Skin Mucosal, Serum Immunity and Antioxidant Capacity of Common Carp ( Cyprinus carpio ) Fed Artemisia ( Artemisia annua )

Dietary Artemisia arborescens Supplementation Effects on Growth, Oxidative Status, and Immunity of Gilthead Seabream (Sparus aurata L.)

Fish infectious diseases are one of the main constraints of the aquaculture sector. The use of medicinal plants provides a sustainable way of protection using safe, eco-friendly compounds in a more cost-effective way of treatment, compared to antibiotics. The aim of the present study is the assessment of Artemisia arborescens (AA) feed-supplementation effects on gilthead seabream (Sparus aurata). Fish with an average initial body weight of 109.43 ± 3.81 g, were divided into two groups based on AA feed composition (A25 and A50). Following two months of ad libitum feeding, the effect of diets on fish weight and length were measured. Fish serum and mucus were analyzed for non-specific immune parameters (nitric oxide, lysozyme, myeloperoxidase, protease-/anti-protease activity, and complement), antibody responses, oxidative stress (cytochrome P450 1A1, metallothionein), and metabolism markers (total protein, alkaline phosphatase, and glucose). Expression levels of antioxidants (sod1, gpx1), cytokines (il-1b, il-10, tfgb1, and tnfa), hepcidin, and heat shock protein grp75 genes were measured in spleen samples. A results analysis indicated that A. arborescens use as a feed supplement has a compromised positive effect on the growth performance, immune response, and blood parameters of gilthead seabream. Overall, the suitability of A. arborescens as an efficient food supplement for gilthead seabream health improvement was investigated, setting the basis for its application assessment in Mediterranean aquaculture.

Feasibility of replacing fish oil with sunflower oil on the growth, body composition, fatty acid profile, antioxidant activity, stress response, and blood biomarkers of Labeo rohita

A 90-day study was conducted to investigate the effects of substituting sunflower oil (SFO) for fish oil (FO) on various parameters in Labeo rohita (initial weight 18.21 ± 0.22 g). Five experimental diets with different levels of SFO (up to 7%) substitution for FO (0%, 25%, 50%, 75%, and 100%) were formulated, ensuring equal levels of nitrogen and lipids. The results indicated that even with 100% substitution of SFO with FO, there were no significant differences (P>0.05) were observed in growth performance. The survival rate (SR), hepato-somatic index (HSI), and viscero-somatic index (VSI) as well as whole-body composition were also nonsignificant by SFO substitution. However, the fatty acid profiles in both muscle and liver were influenced (P<0.05) by dietary substitution. Saturated fats (SFA) decreased, while monounsaturated fats (MUFA), and linoleic acid (LA) increased (P<0.05). On the other hand, the contribution of linolenic acid (ALA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA) decreased (P<0.05) as the amount of SFO in the diet increased. Hematology parameters, including red blood cells (RBCs), hemoglobin (Hb), and hematocrit (Hct), were not affected. Globulin (GLO) levels decreased significantly (P<0.05), while alanine transaminase (ALT) and aspartate transaminase (AST) activity showed nonsignificant increases (P>0.05). Total protein (TP) increased (P<0.05) at 100% SFO inclusion in the diet, and albumin (ALB) levels increased (P<0.05) at 75% and 100% SFO inclusion in the diet. Cholesterol (CHOL), triacylglycerol (TG), and high-density lipids (HDL) were not significantly affected (P>0.05), while low-density lipids (LDL) were significantly increased (P<0.05) compared to the control group. Cortisol (CORT) and glucose (GLU) levels showed nonsignificant (P>0.05) changes. Superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) activities in the liver and serum were not significantly (P>0.05) affected, while malondialdehyde (MDA) status was significantly (P<0.05) reduced. In conclusion, the fatty acid profile of the muscle and liver of fish was modified by the diets, and FO can be substituted with SFO up to 100% for L. rohita, which is beneficial for growth and immunity while marinating the lipid contents in fish. Our study revealed that fully replacing fish oil with SFO shows promise in fully replacing FO without compromising the growth and overall health status of the fish.

