The Effects of Glutamine Supplementation on Liver Inflammatory Response and Protein Metabolism in Muscle of Lipopolysaccharide-Challenged Broilers.

The aim of our present study was to investigate the effects of Gln supplementation on liver inflammatory responses as well as protein synthesis and degradation in the muscle of LPS-challenged broilers. A total of 120 one-day-old male broiler chickens (Arbor Acres Plus) were randomly arranged in a 2 × 2 factorial design with five replicates per treatment and six broilers per replicate, containing two main factors: immune challenge (injected with LPS in a dose of 0 or 500 µg/kg of body weight) and dietary treatments (supplemented with 1.22% alanine or 1% Gln). After feeding with an alanine or Gln diet for 15 days, broilers were administrated an LPS or a saline injection at 16 and 21 days. The results showed that Gln supplementation alleviated the increased mRNA expressions of interleukin-6, interleukin-1ß, and tumor necrosis factor-α induced by LPS in liver. Moreover, the increased activity of aspartate aminotransferase combined with the decreased expression of glutaminase in muscle were observed following Gln addition. In addition, in comparison with the saline treatment, LPS challenge altered the signaling molecules' mRNA expressions associated with protein synthesis and degradation. However, Gln supplementation reversed the negative effects on protein synthesis and degradation in muscle of LPS-challenged broilers. Taken together, Gln supplementation had beneficial effects: alleviating inflammatory responses, promoting protein synthesis, and inhibiting protein degradation of LPS-challenged broilers.

Dietary Glutamine Supplementation Alleviated Inflammation Responses and Improved Intestinal Mucosa Barrier of LPS-Challenged Broilers.

The present study was conducted to investigate the effects of glutamine (Gln) supplementation on intestinal inflammatory reaction and mucosa barrier of broilers administrated with lipopolysaccharide (LPS) stimuli. A total of 120 1-d-old male broilers were randomly divided into four treatments in a 2 × 2 experimental arrangement, containing immune challenge (injected with LPS in a dose of 0 or 500 µg/kg of body weight) and dietary treatments (supplemented with 1.22% alanine or 1% Gln). The results showed that growth performance of broilers intra-abdominally injected with LPS was impaired, and Gln administration alleviated the adverse effects on growth performance induced by LPS challenge. Furthermore, Gln supplementation reduced the increased concentration of circulating tumor necrosis factor-α, interleukin-6 and interleukin-1ß induced by LPS challenge. Meanwhile, D-lactic acid and diamine oxidase concentration in plasma were also decreased by Gln supplementation. In addition, the shorter villus height, deeper crypt depth and the lower ratio of villus height to crypt depth of duodenum, jejunum and ileum induced by LPS stimulation were reversed by Gln supplementation. Gln administration beneficially increased LPS-induced reduction in the expression of intestine tight junction proteins such as zonula occludens protein 1 (ZO-1), claudin-1 and occludin except for the ZO-1 in duodenum and occludin in ileum. Moreover, Gln supplementation downregulated the mRNA expression of toll-like receptor 4, focal adhesion kinase, myeloid differentiation factor 88 and IL-1R-associated kinase 4 in TLR4/FAK/MyD88 signaling pathway. Therefore, it can be concluded that Gln administration could attenuate LPS-induced inflammatory responses and improve intestinal barrier damage of LPS-challenged broilers.

Gastrointestinal Interaction between Dietary Amino Acids and Gut Microbiota: With Special Emphasis on Host Nutrition.

The gastrointestinal tract (GIT) of humans and animals is host to a complex community of different microorganisms whose activities significantly influence host nutrition and health through enhanced metabolic capabilities, protection against pathogens, and regulation of the gastrointestinal development and immune system. New molecular technologies and concepts have revealed distinct interactions between the gut microbiota and dietary amino acids (AAs) especially in relation to AA metabolism and utilization in resident bacteria in the digestive tract, and these interactions may play significant roles in host nutrition and health as well as the efficiency of dietary AA supplementation. After the protein is digested and AAs and peptides are absorbed in the small intestine, significant levels of endogenous and exogenous nitrogenous compounds enter the large intestine through the ileocaecal junction. Once they move in the colonic lumen, these compounds are not markedly absorbed by the large intestinal mucosa, but undergo intense proteolysis by colonic microbiota leading to the release of peptides and AAs and result in the production of numerous bacterial metabolites such as ammonia, amines, short-chain fatty acids (SCFAs), branched-chain fatty acids (BCFAs), hydrogen sulfide, organic acids, and phenols. These metabolites influence various signaling pathways in epithelial cells, regulate the mucosal immune system in the host, and modulate gene expression of bacteria which results in the synthesis of enzymes associated with AA metabolism. This review aims to summarize the current literature relating to how the interactions between dietary amino acids and gut microbiota may promote host nutrition and health.

Reclamation of Astragalus By-Product through Dietary Inclusion in Ruminant Diets: Effects on Growth Performance, Nutrient Digestibility, Rumen Fermentation, Blood Biochemical Parameters, and Humoral Immune Response in Sheep.

