Acanthopanax senticosus cultures fermented by Lactobacillus rhamnosus enhanced immune response through improvement of antioxidant activity and inflammation in crucian carp (Carassius auratus).

Lactic acid bacteria (LAB) have been recognized as safe microorganism that improve micro-flora disturbances and enhance immune response. A well-know traditional herbal medicine, Acanthopanax senticosus (As) was extensively utilized in aquaculture to improve growth performance and disease resistance. Particularly, the septicemia, skin wound and gastroenteritis caused by Aeromonas hydrophila threaten the health of aquatic animals and human. However, the effects of probiotic fermented with A. senticosus product on the immune regulation and pathogen prevention in fish remain unclear. Here, the aim of the present study was to elucidate whether the A. senticosus fermentation by Lactobacillus rhamnosus improve immune barrier function. The crucian carp were fed with basal diet supplemented with L. rhamnosus fermented A. senticosus cultures at 2 %, 4 %, 6 % and 8 % bacterial inoculum for 8 weeks. After trials, the weight gain rate (WGR), specific growth rate (SGR) were significantly increased, especially in LGG-6 group. The results confirmed that the level of the CAT, GSH-PX, SOD, lysozyme, and MDA was enhanced in fish received with probiotic fermented product. Moreover, the L. rhamnosus fermented A. senticosus cultures could trigger innate and adaptive immunity, including the up-regulation of the C3, C4, and IgM concentration. The results of qRT-PCR revealed that stronger mRNA transcription of IL-1ß, IL-10, IFN-γ, TNF-α, and MyD88 genes in the liver, spleen, kidney, intestine and gills tissues of fish treated with probiotic fermented with A. senticosus product. After infected with A. hydrophila, the survival rate of the LGG-2 (40 %), LGG-4 (50 %), LGG-6 (60 %), LGG-8 (50 %) groups was higher than the control group. Meanwhile, the pathological damage of the liver, spleen, head-kidney, and intestine tissues of probiotic fermentation-fed fish could be alleviated after pathogen infection. Therefore, the present work indicated that L. rhamnosus fermented A. senticosus could be regard as a potential intestine-target therapy strategy to protecting fish from pathogenic bacteria infection.

Blood cell characterization and transcriptome analysis reveal distinct immune response and host resistance of different ploidy cyprinid fish following Aeromonas hydrophila infection.

Aeromonas hydrophila can pose a great threat to survival of freshwater fish. In this study, A. hydrophila infection could decrease blood cell numbers, promote blood cell damage as well as alter the levels of alkaline phosphatase (ALP), lysozyme (LZM), aspartate aminotransferase (AST), total antioxidant capacity (T-AOC), total superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) in immune-related tissues of red crucian carp (RCC, 2 N = 100) and triploid cyprinid fish (3 N fish, 3 N = 150). In addition, the significant alternation of antioxidant status was observed in PBMCs isolated from RCC and 3 N following LPS stimulation. The core differential expression genes (DEGs) involved in apoptosis, immunity, inflammation and cellular signals were co-expressed differentially in RCC and 3 N following A. hydrophila challenge. NOD-like receptor (NLR) signals appeared to play a critical role in A. hydrophila-infected fish. DEGs of NLR signals in RCCah vs RCCctl were enriched in caspase-1-dependent Interleukin-1ß (IL-1ß) secretion, interferon (IFN) signals as well as cytokine activation, while DEGs of NLR signals in 3Nah vs 3Nctl were enriched in caspase-1-dependent IL-1ß secretion and antibacterial autophagy. These results highlighted the differential signal regulation of different ploidy cyprinid fish to cope with bacterial infection.

Remarkable positive effects of figwort (Scrophularia striata) on improving growth performance, and immunohematological parameters of fish.

