Gossypol detoxification in the rumen and Helicoverpa armigera larvae: A review.

Gossypol, a phenolic compound found in the cotton plant, is widely distributed in cottonseed by-products. Although ruminant animals are believed to be more tolerant of gossypol toxicity than monogastric animals due to rumen microbial fermentation, the actual mechanisms of detoxification remain unclear. In contrast, the metabolic detoxification of gossypol by Helicoverpa armigera (Lepidoptera: Noctuidae) larvae has achieved great advances. The present review discusses the clinical signs of gossypol in ruminant animals, as well as summarizing advances in the study of gossypol detoxification in the rumen. It also examines the regulatory roles of several key enzymes in gossypol detoxification and transformation known in H. armigera. With the rapid development of modern molecular biotechnology and -omics technology strategies, evidence increasingly indicates that research into the biological degradation of gossypol in H. armigera larvae and some microbes, in terms of these key enzymes, could provide scientific insights that would underpin future work on microbial gossypol detoxification in the rumen, with the ultimate aim of further alleviating gossypol toxicity in ruminant animals.

Replacement of forage fiber with non-forage fiber sources in dairy cow diets changes milk extracellular vesicle-miRNA expression.

Milk is a dynamic source of nutrients and bioactive factors, varying with the nutrition status of the cattle. We partly replaced alfalfa hay with whole cotton seed and soybean hull (non-forage fiber source, NFFS) in the feed formula of treated cows and evaluated the effects on milk extracellular vesicles (EVs). The NFFS supplement did not affect the shape of milk EVs observed using a transmission electron microscope. Nanoparticle tracking analysis revealed that the EV concentration increased significantly in treated cows (P = 0.019), with the peak diameter unaffected by the treatment. The EV-RNA concentration and small RNA content, particularly rRNAs and tRNAs, significantly increased in the treated cows (P < 0.05). The other small RNAs, i.e. miRNAs, cis-regulatory elements, snRNAs, and other Rfam RNAs showed no significant difference between the two groups. Totally 276 milk EV-miRNAs were identified. Thirteen miRNAs, accounting for 76%, in the highly expressed top 20, were immune-related. In addition, 9 differently expressed miRNAs (4 up-regulated and 5 down-regulated) were identified (P < 0.05). Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that the differently expressed miRNAs were related to the citrate cycle, fat digestion and absorption process, taurine and hypo-taurine metabolism, and glycosphingolipid biosynthesis. This study documents the milk nutrition assessment from macromolecules, especially EVs.

Effects of tributyrin supplementation on ruminal microbial protein yield, fermentation characteristics and nutrients degradability in adult Small Tail ewes.

Two trials were conducted to assess the effects of tributyrin (TB) supplementation on ruminal microbial protein yield and fermentation characteristics in adult sheep. In an in vitro trial, substrate was made to offer TB at 0, 2, 4, 6, and 8 g/kg on a dry matter (DM) basis and incubated for 48 hr. In an in vivo trial, 45 adult ewes were randomly assigned by initial body weight (55 ± 5 kg) to five treatments of nine animals over an 18-day period. Total mixed ration was made to offer TB to ewes at 0, 2, 4, 6, and 8 g/kg on a DM basis. The in vitro trial showed that TB enhanced apparent degradation of DM (p = .009), crude protein (p < .001), neutral detergent fiber (p = .007) and acid detergent fiber (p = .010) and increased methanogenesis (p < .001), respectively. The in vivo trial showed that TB decreased DM intake (p < .001) and enhanced rumen microbial N synthesis (p < .001), respectively. Both in vitro and in vivo trials showed that TB increased total volatile fatty acid concentration and enhanced fibrolytic enzyme activity. The results indicated that TB might exert positive effects on microbial protein yield and fermentation in the rumen.

Punicalagin protects bovine endometrial epithelial cells against lipopolysaccharide-induced inflammatory injury.

OBJECTIVE: Bovine endometritis is one of the most common reproductive disorders in cattle. The aim of this study was to investigate the anti-inflammation potential of punicalagin in lipopolysaccharide (LPS)-induced bovine endometrial epithelial cells (bEECs) and to uncover the underlying mechanisms. METHODS: bEECs were stimulated with different concentrations (1, 10, 30, 50, and 100 µg/ml) of LPS for 3, 6, 9, 12, and 18 h. MTT assay was used to assess cell viability and to identify the conditions for inflammatory injury and effective concentrations of punicalagin. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to assess gene expression of pro-inflammatory cytokines. Western blotting was used to assess levels of inflammation-related proteins. RESULTS: Treatment of bEECs with 30 µg/ml LPS for 12 h induced cell injury and reduced cell viability. Punicalagin (5, 10, or 20 µg/ml) pretreatment significantly decreased LPS-induced productions of interleukin (IL)-1ß, IL-6, IL-8, and tumor necrosis factor-α (TNF-α) in bEECs. Molecular research showed that punicalagin inhibited the activation of the upstream mediator nuclear factor-κB (NF-κB) by suppressing the production of inhibitor κBα (IκBα) and phosphorylation of p65. Results also indicated that punicalagin can suppress the phosphorylation of mitogen-activated protein kinases (MAPKs) including p38, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK). CONCLUSIONS: Punicalagin may attenuate LPS-induced inflammatory injury and provide a potential option for the treatment of dairy cows with Escherichia coli endometritis.

