Optimization of the preparation of fish protein anti-obesity hydrolysates using response surface methodology

Lemon basil seed-derived peptide: Hydrolysis, purification, and its role as a pancreatic lipase inhibitor that reduces adipogenesis by downregulating SREBP-1c and PPAR-γ in 3T3-L1 adipocytes

The purpose of this study is to assess the bioactive peptides derived from the defatted lemon basil seeds hydrolysate (DLSH) for their ability to inhibit pancreatic lipase, decrease intracellular lipid accumulation, and reduce adipogenesis. Response surface methodology (RSM) was employed to optimize trypsin hydrolysis conditions for maximizing lipase inhibitory activity (LI). A hydrolysis time of 387.06 min, a temperature of 49.03°C, and an enzyme concentration of 1.61% w/v, resulted in the highest LI with an IC50 of 368.07 μg/mL. The ultrafiltration of the protein hydrolysate revealed that the fraction below 0.65kDa exhibited the greatest LI potential. Further purification via RP-HPLC identified the Gly-Arg-Ser-Pro-Asp-Thr-His-Ser-Gly (GRSPDTHSG) peptide in the HPLC fraction F1 using mass spectrometry. The peptide was synthesized and demonstrated LI with an IC50 of 0.255 mM through a non-competitive mechanism, with a constant (Ki) of 0.61 mM. Docking studies revealed its binding site with the pancreatic lipase-colipase complex. Additionally, GRSPDTHSG inhibited lipid accumulation in 3T3-L1 cells in a dose-dependent manner without cytotoxic effects. Western blot analysis indicated downregulation of PPAR-γ and SREBP-1c levels under GRSPDTHSG treatment, while an increase in AMPK-α phosphorylation was observed, suggesting a role in regulating cellular lipid metabolism. Overall, GRSPDTHSG demonstrates potential in attenuating lipid absorption and adipogenesis, suggesting a prospective application in functional foods and nutraceuticals.

Exploring the inhibitory potential of KPHs-AL-derived GLLF peptide on pancreatic lipase and cholesterol esterase activities

The effective modulation of pancreatic lipase and cholesterol esterase activities proves critical in maintaining circulatory triglycerides and cholesterol levels within physiological boundaries. In this study, peptides derived from KPHs-AL, produced through the enzymatic hydrolysis of skipjack tuna dark muscle using alkaline protease, have a specific inhibitory effect on pancreatic lipase and cholesterol esterase. It is hypothesized that these peptides target and modulate the activities of enzymes by inducing conformational changes within their binding pockets, potentially impacting the catalytic functions of both pancreatic lipase and cholesterol esterase. Results revealed these peptides including AINDPFIDL, FLGM, GLLF and WGPL, were found to nestle into the binding site groove of pancreatic lipase and cholesterol esterase. Among these, GLLF stood out, demonstrating potent inhibition with IC50 values of 0.1891 mg/mL and 0.2534 mg/mL for pancreatic lipase and cholesterol esterase, respectively. The kinetics studies suggested that GLLF competed effectively with substrates for the enzyme active sites. Spectroscopic analyses, including ultraviolet-visible, fluorescence quenching, and circular dichroism, indicated that GLLF binding induced conformational changes within the enzymes, likely through hydrogen bond formation and hydrophobic interactions, thereby increasing structural flexibility. Molecular docking and molecular dynamics simulations supported these findings, showing GLLF's stable interaction with vital active site residues. These findings position GLLF as a potent inhibitor of key digestive enzymes, offering insights into its role in regulating lipid metabolism and highlighting its potential as functional ingredient.

Evaluating the Potential of Plukenetia volubilis Linneo (Sacha Inchi) in Alleviating Cardiovascular Disease Risk Factors: A Mini Review

Plukenetia volubilis Linneo or Sacha Inchi (SI), a traditional natural remedy indigenous to Peru and Brazil, has garnered global attention due to its exceptional nutritional composition. Its protective effects against various non-communicable diseases, notably cardiovascular disease (CVD), have become a subject of interest in recent research. This comprehensive review summarizes the existing evidence from 15 relevant articles concerning the impact of SI on common CVD risk factors, including dyslipidemia, obesity, diabetes, and hypertension. The relevant articles were derived from comprehensive searches on PubMed, Scopus, Google Scholar, and Web of Science using predefined criteria and keywords related to the topic. Overall, SI demonstrated positive effects in attenuating dyslipidemia, obesity, diabetes, and hypertension. The multifaceted mechanisms responsible for the protective effects of SI against these CVD risk factors are primarily attributed to its antioxidative and anti-inflammatory properties. While preclinical studies dominate the current scientific literature on SI, there are limited clinical trials to corroborate these findings. Therefore, future well-designed, large-scale randomized clinical trials are highly recommended to establish the efficacy of SI and determine its optimal dosage, potential drug and food interactions, and practical integration into preventive strategies and dietary interventions for the high-risk populations.

