Effects of dietary blackberry syrup supplement on growth performance, antioxidant, and immunological responses, and resistance of Nile tilapia, Oreochromis niloticus to Plesiomonas shigelloides

Arthrospira platensis nanoparticles dietary supplementation improves growth performance, steroid hormone balance, and reproductive productivity of Nile tilapia (Oreochromis niloticus) broodstock

This study evaluates the impact of dietary supplementation of the blue-green alga Arthrospira platensis NIOF17/003 nanoparticles (AN) on the growth performance, whole-body biochemical compositions, blood biochemistry, steroid hormonal, and fry production efficiency of Nile tilapia (Oreochromis niloticus) broodstock, during the spawning season. After a 21-day preparation period to equip the females and ensure that their ovaries were filled with eggs, mating between the mature females and males took place in a 3:1 ratio during a 14-day spawning cycle. A total of 384 tilapia broodstock 288 females and 96 males with an initial body weight of 450.53±0.75, were divided into four groups; AN0: a basal diet as a control group with no supplementation of Arthrospira platensis, and the other three groups (AN2, AN4, and AN6) were diets supplemented with nanoparticles of A. platensis at levels of 2, 4, and 6 g kg─1 diet, respectively. The results found that fish-fed group AN6 showed the highest significant differences in weight gain (WG), final weight (FW), feed conversion ratio (FCR), protein efficiency ratio (PER), and feed efficiency ratio (FER). Females fed the AN6 diet showed the highest significant fat content. Compared to the AN0 group, fish fed on the supplemented diets showed significant improvement (p < 0.05) in triglyceride, glucose, and aspartate aminotransferase (AST). A gradual increase in AN inclusion level resulted in a gradual increase in the concentrations of luteinizing hormone (LH), and follicle-stimulating hormone (FSH), testosterone, progesterone, and prolactin. The rates (%) of increase in fry production for females fed supplemented diets were 10.5, 18.6, and 32.2% for AN2, AN4, and AN6, respectively, compared to the control group. This work concluded that the inclusion levels of 6 g kg─1 of A. platensis nanoparticles in the diet of Nile tilapia broodstock significantly improved the growth performances, steroid hormone concentrations, and increased the fry production efficiency by 32.2%, respectively. These findings revealed that A. platensis nanoparticles resulted in a significantly enhanced female' reproductive productivity of Nile tilapia broodstock.

Effects of methomyl on the intestinal microbiome and hepatic transcriptome of tilapia, and the modifying effects of mint co-culture

Methomyl (MET) is an oxime carbamate insecticide that can contaminate aquatic systems resulting in toxicological effects. It can harm some fish species possibly through the anti-oxidative, phagosome pathway. Mint is one of the most widely herbal plants exhibiting antioxidant activities. In this study, we investigated the impact of MET on the antioxidant system of Oreochromis niloticus in presence of mint as a floating bed. Results revealed that the superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase, and glutathione S-transferase significantly decreased and the GSH content significantly increased in the intestine. The hepatic peroxisome proliferator-activated receptor (PPAR) signalling pathway, carbon metabolism, renal phosphoinositide 3-kinase (PI3K)-Akt, mitogen-activated protein kinase (MAPK) signalling pathway, and phagosomes were significantly affected. Upon long-term exposure, circadian rhythm and phagosomes were enriched in the liver and kidney. However, mint increased the enriched pathways of Toll-like receptor, PPAR, p53, NF-kappa B, MAPK, oestrogen, and B cell receptor signalling pathways. MET with different concentrations destroyed the balance of gut microbiota, mint decreased Verrucomicrobia and Akkermansia for the maintenance resulted from MET. Cetobacterium had a positive impact on total nitrogen (TN), chemical oxygen demand (CODMn), and glutathione reductase (GR), while Akkermansia had a positive impact on feed conversion ratio (FCR), SOD and CAT, and the abundance of both decreased due to MET exposure. High mint density removed more concentrations of nitrogen and phosphorus in the tilapia cultivation wastewater. Therefore, planting with mint can alleviate the toxicological effects produced by MET, shape the intestinal microbiota, and strengthen the connection between water quality and the metabolic parameters.

Effects of florfenicol on the antioxidant and immune systems of Chinese soft-shelled turtle (Pelodiscus sinensis)

Florfenicol is a commonly used antibiotic for the treatment of bacterial diseases of the Chinese soft-shelled turtle (Pelodiscus sinensis). The study investigated the effects of florfenicol on the antioxidant and immune system of P. sinensis. Results showed that the total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and catalase (CAT) activities were significantly increased in the 10 mg/kg and 40 mg/kg florfenicol treatment groups compared with the control group. Besides, the malondialdehyde (MDA) content was significantly increased, and the glutathione peroxidase (GSH-Px) activity was significantly decreased with 40 mg/kg florfenicol treatment. In addition, florfenicol has effects on the immune system, 10 mg/kg of florfenicol significantly promoted the activities of acid phosphatase (ACP) and alkaline phosphatase (AKP), whereas 40 mg/kg of florfenicol significantly inhibited their activities. To elucidate the molecular mechanisms, a comparative transcriptome analysis was conducted. A total of 59 differentially expressed genes (DEGs) and 12 significantly enriched KEGG pathways were identified in the 10 mg/kg group; 150 DEGs and 10 significantly enriched KEGG pathways were identified in the 40 mg/kg group. Among them, the complement and coagulation cascade pathways were the most significant which may play an important regulatory role in the immune response. The MADCAM1, STAT3, and IL4I1 genes may be the key genes of florfenicol affecting the immune response. The APOA1, APOA4, SPLA2, FADS1, and FADS2 genes may play a key role in anti-inflammatory and antioxidant effects through redox-related pathways. The study lays the foundation for a deeper understanding of the mechanism of the florfenicol effect on P. sinensis.

Effect of anthocyanin-rich blackberry juice on endoplasmic reticulum stress in streptozotocin-induced diabetic rats

This study investigates blackberry juice's effects on glucose metabolism, oxidative stress, inflammation, and endoplasmic reticulum stress (ER) in streptozotocin (STZ)-induced diabetic rats. Fifty Wistar rats were distributed to five groups randomly of ten rats each: Normal control, diabetic control, 9 mL/kg body weight (b.wt) blackberry juice only, blackberry juice plus diabetes, and 500 mg/kg b.wt metformin plus diabetes. A single intraperitoneal injection of 50 mg/kg b.wt STZ induced diabetes in the rats. This animal study continued for 56 days after the confirmation of diabetes. The levels of liver function and renal function, as well as insulin, glucose-6-phosphatase, glucokinase, and malondialdehyde (MDA) levels, and the activities of catalase (CAT) and superoxide dismutase (SOD), were determined. Additionally, interleukin-6 (IL-6) levels, tumor necrosis factor-alpha (TNF-α), and activated transcription factor 4 (ATF4) expressions were examined in the liver homogenate of rats. Furthermore, the liver tissues were utilized for histopathological examination. The results showed that blackberry juice prevented drastic loss of body weight and reduced food consumption in diabetic rats. Additionally, the levels of blood glucose, total protein, aspartate aminotransferase (AST), albumin, alanine aminotransferase (ALT), uric acid, creatinine, and urea improved after the administration of blackberry juice in diabetic rats. Blackberry juice significantly increased glucose metabolism and antioxidant status while reducing ER stress and inflammation in diabetic rats. Moreover, blackberry juice improved glucose metabolism by increasing insulin levels and improving the dysregulated activities of glucose-metabolizing enzymes. The microstructure of liver tissues in diabetic rats was also improved with blackberry juice treatment. Therefore, blackberry juice has the potential to alleviate diabetes in rats and could be considered as a functional food for people with diabetes.