An update about beneficial effects of medicinal plants in aquaculture: A review

Aquaculture is an essential and growing component of agricultural and global ecosystems worldwide. Aquaculture provides more than 25% of the total aquatic food consumption by humans. The development of the aquaculture industry should be followed in successive industrial years, and therefore it is necessary to pay attention to the management and type of farming system that is compatible with the environment. The use of antibiotics for disease control has been criticised for their negative effects, including the emergence of antibiotic-resistant bacteria, the suppression of the immune system and the environment, and the accumulation of residue in aquatic tissues. The use of these products reduces the need for treatments, enhances the effect of vaccines, and, in turn, improves production indicators. Medicinal plants have increasingly been used in recent years as a disease control strategy in aquaculture, boosting the immune system of aquatic animals and helping to develop strong resistance to a wide range of pathogens. Therefore, this review aims to provide an overview of the recent evidence on the beneficial use of medicinal plants to promote growth and strengthen the immune system in farmed aquatic animals.

The Biological Activity of Illicium verum (Star Anise) on Lernaea cyprinacea-Infested Carassius auratus (Goldfish): In Vivo Study

Lernaea cyprinacea infestation is considered a serious economic problem in the fish market. An assessment to control this parasite is needed to manage this problem. The Illicium verum oil extract has considerable antioxidant activity and scavenges 96.22% of free radicals; the high antioxidant activity refers to the phenolic content presence. The extract contains minerals, especially K, fibers, and dry matter. So, the Illicium verum ingredients were tested against this copepod for in vitro and in vivo investigation with the assessment of the treatment trial using a scanning electron microscope and evaluating the change in different immunological genes in goldfish. Female parasitic L. cyprinacea worms were blackish and hairy. The in vitro study on L. cyprinacea adults using star anise revealed that the LC50 was 12.5 and 25 μg/mL for 2 and 1 h exposure periods, respectively. Interleukin (IL-1β) and IL-6 were grossly upregulated in C. auratus-infested skin by L. cyprinacea after treatment by 1 week, then declined after 3 weeks. In contrast, TNF-α was 18 folds upregulated in the first week after treatment, with a decline after 3 weeks. In conclusion, star anise is recommended as a safe and economical agent for controlling L. cyprinacea infestation in fish.

Ameliorative effects of Artemisia and Echinacea extracts against hepato and cardiotoxicity induced by DMBA on albino rats: experimental and molecular docking analyses

Background

Herbal therapy for healing disease has many advantages than drugs. This study investigates the protective efficacy of Artemisia annua (Art) and Echinacea pupurea (Ech) extracts against 7, 12-dimethylbenz (α) anthracene (DMBA) toxicity.

Results

DMBA-treated rats showed a significant increase in the level of serum ALT, AST, LDH and CKMB, also reduction in body weight gain (BWG) ℅, HB, WBCs, RBCs and platelet counts, in addition to histopathological and ultrastructural alterations. Rats treated with Art or Ech after DMBA showed little improvements in the biochemical, hematological, histopathological, ultrastructural and molecular docking results than before DMBA.

Conclusions

This study suggested the ameliorative effect of Ech and Art due to their antioxidant properties, but Ech and Art were more effective if they are given before than after DMBA administration and the marked effect against DMBA toxicity with Ech before DMBA exposure. Also, the molecular docking, molecular properties descriptors, and pharmacoinformatic studies of constituents of extract from Artemisia annua L. and Echinacea purpurea L. exhibited that all studied compounds have better ADMET and physicochemical properties, especially compounds extract from Echinacea purpurea L.

Graphical Abstract

Herbal Vitamin C Prevents DNA Oxidation and Modifies the Metabolomic Water Profile of Tilapia (Oreochromis spp.)

This experiment aimed to evaluate the effects of herbal vitamin C at different levels on tilapia (Oreochromis spp.) growth, potential DNA damage, and the metabolomic profile of water effluent. Forty-five tilapias were housed in separate plastic tanks (80 L), and these were randomly assigned to three treatments: (a) a commercial diet (CD) only; (Nutripec Purina^®); (b) the commercial diet plus 250 mg of herbal vitamin C (HVC)/kg (CD250); and (c) the commercial diet plus 500 mg of HVC/kg (CD500). Biometric measurements were taken each week, blood samples were collected from the caudal vein on the final day, and water effluent was taken each week and immediately frozen (-80 °C) until further analysis (gas chromatography/mass spectrometry (GC/MS) systems). Data were completely randomized with a 2 × 2 factorial arrangement of treatments. Upon including herbal vitamin C, the final BW (p = 0.05) and BWG (p = 0.06) increased linearly. Herbal vitamin C decreases DNA damage (p ≥ 0.05). PLS-DA showed a 41.6% variation between treatments in the water samples. Fifteen metabolites had the best association between treatments, with a stronger correlation with CD500. Herbal vitamin C could improve fish performance, prevent DNA damage, and influence changes in the metabolomic profile of the water.