Isolation and Identification of Lipid-Lowering Peptides from Sacha Inchi Meal

Sacha inchi meal (SIM) is a by-product of sacha inchi (considered as a "super-food") processing. In previous studies, we found that SIM protein hydrolysates exhibited pancreatic lipase inhibition activity. In this study, 10 bioactive peptides from those hydrolysates were identified. The top five peptides (NLYYKVV (NV-7), WWYVK (WK-5), WLLMWPYK (WK-8), EGLLMWPY (EY-8), and FPFFGYVWK (FK-9)) with strong pancreatic lipase inhibition activity had IC₅₀ values of 34.01-246.50 µM, and displayed various inhibition types (mixed, non-competitive, and competitive type) by enzyme inhibition kinetics analysis. Fluorescence quenching analysis demonstrated that the interaction between the peptides and pancreatic lipase was mainly hydrogen bond and van der Waals force. The key residues involved in the peptide-enzyme interaction were determined by molecular docking. Moreover, the top two peptides were found to significantly inhibit fat accumulation and regulate lipid metabolism by alleviating the level of reactive oxygen species in HepG2 cells. Collectively, sacha inchi meal-derived peptides displayed potent lipid-lowering activity and could be used as materials of functional food.

Hydrolysates and peptide fractions from pork and chicken skin collagen as pancreatic lipase inhibitors

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Pork and chicken skin collagen hydrolysates were able to inactivate pancreatic lipase.

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Hydrolysates had a similar or higher inhibition ability than ultrafiltrated fractions.

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Fractions >5 and  <1 kDa had the highest pancreatic lipase inhibition activity.

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First report of skin collagen hydrolysates’ ability to inhibit lipase activity.

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Skin collagen hydrolysates and fractions may act as a novel anti-obesogenic coadjuvant.

The objective of this work was to obtain hydrolysates and peptide fractions from pork (PSC) and chicken (CSC) skin collagen extracts and to evaluate their ability as pancreatic lipase inhibitors. Collagen extracts were hydrolyzed with collagenase or a protease from Bacillus licheniformis (MPRO NX®) at 6, 12, and 24 h. After 24 h incubation, the highest degree of hydrolysis of PSC (p < 0.05) was obtained with collagenase (72.58%), while in CSC was obtained with MPRO NX® (64.45%). Hydrolysates obtained at 24 h had the highest inhibitory activity of lipase (p < 0.05). CSC/collagenase hydrolysates (10 mg/mL) presented the highest inhibitory activity (75.53%) (p < 0.05). Ultrafiltrated fractions >5 kDa from CSC/collagenase and PSC/MPRO NX® hydrolysates were the most bioactive fractions (IC₅₀: 4.33 mg/mL). The highest were obtained by CSC peptides (IC₅₀s: 6.30 and 6.08 mg/mL). These results may be considered as a novel approach to use collagen hydrolysates, or their peptide fractions, as promising natural inhibitors of pancreatic lipase.

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 .

Bioactive peptides from fisheries residues: A review of use of papain in proteolysis reactions

Papain is a cysteine endopeptidase of vegetal origin (papaya (Carica papaya L.) with diverse applications in food technology. In this review we have focused our attention on its application in the production of bio-peptides by hydrolysis of proteins from fish residues. This way, a residual material, that can become a contaminant if dumped without control, is converted into highly interesting products. The main bioactivity of the produced peptides is their antioxidant activity, followed by their nutritional and functional activities, but peptides with many other bioactivities have been produced. Thera are also examples of production of hydrolysates with several bioactivities. The enzyme may be used alone, or in combination with other enzymes to increase the degree of hydrolysis.