This study was conducted to investigate the effects of Astragalus by-product (ABP) through dietary supplementation at different levels on performance, nutrient digestibility, rumen fermentation, blood metabolites, and immune response in sheep. Twenty-four Doper × Small Tail Han ewes (6-7 months of age; 29.07 ± 2.28 kg initial body weight) were randomly assigned to one of three treatments for a 47 d feeding period. Treatments consisted of the sheep diet supplemented with 0% ABP-control, 10% ABP, or 15% ABP of the diet (dry matter basis). Blood samples were collected on days 0, 15, 30, and 45 of the feeding period. APB supplementation did not affect growth performance and apparent digestibility of organic matter, crude protein, and acid detergent fibre (P > 0.05). However, ether extract digestibility was decreased in the 10% ABP group and increased in the 15% ABP group (P < 0.001), and both 10% ABP and 15% ABP decreased the neutral detergent fibre digestibility (P=0.005). Feeding ABP increased rumen pH (P < 0.001) and ammonia N (P < 0.001) and decreased concentrations of acetate (P=0.007) and propionate (P=0.001) which resultantly increased the acetate-to-propionate ratio (P < 0.001) in ruminal fluid. There were no interaction effects between treatment and sampling time for plasma metabolites and immunity (P > 0.05). However, inclusion of dietary 10% ABP decreased concentrations of plasma cholesterol (P=0.043). Also, plasma concentrations of low-density lipoprotein decreased on days 30 and 45 (P=0.017) of the feeding period. Metabolite concentrations of total protein, albumin, globulin, blood urea N, glucose, triglyceride, and high-density lipoprotein cholesterol and humoral immune indicators were not affected (P > 0.05) by dietary ABP supplementation. The results suggest that ABP could be reclaimed through dietary inclusion in animal feed since it had beneficial effects on rumen fermentation patterns and lipid metabolism and had no adverse effects on performance and humoral immunity in sheep.

Application of Traditional Chinese Herbal Medicine By-products as Dietary Feed Supplements and Antibiotic Replacements in Animal Production.

BACKGROUND: Misuse of synthetic antibiotics in livestock leads to the transfer of antibiotic resistant pathogens into humans and deposits toxic residues in meat and milk. There is therefore an urgent need for safe and viable alternative approaches to improve the nutrition and wellbeing of farm animals. An alternative source that has been widely exploited is Traditional Chinese Herbal Medicine (TCHM). These herbs contain several but less toxic bioactive compounds which are generally regarded as biodegradable. Recently, advances in the knowledge of the importance of TCHM have led to a rapid increase in its production and hence, increasing the amount of by-products generated. Such by-products have become a serious environmental challenge because producers regard them as industrial waste and discard them directly. This review summarizes scientific findings on the bioactive compounds in TCHM and TCHM by-products, discusses functional dietary patterns and outlines challenges that may hinder full utilization of TCHM by-products in animal production. METHODS: Information for this review was obtained through scientific databases and websites such as Pubmed and Google scholar from 2004 to 2017 using experimental studies on bioactive compounds in TCHM and their effects in animal production. RESULTS: Studies have shown that TCHM by-products contain high amounts of bioactive compounds which confer several nutritional and health benefits to animals and thus could be incorporated as feed additives. CONCLUSION: The findings for this review indicate that TCHM by-products apart from being a good alternative for synthetic antibiotics could also minimize the current environmental challenges associated with its disposal.

Upregulation of miRNA-155 expression by OxLDL in dendritic cells involves JAK1/2 kinase and transcription factors YY1 and MYB.

Dendritic cells (DCs) have been implicated in the pathogenesis of atherosclerosis (AS). Whereas the pathogenic role of oxidized low-density lipoprotein (oxLDL) in the development and progression of AS has been recognized previously, the contribution of microRNA-155 (miR-155) to AS was previously not fully understood. It had also been noted that miR-155 levels were upregulated by oxLDL in various cell types under different (patho)physiological conditions, but its underlying mechanisms had not been examiend in detail. Thus, in the present study, we observed that oxLDL treatment increased miR-155 expression in DCs, and transfecting DCs with siRNA against scavenger receptor A (SRA) revealed that repression of SRA attenuated this upregulation. We also noted that miR-155 negatively regulated SRA expression by suppressing the JNK pathway. Furthermore, we noted that Yin Yang 1 (YY1) and V-Myb avian myeloblastosis viral oncogene homolog (MYB), which were also upregulated by oxLDL, directly bound to the cognate sequences of the promoter region of miR-155 to activate its transcription. In addition, using SP600125, a specific inhibitor for c-Jun N-terminal kinase (JNK) signaling, we demonstrated that JNK signaling was involved in the miR­155-mediated suppression of SRA expression. Thus, in the present study we uncovered the molecular mechanism through which miR-155 expression is regulated by oxLDL, and we also identified a negative feedback loop, miR­155-JNK-SRA-miR-155. Our findings thus provide novel insights into the regulatory network underlying the expression and activity of miR-155 in DCs.