Individual and combined effects of the dietary Spirulina platensis and Bacillus licheniformis supplementation on growth performance, antioxidant capacity, innate immunity, relative gene expression and resistance of goldfish, Carassius auratus to Aeromonas hydrophila

This study evaluated the individual and combined effects of the dietary Spirulina platensis (SP) and probiotic bacterium Bacillus licheniformis (BL) on the growth performance, immune responses, and disease resistance in goldfish (Carassius auratus). A total of 216 fish (3.39 ± 0.24 g) were randomly distributed in 12 tanks with 18 fish per tank (4 treatments with 3 replications) and fed with diets containing 0% S. platensis and B. licheniformis (T0), 10⁸ CFU/g B. licheniformis (T1), 2.5% S. platensis (T2), and 10⁸ CFU/g B. licheniformis + 2.5% S. platensis (T3(. There were no significant differences in growth parameters. The alternative complement pathway (ACH50) and lysozyme activity were significantly increased in T2 and T3 treatments. No marked differences were observed in total immunoglobulin and protease activity among treatments (P > 0.05). The relative expression of IGF-1 was not affected by experimental diets (P > 0.05). Ghrelin gene showed significantly higher mRNA levels in fish fed with SP and BL (P < 0.05). The relative expression of catalase (CAT), and glutathione reductase (GSR) significantly increased in fish fed with the SP and BL (P < 0.05). No marked difference in glutathione peroxidase (GPX) gene expression was seen between the treatments (P > 0.05). The mRNA levels of lysozyme, IL6, IL-1β, TGF, and TNF2 transcription were higher in fish fed with SP and BL (P < 0.05). No notable difference was observed in TNF1 and IL10 gene expression between treatments (P > 0.05). Moreover, the result of the challenge test with A. hydrophila showed that goldfish fed with SP and BL had a lower mortality rate than the control. In conclusion, the supplementation of SP and BL can be used as feed additives to enhance disease resistance against A. hydrophila infection by stimulating the immune system in goldfish.

Immune responses of Cyprinus carpio induced by protein extracts of Lernaea cyprinacea Linnaeus, 1758

Lernaea cyprinacea Linnaeus, 1758 is an ectoparasite showing widespread infections in tropical aquaculture, and the present study aimed to determine the specific immune responses against this parasite. For the experiment, whole parasite extracts were injected intraperitoneally into Cyprinus carpio Linnaeus, 1758, and samples of epidermal mucus and blood were drawn at 0, 1, 7 and 14-days post-injection (DPI). The results revealed high levels of protein, protease and lysozyme activities in the experimental fish which were injected with L. cyprinacea protein extract. In the epidermal mucus, the total protein concentration of the control fish was 460 μg/mL, and the level raised significantly to 800 μg/mL in the experimental fish. The lysozyme activity increased from 741.5 u/mL to a peak level of 1448.5 u/mL at 7DPI. The protease activity was also found elated gradually from 2.91 u/μL to 4.49 u/μL at 1 to 14 DPI. In the serum samples, the protein concentration remained steady throughout the experiment period. However, all the experimental fish displayed statistically high levels of lysozyme and protease activity, from 890 u/mL to 1220 u/mL, and 6.10 u/μL to 11.88 u/μL, respectively. In the whole blood samples, the haemoglobin content and the red blood cells (RBC) count did not show any significant change in any of the experimental groups. But, the percentage of lymphocytes showed a marginal increase from 0.47 to 0.6 in the experimental groups. Overall, the immune responses induced by L. cyprinacea protein extracts depicts a pattern of specific responses, in which the local humoral responses dominate the systemic humoral/cellular response. The results further revealed the possibility of futuristic approaches to control freshwater ectoparasites.

