ABSTRACT
In farm animals, oxidative stress can be involved in several intestinal pathological disorders, and many antioxidant molecules, especially those of plant origin, can counteract free radicals, thus stabilizing the gut environment and enhancing health. The aim of the study was to investigate whether the use of verbascoside (VB), a polyphenol plant compound, in pig feeding could modulate oxidative and/or nitrosative stress in the gut. Eighteen male piglets (Dalland) were assigned to two groups, which were fed with either a control diet (CON) or a diet supplemented with 5 mg/kg of verbascoside (VB) for 166 days. At slaughter, duodenum and jejunum specimens were collected. Immunohistochemistry and Western blot analyses were performed on the samples to evaluate free radical adducts, including acrolein (ACR), 8-hydroxydeoxyguanosine (8-OHdg) and nitrotyrosine (NT). A KRL test was also used to assess the total blood antioxidant activity, and no difference was observed. Immunohistochemistry and Western blot showed that dietary treatment decreased the levels of nitrotyrosine in enteroendocrine cell populations(P<0.05). Characterization of the enteroendocrine cell typology was then performed, and serotonin-immunoreactive cells were revealed to be directly involved in decreasing the nitrosative stress status. This preliminary study demonstrates the important role of dietary VB in decreasing stress biomarkers in swine gut, thus highlighting a possible intervention aimed at building a large prospective for antioxidant dietary supplementation in food animal species.
Subject(s)
Antioxidants/administration & dosage , Diet , Duodenum/drug effects , Glucosides/administration & dosage , Jejunum/drug effects , Oxidative Stress/drug effects , Phenols/administration & dosage , 8-Hydroxy-2'-Deoxyguanosine , Acrolein/metabolism , Animal Feed , Animals , Biomarkers/metabolism , Deoxyguanosine/analogs & derivatives , Deoxyguanosine/metabolism , Diet Therapy , Duodenum/metabolism , Duodenum/pathology , Free Radicals/analysis , Free Radicals/chemistry , Jejunum/metabolism , Jejunum/pathology , Male , Nitrosation/drug effects , Swine , Tyrosine/analogs & derivatives , Tyrosine/metabolismABSTRACT
Ghrelin is involved in many biological processes, ranging from appetite regulation and the release of growth hormone to the regulation of gastrointestinal motility and secretion processes. Ghrelin expression is not homogenously distributed throughout the gastrointestinal tract; expression is species-specific and can also depend on the animal age. This study was performed to investigate ghrelin immunolocalization in the gastrointestinal tract of pigs at different ages: 1 day (birth), 28 days (weaning), 2 months, 4 months, and 7 months (pre-puberty). Tissue samples were collected along the entire gastrointestinal tract and were examined by immunohistochemistry and double-immunofluorescence. Histometry was performed by counting the number of endocrine ghrelin immunopositive cells in the gastrointestinal mucosa. Ghrelin was found to be present along the swine alimentary canal from the stomach to the caecum. In all regions of the alimentary canal of the animals studied, ghrelin-immunoreactive (IR) cells co-localized with chromogranin-A and were therefore identified as endocrine cells. In the gastric fundus, ghrelin-immunoreactivity was partially detected in co-localization with H-K-adenosine triphosphatase and pepsinogen. Ghrelin-IR endocrine cells were abundant in the oxyntic mucosa but less present in the small intestine and rare in the large intestine. The cell density of the ghrelin-IR endocrine cells was lowest in the oxyntic mucosa of 1-day-old pigs. We can conclude that gastric ghrelin expression is not related merely to age but could also potentially be influenced by food intake.
