Immunomodulatory effect of Withania somnifera supplementation diet in the giant freshwater prawn Macrobrachium rosenbergii (de Man) against Aeromonas hydrophila

Effectiveness of various cacao pod husk extraction byproducts in promoting growth and immunocompetence in Litopenaeus vannamei

Extracts from plant products can promote growth, can act as immunostimulants, and have antibacterial and antiparasitic properties. These extracts can be used as alternatives to the chemical treatments commonly used to prevent and control disease in aquatic species. Research on the subject has focused on identifying invasive plants or agricultural waste products that can be used as immunostimulants. The present study further identified an optimal means of extracting pectin from cacao pod husks to promote growth performance and immunocompetence in Litopenaeus vannamei that would both reduce production costs and enable waste recycling. The byproducts of pectin extraction from cacao pod husks, that is, dried cacao pod husk powder (DCP), steamed DCP (sDCP), hot water-treated cacao pod husk powder (HCP), hot water-treated cacao pod husk supernatant (HCS), and cacao pod husk pectin (CPH pectin), were used to create five experimental diets, which were administered to five groups. The control group was fed a basal diet. The growth and immunocompetence of the shrimp were determined after 30, 60, 90 and 120 days of feeding. To identify the most cost-effective means of obtaining dried cacao pod husks, this study firstly determined the costs and effectiveness of the sun-drying, dehumidification, and heated-wind drying techniques. According to the results of growth performance, the CPH pectin group had higher survival but lower weight gain than the DCP, sDCP, HCP, and HCS groups did. At 30, 60, and 90 days, the clearance efficiency of the experimental groups was higher than that of the control group. At 60 days, the experimental groups had significantly higher phagocytic activity than the control group did. However, at 30 and 90 days the HCP, HCS and CPH pectin group had higher phagocytic activity. The total hemocyte count, differential hemocyte count, phenoloxidase activity, and respiratory bursts of the CPH pectin group were higher at 30 days but the same as those of the control group at 60 and 90 days. After 120 days of feeding trial, the resistance of L. vannamei fed with diets containing byproducts of pectin extraction from cacao pod husks significantly enhanced compared to that in BD group when they were infected with Vibrio aliginolyticus for 168 h, and the related higher survival rate can be observed in HCP, HCS and CPH pectin groups. The study findings suggest that diet-administered HCP and HCS have long-term immunostimulant potential and that CPH pectin has potential in the early stages of feeding. In addition, when heated air drying was employed, a moisture level of below 10% was obtained within 12 h. The results of this study indicate that adding HCP obtained from heated air-dried cacao pod husks to the feed of L. vannamei is the most cost-effective and sustainable means of promoting long-term growth performance and immunocompetence in the species.

The growth performance, antioxidant and immune responses, and disease resistance of Litopenaeus vannamei fed on diets supplemented with Indian ginseng (Withania somnifera)

In the current study, white-leg shrimp (Litopenaeus vannamei) were fed on diets containing varying doses of Withania somnifera aqueous extract (WSAE) at a rate of 0 (control), 0.5, 1.0, and 2.0 g/kg feed for 56 days. After the feeding trial, shrimps in all groups were challenged with the exposure to Vibrio harveyi for ten days during which animals' mortality was observed. It is noted that the dietary WSAE linearly and quadratically stimulated shrimp's growth indices particularly at the treatment of 2.0 g/kg feed. Compared to the control group, the WSAE-fed L. vannamei had significantly higher villi length, villi width, and absorption area particularly in the treatment of 2.0 g/kg feed. Furthermore, L. vannamei fed on WSAE-enriched diets consumed more feed and exhibited higher total proteolytic activity, lipase, and α-amylase activities as compared with the control group. The dietary WSAE at escalating levels linearly and quadratically enhanced the antioxidant activity (serum superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), total antioxidant capacity, and reduced glutathione) and the immune response (total hemocyte counts, total protein, lysozyme, and phagocytic activity). Similarly, the mRNA expression levels of cMn-SOD, CAT, and GPx genes were linearly and quadratically upregulated in the hepatopancreas of L. vannamei fed on WSAE-enriched diets (especially in the 2.0 g/kg feed treatment), while their lowest levels were significantly observed in the control group. On the other hand, malondialdehyde levels were significantly decreased in WSAE-supplemented shrimp groups, and its highest levels were observed in animals fed on the control diet. After the bacterial exposure, the survival rates of L. vannamei fed on 1.0 and 2.0 g WSAE/kg feed (61.3% and 66.7%, respectively) were higher than those in the control animals. Taken together, the results obtained herein indicate that inclusion of WSAE in diets of L. vannamei effectively enhanced the growth, antioxidant biomarkers, immune response, and resistance to the V. harveyi infection, particularly at the treatment of 2.0 g/kg feed.