Assessment of the biological activity of fish muscle protein hydrolysates using in vitro model systems

The generation of biologically active fish protein hydrolysates (FPH) is a useful technique to produce value-added products with potential application in the functional food and nutraceutical industries. Fish muscle is an attractive substrate for the production of protein hydrolysates due to its rich protein content, containing 15-25% of total fish protein. This paper reviews the production of protein hydrolysates from fish muscle, most commonly via enzymatic hydrolysis, and their subsequent bioactivities including anti-obesity, immunomodulatory, antioxidant, angiotensin I-converting enzyme (ACE)-inhibitory, anti-microbial, and anti-cancer activities as measured by in vitro testing methods. Disease prevention with FPH potentially offers a safe and natural alternative to synthetic drugs. Small molecular weight (MW) FPHs generally exhibit favourable bioactivity than large MW fractions via enhanced absorption through the gastrointestinal tract. This review also discusses the relationship between amino acid (AA) composition and AA sequence of FPH and peptides and their exhibited in vitro bioactivity.

Biodecolourisation of Reactive Red 120 as a Sole Carbon Source by a Bacterial Consortium-Toxicity Assessment and Statistical Optimisation

The application of microorganisms in azo dye remediation has gained significant attention, leading to various published studies reporting different methods for obtaining the best dye decolouriser. This paper investigates and compares the role of methods and media used in obtaining a bacterial consortium capable of decolourising azo dye as the sole carbon source, which is extremely rare to find. It was demonstrated that a prolonged acclimation under low substrate availability successfully isolated a novel consortium capable of utilising Reactive Red 120 dye as a sole carbon source in aerobic conditions. This consortium, known as JR3, consists of Pseudomonas aeruginosa strain MM01, Enterobacter sp. strain MM05 and Serratia marcescens strain MM06. Decolourised metabolites of consortium JR3 showed an improvement in mung bean's seed germination and shoot and root length. One-factor-at-time optimisation characterisation showed maximal of 82.9% decolourisation at 0.7 g/L ammonium sulphate, pH 8, 35 °C, and RR120 concentrations of 200 ppm. Decolourisation modelling utilising response surface methodology (RSM) successfully improved decolourisation even more. RSM resulted in maximal decolourisation of 92.79% using 0.645 g/L ammonium sulphate, pH 8.29, 34.5 °C and 200 ppm RR120.

Hairless canary seeds (Phalaris canariensis L.) as a potential source of antioxidant, antihypertensive, antidiabetic, and antiobesity biopeptides

Rising consumer concerns with synthetic drugs to treat non-communicable diseases (NCDs) have promoted a shift towards using natural biological active constituents that offer similar health benefits. Hairless canary seed (Phalaris canariensis L) is an emerging crop traditionally used in Mexico to treat NCDs. Peptides liberated during simulated digestion of canary seed protein are believed to be responsible for their biological activity; however, no studies have shown the effect of controlled protein hydrolysis using commercial proteases on canary seed protein’s biological activity. Therefore, this study aimed to explore the in vitro antihypertensive, antidiabetic, and anti-obesity activity of canary seed peptides derived from proteolysis with Alcalase®. Protein fractions were primarily composed of prolamins (54.07 ± 1.8%), glutelins (32.19 ± 3.18%), globulins (5.97 ± 0.52%) and albumins (5.97 ± 0.52%). The < 3 kDa and 3–10 kDa peptide fractions showed the highest inhibition capacity (p < 0.05) towards angiotensin-converting enzyme (IC50= 0.028–0.032 mg/mL) lipase (IC50= 2.15–2.27 mg/mL), α-glucosidase (IC50= 0.82–1.15 mg/mL), and dipeptidyl-peptidase-IV (IC50= 1.27–1.60 mg/mL). Additionally, these peptide fractions showed high antioxidant activity against DPPH (134.22–150.66 μmol TE/mg) and ABTS (520.92–813.33 μmol TE/mg). These results provide an insight into the potential development of functional foods using commercial enzymatic hydrolysis of canary seed proteins for treating hypertension, type-2 diabetes, and obesity.

An in vitro study of lipase inhibitory peptides obtained from de-oiled rice bran

De-oiled rice bran (DORB) is a potentially useful by-product of the rice bran oil industry.

