Enzyme-Assisted Release of Antioxidant Peptides from Porphyra dioica Conchocelis

Effects of Pyropia yezoensis enzymatic hydrolysate on the growth and immune regulation of the zebrafish

The supplemental effect of Pyropia yezoensis enzymatic hydrolysate (PYE) in fish diet was evaluated in zebrafish (Danio rerio) model. A basal diet supplemented with PYE at 0, 0.1, 1.0 and 2.0% were fed to one-month old zebrafish for 6 weeks, its growth performance and immunity index were evaluated. The increase in weight gain was significantly higher when supplementary 1% PYE which shows a positive effect on growth performance of zebrafish. In addition, crude protein content of fish body was increased in all PYE supplemental groups. The innate immune responses and activity of digestive enzymes in zebrafish were enhanced with dietary supplementation of PYE additives. Compared with the control group, lysozyme (LYZ) and interleukin-10 (IL-10) content in zebrafish intestines were up-regulated in groups fed with 0.1% and 1% PYE. The mRNA expression levels of LYZ and IL-10 in zebrafish intestines were consistent with ELISA results. The content of tumor necrosis factor (TNF-α) reduced in 1% and 2% PYE groups. Furthermore, PYE down-regulated the relative abundance of pathogenic bacteria (Aeromonadaceae) and up-regulated the relative abundance of fish probiotics (Brevibacillus) in intestinal flora. The findings in this study indicated that PYE supplementation in diet could promote growth, improve immunity and regulate intestinal flora, which made PYE considered as an potential aquatic additive.

Recent Progress in Antioxidant Active Substances from Marine Biota

BACKGROUND

The well-recognized but not fully explored antioxidant activity of marine-biota-derived, biologically active substances has led to interest in their study as substitutes of antibiotics, antiaging agents, anticancer and antiviral drugs, and others. The aim of this review is to present the current state of the art of marine-biota-derived antioxidants to give some ideas for potential industrial applications.

METHODS

This review is an update for the last 5 years on the marine sources of natural antioxidants, different classes antioxidant compounds, and current derivation biotechnologies.

RESULTS

New marine sources of antioxidants, including byproducts and wastes, are presented, along with new antioxidant substances and derivation approaches.

CONCLUSIONS

The interest in high-value antioxidants from marine biota continues. Natural substances combining antioxidant and antimicrobial action are of particular interest because of the increasing microbial resistance to antibiotic treatments. New antioxidant substances are discovered, along with those extracted from marine biota collected in other locations. Byproducts and wastes provide a valuable source of antioxidant substances. The application of optimized non-conventional derivation approaches is expected to allow the intensification of the production and improvement in the quality of the derived substances. The ability to obtain safe, high-value products is of key importance for potential industrialization.

Seaweed-Derived Proteins and Peptides: Promising Marine Bioactives

Seaweeds are a typical food of East-Asian cuisine, to which are alleged several beneficial health effects have been attributed. Their availability and their nutritional and chemical composition have favored the increase in its consumption worldwide, as well as a focus of research due to their bioactive properties. In this regard, seaweed proteins are nutritionally valuable and comprise several specific enzymes, glycoproteins, cell wall-attached proteins, red algae phycobiliproteins, lectins, peptides, or mycosporine-like amino acids. This great extent of molecules has been reported to exert significant antioxidant, antimicrobial, anti-inflammatory, antihypertensive, antidiabetic, or antitumoral properties. Hence, knowledge on algae proteins and derived compounds have gained special interest for the potential nutraceutical, cosmetic or pharmaceutical industries based on these bioactivities. Although several molecular mechanisms of action on how these proteins and peptides exert biological activities have been described, many gaps in knowledge still need to be filled. Updating the current knowledge related to seaweed proteins and peptides is of interest to further asses their potential health benefits. This review addresses the characteristics of seaweed protein and protein-derived molecules, their natural occurrence, their studied bioactive properties, and their described potential mechanisms of action.