Comparative Analysis between Synthetic Vitamin E and Natural Antioxidant Sources from Tomato, Carrot and Coriander in Diets for Market-Sized Dicentrarchus labrax

Synthetic vitamin E is commonly used in aquafeeds to prevent oxidative stress in fish and delay feed and flesh oxidation during storage, but consumers’ preferences tend towards natural antioxidant sources. The potential of vegetable antioxidants-rich coproducts, dried tomato (TO), carrot (CA) and coriander (CO) was compared to that of synthetic vitamin E included in diets at either a regular (CTRL; 100 mg kg⁻¹) or reinforced dose (VITE; 500 mg kg⁻¹). Natural antioxidants were added at 2% to the CTRL. Mixes were then extruded and dried, generating five experimental diets that were fed to European sea bass juveniles (114 g) over 12 weeks. Vitamin E and carotenoid content of extruded diets showed signs of degradation. The experimental diets had very limited effects on fish growth or body composition, immunomodulatory response, muscle and liver antioxidant potential, organoleptic properties or consumer acceptance. Altogether, experimental findings suggest that neither a heightened inclusion dose of 500 mg kg⁻¹ of vitamin E, nor a 2% inclusion of natural antioxidants provided additional antioxidant protection, compared to fish fed diets including the regular dose of 100 mg kg⁻¹ of vitamin E.

Pharmacological and ameliorative effects of Withania somnifera against cadmium chloride-induced oxidative stress and immune suppression in Nile tilapia, Oreochromis niloticus

This study was carried out to evaluate the effects of dietary supplementation of aqueous extract of Withania somnifera (W. somnifera) against cadmium chloride-induced toxicity in the Nile tilapia, Oreochromis niloticus. Five experimental groups were designed: group (I) was free from cadmium chloride and W. somnifera and served as a control, group (II) was exposed to 1.775 mg L^-1 of cadmium chloride only (which is equivalent to 1/4 96-h LC50), while groups (III), (IV), and (V) were exposed to 1.775 mg cadmium chloride L^-1 with co-supplementation of dietary W. somnifera in doses of 1.0, 2.0, and 3.0 mL kg^-1 body weight (bwt), respectively. The experiment lasted for 4 weeks. In the second and fourth weeks of the experiment, the following indicators were evaluated: hematological (hemogram and blood protein profile), biochemical (activities of serum liver enzymes, namely alanine transaminase (ALT) and aspartate transaminase (AST)), immunological (immunoglobulin M (IgM), serum lysozyme), and tissue antioxidant changes (malondialdehyde (MDA) levels and activities of catalase (CAT) and superoxide dismutase (SOD)). Additionally, gene expressions of glutathione-S-transferase (GST) in the liver were assessed. At the end of the experiment, all fish in all groups were experimentally challenged with Aeromonas hydrophila and the relative protection survival (RPS) was demonstrated. The results revealed that groups exposed to cadmium chloride toxicity and co-supplemented with dietary aqueous extract of W. somnifera at high doses showed significant ameliorative effects in hemogram parameters, total protein, globulin, IgM, and lysozyme against cadmium chloride-induced toxicity compared to the control group and the group exposed to a sublethal dose of cadmium chloride without co-suplemntation of W. somnifera. The results showed also that groups supplemented orally with W. somnifera at high doses have higher antioxidant activities of CAT and SOD and reduction of MDA formation. Levels of gene expressions of GST in the liver were higher in W. somnifera extract-supplemented groups more than those in the group exposed to cadmium chloride-induced toxicity without W. somnifera supplementation. In addition, the results revealed improved RPS with the dietary supply of W. somnifera extract in high doses. In conclusion, this study showed that the dietary supplementation of W. somnifera extract to diets of O. niloticus could be suggested as an effective way to overcome cadmium chloride-induced toxicity because it improves blood parameters and antioxidants, and it can be used as an immunostimulant against the invading bacterial pathogens.

Injection of an extract of fresh cacao pod husks into Litopenaeus vannamei upregulates immune responses via innate immune signaling pathways

