Search Results (213)

Mori Cortex Radicis (MCR), which is abundant in resources and low in cost, is a Chinese herbal medicine with antitussive, anti-inflammatory, analgesic, and hypoglycemic effects; however, its application in the prevention and control of aquatic pathogens remains understudied. In this study, a MCR water extract (MCR-WE) was prepared, and its contents of polysaccharides, polyphenols, and proteins were found to be 0.63%, 1.17%, and 2.79%, respectively. LC-MS metabolomics revealed that L(+)-Arginine, 9,12,13-Todea, Citric acid, 1-Deoxynojirimycin, and 4-Guanidinobutanoic acid were the most abundant compounds. Subsequently, by feeding the MCR-WE to crucian carp (Carassius auratus) and challenging them with Aeromonas veronii, it was found that the MCR-WE enhanced the activities of immune factors (AKP, ACP, LZM) and the phagocytic activity of leukocytes (p < 0.05). Furthermore, the MCR-WE improved the survival rate of crucian carp (p < 0.05), reduced the bacterial load in the kidneys (p < 0.05), decreased the mRNA expression of inflammatory factors (IL-6, IL-1β, TNF-α), and lowered the expression levels of antioxidant-related factors (CAT, GSH-Px, SOD, MDA) and the mRNAs of oxidative stress pathway factors (Nrf2, HO-1, Keap1) (p < 0.05). Histopathological sections and immunofluorescence assays showed that the MCR-WE maintained the structural integrity of internal organs and reduced renal cell apoptosis and DNA damage. Therefore, MCR-WE is rich in immunologically active substances, can activate the immune response of crucian carp, reduce fish mortality, exert anti-inflammatory and antioxidant activities, and maintain the structural and functional integrity of internal organs. Thus, the MCR-WE holds promise as a therapeutic agent against A. veronii infection in fish. Full article

Mushrooms are considered a significant source of antioxidants, antimicrobials, and phytonutrients. Consequently, they can serve as a phytogenic feed additive to prevent oxidative stress, while improving rumen fermentation efficiency. The aim of the present investigation was to evaluate the effects of bolete mushroom extract (BME) supplementation on in vitro digestive enzymes, nutrient degradability, antioxidant capacity, rumen fermentation, and methane production. In a completely randomized design, six treatment levels of BME were implemented. The total dry matter (DM) substrate of BME was supplemented at 0%, 1%, 2%, 3%, 4%, and 5%. The results demonstrated that BME increased the activity of digestive enzymes, particularly amylase activity and in vitro dry matter degradability. Importantly, at 4% of the total DM substrate, BME significantly increased levels of total antioxidant and catalase activity, while malondialdehyde activity was reduced. BME addition contributed to an increase in propionate and total volatile fatty acid production, while methane production was decreased. As a result, BME could be effective as a sustainable feed additive comprising phytonutrients to enhance rumen fermentation and reduce methane emissions in ruminants. Full article

The goal of this study was to replace the costly fishmeal (FM) with Tenebrio molitor larvae meal (TMLM) in diets for Nile tilapia (Oreochromis niloticus) juveniles. Six isonitrogenous diets were created in order to examine the viability of substituting FM protein with stepwise inclusion levels of TMLM protein, i.e., 0%, 15%, 30%, 45%, 60%, and 75% represented by TMLM0, TMLM15, TMLM30, TMLM45, TMLM60, and TMLM75, respectively. For 90 days, Nile tilapia juvenile (8.8–10.5 g) were fed on TMLM diets three times a day until apparent satiation. Nile tilapia fed on TMLM levels were found to significantly (p < 0.05) boosted their growth and feed efficiency indices by up to 45%, after which their performance declined. In comparison to other treatments, larger villi length/width and increased digestive enzymes activity were observed at this level (TMLM45). At TMLM45, there were no signs of inflammation in the liver tissues but feeding the fish on TMLM60 and TMLM75 showed more vacuolated hepatocytes and fewer hepatic sinusoids. Total protein, albumin, and globulin contents showed significant (p < 0.05) increases in response to TMLM levels in fish feeds; meanwhile no significant (p > 0.05) changes in blood glucose were observed compared to the control one (TMLM0). The values of alanine and aspartate aminotransferase, total cholesterol, and triglycerides decreased significantly (p < 0.05) as TMLM levels increased in fish feeds. In addition, significant (p < 0.05) increases in antioxidant and immunological variables were observed in fish fed with TMLM diets, in particular TMLM45. The current study concluded that the substitution of FM protein by 45% TMLM protein in diets administered to Nile tilapia juveniles significantly improved (p < 0.05) their growth, antioxidant, and immune response compared to the control diet (FM-based diet). Full article

