Immuno- and glyco-histochemistry as a tool to evaluate the oregano supplemented feed effects in pig gut

Abstract

Among oregano properties, its antioxidant and antibacterial effects are particularly interesting. Oregano is also able to induce a higher glycoconjugate production in gut, creating a physical barrier against microorganisms. This study evaluated the effects of adding an aqueous extract of oregano (OAE) to the diet of two homogenous groups of pigs during the finisher phase. The diets were as follows: control commercial diet (CTR group) and CTR diet supplemented (2 g/kg) with OAE (O group). Samples of ileum and caecum from the two groups were examined by conventional histochemistry to analyze complex carbohydrates and by immunohistochemistry to detect Bcl-2 Associate X protein (BAX), an indicator of oxidative stress. Glyco-histochemistry showed significant differences between the two groups. Immunohistochemistry revealed a lower presence of BAX in O group. The OAE supplementation improved the production of glycoconjugates, able to enhance in pig the protection of intestinal mucosa by means of direct and indirect defense actions. The reduced BAX immunostaining observed in O group may be an indicator of enhanced antioxidant action promoted by oregano. The results of this study can be used in further research to identify ways to improve endogenous defence ability, with the aim of reducing antibiotic use and preventing antimicrobial resistance.

Productive Performance and Meat Characteristics of Kids Fed a Red Orange and Lemon Extract

“…In addition, at intestinal level, the increased goblet cells reactivity to AB pH 2.5 of animals fed with RLE extract, rich in anthocyanin, suggests that the supplemented feed determines a higher production of acidic carboxylated residues than neutral carbohydrates, which may have a direct influence on nutrient absorption and microbial intestinal colonization and action [ 64 , 65 ]. Remarkably, at the gastrointestinal level, RLE used as feed additives in goats determined an increase of NPY in the enteroendocrine cells of the abomasum and pancreas, but not in the duodenum [ 66 ].…”

A Detailed Study of Rainbow Trout (Onchorhynchus mykiss) Intestine Revealed That Digestive and Absorptive Functions Are Not Linearly Distributed along Its Length

“…Other sections were stained with Periodic acid-Schiff (PAS) or with Alcian Blue pH 2.5 (AB) for histochemical purposes. Subsequently, new slides, were stained with Periodic acid-Schiff (PAS)/Alcian Blue pH 2.5 staining kit (Bio Optica, to analyze the overall complex carbohydrates [11,12].…”

A morphological, glycohistochemical and ultrastructural study on the stomach of adult Rainbow trout Oncorhynchus mykiss

“…Heparin and/or heparansulphated-like glycosaminoglycan production can be excluded by the lack of metachromatic response of toluidin blue treated samples. The great amount of glycosaminoglycans draws large quantities of water to form a viscoelastic barrier able to guarantee a good mucosae hydration degree, in addition to protect the epithelial apical membrane from both HCl and peptidase action (Mercati et al 2020;Dall'Aglio et al 2020a). Finally, an important involvement of produced complex carbohydrates in the defense of rainbow trout stomach mucosae from pathogen agents have to be considered; in fact, the several kinds of glycoconjugates could hamper the attach of viruses and/or bacteria to the stomach mucosae, acting as hapten-like sites and enveloping showing the epithelial columnar lining (▲), the gastric pits (↑) and the tubular gastric glands (*).…”

“…Arbitrary units of glycohistochemical reactivity sorted from 0 (negative) to 4 (very strong), were converted into ranks to run the statistical analysis (Scocco et al 2017;Dall'Aglio et al 2020a). To test the null hypothesis that the location shift between histochemical treatments was equal to zero, we performed paired t-test if the variables satisfied conditions for parametric tests or Wilcoxon signed rank test when they did not.…”