Antioxidant properties of camelina (Camelina sativa (L.) Crantz) protein hydrolysates

Camelina seed meal was used to produce protein hydrolysates using Alcalase and Flavourzyme. The hydrolysates were then fractionated by employing ultrafiltration membranes (3, 10 kDa). The antioxidant activities of camelina protein hydrolysates and peptide fractions were investigated. The essential amino acid content of camelina protein isolates and hydrolysates was comparable and adequate. All camelina hydrolysates exhibited the highest radical scavenging activity in both DPPH and ABTS assay compared to camelina protein isolates. When comparing the overall DPPH and ABTS radical scavenging activity of peptide fractions, smaller-size peptides (<3 kDa) displayed considerably higher values and hence more potency than larger-sized peptides (>3 kDa). Peptide fractions with 3-10 kDa had better metal chelation and reducing power than those < 3 kDa and > 10 kDa. These findings suggest that camelina protein hydrolysates could be employed as bioactive ingredients in the formulation of functional foods and against oxidative stress.

The Bioactivity Prediction of Peptides from Tuna Skin Collagen Using Integrated Method Combining In Vitro and In Silico

The hydrolysates and peptide fractions of bigeye tuna (Thunnus obesus) skin collagen have been successfully studied. The hydrolysates (HPA, HPN, HPS, HBA, HBN, HBS) were the result of the hydrolysis of collagen using alcalase, neutrase, and savinase. The peptide fractions (PPA, PPN, PPS, PBA, PBN, PBS) were the fractions obtained following ultrafiltration of the hydrolysates. The antioxidant activities of the hydrolysates and peptide fractions were studied using the DPPH method. The effects of collagen types, enzymes, and molecular sizes on the antioxidant activities were analyzed using profile plots analysis. The amino acid sequences of the peptides in the fraction with the highest antioxidant activity were analyzed using LC-MS/MS. Finally, their bioactivity and characteristics were studied using in silico analysis. The hydrolysates and peptide fractions provided antioxidant activity (6.17–135.40 µmol AAE/g protein). The lower molecular weight fraction had higher antioxidant activity. Collagen from pepsin treatment produced higher activity than that of bromelain treatment. The fraction from collagen hydrolysates by savinase treatment had the highest activity compared to neutrase and alcalase treatments. The peptides in the PBN and PPS fractions of <3 kDa had antidiabetic, antihypertensive and antioxidant activities. In conclusion, they have the potential to be used in food and health applications.

Formulating a functional drink with antiosteoporosis effects

Introduction. Osteoporosis is one of the most common diseases of the musculoskeletal system in modern clinical practice. Its prevention and treatment requires a diet with a sufficient intake of calcium, vitamins, and connective tissue proteins that regenerate cartilage and bone tissue. We aimed to formulate a functional product based on collagen fermentolysate to prevent osteoporosis and prove its effects in experiments on laboratory rats. Study objects and methods. Our study objects were collagen fermentolysate obtained from pork ears and legs (1:1) and the functional product based on it. The biological experiment was carried out on Wistar female rats exposed to osteoporosis through complete ovariectomy. Their femurs were analyzed for the contents of phosphorus, magnesium, and calcium, as well as cytometric and biochemical blood parameters. Results and discussion. The formulated functional product based on collagen fermentolysate contained 41% of the most easily assimilable peptide fractions with a low molecular weight of 10 to 20 kDa. Other components included pumpkin powder, dietary fiber, calcium, chondroprotectors, and vitamins E, C, and D3. Compared to the control, the experimental rats that received the functional product had increased contents of calcium and magnesium in the bone tissue (by 25.0 and 3.0%, respectively), a decreased content of phosphorus (by 7.0%), a calcium-to-phosphorus ratio restored to 2.4:1.0, and a higher concentration of osteocalcin in the blood serum (by 15%). Conclusion. The developed functional product based on collagen fermentolysate can be used as an additional source of connective tissue protein, calcium, vitamins C, E, and D3, dietary fiber, and chondroprotectors to prevent osteoporosis.

Antioxidant Activity of Bioactive Peptide Fractions from Germinated Soybeans Conjugated to Fe3O4 Nanoparticles by the Ugi Multicomponent Reaction

The conjugation of biomolecules to magnetic nanoparticles has emerged as promising approach in biomedicine as the treatment of several diseases, such as cancer. In this study, conjugation of bioactive peptide fractions from germinated soybeans to magnetite nanoparticles was achieved. Different fractions of germinated soybean peptides (>10 kDa and 5–10 kDa) were for the first time conjugated to previously coated magnetite nanoparticles (with 3-aminopropyltriethoxysilane (APTES) and sodium citrate) by the Ugi four-component reaction. The crystallinity of the nanoparticles was corroborated by X-ray diffraction, while the particle size was determined by scanning transmission electron microscopy. The analyses were carried out using infrared and ultraviolet–visible spectroscopy, dynamic light scattering, and thermogravimetry, which confirmed the coating and functionalization of the magnetite nanoparticles and conjugation of different peptide fractions on their surfaces. The antioxidant activity of the conjugates was determined by the reducing power and hydroxyl radical scavenging activity. The nanoparticles synthesized represent promising materials, as they have found applications in bionanotechnology for enhanced treatment of diseases, such as cancer, due to a higher antioxidant capacity than that of fractions without conjugation. The highest antioxidant capacity was observed for a >10 kDa peptide fraction conjugated to the magnetite nanoparticles coated with APTES.

