KLHL6 and SYK gene methylation in chicken liver after in ovo stimulation with bioactive substances

In general, most of the bioactive compounds have a marked antioxidant capacity. Prebiotics are compounds in food that induce the growth or activity of beneficial microorganisms such as bacteria and fungi. Probiotics are live bacteria which are intended to colonize the large intestine. The term synbiotic is used to describe synergistic combinations of prebiotics and probiotics. Epigenetic mechanisms such as DNA methylation have been shown to regulate gene expression. When DNA methylation of some candidate genes is measured in tissues, it can be informative about the epigenetic effect of bioactive substances. The role of bioactive compounds on DNA methylation levels in the liver is currently unknown. The aim of this study was to investigate the effect of bioactive substances (prebiotics, probiotics alone or combined into synbiotics) on DNA methylation profile of SYK and KLHL6. It was hypothesized that bioactive compounds can modulate the epigenetic changes of the host in liver. DNA was extracted from 20 Ross liver samples and 20 Green-legged Partridge liver samples using phenol/chloroform method. The effects of prebiotic (galactooligosaccharide), probiotic (Lactococcus lactis subsp. cremoris), synbiotics (probiotic and prebiotic combination) on the methylation levels of SYK and KLHL6 genes were examined. DNA methylation ratios determined by Quantitative Methylation Specific PCR. In ovo injection of prebiotics, probiotics and synbiotics on the 12th day of embryonic development caused increased levels of methylation of immune-related genes in the liver of Ross and Greenlegged-Partridgelike chickens. If the methylation profile of KLHL6 and SYK genes in the liver is evaluated as biomarker, we think that it can give information about its effect on immune pathways. Understanding the molecular mechanism underlying the effects of bioactive substances may be a useful approach to finding natural alternatives to antibiotics.