Magnolol pretreatment attenuates heat stress-induced IEC-6 cell injury.

OBJECTIVE: Heat stress (HS) is an important environmental stressor that adversely influences livestock during the summer. The aim of this study was to investigate whether magnolol protects against HS-induced intestinal epithelial cell injury. MATERIALS AND METHODS: An intestinal epithelial cell line (IEC-6) was subjected to HS at 42 °C, with and without magnolol pretreatment. Cell injury was detected by monitoring lactate dehydrogenase (LDH) release. MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay was used to assess cell proliferation and viability, including identifying effective concentrations of magnolol. Flow cytometry confirmed G1-phase cell-cycle arrest and its alleviation by magnolol. Active DNA synthesis was measured by incorporation of nucleic acid 5-ethynyl-2'-deoxyuridine (EdU). G1-phase cell-cycle-related gene expression was assessed by real-time reverse transcription polymerase chain reaction (RT-PCR) and levels of G1-phase-related proteins by Western blotting. RESULTS: HS induced IEC-6 cell injury and decreased cell viability, as demonstrated by data from LDH and MTS assays, respectively. Based on a number of criteria, IEC-6 cells subjected to HS were arrested in the G1 phase of the cell cycle. Magnolol pretreatment decreased HS-induced cell injury through relief of this cell-cycle arrest. CONCLUSIONS: Magnolol pretreatment attenuates HS-induced injury in IEC-6 cells. Magnolol is potentially promising as a protective strategy for HS in livestock.

Microbial release of ferulic and p-coumaric acids from forages and their digestibility in lactating cows fed total mixed rations with different forage combinations.

BACKGROUND: Ferulic acid (FA) and p-coumaric acid (PCA) are widely distributed in graminaceous plant cell walls. This study investigated the in vitro and in vivo digestibility of ester-linked FA (FAest) and PCA (PCAest) in lactating dairy cows. RESULTS: Regarding corn stover, ensiled corn stover, whole corn silage, Chinese wild ryegrass and alfalfa hay with different phenolic acid profiles, the in vitro rumen digestibility of forage FAest and PCAest was negatively correlated with the ether-linked FA content and original PCA/FA ratio in the forages. The concentration of both phenolic acids in culture fluids was low after a 72 h incubation, and the mixed rumen microorganisms metabolized nearly all phenolic acids released into the culture fluids. FAest digestibility in the whole digestive tract was negatively correlated with dietary PCA/FA ratio, but a converse result occurred with dietary PCAest digestibility. The digestibility in either the rumen or the whole digestive tract was greater for FAest than for PCAest. CONCLUSION: Forage PCAest in comparison with FAest is not easily digested in either the rumen or the whole digestive tract, and they were negatively affected by forage FAeth content and lignification extent indicated by the original dietary PCA/FA ratio.

Characterization of a novel xylanase gene from rumen content of Hu sheep.

A novel xylanase gene, xyn-lxy, was cloned from a metagenomic fosmid library, which was previously constructed from the rumen contents of Hu sheep and was functionally characterized in Escherichia coli. The open reading frame was composed of 1923 bp and encoded for 640 amino acids, including a catalytic domain of glycosyl hydrolase family 10 and carbohydrate-binding module 9. The gene showed 97 % identity with uncultured bacterium Contig1552 but low similarity with xylanases from known cellulolytic-degrading microorganisms in the rumen. The recombinant XYN-LXY showed a specific activity of 664.7 U mg(-1). The optimal temperature and pH of the enzyme were 50 °C and 6.0, respectively. Specifically, XYN-LXY was exclusively activated by Mn(2+) among all of the cations and reducing agents tested in this study. An enzymatic hydrolysis assay revealed that XYN-LXY degraded birchwood xylan into xylooligosaccharide with a low degree of polymerization. After incubation for 4 h, the concentration of the dominant product, xylobiose, was 2.297 ± 0.175 mg ml(-1) (74.07 % of total product) followed by xylose with a concentration of 0.656 ± 0.010 mg ml(-1) (21.14 % of total product). The XYN-LXY exhibited deep degradation effects on the xylan substrate, which were rarely observed with endo-xylanase, making it a promising candidate for industrial application, especially in biofuel production.