Effects of dietary walnut (Juglans regia) leaves extract on immunity, gene expression responses, and disease resistance in Oreochromis niloticus

The dietary effects of walnut leaf extract (WLE) on the growth, immunity, and resistance of Oreochromis niloticus to bacterial infection have been investigated. Five diets were prepared with various WLE doses of 0, 250, 500, 750, and 1000 mg/kg, termed as Con (control), WLE250, WLE500, WLE750, and WLE1000, respectively. Fish (11.67 ± 0.21 g) were fed these diets for 60 days and then challenged with Plesiomonas shigelloides. Before the challenge, it was observed that dietary WLE did not significantly affect the growth, blood proteins (globulin, albumin, and total protein), and liver function enzymes (ALT and AST) activities. The WLE250 group significantly increased serum SOD and CAT activities more than other groups. The serum immunological indices (lysozyme and myeloperoxidase activities) and hematological parameters (phagocytic activity %, phagocytic index, respiratory burst activity, and potential activity) were significantly increased in the WLE groups compared with the Con group. The expression of IgM heavy chain, IL-1β, and IL-8 genes were significantly upregulated in all WLE-supplemented groups in comparison with the Con group. The fish survival rates (SR; %) post challenge in the Con, WLE250, WLE500, WLE750 and WLE1000 groups were 40.0%, 49.3%, 86.7%, 73.3%, and 70.7%, respectively. The Kaplan-Meier survivorship curves illustrated that the highest SR% was found in the WLE500 group (86.7%) amongst the other groups. Accordingly, we can suggest that feeding O. niloticus with a diet supplied with WLE at a dose rate of 500 mg/kg over 60 days could enrich haemato-immune responses and increase the fish survival against the challenge with P. shigelloides. These results recommend using WLE as a herbal dietary supplement to substitute antibiotic use in aquafeed.

Pathogenicity of Plesiomonas shigelloides causing mass mortalities of largemouth bass (Micropterus salmoides) and its induced host immune response

The outbreak of mass mortality of M. salmoides occurred in an aquaculture farm in Jiangsu province of China, showing signs of skin ulceration and haemorrhages. The bacteria were isolated from diseased largemouth bass, and identified as Plesiomonas shigelloides based on morphological, physiological and biochemical features, as well as 16S rRNA gene sequence analysis. The pathogenicity of P. shigelloides was determined by challenge experiments, and the median lethal dosage (LD₅₀) of the isolate NJS1 for M. salmoides was calculated as 1.6 × 10⁵ CFU/mL at 7 d post-infection. Histopathological analysis revealed that extensive necrosis, vacuolization and inflammation were presented in the kidney, liver and gill of the diseased fish. Detection of virulence-related genes showed that P. shigelloides NJS1 was positive for astA, astB, astD, astE, actP and 6 ahpA. Additionally, the host defensive response of M. salmoides infected by P. shigelloides was analyzed by quantitive real-time PCR (qRT-PCR), and the results showed that the expression levels of Cas3, Hep1, HIF, IgM, IL15 and TGF were significantly up-regulated in head kidney, liver and spleen in different hours post-infection, which revealed varying expression profiles and clear transcriptional activation of immune related genes. The results suggested that P. shigelloides was an etiological element in the mass mortalities of M. salmoides and this study provided deeper insights for the pathogenesis and host defensive system in P. shigelloides invasion.

Aaqueous exposure to silver nanoparticles synthesized by abalone viscera hydrolysates promotes the growth, immunity and gut health of zebrafish (Danio rerio)

Silver nanoparticles (AgNPs) have the potential to be used in aquaculture, but their influence on the growth and health of aquatic organisms has not been extensively investigated. In this study, the abalone viscera hydrolysates decorated AgNPs (AVH-AgNPs) were dispersed into aquaculture water at different concentrations (0, 6, 9, and 18 μg/l) to evaluate the biological effects on zebrafish (Danio rerio). The results showed that the AVH-AgNPs treatments of 6 and 9 μg/l promoted the growth and did not cause obvious damage to the gills, intestines, and livers of zebrafish. All the treatments induced catalase (CAT) and superoxide dismutase (SOD) activities and increased glutathione (GSH) content in the livers and upregulated the expression of immune related genes. The effects of 9 and 18 μg/l AVH-AgNPs treatments were more obvious. After AVH-AgNPs treatment, the abundances of some potential pathogens, such as species Plesimonas shigelloides and Pseudomonas alcaligenes and genus Flavobacterium decreased significantly. In contrast, the abundance of some beneficial bacteria that can degrade pollutants and toxins (e.g., Rhodococcus erythropolis) increased significantly. Thus, the application of low concentrations (6 ~ 18 μg/l) of AVH-AgNPs in aquaculture water is relatively safe and has a positive effect on zebrafish farming.

Streptococcosis a Re-Emerging Disease in Aquaculture: Significance and Phytotherapy

Simple Summary

Streptococcosis is an economical important bacterial disease that can seriously cause huge losses in the global aquaculture sector. In recent years studies have focused on to use extracts or essences of medicinal herbs and plants to control or treat the disease outbreaks and, in most cases the results were promising. The essential oils of the herbs or plants are more effective than the extracts and, the extracts examined have moderate efficacy in term of increasing fish survival against fish streptococcosis that could be due to the enhancement of fish immunity by the herb bio-compounds. The lack of dosage optimization, toxicity and bioavailability assays of a specific herb/plant or its bioactive compound in fish organs make it difficult to judge the validation of clinical efficacy of a particular herb/plant against fish streptococcosis, and thus, required further investigations.

Abstract

Streptococcosis, particularly that caused by S. iniae and S. agalactiae, is a major re-emerging bacterial disease seriously affecting the global sustainability of aquaculture development. Despite a wide spread of the disease in aquaculture, few studies have been directed at assessing the in vitro antagonistic activity and in vivo efficacy of medicinal herbs and other plants against streptococcal agents. Most in vitro studies of plant extractives against S. iniae and S. agalactiae have found antibacterial activity, but essential oils, especially those containing eugenol, carvacrol or thymol, are more effective. Although essential oils have shown better anti-streptococcal activity in in vitro assays, in vivo bioassays require more attention. The extracts examined under in vivo conditions show moderate efficacy, increasing the survival rate of infected fish, probably through the enhancement of immunity before challenge bioassays. The available data, however, lack dosage optimization, toxicity and bioavailability assays of a specific plant or its bioactive compound in fish organs; hence, it is difficult to judge the validation of clinical efficacy for the prevention or treatment of fish streptococcosis. Despite the known bioactive compounds of many tested plants, few data are available on their mode of action towards streptococcal agents. This review addresses the efficacy of medicinal plants to fish streptococcosis and discusses the current gaps.