Bio-active components in medicinal plants: A mechanistic review of their effects on fish growth and physiological parameters

World population is increasing at a tremendous rate so is the demand for animal-based protein. Aquaculture is a promising industry that has the potential to supply high quality protein for mankind with minimum environmental impact. In the past decade, aquaculture practices have been shifting from extensive to intensive culture. To achieve maximum production per unit area, high stocking densities are maintained in intensive aquaculture. If not managed properly, this may lead to stress in fish. Fish under stress condition show decreased growth, suppressed appetite, weakened immunity and increased susceptibility to infections. Chemicals, vaccines and antibiotics are used for the treatment of diseased fish. Use of synthetic chemicals, vaccines and antibiotics is not sustainable because pathogens develop resistance against them and they have high residues. Moreover, certain chemicals used for the treatment of fish diseases are not safe for humans therefore, are banned in some countries. Plant parts and their extracts are used in traditional medicines to cure many diseases and to improve health of mankind. In aquaculture industry, use of plants and their derivatives in fish feed to improve health status of fish is increasing. Several plants improve growth and overall health status of fish, some provide protection against pathogens by improving the immune system while others increase appetite by direct action on neuro-endocrine axis of fish. This review provides an in depth and up to date information about use of medicinal plants and their derivatives to improve growth and physiological status of fish and their possible mechanism of action.

Immune-antioxidant trait, Aeromonas veronii resistance, growth, intestinal architecture, and splenic cytokines expression of Cyprinus carpio fed Prunus armeniaca kernel-enriched diets

Currently, the intervention of plant by-products in the fish diet has gained tremendous attention owing to the economic and high nutritious value. The current study is a pioneer attempt to incorporate the apricot, Prunus armeniaca kernel powder (PAKP) into the Common carp, Cyprinus carpio diets, and assess its efficacy on growth, digestion, intestinal morphology, immunity, antioxidant capacity, and splenic cytokines expression, besides the antibacterial role against Aeromonas veronii infection. Apparently healthy fish (N = 120) with an initial body weight of 24.76 ± 0.03g were allotted in 12 glass aquaria (60 L) and randomly distributed into four groups (triplicates, 10 fish/aquarium). The control group (PAKP0) was fed a basal diet without additives. The second, third, and fourth groups were provided PAKP diets with various concentrations (2.5 (PAKP2.5), 5 (PAKP5), and 10 g kg^-1 (PAKP10)) respectively. After 60 days (feeding trial), sub-samples of the fish (12 fish/group) were intraperitoneally injected with 1 × 10⁷ CFU mL^-1 of A. veronii. Results revealed that body weight gain, feed conversion ratio, and specific growth rates were significantly augmented in the PAKP10 group in comparison to the other groups. The dietary inclusion of PAKP at all concentrations boosted the digestive capacity and maintained the intestinal morphology (average villus length, villus width, and goblet cells count) with a marked improvement in PAKP10. Moreover, fish fed on PAKP10 followed by PAKP5 then PAKP2.5 diets had noticeably elevated values of immunological biomarkers (IgM, antiprotease, and lysozyme activity) and antioxidant capabilities (the total antioxidant capacity, superoxide dismutase, and reduced glutathione) as well as significant up-regulation of immune and antioxidant-related genes (TGF-β2, TLR-2, TNF-α, IL-10, SOD, GPx, and GSS). Fourteen days post-infection with A. veronii, the highest relative percentage survival of fish was observed in PAKP10 (83.33%), followed by PAKP5 (66.67%), and PAKP2.5 (50%). Our results indicated that a dietary intervention with PAKP could promise growth, digestion, immunity, and protect C. carpio against A. veronii infection in a dose-dependent manner. This offers a framework for future application of such seeds as a growth promotor, immune-stimulant, and antioxidant, besides an alternative cheap therapeutic antibacterial agent for sustaining the aquaculture industry.

Effect of garlic (Allium sativum) extract on growth, enzymological and biochemical responses and immune-related gene expressions in giant freshwater prawn (Macrobrachium rosenbergii)

In the current study, growth performance, biochemical constituents of muscle, activities of enzymes in the haemolymph, and expressions of immune-related genes were evaluated in the giant freshwater prawns Macrobrachium rosenbergii fed diets supplemented with aqueous garlic (Allium sativum) extract at 0, 5, 10 and 20 g/kg (w/w) for 60 days. At the end of the feeding trial, weight gain and specific growth rate were significantly improved in garlic-fed prawn groups compared with the control (p < 0.05). Moreover, feed conversion ratio was significantly lower in the garlic-fed groups than in the control (p < 0.05). Activities of catalase, superoxide dismutase and glutathione peroxidase in the hepatopancreas, activities of alanine aminotransferase, aspartate aminotransferase and levels of albumin and total protein in the hemolymph were significantly increased in the garlic treatments (p < 0.05). Furthermore, garlic supplemented diets improved muscle biochemical profiles, particularly contents of crude protein and total ash and upregulations of immune deficiency and heat shock proteins (HSP70) gene expression (p < 0.05). Therefore, garlic has positive effects on growth performance and physio-biochemical responses of M. rosenbergii, and thus, it can be used as an additive for stress resistance and as a growth promoter in sustainable aquaculture.