Immunostimulation is a novel method and a promising development in aquaculture. Products derived from plants exhibit various biological activities. In this study, the hot-water extract isolated from fresh cacao (Theobroma cacao) pod husks (CPHs) was administered by injection to evaluate cellular signaling pathways of innate immunity, the immunostimulating potential, disease resistance, and hypothermal tolerance of white shrimp, Litopenaeus vannamei. Results showed significant increases in the total hemocyte count, semigranular cells, granular cells, phenoloxidase activity, and respiratory bursts (RBs) of hemocytes per unit of hemolymph at 1 day, and in phagocytic activity toward and the clearance efficiency of Vibrio alginolyticus at 1-3 days after shrimp were injected with fresh CPH extract at 40 μg shrimp^-1. However, only RBs per hemocyte had significantly decreased at 1 day after the injection. All immune parameters had returned to control levels by 3 days after receiving fresh CPH extract except for RBs, phagocytic activity, and the clearance efficiency, which had returned to control values by 7 days. Furthermore, at 1 day after the injection, the peroxinectin, prophenoloxidase (proPO) II, toll-like receptors (TLR) 3, signal transducer and activator of transcription (STAT), and crustin in shrimp receiving fresh CPH extract at 20 μg shrimp^-1, and the lipopolysaccharide and β-1,3-glucan-binding protein, proPO II, TLR1, and STAT in shrimp receiving fresh CPH extract at 40 μg shrimp^-1 were significantly higher than those of shrimp receiving saline. After injecting fresh CPH extract at 10-40 μg shrimp^-1 and 40 μg shrimp^-1, the mortality of shrimp challenged with V. alginolyticus and exposed to 14 °C for 96 h significantly decreased, respectively. These results suggest that fresh CPH extract can be used as an immunostimulant and a physiological regulator for shrimp through injection administration to enhance immunological and physiological responses, which can elevate the resistance against V. alginolyticus and tolerance against hypothermal stress in L. vannamei.

Screening of immuno-modulatory potential of different herbal plant extracts using striped catfish (Pangasianodon hypophthalmus) leukocyte-based in vitro tests

Many medicinal plants have been shown to possess biological effects, including immuno-modulatory activities on human and other mammals. However, studies about the potential mechanisms of plant extracts on the humoral and tissular immunities in fish have received less attention. This study aimed to screen the immunestimulating properties of 20 ethanol plant extracts on striped catfish Pangasianodon hypophthalmus leukocytes. The peripheral blood mononuclear cells (PBMCs) and head kidney leukocytes (HKLs) of striped catfish (50 ± 5 g per fish) were stimulated at 10 and 100 μg of each plant extract per mL of cell culture medium. Several humoral immune parameters (lysozyme, complement and total immunoglobulin) were examined at 24-h post stimulation (hps). Furthermore, the responses of four cytokine genes, namely il1β, ifrγ 2a and b, and mhc class II were assessed by quantitative real-time PCR at 6, 12, 24, and 48 hps. The results showed that lysozyme, complement as well as total immunoglobulin levels in both PBMCs and HKLs were regulated by some of the plant extracts tested in a concentration-dependent manner; some plant extracts induced the highest immune responses at the low dose (10 μg mL^-1) while others were more efficient at high dose (100 μg mL^-1). Among the extracts, five extracts including garlic Allium sativum L. (As), neem Azadirachta indica A. Juss (Ai), asthma-plant Euphorbia hirta L. (Eh), bhumi amla Phyllanthus amarus Schum. et Thonn (Pa), and ginger Zingiber officinale Rosc (Zo) induced significant changes in the expression of pro-inflammatory cytokine (il1β), antiviral cytokines (ifrγ 2a and b) and adaptive immune cytokine (mhc class II) in striped catfish cells. Pa always modulated the strongest expression of the four cytokines in PBMCs and HKLs over the whole experimental period (p < 0.05), whereas Zo did not stimulate the mhc class II expression in striped catfish leukocytes throughout experimental periods. These in vitro results demonstrated that some plant extracts could differently modulate great potential immune response in fish, supporting their applications in further in vivo experiments.

Involvement of tetraspanin 8 in the innate immune response of the giant prawn, Macrobrachium rosenbergii

The tetraspanins, representing a conserved superfamily of four-span membrane proteins, are highly involved in viral and bacterial infections. Thus far, the function of the tetraspanins in crustaceans remains largely unknown. In this study, we report the cloning and expression analysis of a tetraspanin 8 from the giant freshwater prawn, Macrobrachium rosenbergii (named as MrTspan8). MrTspan8 contains a 720-bp open reading frame encoding a 239-amino acids protein, which exhibits four transmembrane domains and two extracellular loops that are typical for tetraspanins. MrTspan8 was found to be widely expressed in a variety of prawn tissues including heart, gill, muscle, gut, and hepatopancreas. Additionally, MrTspan8 expression was significantly increased in the hepatopancreas and gill of the prawns challenged by the bacterial pathogen Aeromonas hydrophila. Moreover, we show that pre-incubation of the peptides from the large extracellular loop of MrTSPAN8 protein reduced the cell death caused by A. hydrophila infection in prawn tissue, suggesting that MrTSPAN8 could be a mediator for bacterial infection to prawn.