Dietary Supplementation with Eucommia ulmoides Leaf Extract Improved the Intestinal Antioxidant Capacity, Immune Response, and Disease Resistance against Streptococcus agalactiae in Genetically Improved Farmed Tilapia (GIFT; Oreochromis niloticus)

A 7-week rearing trial was designed to investigate the effects of Eucommia ulmoides leaf extract (ELE) on growth performance, body composition, antioxidant capacity, immune response, and disease susceptibility of diet-fed GIFT. The results showed that dietary ELE did not affect growth performance or whole-body composition (p > 0.05). Compared with the control group, plasma ALB contents increased in the 0.06% dietary ELE group (p < 0.05), and plasma ALT and AST activities decreased in the 0.08% dietary ELE group (p < 0.05). In terms of antioxidants, compared with GIFT fed the control diet, 0.06% dietary ELE upregulated the mRNA expression levels of Nrf2 pathway-related antioxidant genes, including CAT and SOD (p < 0.05), and 0.06% and 0.08% dietary ELE upregulated the mRNA levels of Hsp70 (p < 0.05). In terms of immunity, 0.06% dietary ELE suppressed intestinal TLR2, MyD88, and NF-κB mRNA levels (p < 0.05). Moreover, the mRNA levels of the anti-inflammatory cytokines TGF-β and IL-10 were upregulated by supplementation with 0.04% and 0.06% dietary ELE (p < 0.05). In terms of apoptosis, 0.06% and 0.08% ELE significantly downregulated the expression levels of FADD mRNA (p < 0.05). Finally, the challenge experiment with S. agalactiae showed that 0.06% dietary ELE could inhibit bacterial infection, and significantly improve the survival rate of GIFT (p < 0.05). This study demonstrated that the supplementation of 0.04−0.06% ELE in diet could promote intestinal antioxidant capacity, enhance the immune response and ultimately improve the disease resistance of GIFT against Streptococcus agalactiae.

Influence of black rice (Oryza sativa L.) bran derived anthocyanin-extract on growth rate, immunological response, and immune-antioxidant gene expression in Nile tilapia (Oreochromis niloticus) cultivated in a biofloc system

This study investigated the effects of dietary supplementation with anthocyanin extracted from black rice bran (AR) on the growth rate, immunological response, and expression of immune and antioxidant genes in Nile tilapia raised in an indoor biofloc system. A total of 300 Nile tilapia fingerlings (15.14 ± 0.032 g) were maintained in 150 L tanks and acclimatized for two weeks. Five experimental AR diets (0, 1, 2, 4, and 8 g kg^-1) with various anthocyanin doses were used to feed the fish. We observed that the growth and feed utilization of fish fed with different dietary AR levels increased significantly after eight weeks (p < 0.05). In addition, the serum immunity of fish fed AR diets was much greater than that of those fed non-AR diets (p < 0.05). However, there were little or no difference in between fish fed AR enriched diets and the control AR-free diet (p > 0.05). After eight weeks, fish fed AR-supplemented diets had significantly higher mRNA transcript levels in immune (interleukin [IL]-1, IL-8, and liposaccharide-binding protein [LBP]) and antioxidant (glutathione transferase-alpha [GST-α] and glutathione reductase [GSR]) genes compared to control fish fed the AR-free diet, with the greatest enhancement of mRNA transcript levels (in the case of IL-8 by up to about 5.8-fold) in the 4 g kg^-1 AR diet. These findings suggest that dietary inclusion of AR extract from black rice bran at 4-8 g kg^-1 could function as a herbal immunostimulant to enhance growth performance, feed consumption, and immunity in Nile tilapia.

Effects of Elephantopus scaber extract on growth, proximate composition, immunity, intestinal microbiota and resistance of the GIFT strain of Nile tilapia Oreochromis niloticus to Streptococcus agalactiae

This study aimed to investigate the effects of Elephantopus scaber extract on the GIFT (genetic improvement of farmed tilapia) strain of Nile tilapia Oreochromis niloticus. A total of 800 tilapia with an initial body weight of 1.34 ± 0.09 g each were randomly divided into five groups. The tilapia in the control group (E0 group) were fed on a basal diet only. Meanwhile, tilapia in the four experimental groups were fed on a basal diet supplemented with 1 g/kg (E1 group), 3 g/kg (E2 group), 5 g/kg (E3 group), and 7 g/kg (E4 group) of E. scaber extract for 10 weeks. Results showed that the survival rate was higher in the experimental groups than in the control group. Compared with the control group, some growth parameters (FW, WGR, SGR, VSI, and HSI) were significantly improved in the E1 group and E2 group. The crude lipid content in the dorsal muscle and liver was lower in the E1 group than in the control group. After E. scaber extract supplementation, activities of immunity-related enzymes (ACP, AKP, T-AOC, SOD, CAT, GSH-Px and LZM) in plasma, liver, spleen and head kidney, and expressions of immunity-related genes (IL-1β, IFN-γ, TNF-α, and CCL-3) in liver, spleen and head kidney showed various degrees of improvement, while MDA content and Hsp70 expression level were decreased. The survival rate of tilapia increased in all the supplementation groups after Streptococcus agalactiae treatment. E. scaber extract addition changed the species composition, abundance, and diversity of intestinal microbiota in tilapia. These results demonstrate that E. scaber extract supplementation in diet can improve the growth, immunity, and disease resistance of GIFT against S. agalactiae. E. scaber extract supplementation can also change intestinal microbiota and reduce crude lipid content in dorsal muscle and liver. The above indicators show that the optimal dose of E. scaber extract for GIFT is 1 g/kg.

Research progress of anthocyanin prebiotic activity: A review

BACKGROUND

Anthocyanins are a kind of flavonoids and natural water-soluble pigments, which endow fruits, vegetables, and plants with multiple colors. They are important source of new products with prebiotic activity. However, there is no systematic review documenting prebiotic activity of anthocyanins and their structural analogues. This study aims to fill this gap in literature.

PURPOSE

The objective of this review is to summarize and evaluate the prebiotic activity of anthocyanin's, and discuss the physical and molecular modification methods to improve their biological activities.

STUDY DESIGN AND METHODS

In this review, the databases (PubMed, Google Scholar, Web of Science, Researchgate and Elsevier) were searched profoundly with keywords (anthocyanin's, prebiotics, probiotics, physical embedding and molecular modification).