The influence of coconut oil on the growth, immune, and antioxidative responses and the intestinal digestive enzymes and histomorphometry features of Nile tilapia (Oreochromis niloticus)

The trials of finding non-conventional and alternative aquafeed ingredients are increasing. In this sense, this study evaluated the influence of coconut oil on the growth, feed utilization, immune, and antioxidative responses of Nile tilapia. Five test diets were formulated by mixing coconut oil with the other ingredients at 0, 1, 2, 3, and 4% of the total ration and presented for tilapia for 60 successive days. The final weight, SGR, weight gain (WG), and feed intake were superior in fish delivered 2% of coconut oil (P < 0.05). Concurrently, fish that received 2% coconut oil had lower FCR and higher PER than fish of the control and 4% groups (P < 0.05). Higher lipase activity was observed in fish of 2% and 3% levels than the remaining groups (P < 0.05). Besides, the amylase and protease activities of fish in 1%, 2%, and 3% groups were higher than the 0% level (P < 0.05). The total blood cholesterol, RBCs, and PCV showed higher values in Nile tilapia fed 2% and 3% coconut oil (P < 0.05). The lysozyme and phagocytic activities were higher in fish fed 2% and 3% levels than the control (P < 0.05), while the phagocytic index in 2% and 3% levels was higher than 0% and 4% levels. Furthermore, SOD and CAT were higher in fish fed 1%, 2%, and 3% than fish fed 0% and 4% levels while GSH was higher in fish of 1%, 2%, and 3% than fish fed 0% level (P < 0.05). However, the MDA level was markedly lower in fish fed 25, 3%, and 4% coconut oil than the 0% level (P < 0.05). The intestine's histological structure in all groups appeared normal, forming of intestinal villi projecting from the intestinal wall. Also, the structure of the hepatopancreas had a normal architecture in all groups. To sum up, the inclusion of coconut oil at 2 to 3% is recommended as a replacer for fish oil in Nile tilapia diets.

Antiparasitic and Antibacterial Functionality of Essential Oils: An Alternative Approach for Sustainable Aquaculture

Using synthetic antibiotics/chemicals for infectious bacterial pathogens and parasitic disease control causes beneficial microbial killing, produces multi-drug resistant pathogens, and residual antibiotic impacts in humans are the major threats to aquaculture sustainability. Applications of herbal products to combat microbial and parasitic diseases are considered as alternative approaches for sustainable aquaculture. Essential oils (EOs) are the secondary metabolites of medicinal plants that possess bioactive compounds like terpens, terpenoids, phenylpropenes, and isothiocyanates with synergistic relationship among these compounds. The hydrophobic compounds of EOs can penetrate the bacterial and parasitic cells and cause cell deformities and organelles dysfunctions. Dietary supplementation of EOs also modulate growth, immunity, and infectious disease resistance in aquatic organisms. Published research reports also demonstrated EOs effectiveness against Ichthyophthirius multifiliis, Gyrodactylus sp., Euclinostomum heterostomum, and other parasites both in vivo and in vitro. Moreover, different infectious fish pathogenic bacteria like Aeromonas salmonicida, Vibrio harveyi, and Streptococcus agalactiae destruction was confirmed by plant originated EOs. However, no research was conducted to confirm the mechanism of action or pathway identification of EOs to combat aquatic parasites and disease-causing microbes. This review aims to explore the effectiveness of EOs against fish parasites and pathogenic bacteria as an environment-friendly phytotherapeutic in the aquaculture industry. Moreover, research gaps and future approaches to use EOs for sustainable aquaculture practice are also postulated.

The blood and mRNA levels of antioxidant-related factors in common carp (Cyprinus carpio) fed p-Coumaric acid