Optimization of Oyster (Crassostrea talienwhanensis) Protein Hydrolysates Using Response Surface Methodology

Oyster (Crassostrea talienwhanensis) protein was hydrolyzed by trypsin to produce peptides with different response values, and response surface methodology (RSM) was applied to optimize the hydrolysis conditions. The highest degree of hydrolysis (DH) of the oyster peptide (OP) was obtained at an enzyme concentration of 1593.2 U/g, a pH of 8.2, a hydrolysis temperature of 40.1 °C, a hydrolysis time of 6.0 h, and a water/material ratio of 8.2. The greatest hydroxyl-radical-scavenging activity of OP was obtained at an enzyme concentration of 1546.3 U/g, a pH of 9.0, a hydrolysis temperature of 50.2 °C, a hydrolysis time of 5.1 h, and a water/material ratio of 5.6. The largest branched-chain amino acid (BCAA) content of OP was obtained at an enzyme concentration of 1323.8 U/g, a pH of 8.3, a hydrolysis temperature of 41.7 °C, a hydrolysis time of 6.7 h, and a water/material ratio of 4.8. The three experimental values were significantly in agreement with the predicted values within the 95% confidence interval. Furthermore, ultrafiltration and chromatographic methods were used to purify the OP, and 13 peptides that were rich in Lys, Arg, His, and Thr were identified by LC-MS/MS. The results of this study offer different optimum hydrolysis conditions to produce target peptides from oyster protein by using RSM, and this study provide a theoretical basis for the high-value utilization of oyster protein.

Hypolipidemic effects of protein hydrolysates from Trachinotus ovatus and identification of peptides implied in bile acid-binding activity using LC-ESI-Q-TOF-MS/MS

In the present work, analysis of the hypolipidemic properties of Trachinotus ovatus protein hydrolysates (TOPHs) and identification of peptides with bile acid-binding activity were performed. Hydrolysates prepared by trypsin digestion exhibited the highest in vitro bile acid-binding capacities compared with hydrolysates prepared with the other four proteases and were mainly composed of small peptides and amino acids with molecular weights <3 kDa, accounting for 77.30%. Among the five ultra-filtration fractions of TOPHs, TOPHs-5 (<3 kDa) exhibited the highest in vitro bile acid-binding capacity, which was equivalent to 77.97% of cholestyramine at the same concentration. A total of 68 peptides were identified from TOPHs-5 by LC-ESI-Q-TOF-MS/MS and 9 of them had hydrophobicity of more than 60%. These highly hydrophobic peptides might be associated with the bile acid-binding activity of TOPHs-5. In vivo experiments indicated that the TOPHs could effectively reduce total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and the atherogenic index (AI), while they could evidently increase the high-density lipoprotein cholesterol (HDL-C) content. Furthermore, TOPHs exerted a marked protective effect on hepatorenal function, as evidenced by decreased levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and creatinine (CREA). Histopathological studies confirmed that TOPHs evidently protected the liver from histological alterations. In summary, for the first time, hypolipidemic effects and subsequential identification were obtained from TOPHs, which are promising natural ingredients that could potentially be employed in the management of hyperlipidemia.

Fabrication, modeling and optimization of lyophilized advanced platelet rich fibrin in combination with collagen-chitosan as a guided bone regeneration membrane

In this study, lyophilized advanced platelet rich fibrin (A-PRF) was used in combination with collagen-chitosan membrane for the first time to combine advantages of both collagen and A-PRF membranes. Response surface methodology (RSM) was used to design the experimental condition and to correlate the effects of parameters, including chitosan/collagen (chit/col) weight ratio and A-PRF concentration on Young's modulus, mesenchymal stem cell (MSCs) viability and degradation rate of the membranes. Results showed that Young's modulus of the membranes was intensified by increasing chit/col weight ratio and decreasing A-PRF concentration from 3 to 8 MPa. Cell viability of MSCs was improved by both increasing chit/col weight ratio and A-PRF concentration. Moreover, as chit/col weight ratio increased from 0 to 4 and A-PRF concentration decreased from 5 to 0, degradation rate of the membranes decreased from 90 to 20% after four weeks incubation. Finally, based on Design Expert Software calculation for minimizing the degradation rate and maximizing both Young's modulus and cell viability, the values of chit/col weight ratio and A-PRF concentration were suggested to be 4 and 0.58 mg/ml, respectively. Alkaline phosphatase (ALP) activity analysis showed that the addition of A-PRF caused higher osteogenic differentiation.