RESULTS

A total of 34 articles were considered for reviewing. These studies approved that anthocyanins play an important role in promoting the proliferation of probiotics, inhibiting the growth of harmful bacteria and improving the intestinal environment. In addition, physical embedding and molecular modification have also been proved to be effective methods to improve the prebiotic activity of anthocyanins. Anthocyanins could promote the production of short chain fatty acids, accelerate self degradation and improve microbial related enzyme activities to promote the proliferation of probiotics. They inhibited the growth of harmful bacteria by inhibiting the expression of harmful bacteria genes, interfering with the role of metabolism related enzymes and affecting respiratory metabolism. They promoted the formation of a complete intestinal barrier and regulated the intestinal environment to keep the body healthy. Physical embedding, including microencapsulation and colloidal embedding, greatly improved the stability of anthocyanins. On the other hand, molecular modification, especially enzymatic modification, significantly improved the biological activities (antioxidant, prebiotic activity and so on) of anthocyanins.

CONCLUSION

All these research results displayed by this review indicate that anthocyanins are a useful tool for developing prebiotic products. The better activities of the new anthocyanins formed by embedding and modification may make them become more effective raw materials. Our review provides a scientific basis for the future research and application of anthocyanins.

Immunopotentiators improve the antioxidant defense, apoptosis, and immune response in Shaoxing ducklings

The abuse of antibiotics for agricultural purposes has been under scrutiny. Therefore, there is an urgent need to find antibiotic substitutes in animal production. The effects of chlorogenic acid, β-D-Glucan, astragalus flavone, CpG-DNA, and chicken IgG on spleen antioxidant capacity, apoptosis, and the immune response in Shaoxing ducklings were investigated in this study. The ducklings treated with β-D-Glucan, astragalus flavone, CpG-DNA, and chicken IgG showed significant reduction in catalase and superoxide dismutase activities. The five immunopotentiators facilitated caspase 3 expression and reduced Bcl2 expression in the spleen. Compared to the control group, the protein level of COX2 was significantly upregulated in the chlorogenic acid, CpG-DNA, and chicken IgG groups. The protein level of iNOS expression was significantly improved in all immunopotentiator groups, except for the astragalus flavone group. The five immunopotentiators induced IL-1β, IFN-α, IFN-β, TNF-α, RIG-I, TLR3, and TLR7 gene expression. In summary, chlorogenic acid, β-D-Glucan, astragalus flavone, CpG-DNA, and chicken IgG, as immunopotentiators, improved the innate immune response in the ducklings, which not only provides a new avenue for the development of efficient approaches to prevent pathogen infections, but also offers an alternative to antibiotics in animal production.

Maximum levels of cross-contamination for 24 antimicrobial active substances in non-target feed. Part 7: Amphenicols: florfenicol and thiamphenicol

The specific concentrations of florfenicol and thiamphenicol in non-target feed for food-producing animals, below which there would not be an effect on the emergence of, and/or selection for, resistance in bacteria relevant for human and animal health, as well as the specific antimicrobial concentrations in feed which have an effect in terms of growth promotion/increased yield, were assessed by EFSA in collaboration with EMA. Details of the methodology used for this assessment, associated data gaps and uncertainties, are presented in a separate document. To address antimicrobial resistance, the Feed Antimicrobial Resistance Selection Concentration (FARSC) model developed specifically for the assessment was applied. The FARSC for florfenicol was estimated. However, due to the lack of data, the calculation of the FARSC for thiamphenicol was not possible until further experimental data become available. To address growth promotion, data from scientific publications obtained from an extensive literature review were used. Levels in feed that showed to have an effect on growth promotion/increased yield were reported for florfenicol, whilst for thiamphenicol no suitable data for the assessment were available. Uncertainties and data gaps associated to the levels reported were addressed. For florfenicol, it was recommended to perform further studies to supply more diverse and complete data related to the requirements for calculation of the FARSC, whereas for thiamphenicol, the recommendation was to generate the data required to fill the gaps which prevented the FARSC calculation.

The impact of acute cold water stress on blood parameters, mortality rate and stress-related genes in Oreochromis niloticus, Oreochromis mossambicus and their hybrids

This study aims to evaluated the response of Oreochromissp. to cold stress. Two experiments were conducted involving a total of 1080 juvenile Oreochromis niloticus, O. mossambicus, O. niloticus♂ × O.mossambicus♀=F1♂ × O.mossambicus ♀ (Hybrid 1; H1) and O. mossambicus♂ × O. niloticus♀ (Hybrid 2; H2). In the 1st experiment, fish were exposed to cold water (12 °C) for 24 h and then hematological parameters, serum biochemical variables, innate immune responses, antioxidant status, and liver gene expression responses (hsp70, hsp27, hsp90, hsp40, cat, sod, eef1a1 and calreticulin) were analyzed. Hematological and serum biochemical responses involved species-specific differences. At optimal temperatures (28 °C), respiratory burts activity (RBA) and myeloperoxidase (MPO) values of H1, H2 and O. mossambicus were significantly higher than O. niloticus (p< 0.05). While the RBAvalue of O. mossambicus decreased after exposure to cold water (p< 0.05), lysozyme activities of O. niloticus and H2 and MPO activities of all experimental fish increased significantly (p< 0.05). At control conditions (28 °C), cortisol levels were found to be higher in O. mossambicus than in H1 and O. niloticus (p< 0.05). A significant increase in cat and sod transcripts was observed in liver of fish being very pronounced in O. mossambicus and H2. The highest up-regulation was observed for hsp70 target where the lowest but significant up-regulation was observed for hsp90 gene. In 2nd experiment, water temperature was gradually decrease from 28 °C to 12 °C (average, 1 °C/1 h).Survival rates of H1 and H2 were found to be different compared to O. mossambicus and O. niloticus (p< 0.05) after 20 days of cold water challenge.O. mossambicus was the most cold-sensitive group, followed by the H2, H1 and O. niloticus. Our data should be carfully considered in view of the possible physiological and anti-stressor responses being species-specific in fish.

Effects of dietary white mulberry leaves on hemato-biochemical alterations, immunosuppression and oxidative stress induced by Aeromonas hydrophila in Oreochromis niloticus

The present work was designed to assess the potential hemato-biochemical protective action, immunemodulatory and antioxidant conclusions of varied concentration of white mulberry Morus alba leaves (MAL) extract supplementation on Nile tilapia (Oreochromis .niloticus). A total two hundred and forty of O. niloticus were haphazardly sorted into four groups. The control (CT) group was fed on basal diet. A group MAL₁, MAL₃ and MAL₅ was fed on 1, 3 and 5 g/kg MAL respectively for thirty days. On day thirty one, half of replicates in each group were challenged by 0.5 ml × 10⁸Aeromonas hydrophila where, the residual replicates were kept without challenge. A. hydrophila challenged tilapias revealed anemia that alleviated by supplementation with 5 g/kg MAL also, recovers the shift of leucogram prompted by the challenge. Elevation of alkaline phosphatase, aminotransferases, lactate dehydrogenase and malondialdehyde (ALP, ALT, AST, LDH and MDA) in CT, MAL₁ and MAL₃ in the challenged replicates respectively where within normal at MAL₅. Supplementation with MAL₅ showed more potent antioxidant and immune reaction than MAL₁ and MAL₃. There were a rapid increase of immunoglobulin M, lysozymes, nitric oxide, catalase and superoxide dismutase and their allied genes expression (IgM, CAT and SOD) in MAL groups with contrast in CT challenged groups. Where in challenged groups, there was suppression in genes expression of interleukins (8 and 1 beta) and interferon ɤ (IL8. IL-1β and INFɤ). Tilapias challenged by A. hydrophila unveiled plentiful surge in the percentage of mortality in CT challenged fish (80%), followed by the groups supplemented with MAL₁ and MAL₃ were (73.33%) where MAL₅ was 20%. The mortalities have been halted from the 6^th, 13^th, 14^th and 15^th days in, MAL₅, MAL₃, MAL₁, and CT correspondingly. These previous results could be fulfilled that using of MAL 5 g/kg protect tilapias from hemato-biochemical alterations and enhance its immune feedback, antioxidant defense and resistance against A. hydrophila.