The natural antioxidants are well known for their antioxidative activity without side effects when compared to antibiotics. Hence, the present study aimed at evaluating p-Coumaric acid as an antioxidant additive on the blood and mRNA levels of antioxidant-related factors in common carp (Cyprinus carpio). Fish fed the basal diet supplemented with p-Coumaric at 0, 0.5, 1, and 1.5 g/kg for 56 days, then the serum, intestine, and liver samples were collected. The growth performance of fish fed with CA showed significantly (P < 0.05) improved FW, WG, and SGR compared to those of the control one. However, the feed conversion ratio was significantly (P < 0.05) reduced in fish fed 1 and 1.5 g/kg diet levels. SOD was not significantly differed among the groups fed with varied p-Coumaric acid (P > 0.05). Serum GPX and TAC were enhanced considerably by p-Coumaric acid regarding the control with the highest being in fish fed 1.5 g/kg diet (P < 0.05). Serum CAT was more elevated in fish provided p-Coumaric acid at 1 or 1.5 g/kg than the control while fish fed 0.5 g/kg did not display significant changes. MDA level significantly decreased by all p-Coumaric acid groups compared to the control one, and the lowest level was observed in 1.5 g/kg (P < 0.05). The mRNA level of CAT was significantly upregulated in the liver by p-Coumaric acid at 1 or 1.5 g/kg (P < 0.05), while the intestine CAT did not influence by p-Coumaric acid (P > 0.05). The measured SOD in the liver and intestine samples revealed no changes in common carp fed p-Coumaric acid (P > 0.05). GPX was significantly upregulated in the intestine by p-Coumaric acid at 1 or 1.5 g/kg (P < 0.05), whereas the liver GPX was upregulated by p-Coumaric acid at 1.5 g/kg. The mRNA level of the GST gene in the intestine of common carp was upregulated by p-Coumaric acid at 1.5 g/kg, whereas the liver displayed upregulated GST in fish fed 1 g/kg diet. The present study approved the application of p-Coumaric acid as a natural antioxidant for friendly, sustainable aquaculture.

Extract of grape seed enhances the growth performance, humoral and mucosal immunity, and resistance of common carp (Cyprinus carpio) against Aeromonas hydrophila

This study evaluated the effects of grape seed extract (GSE) on the growth performance, immune response, and disease resistance of common carp (Cyprinus carpio). Fish were distributed in four groups and fed diets with varying levels of GSE at 0, 10, 20, and 30 g/kg for 56 days. The final length in fish fed with 20 and 30 g GSE/kg diet significantly increased in comparison with the control group (P<0.05). The final weight and weight gain of fish fed with GSE were statistically higher than for the control diet, while the feed conversion ratio was lower in GSE groups than the control. Hematological parameters did not statistically improve with GSE supplemented diets (P>0.05). However, fish fed with 30 g GSE/kg diet displayed a significantly higher WBC count than the other group (P<0.05). The serum total protein and globulin in fish fed with 20 g GSE/kg diet significantly increased compared to the control (P<0.05). A similar pattern was noticed in results for serum and mucus lysozyme activity with a significant increase in fish fed with 20 and 30 g GSE/kg diet compared to the control (P<0.05). Total antibody levels in serum and mucus samples were also increased in fish by dietary GSE with maximum levels by 20 and 30 g GSE/kg diet. Besides, mucus protease activity was higher in fish that received 20 and 30 g GSE/kg diet with maximum level shown in fish fed with 30 g GSE/kg diet compared to the control group (P<0.05). Meanwhile, all groups showed higher mucus antibacterial activity against Aeromonas hydrophila with the highest activity in 30 g GSE/kg diet in comparison with the control group. The cumulative mortality was 36.67% when fish were fed with 30 g GSE/kg diet and challenged with A. hydrophila. However, the mortality rate was 40% and 53.33% in fish fed 20 and 30 g GSE/kg diet, respectively. This study suggests that supplementation of GSE could significantly enhance the growth performance, immune responses, and disease resistance against A. hydrophila in common carp.

Effects of dietary pomegranate peel meal on the growth performance, blood indices, and innate immune response of rainbow trout (Oncorhynchus mykiss)