Arnica (Chiliadenus glutinosus (L.) Fourr.) is an endemic plant widely used in Spanish traditional medicine as infusions and alcoholic macerates for different ailments. Despite this use, information about the biological activity of these preparations in fish-related models is scarce. In the present study, the arnica extract bioactivity assay evaluated aqueous, ethanolic, and methanolic extracts at different doses (0, 0.001, 0.01, 0.125, 0.25, 0.5, and 1 mg mL⁻¹) to compare their antioxidant activity, effects on four marine fish pathogens (Vibrio harveyi, Vibrio anguillarum, Photobacterium damselae and Tenacibaculum maritimum), cytotoxicity on the PLHC1 tumour cell line, and their impact on immunological parameters in head-kidney leucocytes (HKLs) of gilthead seabream (Sparus aurata). All extracts showed dose-dependent antioxidant activity, while bactericidal effects depended on the solvent and were mainly observed at the highest concentrations. Ethanolic and methanolic extracts displayed clear cytotoxicity, whereas the aqueous extract showed lower toxicity and was selected for further evaluation. In the carrageenan stimulation assay, selected concentrations (0, 0.25, and 0.5 mg mL⁻¹) of the aqueous extract were tested in leucocytes stimulated with λ-carrageenan (0 and 1000 µg mL⁻¹), and respiratory burst and phagocytic activity, cell morphology, and gene expression were analysed. The aqueous extract reduced respiratory burst and phagocytic capacity in activated leucocytes and was associated with morphological signs of cell activation. It also downregulated crel and casp9 expression. These results provide a comparative view of the in vitro bioactivity of different traditional preparations of arnica and show that their biological effects strongly depend on the solvent used and the concentration tested, providing initial experimental information on their cellular effects in fish. Full article

Allergic anisakiasis (AA), caused by the ingestion of fish contaminated with Anisakis larvae, has emerged as a growing global health concern due to the increasing consumption of raw or undercooked seafood. Anisakis simplex is identified as the primary etiologic species, responsible for gastrointestinal symptoms, IgE-mediated (Type I) or cell-mediated (Type IV) manifestations, and gastro-allergic anisakiasis (GAA), a unique clinical overlap between parasitic infection and acute IgE-mediated food allergy. In this review, we analyzed the epidemiology of Anisakis simplex allergy, the main diagnostic methods to confirm a diagnosis of food allergy, its clinical manifestations, and how these differ in different countries around the world. This multidisciplinary synthesis provides, for the first time, an integrated understanding of Anisakis-induced disease mechanisms across human, animal, and cellular levels. The persistence of allergenic proteins despite standard food processing underscores the need for improved diagnostic tools, public health surveillance, and preventive strategies—particularly in populations with high seafood consumption or occupational exposure. A comprehensive approach combining clinical, molecular, and immunological perspectives is essential to address the expanding global burden of allergic anisakiasis. Full article