This study was conducted to investigate the effect of figwort on the growth and immunohematological parameters of common carp (14.20 ± 0.53 g). Four experimental diets were developed to feed fish for eight weeks: control, Figw10 (10 g/kg figwort), Figw20 (20 g/kg figwort), and Figw30 (30 g/kg figwort). The results showed that fish fed dietary Figw10 gained more weight (38.25 g) than control (P < 0.05). Regarding immunohematological parameters, fish fed dietary Figw30 had a higher level of white blood cells (31.2 103/mm3), hematocrit (35.82%), blood performance (14.63), total protein (1.96 g/dL), albumin (0.79 g/dL), globulin (1.17 g/dL), lymphocyte (70.53%), monocyte (3.03%), alternative hemolytic complement activity (ACH50) (147.76 u/mL), lysozyme (62.19 u/mL), and bactericidal activities (135.24) than the control group (P < 0.05). After 14 days of the challenge with Aeromonas hydrophila, the Figw30 treatment had the highest survival ratio (61.76%) compared to the control with 26.46%. Further, after the challenge, fish fed dietary Figw30 had a higher value of immunoglobulin M (42.00 µg/mL), antibody titer (19.23), complement component 3 (296.39 µg/mL), and complement component 4 (97.91 µg/mL) when compared with those fed control diet (P < 0.05). In conclusion, the optimum dosage for providing the best immune response was 30 g/kg in diet.

SCFAs improve disease resistance via modulate gut microbiota, enhance immune response and increase antioxidative capacity in the host.

To evaluate the effects of dietary short chain fatty acids (SCFAs) on the intestinal health and innate immunity in crucian carp, a six-week feeding trial was carried out with following treatments: basal diet (BD), basal diet supplementation with 1% sodium acetate (BDSA), basal diet supplementation with 1% sodium propionate (BDSP) and basal diet supplementation with 1% sodium butyrate (BDSB). The results showed dietary BDSA, BDSP and BDSB could protect the host against oxidative stress by improving the activity of certain antioxidative enzymes (T-SOD, GSH-Px and CAT). Additionally, dietary SCFAs could enhance mucosal and humoral immune responses by improving certain innate immune parameters in serum and skin mucus productions (IgM, ACH50 and T-SOD). Furthermore, dietary BDSA and BDSP could up-regulate the expression of immune related genes (TNF-α, TGF-ß and IL-8) and tight junction protein genes (occludin and ZO-1). Dietary BDSB could also elevate the expression of IL-8, TGF-ß, ZO-1 and Occludin in the midgut. Although dietary differences of SCFAs didn't alter the α-diversity of the intestinal flora, they altered the core microbiota. Finally, the challenge trial showed that dietary basal diet supplementation with SCFAs could protect zebrafish against Aeromonas hydrophila. These results suggest that dietary SCFAs could improve innate immunity, modulate gut microbiota and increase disease resistance in the host, which indicated the potential of SCFAs as immunostimulants in aquaculture.

Metallothionein 3-Zinc Axis Suppresses Caspase-11 Inflammasome Activation and Impairs Antibacterial Immunity.

Non-canonical inflammasome activation by mouse caspase-11 (or human CASPASE-4/5) is crucial for the clearance of certain gram-negative bacterial infections, but can lead to severe inflammatory damage. Factors that promote non-canonical inflammasome activation are well recognized, but less is known about the mechanisms underlying its negative regulation. Herein, we identify that the caspase-11 inflammasome in mouse and human macrophages (Mϕ) is negatively controlled by the zinc (Zn2+) regulating protein, metallothionein 3 (MT3). Upon challenge with intracellular lipopolysaccharide (iLPS), Mϕ increased MT3 expression that curtailed the activation of caspase-11 and its downstream targets caspase-1 and interleukin (IL)-1ß. Mechanistically, MT3 increased intramacrophage Zn2+ to downmodulate the TRIF-IRF3-STAT1 axis that is prerequisite for caspase-11 effector function. In vivo, MT3 suppressed activation of the caspase-11 inflammasome, while caspase-11 and MT3 synergized in impairing antibacterial immunity. The present study identifies an important yin-yang relationship between the non-canonical inflammasome and MT3 in controlling inflammation and immunity to gram-negative bacteria.

Anti-vibrio and immune-enhancing activity of medicinal plants in shrimp: A comprehensive review.