The present study aimed at evaluating the influences of pomegranate peel meal on the growth performance, hematology, and blood biochemistry of rainbow trout. Fish were fed 5 varying levels of pomegranate peel meal (0%, 1%, 2 %, 3%, and 4%) for 60 days. The obtained results showed that weight gain was significantly higher in fish fed at the rate of 1% than the other groups, while specific growth rate (SGR) was significantly increased in fish fed 1% and followed by the ration of 2% (P<0.05). SGR of fish fed at the rate of 4% revealed the lowest value among the groups (P<0.05). However, feed conversion ratio displayed the lowest values in fish fed at the rate of 1% or 2%, while the highest value was observed in fish fed at the rate of 4% (P<0.05). The survival rate was increased by the rate of 1% in relation to the control without differences with the other groups (P<0.05). Red blood cells were significantly higher in fish fed at the rate of 0%, 1%, and 2% than fish fed at the rate of 3% and 4%. Hematocrit and hemoglobin levels were increased by feeding pomegranate meal at the rate of 1% compared to the other groups, while fish fed the control diet displayed higher Hb and HCT levels than fish fed at the rate of 2%, 3%, and 4% (P<0.05). White blood cells displayed significant differences among the groups and increased by increasing the level of pomegranate meal in the diet. The blood total protein was decreased in fish fed 2%, 3%, and 4% compared to fish fed at the rate of 0% and 1% of pomegranate meal. The glucose value displayed the highest level in fish fed at the rate of 3% of pomegranate meal compared to the other groups. The triglycerides were reduced by pomegranate meal at the rate of 2% than 3% and 4% without differences with the control and 1%. The blood total cholesterol was reduced in fish fed at the rate of 1% of pomegranate meal compared to the other groups (P<0.05). The blood IgM and complement components (C3 and C4) were increased by increasing the supplementation level of pomegranate meal with the highest value in fish fed at the rate of 3% (P<0.05). In conclusion, dietary pomegranate meal at the rate of 1% is recommended for enhancing the growth rate and health status of rainbow trout.

Supplementation of AQUAGEST® as a Source of Medium-Chain Fatty Acids and Taurine Improved the Growth Performance, Intestinal Histomorphology, and Immune Response of Common Carp (Cyprinus carpio) Fed Low Fish Meal Diets

Four diets were prepared to include a mixture of medium-chain fatty acids and taurine as a digestive/ metabolic enhancer (DME, AQUAGEST®) at 0, 1, 2, and 3 g DME/kg diet and fed to common carp (initial weight, 4.55±0.03 g) for 70 days. Dietary DME significantly increased the final weight, weight gain, specific growth rate, feed intake, and protein efficiency and decreased feed conversion ratio in a dose-dependent manner (P<0.05). The body lipid composition was significantly improved by feeding DME at 2 g/kg diet (P=0.0141). The intestine villus length and the number of goblet cells were significantly increased in fish fed 2 g DME/kg diet (P<0.05). The intestinal villi displayed increased length, branching, and density by supplementing DME to common carp diets. Fish fed DME at 2 g/kg diet displayed markedly decreased aspartate aminotransferase (AST) and alanine aminotransferase (ALT ) (P=0.025 and P=0.043) and increased total protein and globulin (P =0.002 and P=0.003). Additionally, fish fed 2 and 3 g DME/kg levels displayed significantly increased albumin levels (P=0.006). Lysozyme and phagocytic activities were increased by feeding DME at 2 g/kg diet, while the phagocytic index increased by 2 and 3 g/kg diet (P<0.05). The optimal supplementation level of DME is 1.63 to 2.05 g/kg for common carp based on the polynomial regression analysis. In conclusion, common carp fed diets with a mixture of medium-chain fatty acids and taurine displayed improved growth, digestion activity, and immune response.

Assessing the Impact of Purslane (Portulaca oleracea L.) on Growth Performance, Anti-Oxidative, and Immune Activities in Grass Carp (Ctenopharyngodon idella)

In this study, the basal diet was supplemented with ethanolic extract of purslane (Portulaca oleracea L.) and the possible effects on growth performance, anti-oxidative, and immune activities of grass carp were evaluated. Fish with initial weight 1.23 ± 0.11 g were randomly divided into four groups (triplicates) and fed purslane extract at 0% (T0), 0.5% (T1), 1% (T2), and 1.5% (T3) for 56 days. At the end of the feeding trial, the results showed that growth parameters were enhanced in T1 groups compared to the control group (P<0.05). Lipase activity in T1 and T2 groups increased, whereas no significant changes were noticed in cases of amylase and protease activities (P>0.05). Catalase and superoxide dismutase activities were enhanced in all groups fed the supplemented diets in comparison with the control group (P<0.05). However, no significant alteration was noticed in the case of glutathione peroxidase activity following the administration of purslane extract (P>0.05). A significant increase in total immunoglobulin level was noted in the T1 group, but lysozyme activity was higher in T1 and T2 groups compared to the control group (P<0.05). In conclusion, supplementation of grass carp diet with the purslane ethanolic extract, especially at 0.5%, can improve growth performance, lipase activity, the antioxidant enzyme activities as well as the immune response of grass carp fingerlings.

