Steelhead trout Oncorhynchus mykiss metabolic rate is affected by dietary Aloe vera inclusion but not by mounting an immune response against formalin‐killed Aeromonas salmonicida

The role of glucan as a biologically active immunomodulator has been well documented for more than 40 years. However, the wide diversity of β-glucan forms and the extraction process has implications for the benefits of these compounds. Biorigin developed two samples of β-glucans using different biotechnological processes. Thus, in the present study, we fed Nile tilapia (Oreochromis niloticus) diets containing these two β-glucan molecules (BG01 and BG02) for 30 days prior to bacterial infection with Streptococcus agalactiae. The results showed that the different β-glucan samples exhibited biologically differently behaviors, but both increased the resistance against bacterial infection. Specifically, BG01 increased immunostimulation, while BG02 improved growth performance. In summary, these findings confirm the benefits of β-glucans in aquaculture and also provide further evidence of the growth promotion of these compounds.

Section: Discussionmentioning

confidence: 99%

Different β-glucans improve the growth performance and bacterial resistance in Nile tilapia

Pilarski

Oliveira²,

Souza³

et al. 2017

“…At present, we do not have an explanation for this result. Zanuzzo et al [53] showed that steelhead trout (Oncorhynchus mykiss) fed with 0.5% A. vera during 8 weeks had resting cortisol levels one-half of those of the control fish. Tilapia (Oreochromis niloticus) fed with A. vera diets during 60 days also had significantly difference in cortisol level compare to control fish [39].…”

Section: Discussionmentioning

confidence: 99%

Aloe vera enhances the innate immune response of pacu (Piaractus mesopotamicus) after transport stress and combined heat killed Aeromonas hydrophila infection

Zanuzzo

Sabioni

Montoya

et al. 2017

In this study, pacu (Piaractus mesopotamicus) were fed with diets containing Aloe vera for 10 days prior to transport stress and infection with heat killed Aeromonas hydrophila. A. vera is popular around the world due to its medicinal properties, including immunostimulatory effects which was observed in this study. The results show that transport causes immunosuppression, an effect that was prevented by A. vera. Specifically, A. vera prevented reductions of both leukocyte respiratory burst and hemolytic activity of complement system caused by transport. Further, fish fed with A. vera also showed significantly higher leukocyte respiratory burst, serum lysozyme concentrations and activity of complement system 24 h after bacterial infection. Additionally, we observed that A. vera may modulate the innate response through activation of complement system during bacterial immune stimulation. In summary, A. vera extract enhanced innate immune parameters and consequently the ability of fish to cope with pathogens following transport stress. These findings show that A. vera has promise for use in aquaculture and add further evidence that medicinal herbs added to fish feed assist to prevent disease outbreaks.

“…Nevertheless, as mounting an immune response could be costly (see [66] for discussion) the dietary composition should be monitored carefully and adapted if necessary.…”

Section: Accepted Manuscriptmentioning

confidence: 99%

Dietary β-glucan (MacroGard®) enhances survival of first feeding turbot (Scophthalmus maximus) larvae by altering immunity, metabolism and microbiota

Miest

Arndt

Adamek

et al. 2016

Please cite this article as: Miest JJ, Arndt C, Adamek M, Steinhagen D, Reusch TBH, Dietary β-glucan (MacroGard ® ) enhances survival of first feeding turbot (Scophthalmus maximus) larvae by altering immunity, metabolism and microbiota, Fish and Shellfish Immunology (2015), doi: 10.1016/ j.fsi.2015 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. (1 nauplius ml/L). Daily mortality was monitored and larvae were sampled at 11 and 24 dph for expression of 30 genes, microbiota analysis, trypsin activity and size measurements.Along with the feeding of β-glucan daily mortality was significantly reduced by ca. 15% and an alteration of the larval microbiota was observed. At 11 dph gene expression of trypsin and chymotrypsin was elevated in the MacroGard ® fed fish, which resulted in heightened tryptic enzyme activity. No effect on genes encoding antioxidative proteins was observed, whilst the immune response was clearly modulated by β-glucan. At 11 dph complement component c3 was elevated whilst cytokines, antimicrobial peptides, toll like receptor 3 and heat shock protein 70 were not affected. At the later time point (24 dph) an anti-inflammatory effect in form of a down-regulation of hsp 70, tnf-α and il-1β was observed. We conclude that the administration of MacroGard ® induced an immunomodulatory response and could be used as an effective measure to increase survival in rearing of turbot.