Disease epidemics in shrimp aquaculture increase apace with the development of aquaculture systems throughout the world. The disease caused by Vibrio spp. (vibriosis) is considered the most devastating, which has made it the most feared bacterial disease in the shrimp sector. In aquaculture, several strategies have already been applied to control Vibrio strains, including chemicals, probiotics, antibiotics, natural products from plants, including plant oils; hence, there has been considerable attention for using plants in shrimp aquaculture to provide sustainable, eco-friendly and safe compounds, such as alkaloids, saponins, terpenoids and flavonoids for replacing chemical compounds and antibiotics in current aquaculture. Medicinal plants may also have immunostimulating activity, increase growth and resistance in shrimps. The present paper aims to review the inhibition of Vibrio spp. in shrimp by medicinal plants, using both in vitro or/and in vivo techniques. Several medicinal plants appear capable of inhibiting growth of Vibrio pathogens outside living shrimp or in the body of shrimp, through enhancing growth and immune capacity when shrimps are fed or injected with them. In the current review Gracilaria spp. (Gracilariaceae family) and Sargassum spp. (family Sargassaceae) have been used most for in vitro and in vivo experiments. Among the terrestrial plants, Eucalyptus camaldulensis, Psidium guajava, Rhodomyrtus tomentosa, and Syzygium cumini (Myrtaceae family) had significant activity against Vibrio.

Dietary supplementation of fermented lemon peel enhances lysozyme activity and susceptibility to Photobacterium damselae for orange-spotted grouper, Epinephelus coioides.

The waste recycling of lemon peel, as a functional feed additive in aquafeed was evaluated by estimating the effects of fermented lemon peel (FLP) supplementation in diet on growth performance, innate immune responses, and susceptibility to Photobacterium damselae of grouper, Epinephelus coioides. A basal diet was added FLP at 0%, 1%, 3%, and 5%. Four tested diets were each fed to juvenile grouper (initial weight: 15.89 ± 0.10 g, triplicate groups) in a recirculation rearing system for eight weeks. Fish fed diets with 0%-3% FLP exhibited higher (p < 0.05) final weight, weight gain, and feed efficiency than fish fed the 5% FLP-diet. After challenge test, fish fed the 3% FLP-diet appeared the lowest mortality, followed by fish fed the 1% FLP-diet, and lowest in fish fed 0% and 5% FLP-diets. Plasma lysozyme activities were higher in fish fed diets with FLP than in fish fed the FLP-free control diet before challenge test. After challenge, fish fed diets with 1% and 3% FLP showed highest lysozyme activities, followed by fish fed the diet with 5% FLP, and lowest in fish fed the control diet. Hepatic malondialdehyde content was higher in fish fed the control diet than in fish fed diets with 1%-3% FLP. Results found that diets supplemented with 1%-3% fermented lemon peel can enhance lysozyme activity and resistance to pathogen P. damselae of grouper.

Evaluation of Alpha-Ketoglutarate Supplementation on the Improvement of Intestinal Antioxidant Capacity and Immune Response in Songpu Mirror Carp (Cyprinus carpio) After Infection With Aeromonas hydrophila.

As an intermediate substance of the tricarboxylic acid cycle and a precursor substance of glutamic acid synthesis, the effect of alpha-ketoglutarate on growth and protein synthesis has been extensively studied. However, its prevention and treatment of pathogenic bacteria and its mechanism have not yet been noticed. To evaluate the effects of alpha-ketoglutarate on intestinal antioxidant capacity and immune response of Songpu mirror carp, a total of 360 fish with an average initial weight of 6.54 ± 0.08 g were fed diets containing alpha-ketoglutarate with 1% for 8 weeks. At the end of the feeding trial, the fish were challenged with Aeromonas hydrophila for 2 weeks. The results indicated that alpha-ketoglutarate supplementation significantly increased the survival rate of carp after infection with Aeromonas hydrophila (P < 0.05), and the contents of immune digestion enzymes including lysozyme, alkaline phosphatase and the concentration of complement C4 were markedly enhanced after alpha-ketoglutarate supplementation (P < 0.05). Also, appropriate alpha-ketoglutarate increased the activities of total antioxidant capacity and catalase and prevented the up-regulation in the mRNA expression levels of pro-inflammatory cytokines including tumor necrosis factor-α, interleukin-1ß, interleukin-6, and interleukin-8 (P < 0.05). Furthermore, the mRNA expression levels of toll-like receptor 4 (TLR4), and nuclear factor kappa-B (NF-κB) were strikingly increased after infection with Aeromonas hydrophila (P < 0.05), while the TLR4 was strikingly decreased with alpha-ketoglutarate supplementation (P < 0.05). Moreover, the mRNA expression levels of tight junctions including claudin-1, claudin-3, claudin-7, claudin-11 and myosin light chain kinases (MLCK) were upregulated after alpha-ketoglutarate supplementation (P < 0.05). In summary, the appropriate alpha-ketoglutarate supplementation could increase survival rate, strengthen the intestinal enzyme immunosuppressive activities, antioxidant capacities and alleviate the intestinal inflammation, thereby promoting the intestinal immune responses and barrier functions of Songpu mirror carp via activating TLR4/MyD88/NF-κB and MLCK signaling pathways after infection with Aeromonas hydrophila.

