Mucuna pruriens seeds extract boosts growth, immunity, testicular histology, and expression of immune-related genes of mono-sex Nile tilapia (Oreochromisniloticus).

Nutraceuticals have received increased attention in sustainable aquaculture. Consequently, the present study aimed to evaluate the dietary effects of Mucuna pruriens (MP) seed extract on growth performance, immune status, hepatic function, biochemical profiles, gonadal histology, and expression of immune-related genes in mono-sex Nile tilapia (Oreochromis niloticus). Fish were allocated into four groups and received MP at rates of 0 (control), 2, 4, and 6 g/kg diet, respectively, for 90 days. The results revealed that MP significantly (P<0.05) modulated growth performance (specific growth rate, final length, and length gain rate, body mass gain, and feed conversion ratio), lysozyme activity, and liver enzymes (AST, ALT). However, a non-significant effect on nitric oxide (NO) or immunoglobulin M (IgM) levels was detected, whereas the dietary inclusion of MP had a hypoglycemic effect. In terms of plasma globulin, albumin, globulin/albumin ratio, and cortisol, the MP receiving groups showed insignificant difference (P<0.05) when compared to controls, except for the 2 g MP-supplemented group. The lower inclusion concentration of MP (2 g/kg diet) demonstrated the best result (P < 0.05) for gonadosomatic index (GSI) and plasma testosterone level that was consistent with the histological findings reflecting an improvement in the testicular development compared with the control group. Expressions of complement component (C5) and interleukin 1-ß (IL-1ß) genes were significantly up-regulated in MP receiving groups. In conclusion, M. pruriens can be used as a safe natural economic feed additive and a low inclusion level of 2 g/kg diet is recommended to improve growth, enhance immunity, maintain liver functioning, improve testicular development, and to modulate immune-related genes in the mono-sex O. niloticus.

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

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

Astragalus membranaceus nanoparticles markedly improve immune and anti-oxidative responses; and protection against Aeromonas veronii in Nile tilapia Oreochromis niloticus.

The effects of dietary administration of Astragalus membranaceus nanoparticles (ANP) on immune and anti-oxidative responses, growth performance and disease resistance of Oreochromis niloticus were evaluated in the present study. Fish were divided into three groups and received the ANP at rates of 0 (control), 1, and 2%/kg diet for four weeks. After the four-week feeding trial, three fish from each replicate were sampled for immune and anti-oxidative responses evaluation, ten fish from each group were challenged with A. veronii, and nine fish from each group were subjected to cold and hypoxia challenges. It was obvious from the results that ANP significantly enhanced lysozyme activity and nitrous oxide (NO) activities, as well as improved superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities. Also, aspartate aminotransferase, alanine transaminase, glucose, and cortisol measurements showed significantly lower levels in incorporated groups compared to the control. Growth performance; and amylase and lipase digestive enzymes activities also showed markedly improved results. Expression of heat shock protein 70 (HSP70) and interleukin 1, beta (IL-1ß) genes were significantly upregulated throughout the entire experimental period. When challenged with A. veronii, the mortality of treated groups was significantly (P < 0.05) lower than the control. Current results proofs that dietary ANP had a synergistic effect on immune and anti-oxidative responses, growth performance and disease resistance of Oreochromis niloticus.