Encapsulated probiotics, which are promising approaches for improving aquaculture species’ performance and health, have incompletely characterized dose-dependent physiological and immunological effects. This study represents the first report evaluating the probiotic efficacy of a novel encapsulated Lysinibacillus sp. PWR01, originally isolated from rubber latex nodules, in Nile tilapia (Oreochromis niloticus). A total of 300 Nile tilapia (10.80 ± 0.07 g) was allocated to four experimental groups receiving 0, 10⁴, 10⁵, and 10⁶ CFU/g of encapsulated Lysinibacillus sp. PWR01 in their diet. At 8 weeks of the feeding trial, growth performance, feed utilization, serum antioxidant status, intestinal bacterial counts and immune-related gene expression were analyzed. Results demonstrated that fish fed 10⁶ CFU/g achieved a final weight of 51.48 g, representing a 9.88% increase compared with the control (46.85 g), while weight gain (WG) improved by 12.82% and specific growth rate (SGR) by 6.34%. Feed conversion ratio (FCR) was reduced by up to 18.42% at 10⁵ CFU/g relative to the control. Encapsulated groups enhanced serum superoxide dismutase activity without altering malondialdehyde levels, increased total intestinal bacterial and lactic acid bacteria counts, and selectively upregulated TLR2 and MHC II mRNA transcript levels. Histological analysis further revealed increased intestinal villus height and width in encapsulated-fed groups, while liver architecture remained normal across treatments. Multivariate analyses demonstrated strong positive associations among growth performance, gut microbiota enrichment, and immune gene expression. Resistance to Aeromonas hydrophila infection was significantly improved at higher dietary doses, with post-challenge survival reaching 61.67–75% in supplemented groups versus 45.00% in controls. These findings demonstrate that latex-derived Lysinibacillus sp. PWR01 acts as a strain-specific immunomodulatory probiotic that enhances growth, antioxidant capacity, microbial community balance, and disease resistance to Nile tilapia. Future studies should investigate the role of the Nrf2 antioxidant pathway, clarify TLR2-mediated immune signaling, and assess gut microbiota–immune system interactions within commercial-scale production systems. Full article

Aquaculture output, sustainability, and profitability can be enhanced by using functional feed additives. The effect of supplementation with two different dietary levels of propylene glycol (PG) and essential oils (EOs) was evaluated in Nile tilapia. A total of 150 juvenile fish were randomly allocated into five groups. Growth performance, feed utilization, serum biochemistry, hematology, and gene expression were assessed. PG supplementation significantly improved growth performance, feed conversion, protein efficiency, and energy utilization. Both additives significantly reduced cortisol and glucose levels and altered liver enzymes and lipid profiles. PG improved immunological indices, while hematological responses were dose-dependent; both EOs and PG increased hematocrit, mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH). Moreover, the high PG dose significantly increased platelet counts, reduced hemoglobin (Hb), and elevated hematocrit. Additionally, EOs significantly upregulated antifreeze protein IV (AFPIV) and fat metabolism-related genes in a dose-dependent manner, indicating a potential role in lipid mobilization and stress tolerance. Expression analysis of the immunoglobulin H (IGMH) gene revealed a significant increase in PG-supplemented groups, suggesting its immunostimulatory potential. Overall, PG enhanced immunity and growth performance, while EOs promoted AFPIV and fat metabolism gene expression. Therefore, PG and EO supplementation could serve as an effective functional strategy to enhance O. niloticus growth, stress adaptation, and immune resilience. Full article

Fish collagen is derived from processing residues of marine and freshwater fish (such as fish skin, scales, and bones), primarily composed of amino acids including glycine, proline, and hydroxyproline. It functions include maintaining tissue integrity and promoting cell proliferation and repair. Extraction methods primarily include acid, alkali, enzymatic, and physical approaches, while purification techniques involve gel filtration chromatography, ultrafiltration, and precipitation. Furthermore, thermal instability, insufficient mechanical strength, immunological concerns, and biocompatibility limitations restrict its application across various fields. This review summarizes the composition, extraction, purification, and existing challenges of fish collagen, proposing improvement strategies. It systematically addresses issues related to fish collagen’s biocompatibility, filling a gap in the literature. However, effectively enhancing its biocompatibility remains an urgent priority. Approaches such as nanotechnology and composite material development offer novel avenues for improving biocompatibility and future applications. Full article