GAS1: A New ß-Glucan Immunostimulant Candidate to Increase Rainbow Trout (Oncorhynchus mykiss) Resistance to Bacterial Infections With Aeromonas salmonicida achromogenes.

ß-glucans are prebiotic and/or food additives used by the aquaculture industry to enhance the immune response of fish. Their efficiency may vary according to their origin and structure. In this study, the immunostimulant effects of two ß-glucan types extracted from wild-type baker's yeast (Saccharomyces cerevisiae) and its null-mutant Gas1 were investigated. Gas1 has a beta-1,3-glucanosyltransferase activity necessary for cell wall assembly. Using a positive (commercial product MacroGard®) and a negative control (a diet without glucans), we evaluated the immune responses and disease resistance of rainbow trout juveniles (mean weight, ~44 g) fed control, low (0.2%) and high (0.5%) doses of Macrogard®, Gas1, and Wild type-ß-glucan after a short-term (15 days, D15) or mid-term (36 days, D36) feeding periods. We found that ß-glucan supplemented diets did not affect growth performance, mortality, splenic index, or leukocyte respiratory burst activity on D15 nor D36. However, each ß-glucan triggered different immune effectors, depending of the doses or length of exposure compared to others and/or the negative control. Indeed, high dose of MacroGard® significantly increased lysozyme activities at D15 compared with the control and other diets (p<0.05). At D36, MacroGard ß-glucan enhanced the production of lymphocytes in comparison with the control diet (p<0.05). Regarding WT ß-glucan, at D36, WT-ß-glucan, especially the high dose, provided the highest enzymatic activities (lysozyme and ACH50) and Ig level (p<0.01). Furthermore, on D36, Gas1 also increased lysozyme activity, Ig proportion, and some immune genes (mcsfra, hepcidin) compared with MacroGard® (p<0.05). Besides, both doses of Gas1-ß-glucans increased the resistance of juveniles to bacterial infection highlighted by a higher survival rate at 14 days post-challenge compared with the control and other types and doses of ß-glucans (p<0.05). In conclusion, our results suggest that Gas1-ß-glucan could represent a promising immunostimulant that would help to prevent diseases in aquaculture even more efficiently than other ß-glucans already in use. Mode of action and particular efficiency of this new Gas1 mutant are debated.

Protective Effect of Leek Extract (Allium ampeloprasum L.) on Catfish (Clarias gariepinus) Experimentally Challenged with Aeromonas hydrophila.

BACKGROUND AND OBJECTIVE: Leek (Allium ampeloprasum) is one of the most commonly used herbal foods all over the world. This study was conducted to evaluate the protective effect of leek extract on catfish experimentally challenged with Aeromonas hydrophila, a problematic bacterial pathogen that affects various freshwater fish species. MATERIALS AND METHODS: Aeromonas hydrophila was isolated and identified from catfish showing clinical signs of septicemia. The in vitro activity of leek extract to control the growth of Aeromonas hydrophila was investigated. In the in vivo experiment, about 240 adult catfish (Clarias gariepinus) were fed three different leek extract concentrations (10, 25 and 50 mg kg-1 body weight) for 1 month. Later on, a challenge study was conducted using an identified A. hydrophila strain. Morbidity and mortality were recorded throughout one week post-challenge. Furthermore, the effect of leek extract on some immune-related genes was investigated. RESULTS: Under the in vitro testing, a significant increase (10 and 13 mm) in the inhibition zone was recorded in wells treated with 25 and 50 mg L-1 leak extract, respectively. A significant reduction in fish mortalities was reported in all leek extract treated groups compared to the control group which was given water. TLR1 gene expression was upregulated in fish treated with leek extract while TNFα gene expression was down-regulated. CONCLUSION: Overall, results suggested that the leek extract has immunostimulating effects that can help control bacterial infections in catfish and probably other fish species.