Vibriosis in Fish: A Review on Disease Development and Prevention

Current growth in aquaculture production is parallel with the increasing number of disease outbreaks, which negatively affect the production, profitability, and sustainability of the global aquaculture industry. Vibriosis is among the most common diseases leading to massive mortality of cultured shrimp, fish, and shellfish in Asia. High incidence of vibriosis can occur in hatchery and grow-out facilities, but juveniles are more susceptible to the disease. Various factors, particularly the source of fish, environmental factors (including water quality and farm management), and the virulence factors of Vibrio, influence the occurrence of the disease. Affected fish show weariness, with necrosis of skin and appendages, leading to body malformation, slow growth, internal organ liquefaction, blindness, muscle opacity, and mortality. A combination of control measures, particularly a disease-free source of fish, biosecurity of the farm, improved water quality, and other preventive measures (e.g., vaccination) might be able to control the infection. Although some control measures are expensive and less practical, vaccination is effective, relatively cheap, and easily implemented. In this review, the latest knowledge on the pathogenesis and control of vibriosis, including vaccination, is discussed.

Wntless, a conserved Wnt-transport protein, is involved in the innate immune response of Macrobrachium rosenbergii

Wnt signaling plays important roles in a variety of developmental and pathological processes. Here we show that Wntless, the main regulator for Wnt secretion, is involved in the innate immune response of the giant freshwater prawn, Macrobrachium rosenbergii. The full-length cDNA of the prawn Wntless (named MrWntless) is 2173 bp in length and contains a 1602-bp open reading frame (ORF), which is conceptually translated into a 533-amino acids sequence. MrWntless protein contains a highly conserved Wnt-binding domain which is required for secretion of Wnt ligands, and exhibits 57-67% identity with known Wntless proteins of other animals. MrWntless was found to be expressed in a variety of prawn tissues including heart, gill, muscle, gut, hepatopancreas and ovary. Moreover, MrWntless expression was significantly increased in the hepatopancreas and gill of the prawns challenged by the bacterial pathogen Aeromonas hydrophila and Vibrio parahaemolyticus. Knockdown of MrWntless by RNA interference in prawns led to dramatically decreased MrWntless expression of approximately 70%. Furthermore, the cumulative mortality rate of the prawn injected with MrWntless dsRNA was greatly increased in response to A. hydrophila challenge compared with the control prawns. Taken together, we provide evidence that prawn Wntless is important for their innate immune response against bacterial pathogens.

Dietary Withania sominefera root confers protective and immunotherapeutic effects against Aeromonas hydrophila infection in Nile tilapia (Oreochromis niloticus)

In the present study, effect of dietary Withania sominefera (W. sominefera) root powder was evaluated to modulate immune and antioxidant response against Aeromonas hydrophila (A. hydrophila) infection in Nile tilapia (Oreochromis niloticus). W. sominefera root powder supplemented diets at two concentrations 2.5% (W 2.5%) and 5% (W 5%); fed for 6 weeks prior to the A. hydrophila challenge and continued the same respective diets during the post challenge period (2 weeks). Results showed that fish fed W. sominefera at 5% enhanced immune response in both pre and post-challenge period. NBT level exhibited only significant increase (P < 0.05) in the pre-challenge period compared to control. Malondialdehyde (MDA) levels in liver and muscle revealed significant decrease in both Withania supplemented groups compared to the control in post challenge period. Antioxidant enzymes activities (catalase/CAT/, glutathione S-transferase/GST/, glutathione/GSH; and superoxide dismutase/SOD) were improved in liver and muscle in post challenge period. Glutathione peroxidase (GPx) level in muscle and serum total antioxidant capacity (TAC) showed a significant increase in both Withania supplemented groups compared to the control post challenge. Withania supplementation enhanced disease resistance against A. hydrophila and reduced mortalities (20%), especially at supplemented concentration of 5%. Our findings suggest that W. sominefera root powder may have protective and immunotherapeutic roles in Nile tilapia against A. hydrophila infection which may be useful in controlling important fish bacterial diseases.

Effect of microencapsulated probiotic Bacillus vireti 01-polysaccharide extract of Gracilaria folifera with alginate-chitosan on immunity, antioxidant activity and disease resistance of Macrobrachium rosenbergii against Aeromonas hydrophila infection

Polysaccharide from red seaweed Gracilaria folifera has an interesting functional property of antioxidant activity and prebiotic effect. A feeding trial experiment was directed to examine the effect of probiotic bacteria Bacillus vireti 01 microencapsulated with G. folifera polysaccharide against freshwater prawn M. rosenbergii. Three different feeding trials were conducted for 15 days. The first group contained prawns fed with commercial diet. The second group was comprised of Aeromonas hydrophila challenged prawns fed with commercial feed. The third group consisted of A. hydrophila challenged prawns fed with microencapsulated probiotic-polysaccharide. Survival percentage was significantly decreased in prawns of group2 as compared to that of group1 and group3 prawns (p < 0.0001). The immunological parameters and antioxidant activities (p < 0.001) were found to be increased in group three prawns which were fed with encapsulated probiotic-seaweed polysaccharide and challenged with A. hydrophila as compared to that of group1 and group2. Tissue necrosis, fused lamella, haemocyte infiltration and damage of hepatopancreas lumen and tubule were noted in group2 prawns. There was no histological changes were observed in group3 prawns in which the histological architecture was similar to the control group1. The results suggested that combination of encapsulated probiotic B. vireti 01 and seaweed polysaccharide as dietary feed showed an enhancement of immune response, antioxidant activity and disease resistant of M. rosenbergii against A. hydrophila.