Background/Objectives: An attenuated strain of Micropterus salmoides rhabdovirus (MSRV) 0509 with good immunogenicity has been isolated, showing potential as a candidate for live vaccine development. Methods: To improve the shelf life of attenuated strain of MSRV0509, the virus was formulated using three distinct single-protectant formulations and twelve thermostable protective agent formulations (designated T1–T12). Following lyophilization, the thermostability of each formulation was evaluated. Results: Results indicated that formulations T1, T9, and T10 maintained stable viral titers after storage at 25 °C and 37 °C. Moreover, these formulations retained high viral viability after 12 months at 4 °C, with a titer reduction of less than 0.5 log₁₀. Immunological analyses revealed that the freeze-dried MSRV vaccine elicited both humoral and immune factors responses in largemouth bass. Immersion immunization provided effective protection, yielding a survival rate exceeding 80%. Freeze-dried vaccines maintained their immunogenicity (i.e., the ability to induce antibodies) following 12 months of storage at 4 °C. Additionally, expression of IFN-γ and IL-12 was significantly upregulated in fish post-vaccination. Conclusions: In conclusion, the lyophilized MSRV vaccine developed in this study not only exhibits improved thermostability and extended shelf life, but also effectively preserves its immunogenic properties, supporting its potential for practical aquaculture applications. Full article

Several studies have demonstrated that methionine supplementation in fish diets enhances immune status, inflammatory response, and resistance to bacterial infections by modulating for DNA methylation, aminopropylation, and transsulfuration pathways. However, the immunomodulatory effects of methionine in viral infections remain unexplored. This study aimed to evaluate the effect of methionine supplementation on immune modulation and resistance to the viral haemorrhagic septicaemia virus (VHSV) in rainbow trout (Oncorhynchus mykiss). Two diets were formulated and fed to juvenile rainbow trout for four weeks: a control diet (CTRL) with all nutritional requirements, including the amino acid profile required for the species, and a methionine-supplemented diet (MET), containing twice the normal requirement of DL-methionine. After feeding, fish were bath-infected with VHSV, while control fish were exposed to a virus-free bath. Samples were collected at 0 (after feeding trial), 24, 72, and 120 h post-infection for the haematological profile, humoral immune response, oxidative stress, viral load, RNAseq, and gene expression analysis. In both diets, results showed a peak in viral activity at 72 h, followed by a reduction in viral load at 120 h, indicating immune recovery. During the peak of infection, leukocytes, thrombocytes, and monocytes migrated to the infection site, while oxidative stress biomarkers (superoxide dismutase glutathione S-transferase, and glutathione redox ratio) suggested a compromised ability to manage cellular imbalance due to intense viral activity. At 120 h, immune recovery and homeostasis were observed due to an increase in the amount of nitric oxide, GSH/GSSG levels, leukocyte replacement, monocyte influx, and a reduction in the viral load. When focusing on the infection peak, gene ontology (GO) analysis showed several exclusively enriched pathways in the skin and gills of MET-fed fish, driven by the upregulation of several key genes. Genes involved in recognition/signalling, inflammatory response, and other genes with direct antiviral activity, such as TLR3, MYD88, TRAF2, NF-κB, STING, IRF3, -7, VIG1, caspases, cathepsins, and TNF, were observed. Notably, VIG1 (viperin), a key antiviral protein, was significantly upregulated in gills, confirming the modulatory role of methionine in inducing its transcription. Viperin, which harbours an S-adenosyl-L-methionine (SAM) radical domain, is directly related to methionine biosynthesis and plays a critical role in the innate immune response to VHSV infection in rainbow trout. In summary, this study suggests that dietary methionine supplementation can enhance a more robust fish immune response to viral infections, with viperin as a crucial mediator. The improved antiviral readiness observed in MET-fed fish underscores the potential of targeted nutritional adjustments to sustain fish health and welfare in aquaculture. Full article