In vitro evaluation of novel (nanoparticle) oral delivery systems allow selection of gut immunomodulatory formulations.

Oral delivery is the most convenient way to vaccinate cultured fish, however it is still problematic, primarily due to a lack of a commercially valid vaccine vehicle to protect the antigen against gastric degradation and ensure its uptake from the intestine. With the goal of advancing the potential to vaccinate orally, this study evaluates a novel silicon nanoparticle-based vehicle (VacSaf carrier). Aeromonas salmonicida antigens were formulated with the VacSaf carrier using different preparation methods to generate dry powder and liquid formulations. Twelve formulations were first subjected to an in vitro evaluation where the A. salmonicida bacterin conjugated to VacSaf carriers were found superior at inducing pro-inflammatory cytokine expression in primary leucocyte cultures and the macrophage/monocyte cell line RTS-11 compared with A. salmonicida bacterin alone. This was especially apparent after exposure to acid conditions to mimic stomach processing. One formulation (FD1) was taken forward to oral delivery using two doses and two administration schedules (5 days vs 10 days, the latter 5 days on, 5 days off, 5 days on), and the transcript changes of immune genes in the intestine (pyloric caeca, midgut and hindgut) and spleen were evaluated by qPCR and serum IgM was measured by ELISA. The VacSaf carrier alone was shown to be safe for use in vivo, in that no side-effects were seen, but it did induce expression of some cytokines, and may have value as an oral adjuvant candidate. The FD1 bacterin formulation was effective at inducing a range of cytokines associated with innate and adaptive immunity, mainly in the pyloric caeca, compared to A. salmonicida bacterin alone (which had almost no effect), and confirms the immune competence of this gut region following appropriate oral vaccination. These results reveal that in vitro screening of formulations for oral delivery has value and can be used to assess the most promising formulations to test further.

Dietary ß-glucan (MacroGard®) improves innate immune responses and disease resistance in Nile tilapia regardless of the administration period.

The effects of dietary ß-glucan on innate immune responses have been shown in a number of different vertebrate species. However, there is conflicting information about the period of administration (shorter vs. longer), and it is also unclear to what extent ß-glucan's effects can be observed post-treatment in fish. Thus, we fed Nile tilapia for 0 (control group; 45 days of control diet), 15 (30 days of control followed by 15 days of ß-glucan), 30 (15 days of control followed by 30 days of ß-glucan) or 45 days with a diet containing 0.1% of ß-glucan (MacroGard®). We evaluated the growth performance at the end of the ß-glucan feeding trial and the innate immune function immediately after the feeding trial and 7 and 14 days post-feeding trial. In addition, at day 10 post-feeding trial, we assessed the tilapia's resistance against a bacterial infection. No significant differences were observed in growth performance between the groups; however, fish fed with ß-glucan for 30 and 45 days had higher (approx. 8%) relative weight gain compared to the control. Regardless of the administration period, fish fed with ß-glucan had higher innate immune responses immediately after the feeding trial such as lysozyme activity in plasma, liver and intestine and respiratory burst compared to the control, and in general these differences were gradually reduced over the withdrawal period (up to 14 days). No differences were observed in the plasma hemolytic activity of the complement or myeloperoxidase activity in plasma or intestine. Moreover, fish from the control group had early mortalities (2 vs. 4-5 days post-infection, respectively) and a lower survival rate (60 vs. 80%, respectively) compared to fish fed with ß-glucan for 15 or 30 days, and, interestingly, fish fed for 45 days with ß-glucan had no mortality. This study indicates that regardless of the administration period (i.e., 15 up to 45 days), the ß-glucan improved the innate immune responses and the tilapia's resistance to disease, and this protection could be observed up to 10 days post-feeding trial, adding in vivo evidence that ß-glucan may contribute to a trained innate immunity. Additionally, we showed that a longer period of administration did not cause immunosuppression as previously hypothesized but promoted further growth and immune performance. These findings are relevant to the aquaculture industry and demonstrate that a longer ß-glucan feeding protocol may be considered to achieve better results.

