Spirulina (Arthrospira platensis) supplementation: Impact on growth, metabolism, and antioxidant status in zebrafish.

Zebrafish (Danio rerio) is a valuable model for biomedical research because of its mammalian genetic similarities, rapid reproduction, and low maintenance costs. However, further investigation is required regarding their nutritional requirements and standardized laboratory diets. This study evaluated the metabolic and growth responses of zebrafish juveniles fed on diets supplemented with spirulina, Arthrospira platensis (SP) at different levels for 77 days. Six diets with SP inclusion levels of 0%, 2%, 4%, 6%, 8%, and 10% (SP0-SP10) were formulated. A total of 300 zebrafish juveniles with an average initial weight of 0.113 ± 0.10 g (mean ± SD) were randomly distributed across six groups, with five replicates per group, each containing 10 animals. After 77 days, the SP6 group demonstrated significantly enhanced growth performance compared with the other supplementation levels. The condition factor was markedly higher in the SP6 and SP8 groups than in the SP0 group. No significant effects on total cholesterol levels were observed, but the SP4, SP6, and SP10 diets decreased triglyceride levels. Lipase activity was higher in the SP6 and SP8 groups than in the control group, whereas amylase activity showed no significant differences between treatments. Catalase and superoxide dismutase activities were significantly higher in the SP8 and SP10 groups than in the SP0 and SP2 groups. Glutathione S-transferase activity was higher in the SP6, SP8, and SP10 groups than in the SP0 group. In addition, SP inclusion in zebrafish diets improved female gonadal development. In conclusion, this study indicates that SP supplementation has substantial potential as a growth promoter, positively influencing lipid metabolism and antioxidant enzyme activity without affecting zebrafish survival.

Obesity induction in adult zebrafish leads to negative reproduction and offspring effects.

Obesity is a transgenerational epigenetic metabolic disturbance. Although the diet-induced obese (DIO) zebrafish model is well established, reproductive parameters and changes in offspring have not yet been evaluated. Thus, the aim of this study was to evaluate possible changes in reproductive parameters, embryos and offspring (F1) generated by the reproduction of diet-induced obese males and females. The adult zebrafish were divided into two groups: one group receiving a balanced diet (control group) and the other group was overfed (DIO group) . The dietary protocol was maintained for 8 weeks. During this period, males and females in the same group were stimulated through a weekly reproduction protocol. To verify parental obesity, body weight, blood glucose, triglyceride, the hepatosomatic and gonadosomatic index and adipose tissue morphometry evaluations were carried out. Reproductive parameters were evaluated through ovarian and oocyte maturation stage, total spawning, fertility and fertilization index. To verify possible changes caused by parenteral obesity, all offspring were kept in separate groups in correspondence with their parents and were fed a control diet. Plasma glucose, triglycerides, mortality rate, hatching, and deformities were determined. After 8 weeks under the diet protocol, the DIO group exhibited characteristic obesity alterations, displaying significant increases in body mass and hepatosomatic and gonadosomatic indices, hyperglycemia and visceral and subcutaneous adipocyte hypertrophy. In addition, high mortality rates, morphologic deformities and high plasmatic glucose and triglyceride levels, with 100% mortality at 60 dpf, were observed for the offspring. Therefore, obesity induction in adults led to negative effects on their offspring, with a high occurrence of deformities and mortality.

Metabolic effects of physical exercise on zebrafish (Danio rerio) fed a high-fat diet.

The present study aimed to establish zebrafish as an experimental model for investigations into obesity and physical exercise, as well as to assess the effects of these factors on metabolism. The experiment spanned twelve weeks, comprising a feeding trial during which the last four weeks incorporated a physical exercise protocol. This protocol involved placing fifteen animals in a five-liter aquarium, where they were subjected to swimming at an approximate speed of 0.08 m/s for 30 min daily. Throughout the experiment, histological analyses of visceral, subcutaneous, and hepatic adipose tissues were conducted, along with biochemical analyses of total cholesterol and its fractions, triglycerides, glucose, lactate, and alanine aminotransferase (ALT) levels. Additionally, oxidative stress markers, such as reactive oxygen species (ROS) levels, superoxide dismutase (SOD) activity, and catalase activity and the formation of thiobarbituric acid-reactive substances, were investigated. The results revealed that the group fed a high-fat diet exhibited an increase in ROS production and SOD activity. In contrast, the group administered the high-fat diet and subjected to physical exercise demonstrated a notable reduction in visceral adipocyte area, hepatic steatosis levels, ALT levels, and SOD activity. These findings indicate that physical exercise has a positive effect on obesity and oxidative stress in zebrafish, providing promising evidence for future investigations in this field.

Evaluation of the Anti-Inflammatory and Antioxidant Potential of Cymbopogon citratus Essential Oil in Zebrafish.