Isolation and Chemical Characterization of Chondroitin Sulfate from Cartilage By-Products of Blackmouth Catshark (Galeus melastomus)

Chondroitin sulfate (CS) is a glycosaminoglycan actively researched for pharmaceutical, nutraceutical and tissue engineering applications. CS extracted from marine animals displays different features from common terrestrial sources, resulting in distinct properties, such as anti-viral and anti-metastatic. Therefore, exploration of undescribed marine species holds potential to expand the possibilities of currently-known CS. Accordingly, we have studied for the first time the production and characterization of CS from blackmouth catshark (Galeus melastomus), a shark species commonly discarded as by-catch. The process of CS purification consists of cartilage hydrolysis with alcalase, followed by two different chemical treatments and ending with membrane purification. All steps were optimized by response surface methodology. According to this, the best conditions for cartilage proteolysis were established at 52.9 °C and pH = 7.31. Subsequent purification by either alkaline treatment or hydroalcoholic alkaline precipitation yielded CS with purities of 81.2%, 82.3% and 97.4% respectively, after 30-kDa membrane separation. The molecular weight of CS obtained ranges 53–66 kDa, depending on the conditions. Sulfation profiles were similar for all materials, with dominant CS-C (GlcA-GalNAc6S) units (55%), followed by 23–24% of CS-A (GlcA-GalNAc4S), a substantial amount (15–16%) of CS-D (GlcA2S-GalNAc6S) and less than 7% of other disulfated and unsulfated disaccharides.

Marine Waste Utilization as a Source of Functional and Health Compounds

Consumer demand for convenience has led to large quantities of seafood being value-added processed before marketing, resulting in large amounts of marine by-products being generated by processing industries. Several bioconversion processes have been proposed to transform some of these by-products. In addition to their relatively low value conventional use as animal feed and fertilizers, several investigations have been reported that have demonstrated the potential to add value to viscera, heads, skins, fins, trimmings, and crab and shrimp shells by extraction of lipids, bioactive peptides, enzymes, and other functional proteins and chitin that can be used in food and pharmaceutical applications. This chapter is focused on reviewing the opportunities for utilization of these marine by-products. The chapter discusses the various products and bioactive compounds that can be obtained from seafood waste and describes various methods that can be used to produce these products with the aim of highlighting opportunities to add value to these marine waste streams.

Purification and identification of antioxidative peptides from mackerel (Pneumatophorus japonicus) protein

This study reports the preparation, purification and identification of an antioxidative peptide from mackerel (Pneumatophorus japonicus) protein. Neutrase was chosen as the optimum protease, with the highest cellular antioxidant activity of 53.65%. The optimal hydrolysate conditions for mackerel protein hydrolysates (MPH) according to response surface methodology were an enzyme concentration of 1203.2 U g-1, extraction time of 4.53 h, pH of 7.26, water/material ratio of 5.22 v/w and extraction temperature of 43.72 °C. MPH was separated using ultrafiltration membranes, and the fraction MPH-III with molecular weight below 3500 Da showed the highest cellular antioxidant activity. Five fractions were separated from MPH-III on a Sephadex G-25 column, and MPH-III-2, exhibiting the highest cellular antioxidant activity, was further separated with an XBridge® peptide BEH C18 column. The MPH-III-2-6 separated from RP-HPLC was further analysed by Thermo Scientific Q Exactive mass spectrometer, and the heptapeptide LDIQKEV (843.5 Da) and the octapeptide TAAIVNTA (759.4 Da) were identified. The results of this study offer a promising alternative to produce natural antioxidative peptides from fish protein hydrolysate, which may be utilized as functional ingredients in food systems.

Optimization of the Extraction and Stability of Antioxidative Peptides from Mackerel (Pneumatophorus japonicus) Protein

This study optimizes the preparation conditions for mackerel protein hydrolysate (MPH) by response surface methodology (RSM) and investigates the stability of the antioxidant activity of MPHs (<2.5 kDa). The optimal conditions were as follows: enzyme concentration of 1726.85 U/g, pH of 7.00, temperature of 39.55°C, time of 5.5 h, and water/material ratio of 25 : 1, and the maximum DPPH scavenging activity was 79.14%. The MPHs indicated significant cellular antioxidant activity at low concentrations. Furthermore, the temperature and freeze-thaw cycles had little effect on the antioxidative stability while pH had significant effect on the antioxidative stability. In addition, the MPHs were sensitive to the metal ions, such as Fe2+, Fe3+, Zn2+, and Cu2+. Notably, when the concentrations of Fe2+ and Fe3+ were 5 mM, the DPPH scavenging activities were only 1.1% and 0.6%, respectively; furthermore, Cu2+ at a 5 mM concentration could completely inhibit the DPPH scavenging activity of MPHs. In contrast, K+ and Mg2+ had no notable effect on the antioxidant activity of MPHs. These results may provide a scientific basis for the processing and application of MPHs.