Characterization, ACE inhibitory and Antioxidative Properties of Peptide Fractions Obtained from White Shrimp (Litopenaeus vannamei)

Background: Aquatic organisms are considered to be an important source of bioactive peptides with a high antioxidant and antihypertensive capacity. Therefore, the objective of this study was to hydrolyse peptide fractions from white shrimp (Litopenaeus vannamei) muscle by Alcalase and Protamex and to evaluate the angiotensin I-converting enzyme (ACE) inhibitory and the antioxidant activities. Methods: Protein hydrolysates of White shrimp were obtained by enzymatic hydrolysis using Alcalase and Protamex until the degree of hydrolysis reached 10% and 20%. Peptide fractions were obtained from White shrimp protein hydrolysates by ultrafiltration using membranes with sizes of 10 and 3 kDa. The antioxidant activity was evaluated for the three peptide fractions (F1: >10 kDa, F2: 3-10 kDa and F3: <3 kDa). To measure the antihypertensive activity, fractions with molecular sizes of less than 3 kDa were used. Results: The fractions obtained with Alcalase showed greater inhibitory effects on the ACE. In general, the molecular weight of the fractions influenced the antioxidant activity, with fractions smaller than 3 kDa having a high capacity for sequestering the DPPH radical, while peptide fractions with a size greater than 10 kDa presented higher reducing power. However, in capturing the ABTS radical, a high antioxidant capacity was observed for both fractions. Conclusion: The results suggest white shrimp would be an attractive raw material for the manufacture of antioxidant and anti-hypertensive nutraceutical ingredients.

In vitro antiviral activity of peptide-rich extracts from seven Nigerian plants against three non-polio enterovirus species C serotypes

Background As frequent viral outbreaks continue to pose threat to public health, the unavailability of antiviral drugs and challenges associated with vaccine development underscore the need for antiviral drugs discovery in emergent moments (endemic or pandemic). Plants in response to microbial and pest attacks are able to produce defence molecules such as antimicrobial peptides as components of their innate immunity, which can be explored for viral therapeutics. Methods In this study, partially purified peptide-rich fraction (P-PPf) were obtained from aqueous extracts of seven plants by reverse-phase solid-phase extraction and cysteine-rich peptides detected by a modified TLC method. The peptide-enriched fractions and the aqueous (crude polar) were screened for antiviral effect against three non-polio enterovirus species C members using cytopathic effect reduction assay. Results In this study, peptide fraction obtained from Euphorbia hirta leaf showed most potent antiviral effect against Coxsackievirus A13, Coxsackievirus A20, and Enterovirus C99 (EV-C99) with IC50 < 2.0 µg/mL and selective index ≥ 81. EV-C99 was susceptible to all partially purified peptide fractions except Allamanda blanchetii leaf. Conclusion These findings establish the antiviral potentials of plants antimicrobial peptides and provides evidence for the anti-infective use of E. hirta in ethnomedicine. This study provides basis for further scientific investigation geared towards the isolation, characterization and mechanistic pharmacological study of the detected cysteine-rich peptides.

Anti-Salmonella Activity and Peptidomic Profiling of Peptide Fractions Produced from Sturgeon Fish Skin Collagen (Huso huso) Using Commercial Enzymes

This study investigated peptide fractions from fish skin collagen for antibacterial activity against Escherichia coli and Salmonella strains. The collagen was hydrolyzed with six commercial proteases, including trypsin, Alcalase, Neutrase, Flavourzyme, pepsin and papain. Hydrolyzed samples obtained with trypsin and Alcalase had the largest number of small peptides (molecular weight < 10 kDa), while the hydrolysate produced with papain showed the lowest degree of hydrolysis and highest number of large peptides. Four hydrolysates were found to inhibit the growth of the Gram-negative bacteria, with papain hydrolysate showing the best activity against E. coli, and Neutrase and papain hydrolysates showing the best activity against S. abony; hydrolysates produced with trypsin and pepsin did not show detectable antibacterial activity. After acetone fractionation of the latter hydrolysates, the peptide fractions demonstrated enhanced dose-dependent inhibition of the growth (colony-forming units) of four Salmonella strains, including S. abony (NCTC 6017), S. typhimurium (ATCC 13311), S. typhimurium (ATCC 14028) and S. chol (ATCC 10708). Shotgun peptidomics analysis of the acetone fractions of Neutrase and papain hydrolysates resulted in the identification of 71 and 103 peptides, respectively, with chain lengths of 6–22 and 6–24, respectively. This work provided an array of peptide sequences from fish skin collagen for pharmacophore identification, structure–activity relationship studies, and further investigation as food-based antibacterial agents against pathogenic microorganisms.

Chicken Feather Keratin Peptides for the Control of Keratinocyte Migration

FAO estimates that in 2030 the poultry meat production could reach 120 million tons, which is a challenge in terms of waste management. Feathers are mainly composed of keratin, an important biomaterial. Using feathers as a source of keratin will minimize the waste generated, while contributing to supply an important material for several industries, such as pharmaceutical and biomedical. The peptides were extracted from the feathers by microbial degradation. In this study, we evaluated the peptides effect on keratinocyte metabolic activity and migration. The influence of these peptides on non-activated and activated macrophages was also assessed. It was demonstrated that depending on the keratin peptide fraction in contact with keratinocytes, it is possible to modulate the migration rate of the keratinocytes. Peptide fraction with low molecular weight increases migration, while peptides with a high range of molecular sizes decreases it. Some peptide fractions induce the secretion of TNF-α in non-activated macrophages and not on activated macrophages, demonstrating that these peptides should only be placed in contact with cells, in the context of an ongoing inflammatory process. This work is a step forward on the understanding of keratin peptides influence on keratinocytes and immune cells system cells, macrophages.