cinnamaldehyde or carvacrol in combination with food acids adherence/invasion is controlled and this is reflected in the expression levels. Cinnamaldehyde induces Hsp70 and IL-8 indicating cell stress, but Hsp-70 may protect cells if induced before contact with bacteria. Unchanged expression levels of IL-12 indicate that these compounds do not act as anti-inflammatory agents, which is confirmed by the unchanged expression of NOD2, which mediates anti-inflammatory signals.

Fig. 1: Expression levels of IkBa in IPEC-J2 cells in presence/absence of phytochemicals and/or organic acids and after bacterial exposure.