Dietary red macroalgae (Halopithys incurva) improved systemic an mucosal immune and antioxidant parameters and modulated related gene expression in zebrafish (Danio rerio)

Unveiling the role of Alcea rosea in modulating growth, immunity, antioxidant defenses, and gene expression in zebrafish (Danio rerio)

Novel and natural alternative feed ingredients are essential for sustainable aquaculture sector. For a period of 60 days, this study examined the effects of incorporating Hollyhock (Alcea rosea) powder into the diet on gene expressions, growth parameters, serum biochemical and innate immune parameters, as well as antioxidant capacity in zebrafish (Danio rerio). Fish, with an initial weight of (302.66 ± 3.75) mg, were seperated into four groups. Each group was fed a diet containing varying percentages of Hollyhock: 0% (AR0), 0.5% (AR05), 1% (AR1), and 2% (AR2). Growth performance was significantly enhanced in the AR2 group, with no significant differences observed in the other groups. The supplementation of Hollyhock led to significant alterations in the serum biochemical parameters, specifically alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP), resulting in notably lower levels compared to the AR0 group. The Hollyhock-supplemented diet led to a significant increase in both total protein and total immunoglobulin levels, as compared to the AR0 group. There were no changes observed in CAT activity related to antioxidant defense, while exclusive to the AR05 group, a substantial elevation was observed in SOD activity compared to the AR0 group. The results shown that the expression levels of growth-related genes, such as GH and IGF-1, showed an increase in all diets supplemented with Hollyhock. Growth exhibited a statistically significant difference in group AR2, while no significant difference was observed in the other groups. The Heat Shock Protein 70 gene (HSP70) was downregulated specifically in the AR1 group. Immune-related genes, including LYZ, IL-1β, and TNF, were significantly upregulated with Hollyhock supplementation. Both LYZ and TNF showed the highest expression in the AR1 and AR2 groups, while IL-1β peaked in the AR1 group. In terms of antioxidant-related genes, Antioxidant-related genes, SOD and CAT, were significantly upregulated in Hollyhock-treated groups. SOD expression peaked in the AR1 group, and CAT was most upregulated in the AR1 and AR2 groups. Overall, these results suggest that supplementation with 1-2% Hollyhock in the diet of zebrafish positively influenced growth, immunity, antioxidant defense, and serum biochemical parameters, making it a promising feed additive for enhancing aquaculture productivity and fish health.

Effects of Chlorella sp. and Schizochytrium sp. extracts on growth indices, body composition, and gene expression profiles in rainbow trout (Oncorhynchus mykiss)

This study assessed the impact of dietary Chlorella sp. and Schizochytrium sp. extracts on growth performance, feed utilization, body composition, and gene expression related to growth, digestion, antioxidant defense, and immune response in rainbow trout (Oncorhynchus mykiss). A total of 180 fish (average weight 8.92 ± 0.04 g) were randomly distributed into 12 fiberglass tanks (400 L, 15 fish per tank, three replicates per treatment). Fish were divided into four dietary groups for 60 days: 0 % (Control), 0.5 % Chlorella sp. extract (CH), 0.5 % Schizochytrium sp. extract (SC), and a combined 0.25 % Chlorella sp. and 0.25 % Schizochytrium sp. (CH + SC). At trial end, fish in the CH + SC group had a final weight (FW) of 27.06 ± 0.28 g, significantly higher than other groups (P < 0.05), with improved growth parameters (P < 0.05). While body composition showed no differences in moisture, lipid, or ash content, crude protein was significantly higher in CH + SC (P < 0.05). Gene expression analysis showed upregulation of the growth hormone GH-I gene in the CH + SC group (P < 0.05). Genes related to digestive enzymes (trypsin, lipase, amylase) were also upregulated in all microalgae groups, with the highest levels in CH + SC (P < 0.05). Additionally, antioxidant genes (SOD, CAT, GPx) and immune-related genes (LYZII, TNF-α, IL-1β) showed elevated expression in CH + SC (P < 0.05). This study demonstrated that a diet containing Chlorella sp. and Schizochytrium sp. extracts supports growth, enhances nutrient utilization, and upregulates genes related to antioxidant and immune function in rainbow trout. Further research is recommended to assess functional immune responses and enzyme activities to confirm these physiological effects.