The hot-water extract of leaves of noni, Morinda citrifolia, promotes the immunocompetence of giant freshwater prawn, Macrobrachium rosenbergii

The hot-water Morinda citrifolia leaf extract (HMLE) was prepared for in vitro assessment on phenoloxidase (PO) activity, respiratory bursts (RBs), and phagocytic activity (PA). Furthermore, the HMLE was administrated in the diet at 0.6, 3, and 6 g (kg diet)^-1 for Macrobrachium rosenbergii, and the potential effects on the immunocompetence of prawns were evaluated. PO activity, RBs, and PA in hemocytes incubated with the HMLE at 140, 20, 20, and 140 mg l^-1 significantly increased. The immune parameters of the total hemocyte count (THC), differential hemocyte count (DHC), RBs, PO activity, superoxide dismutase (SOD) activity, PA, transglutaminase (TG) activity and hemolymph clotting time were evaluated before and after 1, 3, 5, 7, and 9 weeks of the feeding trial. During 9 weeks of the feeding trial, higher THCs, DHCs, RBs, PO, and TG as well as accelerated clotting times were observed in prawns fed HMLE-containing diets at 0.6 g kg^-1. The mRNA expressions of prophenoloxidase, TG, crustin, and lysozyme of prawns fed HMLE-containing diets at 0.6 g kg^-1 for 9 weeks of the feeding trial significantly increased. The susceptibility of prawns fed the HMLE at 0.6 g kg^-1 to Lactococcus garvieae infection significantly decreased, and the relative survival percentage was 23.1%. We therefore found that HMLE administrated through the diet at 0.6 g kg^-1 was capable of enhancing the immunity and resistance against L. garvieae in M. rosenbergii.

Network ethnopharmacological evaluation of the immunomodulatory activity of Withania somnifera

ETHNOPHARMACOLOGICAL RELEVANCE

Withania somnifera (L.) Dunal (Ashwagandha, WS) is one of the extensively explored Ayurvedic botanicals. Several properties including immunomodulation, anti-cancer and neuro-protection of the botanical have been reported. Even though, in indigenous medicine, WS is well known for its immunomodulatory activity, the molecular mechanism of immunomodulation has not been elucidated.

AIM OF THE STUDY

This study aimed the evaluation of the immunomodulatory effect of WS using network ethnopharmacology technique to elucidate the in silico molecular mechanism.

MATERIALS AND METHODS

Databases- DPED, UNPD, PubChem, Binding DB, ChEMBL, KEGG and STRING were used to gather information to develop the networks. The networks were constructed using Cytoscape 3.2.1. Data analysis was performed with the help of Excel pivot table and Cytoscape network analyzer tool.

RESULTS

Investigation for WS immune modulation mechanism identified five bioactives that are capable of regulating 15 immune system pathways through 16 target proteins by bioactive-target and protein-protein interactions. The study also unveils the potential of withanolide-phytosterol combination to achieve effective immunomodulation and seven novel bioactive-immune target combinations.

CONCLUSION

The study elucidated an in silico molecular mechanism of immunomodulation of WS. It unveils the potential of withanolide-phytosterol combination to achieve a better immunomodulation. Experimental validation of the network findings would aid in understanding the rationale behind WS immunomodulation as well as aid in bioactive formulation based drug discovery.

Withania somnifera as a potential anxiolytic and immunomodulatory agent in acute sleep deprived female Wistar rats

Sleep is a profound regulator of cellular immunity, and the curtailment of sleep in present day lifestyle leads to disruption of neuro-immune-endocrine interactions. No therapeutic remedy is yet known for the amelioration of detrimental effects caused by sleep deprivation (SD). The current study was aimed to elucidate the effects of acute SD on immune function and its modulation by water extract from leaves of Withania somnifera (ASH-WEX). Three groups of animals, i.e. Vehicle-Undisturbed sleep (VUD), Vehicle-Sleep deprived (VSD) and ASH-WEX fed sleep deprived (WSD) rats were tested for their anxiety-like behaviour and further used for the study of inflammatory and apoptotic markers expression in piriform cortex and hippocampus regions of the brain. VSD animals showed high level of anxiety in elevated plus maze test, which was ameliorated in WSD group. The stress induced expression of inflammatory and immune response markers GFAP, TNFα, IL-6, OX-18 and OX-42 in VSD animals was found to be modulated by ASH-WEX. Further, the stress induced apoptosis was suppressed in WSD group as indicated by expression of NF-κB, AP-1, Bcl-xL and Cytochrome c. This study provides scientific validation to the anxiolytic, anti-inflammatory and anti-apoptotic properties of ASH-WEX, which may serve as an effective dietary supplement for management of SD induced stress and associated functional impairments.

