High-throughput gene expression analysis of intestinal intraepithelial lymphocytes after oral feeding of carvacrol, cinnamaldehyde, or Capsicum oleoresin.

Among dietary phytonutrients, carvacrol, cinnamaldehyde, and Capsicum oleoresin are well known for their antiinflammatory and antibiotic effects in human and veterinary medicine. To further define the molecular and genetic mechanisms responsible for these properties, broiler chickens were fed a standard diet supplemented with either of the 3 phytochemicals and intestinal intraepithelial lymphocytes were examined for changes in gene expression by microarray analysis. When compared with chickens fed a nonsupplemented standard diet, carvacrol-fed chickens showed altered expression of 74 genes (26 upregulated, 48 downregulated) and cinnamaldehyde led to changes in the levels of mRNAs corresponding to 62 genes (31 upregulated, 31 downregulated). Most changes in gene expression were seen in the Capsicum-fed broilers with 98 upregulated and 156 downregulated genes compared with untreated controls. Results from the microarray analysis were confirmed by quantitative real-time PCR with a subset of selected genes. Among the genes that showed >2.0-fold altered mRNA levels, most were associated with metabolic pathways. In particular, with the genes altered by Capsicum oleoresin, the highest scored molecular network included genes associated with lipid metabolism, small molecule biochemistry, and cancer. In conclusion, this study provides a foundation to further investigate specific chicken genes that are expressed in response to a diet containing carvacrol, cinnamaldehyde, or Capsicum oleoresin.