Role of soybean ß-conglycinin subunits as potential dietary allergens in piglets.

ß-Conglycinin, a major seed-storage protein in soybeans, is one of the primary antigenic proteins responsible for soybean-meal hypersensitivity in weaned piglets. The protein is a heterotrimer composed of subunits α, α' and ß. It is currently unknown which of the ß-conglycinin subunits are allergenic for piglets. The aim of this study was to identify potential allergenic subunits of ß-conglycinin for soybean sensitive piglets and to characterise these subunits by immunoglobulin (Ig) G and E immunoblotting, ELISA, 'skin prick' and whole blood histamine-release testing. The IgG and IgE binding capabilities of the purified α, α' and ß subunits of ß-conglycinin were determined by immunoblot analysis and ELISA with sera from ß-conglycinin sensitised piglets. Skin prick testing and whole blood histamine release testing were also performed to detect the activated effector cell response to specific allergens. Specific IgG and E antibodies were identified that recognised all three subunits of ß-conglycinin in the sera of ß-conglycinin sensitised piglets. All three subunits of ß-conglycinin elicited positive skin test and specific histamine release responses from the whole blood of ß-conglycinin sensitised piglets. These results suggest that all three ß-conglycinin subunits are potential allergens for piglets.

Effects of soybean agglutinin on intestinal barrier permeability and tight junction protein expression in weaned piglets.

This study was developed to provide further information on the intestinal barrier permeability and the tight junction protein expression in weaned piglets fed with different levels of soybean agglutinin (SBA). Twenty-five weaned crossbred barrows (Duroc × Landrace × Yorkshire) were selected and randomly allotted to five groups, each group with five replicates. The piglets in the control group were not fed with leguminous products. 0.05, 0.1, 0.15 and 0.2% SBA was added to the control diet to form four experimental diets, respectively. After the experimental period of 7 days (for each group), all the piglets were anesthetized with excess procaine and slaughtered. The d-lactic acid in plasma and the Ileal mucosa diamine oxidase (DAO) was analyzed to observe the change in the intestinal permeability. The tight junction proteins occludin and ZO-1 in the jejunum tissue distribution and relative expression were detected by immunohistochemistry and Western Blot. The results illustrated that a high dose of SBA (0.1-0.2%) could increase the intestinal permeability and reduce piglet intestinal epithelial tight junction protein occludin or ZO-1 expression, while low dose of SBA (0.05% of total diet) had no significant affects. The contents of DAO, d-lactic acid, occludin or ZO-1, had a linear relationship with the SBA levels (0-0.2%) in diets. The high dose SBA (0.1-0.2%) could increase the intestinal permeability and reduce piglet intestinal epithelial tight junction protein occludin or ZO-1 expression, while low dose of SBA (0.05% of total diet) had no affects.

The effects of dietary fatty acids on liver fatty acid composition and Delta(6)-desaturase expression differ with ambient salinities in Siganus canaliculatus.

Delta(6)-Desaturase (linoleoyl-CoA desaturase, EC 1.14.19.3) is the rate-limiting enzyme in the biosynthetic pathway of highly unsaturated fatty acid (HUFA). In this report, a Delta6 desaturase-like cDNA was cloned, and the relation of HUFA biosynthetic activity in liver with ambient salinity as well as dietary fatty acids was investigated in the euryhaline teleost Siganus canaliculatus. After the juveniles were fed four formulated diets (D1-D4) with different essential fatty acid composition (D1 with 23.49% HUFA, D2-D4 were HUFA-free, linoleic and alpha-linolenic acids account for 21.1% and 0.38%, 13.99% and 11.64%, 18.31% and 5.82% of the total fatty acids, respectively) for nine weeks, the growth performance showed no difference among groups in brackish water (10 ppt) or seawater (32 ppt) (P>0.05). Comparing liver fatty acids with fish fed D1, the content of arachidonic acid in fish fed D2 or D4 was significantly higher in 10 ppt (P<0.05), but showed no difference in 32 ppt; the contents of eicosapentaenoic (EPA), docosapentaenoic (DPA) and docosahexaenoic (DHA) acids in 10 ppt, as well as EPA in 32 ppt in fish fed D3 showed no difference, whereas those of DPA and DHA were significantly lower in 32 ppt (P<0.05). These data suggest that S. canaliculatus may convert linoleic and alpha-linolenic acids into HUFA and such a capacity was stronger in low salinity than that in high salinity. Consistent with this, the liver levels of Delta6 desaturase mRNA in fish fed D2-D4 were generally higher than in fish fed D1 in both salinities, and the total expression level in 10 ppt was about 1.56 times of that in 32 ppt, suggesting that transcriptional control of Delta6 desaturase is involved in such a HUFA biosynthesis. To our knowledge, this is the first report showing the relation of HUFA biosynthetic activity with ambient salinity in a euryhaline fish.