RNA viruses are major pathogens in fish, causing high mortality and substantial economic losses in aquaculture. To uncover conserved antiviral mechanisms, we investigated the response of turbot (Scophthalmus maximus) to viral hemorrhagic septicemia virus (VHSV), infectious pancreatic necrosis virus (IPNV), and red-spotted grouper nervous necrosis virus (RGNNV) using a comparative proteomic approach complemented by in vivo and in vitro functional assays. Proteomic analyses revealed the central, conserved role of proteins involved in reactive oxygen species (ROS) production and redox homeostasis during early infection. Functional assays using head kidney-derived leukocytes identified neutrophils and macrophages as the primary ROS producers and showed that the modulation of cytoplasmic and mitochondrial ROS, as well as ROS-dependent DNA release, follows virus-specific patterns. The pharmacological inhibition of NADPH oxidase and mitochondrial ROS significantly affected viral replication, demonstrating the direct role of ROS in viral pathogenicity. Collectively, these findings highlight redox modulation as a conserved host response in teleost fish during RNA virus infection, linking oxidative stress regulation to viral progression. This knowledge provides a foundation for developing broad-spectrum therapeutic or preventive strategies to enhance disease resistance and promote sustainable aquaculture. Full article

In vertebrates, the interleukin-1β molecule (IL-1β) is among the most important proinflammatory cytokines and plays crucial roles in shaping injury progression, immunological challenges, and local and systemic responses to infection. In the current study, a cDNA encoding the IL-1β gene in Asian seabass (Lates calcarifer) (LcIL-1β) was identified at both the nucleotide and protein levels. Its immune responses were investigated in various tissues from diseased and normal fish. Recombinant rLcIL-1β was produced in Escherichia coli. Furthermore, its ability to control two fish pathogenic bacteria, Flavobacterium covae and Streptococcus iniae, was assessed in vitro. Transcriptional expression was quantified by qRT–PCR, which revealed the highest levels in whole blood, followed by the liver, gills and midgut. Immune response analyses of the head kidney, whole blood, liver, gills, spleen and intestines of fish infected with F. covae and S. iniae at concentrations of 1 × 10³, 1 × 10⁴ and 1 × 10⁵ CFU/fish, respectively, revealed significant upregulation of LcIL-1β (p < 0.05) for 6–24 h (h) after induction. Interestingly, compared with the control treatment, the application of 1, 10 and 100 µg of rLcIL-1β greatly increased the phagocytic activity and phagocytic index of phagocytes (p < 0.05). Antibacterial function analyses of F. covae and S. iniae revealed minimal inhibitory concentrations (MICs) of 29.17 and 85.25 μg/mL, respectively. Finally, injection of S. iniae following rLcIL-1β revealed that 50 and 100 µg of the target protein demonstrated significant functional activity in safeguarding Asian seabass from these pathogenic bacteria (p < 0.05). This information revealed that LcIL-1β in Asian seabass significantly drives immune defense mechanisms against pathogenic bacteria, which is important for the development of effective disease prevention methods for Asian seabass aquaculture. Full article

In higher vertebrates, Tripartite Motif (TRIM) proteins modulate the immune response by coordinating processes related to inflammation such as antiviral restriction, autophagy and inflammasome activation. In fish, TRIM proteins have been reported mainly in cyprinids (e.g., carp—Cyprinus carpio and zebrafish—Danio rerio) and salmonids (i.e., rainbow trout—Oncorhynchus mykiss). However, their molecular mechanisms and functions are still being described in aquatic animals. Thus, our study focused on characterizing novel TRIM proteins involved in the innate immunity of gill cells from rainbow trout (RTgill-W1 and primary cultures) stimulated with lipopolysaccharide (LPS) or polyinosinic–polycytidylic acid (poly I:C). Furthermore, an in vivo experiment with rainbow trout was performed to detect TRIM proteins after the challenge with Flavobacterium psychrophilum (a major bacterial pathogen affecting Chilean salmonid industry). In vitro results showed that OmTRIM25 triggered an LPS-induced expression of pro-inflammatory cytokines such as TNF-α2 and IL-1β. Moreover, in the fish experiment, OmTRIM25 and finTRIM2 were up-regulated in the gills two days post-infection (dpi), whereas IL-1β and TNF-α2 had a higher gene expression at four and six dpi, respectively. To investigate the immunological role of OmTRIM25, a gene silencing strategy using RNA interference (RNAi) was used, confirming the immunomodulatory function of OmTRIM25. Full article