Ziziphus mauritiana supplementation of Nile tilapia (Oreochromis niloticus) diet for improvement of immune response to Aeromonas hydrophila infection

This study evaluated the effectiveness of dietary Ziziphus mauritiana leaf powder (ZLP) to control Aeromonas hydrophila infection in Nile tilapia and reduce damage to vital immune organs. Four experimental groups were fed a diet supplemented with ZLP at concentrations of 0, 5, 10, and 20 g/kg (w/w) for 6 weeks. At the end of the feeding trial, all groups were intraperitoneally injected with pathogenic A. hydrophila. It was found that Z. mauritiana significantly (P < 0.05) upregulated (lysozyme, interleukin 1 beta) and superoxide dismutase gene expressions as well as improved the activity of serum lysozyme and liver antioxidant enzymes. The fish that were fed a ZLP-supplemented diet also exhibited significantly higher survival rates after A. hydrophila challenge than those that were fed a ZLP-free diet (P < 0.05). Supplementation of 10 g/kg ZLP most effectively reduced the histopathological alterations caused by A. hydrophila challenge in the liver, spleen, kidney, and muscle of the fish. In conclusion, ZLP can be effective in controlling A. hydrophila infection in Nile tilapia (particularly at a concentration of 10 g/kg) through enhancement of its immune and antioxidant status.

Lactobacillus plantarum L-137 and/or β-glucan impacted the histopathological, antioxidant, immune-related genes and resistance of Nile tilapia (Oreochromis niloticus) against Aeromonas hydrophila

A trial was operated to assess the potential of using Lactobacillus plantarum L-137 (L-137) and/or β-glucan (BG) in improving the resistance of Nile tilapia against Aeromonas hydrophila. Control diet and 3 diets supplemented with L-137, BG or L-137 + BG were prepared. Final body weight, specific growth rate, superoxide dismutase, and catalase showed considerably (P < .05) increased values in L-137 or L-137/BG groups, while glutathione peroxidase increased significantly (P < .05) only in L-137/BG group. Fish fed L-137 and/or BG diets showed that feed conversion ratio and malonaldehyde levels were significantly decreased (P < .05). Also, both L-137 and BG helped Nile tilapia to have high phagocytosis activity and relative expression of tumor necrosis factor-alpha (TNF-α) and interleukin 1 beta (IL-1β) and interferon-gamma (INF-γ) genes. After A. hydrophila challenge, the intestinal villi epithelium of the L-137/BG group was intact and denser than the other groups. The hepatopancreas and spleen of the control group displayed severe necrosis in hepatocytes and congestion of blood sinusoids in addition to diffuse vacuolation. Regarding the L-137, BG and L-137/BG groups, there was a moderate and normal degree of vacuolation with focal necrosis and mild to moderate degree of congestion of blood sinusoids. Red blood cells, hemoglobin, and albumin showed meaningfully (P < .05) increased values in L-137 or L-137/BG groups. TNF-α, IL-1β, and INF-γ expressions were upregulated by L-137 and/or BG. The obtained results revealed the ability of L-137 and/or BG to protect Nile tilapia from the effects of A. hydrophila infection by the motivation of the immune, antioxidative, and antiinflammation responses.

Spirulina platensis Reduced Oxidative Damage Induced by Chlorpyrifos Toxicity in Nile Tilapia (Oreochromis niloticus)

Due to the numerous pharmacological impacts of Spirulina platensis (SP), the effects of SP on the oxidative status of Nile tilapia farmed under chlorpyrifos (CPF) ambient toxicity were considered in this study. Fish (60 ± 6.1 g) was randomly stocked in five groups where the SP free diet was fed to the control group while the second one was fed 1% SP without CPF exposure. Additionally, CPF (15 μg/L) was added in water and fish were fed with SP at 0, 0.5, and 1% (third, fourth, and fifth groups, respectively). Samples of blood and gills, kidneys, and liver tissues were assayed for biochemical measurements. Fish exposed to CPF exhibited significant (p ≤ 0.05) increments of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), cholesterol, urea, creatinine, and malondialdehyde (MDA), while significantly decreased total protein, albumin, and antioxidative enzyme activities (superoxide dismutase (SOD) and catalase (CAT) were observed in tilapia exposed to CPF (p ≤ 0.05). In contrast, SP feeding resulted in decreased levels of ALT, AST, ALP, cholesterol, urea, and creatinine as well as increased total protein, albumin, SOD, and CAT activities. Based on the obtained results, it can be suggested that SP is efficient in protecting Nile tilapia from CPF toxicity by increasing the antioxidative response.