Immunomodulatory effects of fish peptides on cardiometabolic syndrome associated risk factors: A review

Rainbow Trout (Oncorhynchus mykiss) as Source of Multifunctional Peptides with Antioxidant, ACE and DPP-IV Inhibitory Activities

The present study aimed at characterizing the possible biological activities of the multifunctional low molecular weight fractions (<3 kDa) peptides isolated from rainbow trout (Oncorhynchus mykiss) obtained by enzymatic hydrolysis. The fish protein hydrolysate (FPH) was tested for its antioxidant property along with its angiotensin converting enzyme (ACE) and dipeptidyl peptidase IV (DPP-IV) inhibitory activities. In particular, the 2,2-diphenyl-1-picrylhydrazyl (DPPH), the ferric reducing antioxidant power (FRAP), the oxygen radical absorbance capacity (ORAC) assay and the 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) assays were carried out for the evaluation of the in vitro antioxidant activity. The cell-free ACE and DPP-IV inhibitory activity assays were also estimated, showing a dose-dependent inhibition. These biological properties were additionally quantified at the cellular level using human intestinal Caco-2 cells. Namely, the antioxidant activity was determined by evaluating the capability of the hydrolysate to reduce the H₂O₂-induced reactive oxygen species (ROS) and lipid peroxidation levels, and the DPP-IV activity assays show a reduction of enzyme activity of up to 27.57 ± 3.7% at 5 mg/mL. The results indicate that Oncorhynchus mykiss-derived peptides may have potential employment as health-promoting ingredients.

Anti-inflammatory effect of fucoidan isolated from fermented Sargassum fusiforme in in vitro and in vivo models

Fucoidans possess potent anti-inflammatory effects. In the present study, the anti-inflammatory effect of the fucoidan (SFF-PS-F5) isolated from fermented Sargassum fusiforme was evaluated in vitro in RAW 264.7 macrophages and in vivo in zebrafish. The in vitro test results demonstrate that SFF-PS-F5 effectively inhibited nitric oxide (NO) production induced by lipopolysaccharides (LPS) in RAW 264.7 cells. SFF-PS-F5 effectively and concentration-dependently improved the viability of LPS-stimulated RAW 264.7 cells, and reduced the level of prostaglandin E2, interleukin-1 beta, tumor necrosis factor-alpha, and interleukin-6. Further results display that these effects were actioned by suppressing the expression of inducible nitric oxide synthase and cyclooxygenase-2 via regulating the nuclear factor kappa-B signaling pathway. The in vivo test results indicate that SFF-PS-F5 remarkably reduced reactive oxygen species, cell death, and NO levels in LPS-treated zebrafish. These results indicate that SFF-PS-F5 could inhibit both in vitro and in vivo inflammatory responses and suggest it is a functional ingredient in the functional food and cosmetic industries.

The current research status and strategies employed to modify food-derived bioactive peptides

The ability of bioactive peptides to exert biological functions has mainly contributed to their exploitation. The exploitation and utilization of these peptides have grown tremendously over the past two decades. Food-derived peptides from sources such as plant, animal, and marine proteins and their byproducts constitute a more significant portion of the naturally-occurring peptides that have been documented. Due to their high specificity and biocompatibility, these peptides serve as a suitable alternative to pharmacological drugs for treating non-communicable diseases (such as cardiovascular diseases, obesity, and cancer). They are helpful as food preservatives, ingredients in functional foods, and dietary supplements in the food sector. Despite their unique features, the application of these peptides in the clinical and food sector is to some extent hindered by their inherent drawbacks such as toxicity, bitterness, instability, and susceptibility to enzymatic degradation in the gastrointestinal tract. Several strategies have been employed to eliminate or reduce the disadvantages of peptides, thus enhancing the peptide bioactivity and broadening the opportunities for their applications. This review article focuses on the current research status of various bioactive peptides and the strategies that have been implemented to overcome their disadvantages. It will also highlight future perspectives regarding the possible improvements to be made for the development of bioactive peptides with practical uses and their commercialization.

Beneficial effects of fish and fish peptides on main metabolic syndrome associated risk factors: Diabetes, obesity and lipemia

The definition of metabolic syndrome (MetS) fairly varies from one to another guideline and health organization. Per description of world health organization, occurrence of hyperinsulinemia or hyperglycemia in addition to two or more factors of dyslipidemia, hypoalphalipoproteinemia, hypertension and or large waist circumference factors would be defined as MetS. Conventional therapies and drugs, commonly with adverse effects, are used to treat these conditions and diseases. Nonetheless, in the recent decades scientific community has focused on the discovery of natural compounds to diminish the side effects of these medications. Among many available bioactives, biologically active peptides have notable beneficial effects on the management of diabetes, obesity, hypercholesterolemia, and hypertension. Marine inclusive of fish peptides have exerted significant bioactivities in different experimental in-vitro, in-vivo and clinical settings. This review exclusively focuses on studies from the recent decade investigating hypoglycemic, hypolipidemic, hypercholesterolemic and anti-obesogenic fish and fish peptides. Related extraction, isolation, and purification methodologies of anti-MetS fish biopeptides are reviewed herein for comparison purposes only. Moreover, performance of biopeptides in simulated gastrointestinal environment and structure-activity relationship along with absorption, distribution, metabolism, and excretion properties of selected oligopeptides have been discussed, in brief, to broaden the knowledge of readers on the design and discovery trends of anti-MetS compounds.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2022.2052261 .