Effects of bovine lactoferrin and chitosan nanoparticles on serum biochemical indices, antioxidative enzymes, transcriptomic responses, and resistance of Nile tilapia against Aeromonas hydrophila.

The present study was carried out to investigate the effects of dietary bovine lactoferrin (BLF) or chitosan nanoparticles (CHN) alone or in combinations on serum biochemical indices, antioxidative capacity, transcriptomic responses, non-specific immunity, and resistance of Nile tilapia (Oreochromis niloticus) against challenge with Aeromonas hydrophila. Fish were fed on the basal diet with no supplements and served as control (CTR), and six other experimental diets containing different levels of BLF (800 and 1200 mg per kg diet), CHN (500 and 1000 mg per kg diet), and their combinations (400 mg BLF plus 250 mg CHN per kg diet, and 600 mg BLF plus 500 mg CHN per kg diet) for 45 days. At the end of the experiment, serum, and tissue specimens (liver and kidney) were collected, fish in all groups were challenged with A. hydrophila and then observed for another ten days to calculate the RPS. Compared to the CTR group, no significant differences were recorded in TP, ALB, GLO, BUN, and CREAT values among all treatments. Serum LYZ, ALT, AST, and ALP enzyme activities were significantly increased in all experimental groups over the CTR (P < 0.05), and their highest values were recorded in the combined treatments. Moreover, dietary supplementation with CHN (1000 mg/kg) and combined treatments significantly increased the SOD, CAT, and GSH-Px enzyme activities compared to other groups (P < 0.05). The highest mRNA expression levels of IGF-1 gene in liver, and IL-1ß, and IFN-γ genes in kidneys were found in CHN (1000 mg/kg) group and combined treatments more than other groups. Interestingly, no, or mild histopathological alterations were noticed in the hepatopancreas and posterior kidney of the treated groups. A significantly higher RPS was identified in the combined treatments challenged with A. hydrophila compared with the CTR group. This study exemplifies the positive impacts of dietary supplementation with BLF or CHN alone or combinations on the antioxidative status, immunity, and disease resistance of Nile tilapia.

Dual effect of selenium loaded chitosan nanoparticles on growth, antioxidant, immune related genes expression, transcriptomics modulation of caspase 1, cytochrome P450 and heat shock protein and Aeromonas hydrophila resistance of Nile Tilapia (Oreochromis niloticus).

Nowadays there is a great attention for nanotechnology in aquaculture production. It has an efficient role in nutrients and drugs delivery, ponds sterilization, water treatment and aquatic diseases reduction. Till now, there is no available data on impact of selenite-loaded chitosan nanoparticles (SeChNPs) on Nile tilapia. Hence, the current study investigated the effects of selenite-loaded chitosan nanoparticles supplementation on the growth, immune, antioxidant and apoptotic related genes as well as resistance to Aeromonas hydrophila of Nile tilapia, Oreochromis niloticus. A total of 400 fish were randomly divided into four groups, and each group retained five replicates. The control group was fed a basal diet (with inorganic se), other groups fed diets supplemented with SeChNPs 0.5, 1 and 2 g/kg diet. The loading concentration of Se to ChNPs was 0.3, 0.6 and 1.2 mg/0.5, 1 and 2 gm respectively. Fish groups fed SeChNPs (0.5 and 1 g/kg) exhibited the highest final body gain, better feed utilization. Additionally, the expression of myostatin gene was down-regulated by 0.2 and 0.3 fold in group fed 0.5 and 1 g/kg SeChNPs when compared with control group. Dietary inclusion of SeChNPs increased serum lysozyme, alternative complement and myeloperoxidase activities and immunoglobulin type M level. Supplementation of SeChNPs at the level of 2 g/kg up-regulated glutathione peroxidase, superoxide dismutase and catalase expression by 1.12, 4.9 and 2.31 folds respectively, in comparison with control group. In contrast, the levels of C- reactive protein and malondialdehyde were reduced. The expression of IL-10, IL-8, TNF-α and IL-1ß genes was up-regulated after dietary inclusion of different levels of SeChNPs in a dose dependent manner. Post-challenge, the highest survival rate was detected in group fed 2 g/kg SeChNPs (93%) in contrast, the control group was displayed the lowest survival rate (45%). After challenge with A. hydrophila, the expression of caspase 1 was up-regulated in groups fed 1 and 2 g/kg of SeChNPs. Moreover, the maximum down-regulation of cytochromes P450 and heat shock protein were found in 2 g/kg SeChNPs supplemented group (reduced by 0.4 and 0.6-fold, respectively, when compared with control group). In conclusion, the ameliorative effects of SeChNPs on Nile tilapia growth resulted from immune stimulatory and free radicals scavenging effects of selenium loaded chitosan nano composite.