Effect of Shilajit enriched diet on immunity, antioxidants, and disease resistance in Macrobrachium rosenbergii (de Man) against Aeromonas hydrophila

The effect of diet supplemented with Shilajit, a multi-component natural mineral substance on the antioxidant activity, immune response, and disease resistance in freshwater prawn, Macrobrachium rosenbergii (de Man) against Aeromonas hydrophila is reported. The total hemocyte count (THC) and phagocytic activity significantly increased with 2 g kg(-1) supplemented diet on first week and with other enriched diets on weeks 2 and 4. The respiratory burst (RB) activity and glutathione peroxidase (GPx) activity were significantly increased with 2 g kg(-1) supplemented diet on weeks 1 and 2 whereas 2 and 4 g kg(-1) diets on week 4. The phenoloxidase (PO) activity increased significantly with 2 g kg(-1) diet only on second week and with other enriched diets only on fourth week. The superoxide dismutase (SOD) activity increased significantly with any enriched diet during the experimental period except with 6 g kg(-1) diets on first week. However, the glutathione reductase (GR) activity was enhanced significantly only with 2 g kg(-1) enriched diets on weeks 2 and 4. The cumulative mortality of the prawn fed with 2 and 4 g kg(-1) enriched diets was 10% and 15% whereas with 6 g kg(-1) diet the mortality was 20%. The results suggest that diet enriched with Shilajit at 2 g kg(-1) or 4 g kg(-1) positively enhances the antioxidant activity, immunity, and disease resistance in M. rosenbergii against A. hydrophila.

The effect of banana (Musa acuminata) peels hot-water extract on the immunity and resistance of giant freshwater prawn, Macrobrachium rosenbergii via dietary administration for a long term: Activity and gene transcription

The non-specific immune parameters, disease resistance and immune genes expressions in Macrobrachium rosenbergii were evaluated at 120 days of post feeding the diets containing the extracts of banana, Musa acuminate, fruit's peel (banana peels extract, BPE) at 0, 1.0, 3.0 and 6.0 g kg(-1). Results showed that prawns fed with a diet containing BPE at the level of 1.0, 3.0 and 6.0 g kg(-1) for 120 days had a significantly higher survival rate (30.0%, 40.0% and 56.7%, respectively) than those fed with the control diet after challenge with Lactococcus garvieae for 144 h, and the respective relative survival percentages were 22.2%, 33.3%, and 51.9%, respectively. Dietary BPE supplementation at 3.0 and/or 6.0 g kg(-1) for 120 days showed a significant increase total haemocyte count (THC), granular cell (GC), superoxide dismutase (SOD) activity, phenoloxidase (PO) activity, transglutaminase (TG) activity, and phagocytic activity and clearance efficiency to L. garvieae infection, and meanwhile, the significant decrease in haemolymph clotting times and respiratory bursts (RBs) per haemocyte of prawns were revealed. Furthermore, the mRNA expressions of prophenoloxidase (proPO), lipopolysaccharide and β-1,3-glucan binding protein (LGBP), peroxinectin (PE), transglutaminase (TG), and crustin (CT) were significantly increased. We therefore recommend that BPE can be used as an immunomodulator for prawns through dietary administration at 6.0 g kg(-1) for a long term (over 120 days) to modify immune responses and genes expression following the enhanced resistance against pathogens.

Dietary supplementation of Avicennia marina extract on immune protection and disease resistance in Amphiprion sebae against Vibrio alginolyticus

The effect of Avicennia marina aqueous leaf extract on innate immune mechanisms such as total white blood cell counts (WBC), serum lysozyme activity, respiratory burst assay, alternative complement (ACH50) assay, phagocytic activity assay, disease resistance, gut bacteria, and survival rate of clownfish (Amphiprion sebae) against Vibrio alginolyticus is reported. Healthy fish challenged with V. alginolyticus (1 × 10(7) cells ml(-1)) were fed with diets supplemented (0, 1, 2, and 4%) with A. marina extract. The survival rate was 85% and 80% in infected fish fed with 4% and 8% supplementation diet; with 1% diet it was 70% while in the infected untreated group it was only 10%. The total gut bacteria flora was high in 8% and 4% supplementation diet groups with 2.8 × 10(5) and 4.7 × 10(4) cfu/g while it was 8.9 × 10(3) cfu/g in 1% diet group. The immunological parameters significantly increased on weeks 6 and 8 when infected fish were fed with 1% or 4% supplementation diet. This study reports that in clownfish challenged with V. alginolyticus, dietary administration of the 1% or 4% of A. marina extract improved the immune status and survival rate.