Nano spirulina dietary supplementation augments growth, antioxidative and immunological reactions, digestion, and protection of Nile tilapia, Oreochromis niloticus, against Aeromonas veronii and some physical stressors

The current study evaluated the effects of nano delivery of Spirulina platensis on growth performance, digestive enzymes, and biochemical, immunological, and antioxidative status, as well as resistance to Aeromonas veronii and some physical stressor challenges in Nile tilapia, Oreochromis niloticus. Three experimental fish groups (n = 270) with mean weights of 26 ± 0.30 g and mean lengths of 10 ± 0.5 cm were used; the first additive-free basal diet served as the control group, whereas the following two groups were supplemented with spirulina nanoparticles (SPNP) at 0 (control), 0.25, and 0.5%/kg diet for 4 weeks. Following the feeding trial, fish were challenged with hypoxia, cold stresses, and pathogenic bacteria (A. veronii) infection (9 × 10⁸ CFU/ml). SPNP supplementation, especially 0.5%, (p < 0.05) significantly increased growth performance (specific growth rate % day^-1, feed conversion ratio, and length gain rate %), immunological (plasma lysozyme and liver nitrous oxide) antioxidants (superoxide dismutase, catalase, and glutathione peroxidase in liver), biochemical (aspartate aminotransferase, alanine transaminase, glucose, and cortisol concentrations in plasma) assays, and digestive enzymes (lipase and amylase in plasma). The expression of liver's heat shock protein 70 (HSP70) and interleukin 1, beta (IL-1β) genes showed a significant upregulation outline of 0.5% SPNP > 0.25% SPNP > 0% SPNP compared with the control. Protection in the incorporated fish groups exposed to A. veronii was 100% compared with the control group, which showed 50% cumulative mortalities. In conclusion, dietary SPNP supplementation improved growth performance, antioxidant activity, immune response, digestive enzymes, related gene expression, and resistance of Nile Tilapia to hypoxia, cold, and A. veronii infection. Thus, SPNP could be used as a natural therapy for controlling those stressors.

Cutaneous mucosal immune-parameters and intestinal immune-relevant genes expression in streptococcal-infected rainbow trout (Oncorhynchus mykiss): A comparative study with the administration of florfenicol and olive leaf extract

This study evaluated changes in cutaneous mucosal immunity (total protein (TP) and immunoglobulin (TIg), lysozyme, protease, esterase, and alkaline phosphatase (ALP)) and some immune-related genes expression (tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-8, hepcidin-like antimicrobial peptides (HAMP), and immunoglobulin M (IgM)) in the intestine of rainbow trout (Oncorhynchus mykiss) orally-administrated florfenicol (FFC) and/or olive leaf extract (OLE), experimentally infected with Streptococcus iniae. The juvenile fish (55 ± 7.6 g) were divided into different groups according to the use of added OLE (80 g kg^-1 food), the presence/absence of FFC (15 mg kg^-1 body weight for 10 consecutive days), and the streptococcal infectivity (2.87 × 10⁷ CFU mL^-1 as 30% of LD₅₀-96h). The extract's chemical composition was analyzed using the high-performance liquid chromatography (HPLC) system. The skin mucus and intestine of fish were sampled after a 10-day therapeutic period for all groups, and their noted indices were measured. Our results signified that the oleuropein, quercetin, and trans-ferulic acid were the most obvious active components of OLE which were found by HPLC analysis. The combined use of OLE and FFC could lowered some skin mucus immunological indices (e.g., TP, TIg, and ALP), and the gene expression of inflammatory cytokines (e.g., TNF-α and IL-1β) of rainbow trout. Moreover, lysozyme and protease activities respectively were invigorated by the FFC and OLE treatment. Also, the use of OLE as a potential medicine induced the gene expression of HAMP. As the prevention approach, it would be recommended to find the best dose of OLE alone or in combination with the drug through therapeutics period before the farm involved in the streptococcal infection.

Dietary supplementation of black mulberry (Morus nigra) syrup improves the growth performance, innate immune response, antioxidant status, gene expression responses, and disease resistance of Nile tilapia (Oreochromis niloticus)

The present study investigated the effects of black mulberry (Morus nigra) syrup supplementation on growth performance, hematological, serum biochemical, innate immune parameters, immune and antioxidant related gene expression responses, and disease resistance of Nile tilapia, Oreochromis niloticus. Five isonitrogenous and isoenergetic diets were formulated to contain black mulberry syrup at levels of 0%, 0.75%, 1.5%, 2.0%, and 3.0%. Fish were fed experimental diets for 60 days. Dietary black mulberry syrup increased activities of serum lysozyme, myeloperoxidase, superoxide dismutase and catalase, and increased the expression levels of immune-related genes (interleukin 1, beta, tumor necrosis factor, immunoglobulin M, interferon gamma and heat shock protein 70) in the spleen and antioxidant-related genes (superoxide dismutase, catalase and glutathione peroxidase) in the liver of fish fed especially with 1.5%, 2.0%, and 3.0% black mulberry syrup supplemented diets. Furthermore, at 2.0% incorporation level, growth performance increased. The findings of the present study indicate that Nile tilapia fed with diet containing 2.0% black mulberry might be adequate to improve the growth performance, innate immune parameters, antioxidant related gene expression responses, and disease resistance against Aeromonas veronii.

