Dietary artemisinin boosts intestinal immunity and healthy in fat greenling (Hexagrammos otakii)

Zearalenone-induced hepatointestinal toxicity in laying hens: unveiling the role of gut microbiota and fecal metabolites

Zearalenone (ZEN), a mycotoxin produced by Fusarium species, is known for its reproductive toxicity as an estrogen analogue. However, there are limited knowledge about its hepatointestinal toxicity, as well as the role that gut microbiota and metabolites play in this process. In this study, a total of 24 thirty-week-old hens were fed to investigate the hepatointestinal toxicity subjected to long-term ZEN consumption at 2.0 mg/kg for 90 d. And we employed uncultured 16S rRNA sequencing for gut microbiota and untargeted metabolomics for fecal metabolites assessment. Notably, ZEN induced significant hepatic damage, as evidenced by hepatocyte necrosis, inflammatory cell infiltrate, increased liver lipopolysaccharide (LPS) and blood aspartate aminotransferase (AST) levels (P < 0.05). The decreased villus height, disruption of simple columnar epithelial cells, and exposure of the mucosal intrinsic layer were observed in the intestine. The gut microbial community composition and metabolites differed between ZEN group and control group. ZEN group exhibited higher gut microbial diversity (P < 0.05), lower Firmicutes/Bacteroidetes ratio and Lactobacillus abundance, and higher abundance in the genus such as Bacteroidetes, Parabacteroidetes and Desulfovibrio. Metabolomic analysis showed that ZEN treatment altered biosynthesis of siderophore group nonribosomal peptides and phenylpropanoids, metabolism of amino acid, digestion and absorption of vitamin and ABC transporters. Differential metabolites suggested that ZEN increase the risk of estrogen disorder, nucleic acid degradation, intestinal oxidative stress and inflammation. Neural network analysis showed that Ruminococcus was positively correlated with glyceric acid, and Prevotella was positively correlated with phenylacetylglycine. Both metabolites were positively correlated with blood AST level (P < 0.05), suggesting that intestinal microbe Ruminococcus and Prevotella might exacerbate liver damage by producing these harmful metabolites. Overall, we conclude that ZEN has damaged hepatointestinal system and the altered gut microbiota with resultant metabolite changes contribute to the adverse hepatointestinal effects of ZEN on laying hens. This study underscores the need for monitoring and mitigating ZEN exposure in poultry diets, highlighting its broader implications for animal health and food safety.

Potential Targets and Signaling Mechanisms of Cinnamaldehyde Enhancing Intestinal Function and Nutritional Regulation in Fat Greenling (Hexagrammos otakii)

Cinnamaldehyde is an ideal feed additive with good immune enhancement and anti-inflammatory regulation effects. However, the anti-inflammatory regulation mechanism in fat greenling (Hexagrammos otakii, H. otakii) remains unclear. The nine targets of cinnamaldehyde were gathered in identified by the Traditional Chinese Medicine Systems Pharmacology database and Uniprot database, and 1,320 intestinal inflammation disease (IIF)-related proteins were screened from DrugBank, Online Mendelian Inheritance in Man (OMIM), Genecards, and Pharmacogenetics and Pharmacogenomics Knowledge Base (PHARMGKB) Databases. According to the Gene Ontology enrichment results and Kyoto Encyclopedia of Genes and Genomes pathway results, cinnamaldehyde may regulated the responses to bacteria, lipopolysaccharide, an inflammatory cytokine, and external stimuli via the nuclear factor kappa-B (NFκB) signaling pathway within on inflammatory network. In addition, the protein-protein interaction analysis assisted in obtaining the closely related inflammatory regulatory proteins, including the C5a anaphylatoxin chemotactic receptor 1 (C5aR1), transcription factor p65 (RELA), prostaglandin G/H synthase 2 (PTGS2), and toll-like receptor 4 (TLR4), which were confirmed as the bottleneck nodes of the network to be more deeply verified via the molecular docking. Moreover, a cinnamaldehyde feeding model was established for evaluating the anti-inflammatory effect of cinnamaldehyde in vivo. According to the current findings implied that cinnamaldehyde may play a protective role against IIF H. otakii by reducing inflammation through the C5 complement (C5)/C5aR1/interleukin-6 (IL-6) and TLR4/NFκB/PTGS2 pathway. The study focused on investigating the action mechanism of cinnamaldehyde on IIF through combining pharmacology and experimental verification in vivo, which provided a fresh perspective on the promoting effect of cinnamaldehyde on IIF in fish.

Mucous cell histopathology and label-free quantitative proteomic analysis of skin mucus in fat greenling (Hexagrammos otakii) infected with Vibrio harveyi

Hexagrammos otakii is favored by consumers and aquaculture practitioners because of its strong adaptability and fast growth. However, recently, frequent outbreaks of diseases in the breeding of H. otakii have led to significant economic losses, especially due to bacterial diseases, which limit the healthy breeding of H. otakii. As a luminescent Gram-negative bacterium, Vibrio harveyi is the main pathogenic bacteria of H. otakii. In this study, the histopathology and label-free quantitative proteomics analysis were performed to reveal the changes of skin mucus proteins in H. otakii after infection with V. harveyi. The histopathological changes in the skin of H. otakii showed that when the bacteria were injected into the epithelial cells, it caused an increase in the number of mucous cells and a certain degree of damage and deformation in skin. Moreover, the quantitative proteomics analysis revealed a total of 364 differentially expressed proteins (DEPs), and these DEPs were found to be involved in environmental information processing, metabolism, infectious diseases: bacteria, replication and repair. More importantly, the enrichment analysis of the DEPs revealed that these different proteins were mainly targeted immune-related pathways. After infection of bacteria, the host's immune ability will be weakened, causing V. harveyi to enter the organism more easily, resulting in increased mucus in H. otakii, which will eventually lead to a decline in its physical function. These results provided an insight into a series of physiological changes after the bacterial infection of fish at the proteomic level and basic data for further exploration of the potential mechanism of skin mucus. Taken together, the results indicated more opportunities for the future designs and discoveries of effective antibacterial vaccines and antibacterial drugs for H. otakii.