Effects of dietary marjoram, Origanum majorana extract on growth performance, hematological, antioxidant, humoral and mucosal immune responses, and resistance of common carp, Cyprinus carpio against Aeromonas hydrophila.

The present study aimed to investigate the potential effects of dietary marjoram extract on growth performance, health, and disease resistance in common carp, Cyprinus carpio. To this purpose, the fish were assigned into four treatments and fed by diets supplemented with 0 (control), 100, 200, and 400 mg marjoram extract kg-1 over eight weeks and then challenged with Aeromonas hydrophila. According to the results, 200 mg kg-1 dietary marjoram extract inclusion showed the highest final weight, weight gain, and specific growth rate, and lowest feed conversion ratio (FCR). White blood cell number, Red blood cells, hematocrit, hemoglobin, mean corpuscular volume and mean corpuscular hemoglobin were markedly increased particularly at 200 mg kg-1 treatment. Marjoram extract significantly increased plasma superoxide dismutase activity and decreased malondialdehyde level compared to the control treatment. Plasma complement and lysozyme activities and total immunoglobulin levels, mucosal complement, lysozyme and alkaline phosphatase activities and immunoglobulin levels were significantly increased compared to the control group. The lowest post-challenge survival rate was observed in the control treatment, whereas the highest value was related to the 200 mg kg-1 marjoram treatment. In conclusion, the present study demonstrated that, marjoram extract is a suitable feed supplements for common carp, as it stimulates the fish growth, antioxidant, and immune systems, which suppress the fish mortality during Aeromonas septicemia. According to the results, 200 mg marjoram extract kg-1 is recommended for carp feed formulation.

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-1ß 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 6th, 13th, 14th and 15th 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.

Stimulatory effect of dietary chasteberry (Vitex agnus-castus) extract on immunity, some immune-related gene expression, and resistance against Aeromonas hydrophila infection in goldfish (Carassius auratus).

Chasteberry is highly recommended as an herbal medicine across the globe for treating of many gynaecological disorders. In this study, chasteberry extract (CBE) was supplemented in goldfish diet to evaluate the immunity responses at the cellular and molecular levels. Moreover, after the feeding trial, the fish were challenged with Aeromonas hydrophila. The fish (300 individuals, 2.4 ± 0.12 g initial weight) were randomly distributed in 12 tanks and were fed with 0 (control), 5, 10, and 15 g CBE per kg of feed for 8 weeks. Based on the results, lysozyme activity, alkaline phosphatase, and total immunoglobulin (Ig) in the skin mucus samples were significantly enhanced in the fish fed with 15 g/kg CBE (P < 0.05). Moreover, dietary CBE positively affected lysozyme activity, complement components, and IgM content of the serum samples compared to the control group. Also, the number of monocytes and lymphocytes were increased significantly with increasing CBE in the diet (P < 0.05). The highest mRNA levels of tumor necrosis factors (TNF-α, TNF-2α) and Lysozyme were observed in 15 g/kg CBE treatment. After the challenge test, the highest relative percentage survival value (60%) was observed in the fish fed with 15 g/kg CBE. We concluded that dietary CBE especially at 15 g/kg has an immunomodulatory effect in goldfish by stimulating the innate immunity and some inflammatory cytokines as well as disease resistance against A. hydrophila.