Effects of dietary fern (Adiantum capillus-veneris) leaves powder on serum and mucus antioxidant defence, immunological responses, antimicrobial activity and growth performance of common carp (Cyprinus carpio) juveniles

A 56-day research was performed to examine the influence of graded levels (0 (control), 0.5, 1 and 2%) of Fern (Adiantum capillus-veneris) leaves powder (FLP) in diet on immune competence and growth of common carp (Cyprinus carpio, initial weight = 20 g). The serum total immunoglobulins content and lysozyme activity in the 1 and 2% FLP groups remarkably increased compared to the other groups (P < 0.05). The skin mucosal lysozyme activity enhanced with increasing dietary FLP level in a dose-response manner. Fish fed on the FLP-supplemented diets had higher skin-mucosal superoxide dismutase activity than the control (P < 0.05). However, serum antioxidant enzymes were not affected by dietary fern (P > 0.05). The serum bactericidal activity against human and fish pathogens increased with enhancing the FLP level in diet against Staphylococcus aureus, Escherichia coli (EHEC ATCC 43895), Escherichia coli (CI), Pseudomonas aeruginosa, Klebsiella pneumonia and Aeromonas hydrophila. The serum antibacterial activity against Yersinia ruckeri in the 2% FLP group was higher than the other treatments. Furthermore, the serum bactericidal activity against P. aeruginosa (ATCC 27853) only observed in fish fed on the 1 and 2% FLP-supplemented diets. The skin mucosal bactericidal activity and inhibitory effects increased with enhancing the FLP level in diet against E. coli, K. pneumonia, Y. ruckeri and A. hydrophila in a dose response manner. Moreover, the skin mucosal bactericidal activity against S. aureus only observed in fish fed on 1 and 2% FLP-supplemented diets. The weight gain values in the 1 and 2% FLP groups were higher than the other treatments (P < 0.05). Feed conversion ratio (FCR) improved with increasing FLP level in diet in a dose-response manner (P < 0.05). By considering serum and mucosal bactericidal activities against different pathogenic bacteria, the supplementation of 2% FLP in diet is recommended for C. carpio during grow-out phase.

The growth performance, antioxidant capacity, immunological responses, and the resistance against Aeromonas hydrophila in Nile tilapia (Oreochromis niloticus) fed Pistacia vera hulls derived polysaccharide

The present study aimed at evaluating the supplementation of dietary Pistacia vera hulls derived polysaccharide (PHDP) at varying levels (0, 2.5, 5, and 10 g/kg diet) on the growth rate, digestive enzyme activity, immune response, and antioxidative capacity of Nile tilapia. After the feeding trial (60 days), fish were injected intraperitoneally with Aeromonas hydrophila, and the cumulative mortality was calculated for 10 days. The final body weight, weight gain, specific growth rate, survival rate, amylase activity, red blood cells, hemoglobin, serum total protein, and serum lysozyme activity (LZM) were significantly higher in fish fed PHDP at 5 and 10 g/kg than fish fed 0 and 2.5 g/kg diet (P ≤ 0.05). However, the feed conversion ratio and glucose levels were significantly decreased by 5 and 10 g PHDP/kg diet. Further, the protease digestive activity, serum alkaline phosphatase, and serum alternative complement (ACH50) had higher values in fish fed 5 g PHDP/kg diet than tilapia fed 0 g PHDP/kg diet (P ≤ 0.05). The serum protease and immunoglobulin (Ig) presented the highest values in fish fed 10 g PHDP/kg diet followed by fish fed 5 g PHDP/kg diet (P ≤ 0.05). The LZM, ACH50, and Ig in the mucus samples were significantly higher in fish fed 5 or 10 g PHDP/kg diet than fish fed 0 g PHDP/kg diet (P ≤ 0.05). The levels of superoxide dismutase and catalase in the liver tissue was significantly higher in fish fed 5 or 10 g PHDP/kg diet than fish fed 2.5 g PHDP/kg diet (P ≤ 0.05). On the other hand, malondialdehyde concentration was significantly lower in tilapia fed 5 and 10 g PHDP/kg diet than tilapia fed 0 and 2.5 g PHDP/kg diet (P ≤ 0.05). The lowest mortality rate and the highest relative percentage survival were in fish fed 5 g/kg followed by 10 g level after 10 days of A. hydrophila injection. Accordingly, dietary PHDP at 5-10 g/kg is recommended to improve the growth performance, antioxidative capacity, immune response, and resistance against A. hydrophila in Nile tilapia.

Antioxidative and immunoprotective potential of Chlorella vulgaris dietary supplementation against chlorpyrifos-induced toxicity in Nile tilapia

This study highlighted the effects of chronic chlorpyrifos (CPF) exposure on Nile tilapia (Oreochromis niloticus) and the benefits of using dietary Chlorella vulgaris (Ch) to ameliorate CPF-induced toxicity. Genes encoding antioxidant enzymes and stress-responsive proteins in the liver as well as cytokine expression in the spleen and head kidney were evaluated in O. niloticus fed with a basal diet or diets containing 1, 2, and 3% of supplementary Ch against 15 mg/L CPF at 4 and 8 weeks. CPF-exposed groups displayed a notable induction in the hepatic expression of heat shock protein 70/hsp70, glutathione peroxidase/GPx, and glutathione synthase/GSS, while glutathione reductase/GSR was markedly decreased. The mRNA levels of interleukin 1β/IL-1β, TNF-α, transforming growth factor β1/TGFβ1, and interleukin 8/ IL-8 in the spleen and head kidney increased significantly after CPF exposure. Interestingly, Ch supplementation, particularly at levels 2 and 3%, was able to modulate the stress and immune-related genes of Nile tilapia sub-chronically exposed to CPF. These outcomes provide valuable insights regarding the toxic impact of chronic exposure to CPF in fish at the molecular level and a better understanding of the Ch dietary vital roles. Besides, our findings encourage adequate monitoring of pesticide levels owing to its impacts on fish health and human as a final consumer.

Effect of Black Mulberry (Morus nigra) Powder on Growth Performance, Biochemical Parameters, Blood Carotenoid Concentration, and Fillet Color of Rainbow Trout

The degree of flesh pigmentation is one of the most important quality criteria dictating the fish market value. It is well known that fish, like other animals, cannot synthesize their own coloring pigments de novo, and must obtain these pigments from their diet. In this study, four levels of black mulberry (Morus nigra) juice powder (BMP) as a natural pigment source were incorporated into a basal diet at concentrations of 0, 0.25, 0.5, and 0.75% and fed to rainbow trout weighing 100±5 g for 8 weeks in triplicate. At the end of the feeding trial, the effect of BMP on growth performance, blood biochemical parameters and fillet color was examined. Fish fed BMP showed significant enhancements in weight gain (WG), specific growth (SGR), food conversion ratio (FCR), and survival rates (SR) (P<0.05). SGR, WG and SR values were increased significantly following dietary supplementation with BMP in a dose dependent manner with the highest values in fish fed 0.75%, while the FCR was decreased (P<0.05). Body crude protein, lipid, and moisture contents were increased significantly in fish fed BMP (P<0.05). Dietary BMP has significantly decreased the levels of blood ALT, AST, and glucose (P>0.05). While the blood carotenoid concentration was increased in fish fed 0.5% BMP compared to other treated groups. Fish fed BMP showed increased fillet yellowness (b*) and redness (a*), while the fillet lightness (L*) was decreased when compared to the control (P<0.05). In conclusion, diets supplemented with BMP increased the growth performance, muscle pigmentation, and health status of rainbow trout.