This study explored the protective capacity of the essential oil (EO) of Cymbopogon citratus against oxidative stress induced by hydrogen peroxide (H2O2) and the inflammatory potential in zebrafish. Using five concentrations of EO (0.39, 0.78, 1.56, 3.12, and 6.25 µg/mL) in the presence of 7.5 mM H2O2, we analyzed the effects on neutrophil migration, caudal fin regeneration, cellular apoptosis, production of reactive oxygen species (ROS), and activities of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST) after 96 h of exposure. A significant decrease in neutrophil migration was observed in all EO treatments compared to the control. Higher concentrations of EO (3.12 and 6.25 µg/mL) resulted in a significant decrease in caudal fin regeneration compared to the control. SOD activity was reduced at all EO concentrations, CAT activity significantly decreased at 3.12 µg/mL, and GST activity increased at 0.78 µg/mL and 1.56 µg/mL, compared to the control group. No significant changes in ROS production were detected. A reduction in cellular apoptosis was evident at all EO concentrations, suggesting that C. citratus EO exhibits anti-inflammatory properties, influences regenerative processes, and protects against oxidative stress and apoptosis.

Diet with different concentrations of lychee peel flour modulates oxidative stress parameters and antioxidant activity in zebrafish.

The agri-food industry generates substantial waste, leading to significant environmental impacts. Lychee (Litchi chinensis Sonnerat), which is rich in bioactive compounds in its peel, pulp, and seeds, offers an opportunity for waste use. This study aimed to evaluate the effects of supplementing a high-carbohydrate diet with varying levels of lychee peel flour on lipid metabolism biomarkers and oxidative stress in a zebrafish (Danio rerio) model. A total of 225 zebrafish, approximately four months old, were divided into five groups: control, high-carbohydrate (HC), HC2%, HC4%, and HC6%. The study did not find significant differences in the growth performance of zebrafish in any group. However, the HC6% group exhibited a significant decrease in glucose and triglyceride levels compared with the HC group. Furthermore, this group showed enhanced activities of the antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD), along with reduced levels of malondialdehyde (MDA). Increased antioxidant activity was also evidenced by DPPH-, ABTS+, and ß-carotene/Linoleic acid assays in the HC6% group. A positive correlation was identified between SOD/CAT activity and in vitro antioxidant assays. These findings suggest that dietary supplementation with 6% lychee peel flour can significantly modulate glucose homeostasis, lipid metabolism, and antioxidant activity in zebrafish.

The toxicological effects of Eryngium foetidum extracts on zebrafish embryos and larvae depend on the type of extract, dose, and exposure time.

Eryngium foetidum is a herbaceous plant found in tropical and subtropical regions. In vivo pharmacological parameters show that leaf extracts of this plant have antioxidant, anti-inflammatory, antidiabetic, and antimicrobial activities due to their bioactive compounds such as flavonoids and phenols. Despite the evidence for several bioactivities of E. foetidum, information on its safety and tolerability is limited. The objective of this study was to assess the effect and concentration of different extracts of E. foetidum on the development of zebrafish (Danio rerio) embryos. To study the impact of aqueous (AE), ethanolic (EE), and methanolic (ME) extracts, the embryos were exposed to 0.625, 1.25, 2.5, 5, and 10 mg mL-1 for up to 120-h postfertilization to assess embryonic developmental toxicity and then to 0.039, 0.078, 0.156, 0.312, and 0.625 mg mL-1 to assess the antioxidant responses of the enzymes superoxide dismutase catalase, glutathione S-transferase (GST), and cell apoptosis. The results showed that, depending on the extraction solvent, concentration used, and exposure time, E. foetidum extracts caused mortality, altered the hatching time, and promoted changes in enzymatic activities. Delays in development and increased GST activity were found in all treatments. Apoptosis was not observed in any of the treatments. In conclusion, AE, EE, and ME concentrations above 0.625 mg mL-1 can cause adverse effects on the early stages of zebrafish development.

Digestible protein requirement for Nile tilapia fed with rations based on soybean meal and corn / Exigência de proteína digestível para tilápias do Nilo alimentadascom rações à base de farelo de soja e milho

The objective was to determine the requirement of digestible protein (DP) for Nile tilapia fed with diets based on soybean meal and corn. Two hundred Nile tilapia juveniles, sexually reversed, were used for a trial period of 100 days. The animals were distributed in 20 boxes of 1000 L-1 in a random design with five treatments and four replications, the boxes were connected to a water recirculation system. Five isoenergetic diets were tested with different levels of digestible protein (DP): 20, 25, 30, 35 and 40%. At the end of the experimental period were evaluated the zootechnical performance data. A quadratic effect (p 0.05) was shown to parameters of final weight, weight gain, final length, fillet yield and visceral fat with the best points that ranged from 28.3 to 29.9% of DP. The largest area of hepatocytes was found to the lowest levels of DP in the diet (20 and 25%) compared to the other levels, which were similar. Thus, Nile tilapia has adequate performance for the consumption of diets based on soybean and corn meal and the recommended level is 28.3% of PD in these conditions.(AU)

