AVIAN GENOMIC AND IMMUNOLOGIC APPROACHES FOR CONTROLLING MUCOSAL PATHOGENS
Title: High-throughput gene expression analysis of intestinal intraepithelial lymphocytes following oral feeding of Carvacrol, cinnamaldehyde, or capsicum oleoresin
Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 5, 2010
Publication Date: April 5, 2011
Citation: Lillehoj, H.S., Kim, D.K., Lee, S.H., Jang, S.I., Bravo, D. 2011. High-throughput gene expression analysis of intestinal intraepithelial lymphocytes following oral feeding of Carvacrol, cinnamaldehyde, or capsicum oleoresin. Poultry Science. 89(1):68-81.
Interpretive Summary: There is much interest to reduce the use of antibiotics in animal production because the use of antibiotics as growth promoters in animal feed has been criticized for the possible emergence of antibiotic resistance in human pathogens. Many countries are now producing significant amounts of poultry without antibiotic growth promoters. In this report, ARS scientists collaborated with a private industry to find an alternative method to reduce economic losses due to infectious diseases. In order to enhance gut immunity, several plant-derived phytonutrients were screened for their effects on gut immunity when used in animal feed. The results showed that 3 novel plant-derived products enhanced poultry gut immunity. In order to better understand the mechanisms underlying nutrition-mediated immunoregulation, ARS scientists conducted global gene expression analysis using chicken microarray and the results clearly demonstrated that high-throughput genomics technology can be applied to identify genetic mechanisms underlying nutrition-gene interaction. The results of this study were used to develop new products by the Pancosma company.
Among dietary phytonutrients, carvacrol, cinnamaldehyde, and Capsicum oleoresin are well-known for their anti-inflammatory 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 three phytochemicals and intestinal intraepithelial lymphocytes were examined for changes in gene expression by microarray analysis. When compared with chickens fed a non-supplemented standard diet, carvacrol-fed chickens showed altered expression of 74 genes (26 up-regulated, 48 down-regulated) and cinnamaldehyde led to changes in the levels of mRNAs corresponding to 62 genes (31 up-regulated, 31 down-regulated). Most changes in gene expression were seen in the Capsicum-fed broilers with 98 up-regulated and 156 down-regulated 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 which 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.