High carbohydrate diet partially protects Nile tilapia (Oreochromis niloticus) from oxytetracycline-induced side effects

Antibiotics used in global aquaculture production cause various side effects, which impair fish health. However, the use of dietary composition such as carbohydrate, which is one of the dominant components in fish diets to attenuate the side effects induced by antibiotics, remains unclear. We determined the ability of high carbohydrate diet to protect Nile tilapia (Oreochromis niloticus) from oxytetracycline-induced side effects. Triplicate groups of thirty O. niloticus (9.50 ± 0.08 g) were fed on medium carbohydrate (MC; 335 g/kg) and high carbohydrate (HC; 455 g/kg) diets without and with 2.00 g/kg diet of oxytetracycline (80 mg/kg body weight/day) hereafter, MCO and HCO for 35 days. Thereafter, we assessed growth performance, hepatic nutrients composition and metabolism, microbiota abundance, immunity, oxidative and cellular stress, hepatotoxicity, lipid peroxidation and apoptosis. To understand the possible mechanism of carbohydrate protection on oxytetracycline, we assessed the binding effects and efficiencies of mixtures of medium and high starch with oxytetracycline as well as the MCO and HCO diets. The O. niloticus fed on the MCO and HCO diets had lower growth rate, nutrients utilization and survival rate than those fed on the MC and HC diets, respectively. Dietary HCO increased hepatosomatic index and hepatic protein content of O. niloticus than MCO diet. The O. niloticus fed on the HCO diet had lower mRNA expression of genes related to protein, glycogen and lipid metabolism compared to those fed on the MCO diet. Feeding O. niloticus on the HCO diet increased innate immunity and reduced pathogenic bacteria, pro-inflammation, hepatotoxicity, cellular stress and apoptosis than the MCO diet. The high starch with oxytetracycline and HCO diet had higher-oxytetracycline binding effects and efficiencies than the medium starch with oxytetracyline and MCO diet, respectively. Our study demonstrates that, high carbohydrate partially protects O. niloticus from oxytetracycline-induced side effects by binding the antibiotic. Incorporating high carbohydrate in diet formulation for omnivorous fish species alleviates some of the side effects caused by antibiotics.

Growth performance, haematological changes, immune response, antioxidant activity and disease resistance in rainbow trout (Oncorhynchus mykiss) fed diet supplemented with ellagic acid

The present study was performed to investigate the effects of various levels of dietary ellagic acid (EA) on growth performance, haematological values, immune response, protection against Yersinia ruckeri infection, and oxidant/antioxidant status in rainbow trout, Oncorhynchus mykiss. Fish were fed with the control diet and three different experimental diets containing three graded levels of EA (50, 100 and 200 mg kg^-1 diet) for 8 weeks. At the end of the experiment, the growth performance [weight gain (WG), specific growth rate (SGR) and feed conversion ratio (FCR)], haematological values [the red blood cell (RBC) count, haemoglobin (Hb) concentration, haematocrit (Ht) level and erythrocyte indices: mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC)], immune response [white blood cell (WBC) count, oxidative radical production (nitroblue tetrazolium (NBT) assay), phagocytic activity (PA) and phagocytic index (PI), total protein (TP) and immunoglobulin M (IgM) levels, serum bactericidal activity (BA), lysozyme (LYZ) and myeloperoxidase (MPO) activities] and oxidant/antioxidant status [tissue malondialdehyde (MDA) levels and superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities] were analysed. In addition, fish were challenged by Y. ruckeri and survival rate was recorded for 14 days. In the groups fed with EA the growth parameters such as WG, SGR, and FCR did not vary significantly. The RBC count, Hb concentration, and Ht level increased in the groups fed with EA when compared with the control group. However, there were no significant differences in the MCV, MCH and MCHC values among the groups. The results demonstrated enhancement in all the immunological parameters in the groups fed with EA compared to the control group. The results obtained from challenge with Y. ruckeri revealed reduction in the mortalities in the groups fed with EA. The dietary EA stimulated the SOD, CAT and GSH-Px activities in liver, head kidney and spleen as compared to the control group; however, a reverse trend was observed in the MDA levels of tissues. The present study suggest that EA can effectively enhance the haematological values, immune response, antioxidant capacity, and disease resistance in rainbow trout.

Bacillus velezensis LF01: in vitro antimicrobial activity against fish pathogens, growth performance enhancement, and disease resistance against streptococcosis in Nile tilapia (Oreochromis niloticus)

Streptococcus agalactiae is a major pathogen causing streptococcosis. To prevent and control this bacterial disease, antagonistic bacteria have become a new research hotspot. This study evaluated the probiotic potential of Bacillus velezensis LF01 strain, which is antagonistic to S. agalactiae. The active compounds produced by LF01 showed antimicrobial activity against a broad spectrum of fish pathogens, including S. agalactiae, Streptococcus iniae, Aeromonas hydrophila, Edwardsiella tarda, Edwardsiella ictaluri, Aeromonas schubertii, Aeromonas veronii, Aeromonas jandaei, and Vibrio harveyi. The antimicrobial compounds were heat stable, pH stable, UV stable, resistant to proteases, and could be stored for a long time. To evaluate the probiotic function of LF01 in Nile tilapia, juveniles were divided into three treatment groups: a control group, an interval feeding group, and a continuous feeding group. Tilapia fed with LF01-supplemented diets (1.0 × 10⁹ CFU/g) showed significantly better growth performances than those of the control group (P < 0.05). Tilapia fed with LF01-supplemented diets significantly increased lysozyme (LZY) and superoxide dismutase (SOD) activities. The expression of three immune-related genes (C3, lyzc, and MHC-IIβ) was higher in the intestine, head kidney, and gill of tilapia from the continuous feeding group than in those from the control group (P < 0.05). Tilapia fed with LF01-supplemented diets showed remarkably improved survival rates after S. agalactiae infection, and analysis of their intestinal tract pathogens revealed that the abundance of Edwardsiella and Plesiomonas had significantly decreased compared with the control group. Our findings demonstrate that LF01 is an effective antagonist against various fish pathogens and has potential for controlling infections by Streptococcus spp. and other pathogens in tilapia.

Effects of dietary anthocyanin on innate immune parameters, gene expression responses, and ammonia resistance of Nile tilapia (Oreochromis niloticus)

The present study investigated the effects of dietary anthocyanin on the growth performance, haematological, non-specific immune, and spleen gene expression responses of Nile tilapia, Oreochromis niloticus. Five experimental groups of fish with mean weights of 8.24 ± 0.64 g were used in the study; four of these were fed with diets incorporating anthocyanin (20 mg kg -¹, 40 mg kg^-1, 80 mg kg^-1 and 160 mg kg^-1), while the fifth was a control group without dietary anthocyanin. Growth performance and haematological parameters of tilapia were not affected by anthocyanin-supplemented diets (p > 0.05). Dietary anthocyanin significantly increased respiratory burst activity, phagocytic activity, phagocytic index, lysozyme activity, myeloperoxidase activity, serum total superoxide dismutase (T.SOD) activity, and serum catalase (CAT) activity (p < 0.05). The total immunoglobulin level was highest in the 80 mg kg^-1 group compared with the other groups (p < 0.05). In addition, with the anthocyanin-containing diets, the gene levels of interleukin 1, beta (IL-1β), interleukin 8 (IL-8), tumor necrosis factor (TNF-α), heat shock protein 70 (HSP70), and interferon gamma (IFN-γ) were increased in the fish spleen, and the gene levels of CAT, GPx, and SOD were also increased in fish liver (p < 0.05). At the end of the experiment, the fish were subjected to ammonia stress. The groups fed with 20 and 40 mg kg^-1 anthocyanin exhibited higher survival rates than the other groups. In summary, feeding Nile tilapia with anthocyanin-containing diets caused increases in the innate immune parameters, gene expression responses, and the survival rate of the fish subjected to ammonia stress.