Objetivou-se determinar a exigência de proteína digestível (PD) para a tilápia do Nilo, alimentada com dietas à base de farelo de soja e milho. Duzentos juvenis de tilápia do Nilo (32,80 ± 0,39 g), sexualmente revertidos, foram utilizados por um período experimental de 100 dias. Os animais foram distribuídos em 20 caixas de 1000L-1 em delineamento aleatório com cinco tratamentos e quatro repetições. As caixas eram ligadas a um sistema de recirculação de água. Foram testadas cinco dietas isoenergéticas com diferentes níveis de PD: 20, 25, 30, 35 e 40%. Ao final do período experimental, foram avaliados os dados de desempenho zootécnico. Um efeito quadrático (p < 0,05) foi mostrado aos parâmetros de peso final, ganho em peso, comprimento final, rendimento de filé e de gordura visceral com os melhores pontos que variaram de 28,3 a 29,9% de PD. A maior área dos hepatócitos foi encontrada para os níveis mais baixos de PD na dieta (20 e 25%), em comparação com os outros níveis, que foram semelhantes. Assim, pode-se afirmar que a tilápia do Nilo tem desempenho adequado para o consumo de dietas baseadas em farelo de soja e milho e o nível recomendado é de 28,3% PD nestas condições.(AU)

Digestible protein requirement for Nile tilapia fed with rations based on soybean meal and corn / Exigência de proteína digestível para tilápias do Nilo alimentadascom rações à base de farelo de soja e milho

The objective was to determine the requirement of digestible protein (DP) for Nile tilapia fed with diets based on soybean meal and corn. Two hundred Nile tilapia juveniles, sexually reversed, were used for a trial period of 100 days. The animals were distributed in 20 boxes of 1000 L-1 in a random design with five treatments and four replications, the boxes were connected to a water recirculation system. Five isoenergetic diets were tested with different levels of digestible protein (DP): 20, 25, 30, 35 and 40%. At the end of the experimental period were evaluated the zootechnical performance data. A quadratic effect (p 0.05) was shown to parameters of final weight, weight gain, final length, fillet yield and visceral fat with the best points that ranged from 28.3 to 29.9% of DP. The largest area of hepatocytes was found to the lowest levels of DP in the diet (20 and 25%) compared to the other levels, which were similar. Thus, Nile tilapia has adequate performance for the consumption of diets based on soybean and corn meal and the recommended level is 28.3% of PD in these conditions.

Objetivou-se determinar a exigência de proteína digestível (PD) para a tilápia do Nilo, alimentada com dietas à base de farelo de soja e milho. Duzentos juvenis de tilápia do Nilo (32,80 ± 0,39 g), sexualmente revertidos, foram utilizados por um período experimental de 100 dias. Os animais foram distribuídos em 20 caixas de 1000L-1 em delineamento aleatório com cinco tratamentos e quatro repetições. As caixas eram ligadas a um sistema de recirculação de água. Foram testadas cinco dietas isoenergéticas com diferentes níveis de PD: 20, 25, 30, 35 e 40%. Ao final do período experimental, foram avaliados os dados de desempenho zootécnico. Um efeito quadrático (p < 0,05) foi mostrado aos parâmetros de peso final, ganho em peso, comprimento final, rendimento de filé e de gordura visceral com os melhores pontos que variaram de 28,3 a 29,9% de PD. A maior área dos hepatócitos foi encontrada para os níveis mais baixos de PD na dieta (20 e 25%), em comparação com os outros níveis, que foram semelhantes. Assim, pode-se afirmar que a tilápia do Nilo tem desempenho adequado para o consumo de dietas baseadas em farelo de soja e milho e o nível recomendado é de 28,3% PD nestas condições.

Digestible protein requirement for Nile tilapia fed with rations based on soybean meal and corn

The objective was to determine the requirement of digestible protein (DP) for Nile tilapia fed with diets based on soybean meal and corn. Two hundred Nile tilapia juveniles, sexually reversed, were used for a trial period of 100 days. The animals were distributed in 20 boxes of 1000 L-1 in a random design with five treatments and four replications, the boxes were connected to a water recirculation system. Five isoenergetic diets were tested with different levels of digestible protein (DP): 20, 25, 30, 35 and 40%. At the end of the experimental period were evaluated the zootechnical performance data. A quadratic effect (p < 0.05) was shown to parameters of final weight, weight gain, final length, fillet yield and visceral fat with the best points that ranged from 28.3 to 29.9% of DP. The largest area of hepatocytes was found to the lowest levels of DP in the diet (20 and 25%) compared to the other levels, which were similar. Thus, Nile tilapia has adequate performance for the consumption of diets based on soybean and corn meal and the recommended level is 28.3% of PD in these conditions.