Dietary supplement of banana (Musa acuminata) peels hot-water extract to enhance the growth, anti-hypothermal stress, immunity and disease resistance of the giant freshwater prawn, Macrobrachium rosenbergii

In the present study, Macrobrachium rosenbergii were fed with diets containing extracts of banana, Musa acuminate, fruit's peel (banana peels extract, BPE) at 0, 1.0, 3.0 and 6.0 g kg(-1). The non-specific immune parameters, disease resistance and anti-hypothermal stress were evaluated at 2, 4, 8, 16 and 32 days of post feeding. Also, we demonstrated the percent weight gain (PWG), percent length gain (PLG), feeding efficiency (FE), and survival rate of giant freshwater prawn at 30, 60, 90, and 120 days of post feeding. The PWG, PLG, FE and survival rate of prawns fed at 0, 1.0, 3.0 and 6.0 g kg(-1) BPE-containing diets after 120 days were 69.5%, 75.4%, 77.8% and 83.3%; 21.8%, 23.6%, 27.8% and 33.9%; 0.60, 0.72, 0.75 and 0.90; and 55.4%, 62.2%, 62.3% and 75.3%, respectively. After 32 days of post feeding, a significant increase in total haemocyte count (THC), different haemocyte count (DHC), respiratory bursts (RBs), superoxide dismutase (SOD) activity, glutathione peroxidase (GPx) activity, phenoloxidase (PO) activity and transglutaminase (TG) activity, and meanwhile, a decreased haemolymph coagulation time was observed. Furthermore, phagocytic activity and clearance efficiency of prawns against Lactococcus garvieae infection were significantly increased. Prawns challenged with L. garvieae after 32 days of feeding at 1.0, 3.0 and 6.0 g kg(-1) had a significantly higher survival rate (33.3%, 40.0% and 56.7%) than those fed with the control diet. Subsequently, hypothermal (14 °C) stress was 43.4%, 50.0% and 50.0%, respectively. Altogether, we therefore recommend the dietary BPE administration at 6.0 g kg(-1) promotes growth, anti-hypothermal stress, and enhance immunity and resistance against L. garvieae in M. rosenbergii.

Effects of hot-water extract of banana (Musa acuminata) fruit's peel on the antibacterial activity, and anti-hypothermal stress, immune responses and disease resistance of the giant freshwater prawn, Macrobrachium rosenbegii

The hot-extracts isolated from fruit's peel of banana, Musa acuminata, was evaluated on the antibacterial activity to pathogens from aquatic animals, and immunostimulating potential, disease resistance and anti-hypothermal stress in giant freshwater prawn, Macrobrachium rosenbergii through injection administration. The banana peel extract (BPE) showed good activity against 1 Gram-positive and 3 Gram-negative pathogens, including Lactococcus garvieae, Photobacteria damsella, Vibrio alginolyticus and Vibrio parahemolyticus especially in prawn pathogen of L. garvieae strain, which were carried out by a disk diffusion method. Prawn received BPE via injection administration at 1-6 μg (g prawn)(-1) significantly increased total haemocyte count (THC), hyaline cell (HC), granular cell (GC), phenoloxidase (PO) activity and phagocytic activity against L. garvieae from 3 to 6 days, and significantly increased clearance efficiency against L. garvieae and a significantly decreased coagulation time of prawn from 1 to 6 days. Prawn injected with BPE at 6.0 μg (g prawn)(-1) for 6 days showed significantly increased superoxide dismutase (SOD) activity, but significantly decreased respiratory bursts (RBs) of per haemocyte. Survival rates of M. rosenbergii injected with BPE at concentrations of 1, 3 and 6 μg (g prawn)(-1) were significantly higher than those injected with saline control after challenge with L. garvieae for 4-6 days, and the respective relative survival percentages of prawn were 28.6%, 38.1%, and 47.8%, respectively at 6 days. The sublethal time of prawns that had received saline and BPE at 1, 3 and 6 μg (g prawn)(-1) for 6 days and then were transferred from 28 °C to 14 °C were 69.4, 79.8, 83.6, and 90.2 h, respectively. It was concluded that the BPE can be used as the bacteriostat, and immunostimulant and physiological regulator for prawn through injection administration to enhance immunity, physiological responses, and resistance against L. garvieae.