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 Nannochloropsis oculata on growth performance, serum biochemical parameters, immune responses, and resistance against Aeromonas veronii challenge in Nile tilapia (Oreochromis niloticus).

The current work was planned to assess the effects of dietary microalga, Nannochloropsis oculata (NP) on the growth indices, serum biochemistry, non-specific immunity, and resistance of Nile tilapia (Oreochromis niloticus) juveniles against challenge with pathogenic Aeromonas veronii. Fish (10.21 ± 0.28 g) were randomly divided into four treatments in triplicates and were fed on diets supplemented with different levels of NP (0, 5, 10, and 15%) for eight weeks. The results showed that the dietary 5% NP significantly improved the growth parameters (final body weight, weight gain, specific growth rate, and total feed intake) (P < 0.05). Meanwhile, the feed conversion ratio was significantly decreased in NP-supplemented groups with respect to the control group. The serum protein profile (total protein, albumin, globulin, and albumin/globulin ratio) was significantly decreased by 15% NP supplemented group. Meanwhile, liver enzymes (alanine transaminase, and aspartate transaminase) activities were not significantly affected by NP dietary supplementation (P < 0.05). Serum lysozyme activity, nitric oxide (NO), and nitroblue tetrazolium (NBT) levels were significantly enhanced only in 5% NP supplemented group (P < 0.05). Interestingly, the hepatopancreatic and intestinal tissues had apparently normal histomorphology of Nile tilapia fed at 5% NP-supplemented diets. Significant upregulation of cytokines [interleukin 1beta (IL-1ß), interleukin 8 (IL-8), interferon-gamma (IFN-γ), transforming growth factor-beta (TGF- ß), and tumor necrosis factor-alpha (TNF-α)], with significant downregulation of the antioxidant gene [superoxide dismutase (SOD)] in 10% and 15% NP supplemented groups. Attractively, the relative level of protection (RLP) against challenge with pathogenic A. veronii was significantly elevated in 10% and 15% NP supplemented groups. Conclusively, the obtained results reflect the beneficial roles of dietary NP to improve growth and boost the immune responses of Nile tilapia.

Potential influence of jaggery-based biofloc technology at different C:N ratios on water quality, growth performance, innate immunity, immune-related genes expression profiles, and disease resistance against Aeromonas hydrophila in Nile tilapia (Oreochromis niloticus).

Biofloc technology is increasingly becoming the most promising aquaculture tool especially in places where water is scarce and the land is very expensive. The dynamics of water quality, as well as plankton and microbial abundance, are collectively necessary for successful fish farming. The prospective use of jaggery as a potential carbon source and its influence on water quality, growth performance, innate immunity, serum bactericidal capacity, and disease resistance to Aeromonas hydrophila was investigated in Oreochromis niloticus. A completely randomized design was used in triplicates, where the control group was reared in a water system with no carbon source, while T1, T2, and T3 groups were raised in biofloc systems at C:N ratios of C:N12, C:N15, and C:N20, respectively. Water specimens were collected daily and fortnightly, while blood, serum, and head kidneys were collected at 75 days of experimental period for further analysis. TAN, nitrite, and ammonia values were considerably reduced, while the TSS values elevated significantly in all treated groups compared to the control. Jaggery-based biofloc system (JB-BFT) has a pronounced effect on hematological and growth performance parameters rather than control. Similarly, serum antioxidants, lysozyme, protease, antiprotease and bactericidal capacity were significantly increased (p < 0.05) in the treated groups in a dose-dependent manner. LYZ, TNF-α, and IL-1ß genes were upregulated in proportion to C:N ratios with the highest fold in C:N20. Furthermore, fish treated with JB-BFT presented lower cumulative mortalities and better relative levels of production (RLP) after experimental challenge with A. hydrophila compared to control. In conclusion, JB-BFT has a robust influence on Nile tilapia (O. niloticus) innate immunity through favorable innovation of various immune-cells and enzymes as well as upregulating the expression levels of immune-related genes. This study offers jaggery as a new carbon source with unique properties that satisfy all considerations of biofloc technology in an eco-friendly manner.