The use of phytobiotics in aquafeeds is a promising strategy to enhance performance and resilience to disease. This study evaluated the protective role of Morus alba (MA) extract against Vibrio cholerae, integrating in vivo responses in Dormitator latifrons (growth, biochemical and enzymatic responses, haemato-immunology and tissue histopathology) with in vitro assessment of V. cholerae growth, virulence-associated gene expression and cellular morphology. D. latifrons juveniles were fed five diets (0, 5, 10, 15 and 20 g/kg feed; three tanks per treatment, 15 fish per tank) for eight weeks, followed by a 7-day challenge with V. cholerae. MA increased growth and feed utilisation (p < 0.05); the 20 g/kg group reached 27.57 g final weight with a feed conversion ratio of 1.24, and whole-body protein and lipid contents rose at higher doses. MA modulated plasma biochemistry and key digestive (amylase, lipase), metabolic (ALT, AST) and antioxidant (SOD, CAT, GPx) enzymes, and improved haematological profiles. Histology of the intestine, liver and spleen showed preserved architecture and reinforced mucosal features in supplemented fish, particularly at 15–20 g/kg. Post-challenge, supplemented groups exhibited higher survival/relative protection than controls, alongside lower transaminases and stronger antioxidant responses. In vitro, MA extract inhibited V. cholerae growth, attenuated virulence-associated gene (toxR, ompU) expression and induced marked morphological damage in planktonic cells. Multivariate analyses (Z-score heatmaps and PCA) linked immune–enzymatic improvements with growth and protection. Overall, 15–20 g/kg MA optimised immunophysiological status and disease resistance, supporting MA as a functional feed additive for sustainable aquaculture of D. latifrons. Full article

The cDNA sequences of the common gonadotrophic hormone α-subunit (ag-Gthα) and of the specific follicle-stimulating hormone β-subunit (ag-Fshβ) of the giant Amazonian fish Arapaima gigas have been previously isolated by our research group. A synthesis of ag-Fsh in HEK293 cells and its purification and preliminary characterization were also carried out. In the present work, ag-Fsh was obtained and purified from the same host cells, and an extensive physical chemical characterization was performed via RP-HPLC, HPSEC, and MALDI-TOF-MS. Ag-Fsh, when compared to human FSH (hFSH), showed a higher hydrophobicity by RP-HPLC and a higher molecular mass (MM) via HPSEC. The same higher MM was also confirmed via MALDI-TOF-MS: 35,353 Da for ag-FSH against 31,969 Da for hFSH. Its immunological activity was also confirmed via an hFSH ELISA, in comparison with the highly purified pituitary preparation of hFSH-AFP7298A, from the National Hormone and Pituitary Program (NHPP-USA), with a clear response that was, however, 1560-fold lower when compared to the purest preparation. Finally, an in vitro bioassay, based on the stimulated release of 11-ketotestosterone (11-KT) from immature A. gigas testis, quantified ag-Fsh biological activity in comparison with human chorionic gonadotropin (hCG) and with human pituitary FSH-AFP7298A, showing a potency clearly higher than that of hCG. This suggests that injections of ag-Fsh in A. gigas and ag-Fsh cDNA gene therapy applications could be used for improving the reproductive functions of this threatened species. Full article