Quality Traits of Fillet of Gilthead Sea Bream (Sparus aurataL.) of Two Market Sizes Reared according to an “Antibiotic-Free” Approach

Rearing of “antibiotic-free” fish is becoming one of the most important goals to be achieved in the near future. Strategies are going to be adopted to increase nonspecific immune system and biosecurity in fish farming. To show the quality traits of gilthead sea breams reared under a prescription of “antibiotic-free” (ABF), two different market sizes (R: about 350 g andM: about 490 g) were analysed at the end of the farming cycle performed in a floating cage plant in the Adriatic sea, in the Gulf of Valona (Albania). Proximate composition and fatty acid profile were determined in April and June 2018. The omega-3 content demonstrated that the ABF samples collected according to the fish size and the harvest month can be defined as “rich in omega-3,” in compliance with the Annex to the Regulation (EC) n. 1924/2006, with a trend to increase in relation to fish growth.

Effects of curcumin on haematological values, immunity, antioxidant status and resistance of rainbow trout (Oncorhynchus mykiss) against Aeromonas salmonicida subsp. achromogenes

The present study was conducted to evaluate the effects of various levels of dietary curcumin on growth performance, haematological values, immunity and protection against Aeromonas salmonicida subsp. achromogenes infection in rainbow trout, Oncorhynchus mykiss. Fish were fed with diets containing different levels of curcumin; 0% (C), %1 (E1), %2 (E2) and %4 (E3), as treatment groups. After 8 weeks of feeding, the growth performance [weight gain (WG), specific growth rate (SGR) and feed conversion ratio (FCR)], haematological values [the red blood cell (RBC) count, haemoglobin (Hb) concentration, haematocrit (Ht) level and erythrocyte indices: mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC)], various immune parameters [white blood cell (WBC) count, oxidative radical production (nitroblue tetrazolium (NBT) assay), phagocytic activity (PA) and phagocytic index (PI), total protein (TP) and immunoglobulin M (IgM) levels, serum bactericidal (BA), lysozyme (LYZ) and myeloperoxidase (MPO) activities] and antioxidant capacity [tissue malondialdehyde (MDA) levels and superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities] were analysed. In addition, fish were challenged by Aeromonas salmonicida subsp. achromogenes and survival rate was recorded for 14 days. The results indicated that the growth performance was significantly influenced by the dietary curcumin levels, the maximal WG and SGR occurred at fish fed the diet containing 2% curcumin. Fish fed the diet containing curcumin had lower FCR than those fed the control diet. The RBC count, Hb concentration, and Ht level increased in the groups fed with curcumin when compared with the control group. However, there were no significant differences in the MCV, MCH and MCHC values among experimental groups. All the chosen immune parameters were enhanced in the groups fed diets containing curcumin. Also, the relative percentage survivals were higher in the groups fed with curcumin, especially in the E2 group, compared to the control. The dietary curcumin stimulated the SOD, CAT and GSH-Px activities in liver, head kidney and spleen as compared to the control group; however, a reverse trend was observed in the MDA levels of tissues. The highest values for haematological, immunological (except TP level of E3 group) and antioxidant parameters were found in the E2 group. These results collectively suggest that curcumin can be used in aquaculture to improve the growth, haematological values, immune responses, antioxidant capacity and disease resistance of rainbow trout, O. mykiss.

Immunomodulatory effects of orally administrated florfenicol in rainbow trout (Oncorhynchus mykiss) following experimental challenge with streptococcosis/lactococcosis

The purpose of the present work was to determine whether florfenicol (FFC) as the prominent broad-spectrum antibiotic could affect serum biochemical and immunological parameters, as well as immune-related genes expression in rainbow trout (55 ± 7.6 g) challenged with the Lactococcus garvieae and Streptococcus iniae. In the first trial, the doses of the pathogens for challenge test were determined based on LD50. The therapeutic dosage of the drug (15 mg.kg^-1 BW for 10 consecutive days) was administrated as medicated feed. After anesthesia, blood and kidney samples were collected from individual fish and were kept in deep freezing mode until the beginning of the measurements. Serum biochemical and enzymatic indices were measured using commercial kits. Immune parameters including total immunoglobulin level, lysozyme, ACH50, respiratory burst (RB), and phagocytic activities (PA) and the expression of immune genes namely TNF-α, IL-1β, IL-8, and IgM was evaluated. The levels of lysozyme and RB activities, as well as the expression of TNF-α and IL-1β genes, showed a significant increase in the FFC treated/infected fish compared to untreated diseased fish (P < 0.05). In contrast, serum total immunoglobulin and IgM-related genes expression were suppressed following drug administration represented by a significant reduction in untreated streptococcal infected fish compared to other treatments (P < 0.05). However, no significant effect of FFC was observed on serum ACH50 activity, PA values and IL-8-related gene expression (P > 0.05). These results demonstrated that FFC treatment could improve some physiological status including stress resistance and some liver function parameters, and much innate immunity was invigorated, but at the same time, the suppressive effects of FFC on acquainted immunity cannot be ignored.

Blackberry juice anthocyanidins limit cisplatin-induced renal pathophysiology in mice

Some studies have showed that intake of blackberry juice (BBJ) can prevent urinary tract infections. However, there is a lack of studies that evaluate the mechanisms by which BBJ has protective effect. Thus, the aim of current study was to evaluate the effects of BBJ supplementation on cisplatin-induced renal pathophysiology in mice. Mice were supplemented with BBJ (10 mL/kg) for seven days. One hour after the last supplementation with BBJ, mice received cisplatin (10 mg/kg, i.p.). Seventy-two hours after cisplatin administration, blood was collected and biochemical analysis were performed (urea and creatinine), kidney was dissected and utilized in histological and oxidative evaluations. Cisplatin caused severe injury in renal tissue, in markers of renal damage (urea and creatinine) generated increased of plasmatic levels. Besides that, the cisplatin induced decreased of enzymes activities in renal tissue (superoxide dismutase, glutathione S-transferase and catalase). In contrast, BBJ supplementation protected against histopathological alterations through decreased in urea and creatinine levels and modulation of catalase enzyme activity. Thus, BBJ supplementation protected the renal system of mice from deleterious effects. We suggest that high concentrations of Cyanidin 3-O-glucoside and Cyanidin 3-O-rutinoside are responsible for antioxidant role of BBJ supplementation in renal pathophysiology induced by cisplatin exposure. Also, these results reinforcing the importance of including BBJ in the human diet aimed at preventing renal diseases.