Incorporation of red macroalgae (Galaxaura oblongata) in roach (Rutilus rutilus) fingerling diet: Effects on growth, immunity, oxidative status and intestinal health

This study investigates the effects of the red macroalgae Galaxaura oblongata diet supplementation on roach (Rutilus rutilus) fingerlings growth and gene expression related to immunity, the intestinal barrier, and antioxidant status. Roach fingerlings (2.26 ± 0.04 g) were fed a basic diet supplemented with three different percentages of G. oblongata powder: 0.25 % (G1), 0.50 % (G2), and 1.0 % (G3) over 8 weeks, with a control group (C) receiving no supplementation. The study found that growth parameters significantly increased in the G1 and G2 groups compared to the C and G3 groups (P < 0.05). Immune responses, measured by total immunoglobulin (Ig) and lysozyme activity, showed a significant increase in the whole-body extract of the G2 group (P < 0.05) and the skin mucus of all treated groups compared to the control (P < 0.05). G. oblongata supplementation did not significantly affect catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities in the whole-body extract, although GPx activity in skin mucus was significantly higher in the supplemented groups. Additionally, the gene expression of interleukin 1-beta (il-1β), occludin, gpx and sod, but not Toll-like receptor increased in G. oblongata treated groups. These results suggest that G. oblongata can serve as a beneficial feed additive in the culture of roach fingerlings, enhancing growth and immune function.

Knowledge mapping analysis of the global seaweed research using CiteSpace

Seaweed research has gained substantial momentum in recent years, attracting the attention of researchers, academic institutions, industries, policymakers, and philanthropists to explore its potential applications and benefits. Despite the growing body of literature, there is a paucity of comprehensive scientometric analyses, highlighting the need for an in-depth investigation. In this study, we utilized CiteSpace to examine the global seaweed research landscape through the Web of Science Core Collection database, assessing publication trends, collaboration patterns, network structures, and co-citation analyses across 48,278 original works published since 1975. Our results demonstrate a diverse and active research community, with a multitude of authors and journals contributing to the advancement of seaweed science. Thematic co-citation cluster analysis identified three primary research areas: "Coral reef," "Solar radiation," and "Mycosporine-like amino acid," emphasizing the multidisciplinary nature of seaweed research. The increasing prominence of "Chemical composition" and "Antioxidant" keywords indicates a burgeoning interest in characterizing the nutritional value and health-promoting properties of seaweed. Timeline co-citation analysis unveils that recent research priorities have emerged around the themes of coral reefs, ocean acidification, and antioxidants, underlining the evolving focus and interdisciplinary approach of the field. Moreover, our analysis highlights the potential of seaweed as a functional food product, poised to contribute significantly to addressing global food security and sustainability challenges. This study underscores the importance of bibliometric analysis in elucidating the global seaweed research landscape and emphasizes the need for sustained knowledge exchange and collaboration to drive the field forward. By revealing key findings and emerging trends, our research offers valuable insights for academics and stakeholders, fostering a more profound understanding of seaweed's potential and informing future research endeavors in this promising domain.

Seaweed for climate mitigation, wastewater treatment, bioenergy, bioplastic, biochar, food, pharmaceuticals, and cosmetics: a review

The development and recycling of biomass production can partly solve issues of energy, climate change, population growth, food and feed shortages, and environmental pollution. For instance, the use of seaweeds as feedstocks can reduce our reliance on fossil fuel resources, ensure the synthesis of cost-effective and eco-friendly products and biofuels, and develop sustainable biorefinery processes. Nonetheless, seaweeds use in several biorefineries is still in the infancy stage compared to terrestrial plants-based lignocellulosic biomass. Therefore, here we review seaweed biorefineries with focus on seaweed production, economical benefits, and seaweed use as feedstock for anaerobic digestion, biochar, bioplastics, crop health, food, livestock feed, pharmaceuticals and cosmetics. Globally, seaweeds could sequester between 61 and 268 megatonnes of carbon per year, with an average of 173 megatonnes. Nearly 90% of carbon is sequestered by exporting biomass to deep water, while the remaining 10% is buried in coastal sediments. 500 gigatonnes of seaweeds could replace nearly 40% of the current soy protein production. Seaweeds contain valuable bioactive molecules that could be applied as antimicrobial, antioxidant, antiviral, antifungal, anticancer, contraceptive, anti-inflammatory, anti-coagulants, and in other cosmetics and skincare products.