Effects of dietary administration of water hyacinth (Eichhornia crassipes) extracts on the immune responses and disease resistance of giant freshwater prawn, Macrobrachium rosenbergii

The hot-water extract of Eichhornia crassipes leaves (ECE) was produced and incorporated into the diet of the prawn, Macrobrachium rosenbergii, as an immunostimulant. Survival rates of prawn against Lactococcus garvieae, and its immune parameters including the total haemocyte count (THC), different haemocyte count (DHC), phenoloxidase (PO) activity, respiratory bursts (RBs), superoxide dismutase (SOD) activity, glutathione peroxidase (GPx) activity, transglutaminase (TG) activity, haemolymph coagulation time, and phagocytic activity and clearance efficiency against L. garvieae by M. rosenbergii were determined when prawn (23.0 ± 2.8 g) were fed ECE-containing diets at 0, 1.0, 2.0 and 3.0 g kg(-1). Prawn fed a diet containing ECE at 2.0 and 3.0 g kg(-1) for 12 days showed significantly increased THC, HC, GC, PO activity, RBs, SOD activity, GPx activity, and TG activity, and a significantly decreased coagulation time. The phagocytic activity and clearance efficiency against L. garvieae of prawn fed the ECE-containing diets at 1.0, 2.0, and 3.0 g kg(-1) were significantly higher than those of prawn fed the control diet at 3-12 days. Survival rates of M. rosenbergii fed the diet containing ECE at concentrations of 2 and 3 g kg(-1) were significantly higher than those fed the control diet after challenge with L. garvieae for 48-144 h. The relative percentage survival of prawn fed the 1.0, 2.0, and 3.0 g kg(-1) ECE-containing diets for 12 days were 17.5%, 39.1%, and 52.2%. It was concluded that the ECE can be used as an immunostimulant for prawn through dietary administration to enhance immune responses and resistance of M. rosenbergii against L. garvieae.

A novel effect of imidazole derivative KK-42 on increasing survival of Aeromonas hydrophila challenged prawn Macrobrachium nipponense

Imidazole derivative KK-42 is well known as the insect growth regulator. Here we find that KK-42 pretreatment could promote the survival of Macrobrachium nipponense infected with Aeromonas hydrophila, which is considered to be possibly related to the prophenoloxidase (proPO), a conserved copper-containing enzyme that plays an important role in defense against pathogens. In this study, a full-length of proPO gene from M. nipponense haemocytes, designated as MnproPO, was firstly cloned and characterized. The full-length cDNA contained 2428 bp with a 2013 bp open reading frame encoding a putative proPO protein of 671 amino acids with a predicted molecular mass of 76.5 kDa and pI of 7.31. It was predicted to possess all the expected features of proPO members, including two putative copper-binding sites with six histidine residues and a thiol ester-like motif. Sequence analysis showed that MnproPO exhibited the highest amino acid sequence similarity (93%) to a proPO of Macrobrachium rosenbergii. The gene was expressed highly in haemocytes and weakly in hepatopancreas. Real-time PCR analysis revealed that the MnproPO expression increased significantly at 3, 12 and 24 h after KK-42 treatment, the PO activity also importantly rose from 6 to 48 h in KK-42-treated prawns and reached the maximum at 24 h with a 2.3-fold higher than that in control group. Injection of A. hydrophila could stimulate the MnproPO transcription and PO activity whether or not the prawns were pretreated by KK-42, the mRNA level increased obviously only at 3 h and 6 h after the bacterium injection (challenged control), but increased constantly during the phase of experiment except at 6 h under the condition of KK-42 pretreatment (challenged treatment group). The change trend of PO activity was basically similar to that of MnproPO expression. Our present results demonstrate that the MnproPO expression as well as PO activity may be induced by KK-42, which is likely one of the molecular mechanisms of KK-42 acts for increasing survival of the prawn infected with A. hydrophila.

The role of bioactive compounds on the promotion of neurite outgrowth

Neurite loss is one of the cardinal features of neuronal injury. Apart from neuroprotection, reorganization of the lost neuronal network in the injured brain is necessary for the restoration of normal physiological functions. Neuritogenic activity of endogenous molecules in the brain such as nerve growth factor is well documented and supported by scientific studies which show innumerable compounds having neurite outgrowth activity from natural sources. Since the damaged brain lacks the reconstructive capacity, more efforts in research are focused on the identification of compounds that promote the reformation of neuronal networks. An abundancy of natural resources along with the corresponding activity profiles have shown promising results in the field of neuroscience. Recently, importance has also been placed on understanding neurite formation by natural products in relation to neuronal injury. Arrays of natural herbal products having plentiful active constituents have been found to enhance neurite outgrowth. They act synergistically with neurotrophic factors to promote neuritogenesis in the diseased brain. Therefore use of natural products for neuroregeneration provides new insights in drug development for treating neuronal injury. In this study, various compounds from natural sources with potential neurite outgrowth activity are reviewed in experimental models.