Peptides from Mucuna pruriens L., with protection and antioxidant in vitro effect on HeLa cell line

Sacha Inchi (Plukenetia volubilis L.) Protein Hydrolysate as a New Ingredient of Functional Foods

Sacha inchi (Plukenetia volubilis L.) is an under-exploited crop with great potential due to its nutritional and medicinal characteristics. A Sacha inchi protein isolate (SII), obtained from defatted Sacha inchi flour (SIF), was hydrolyzed by Bioprotease LA 660 under specific conditions. The hydrolysates were characterized chemically, and their digestibility and antioxidant capacity were evaluated by in vitro cell-free experiments to select the hydrolysate with major antioxidant activity. Sacha inchi protein hydrolysate at 20 min (SIH20B) was selected, and the anti-inflammatory capacity was evaluated by RT-qPCR and ELISA techniques, using two different doses in monocytes THP-1 stimulated with lipopolysaccharide (LPS). The results obtained showed that the in vitro administration of SIH20B down-regulated the TNF-α gene and reduced the release of this cytokine, whereas the anti-inflammatory cytokines IL-10 and IL-4 were up-regulated in LPS-stimulated monocytes and co-administrated with SIH20B. The peptides contained in SIH20B were identified, and the 20 more relatively abundant peptides with a mass by 1 kDa were subjected to in silico analysis to hypothesize those that could be responsible for the bioactivity reported in the hydrolysate. From the identified peptides, the peptides AAGALKKFL and LGVKFKGGL, among others, are proposed as the most biologically actives. In conclusion, SIH20B is a novel, natural source of high-value-added biopeptides that could be used as an ingredient in formulations of food or nutraceutical compounds.

Chemical and cell antioxidant activity of amaranth flour and beverage after simulated gastrointestinal digestion. Role of peptides

The potential of peptides generated by simulated gastrointestinal digestion (SGID) of two products derived from Amaranthus manteggazianus seeds, flour (F) and beverage (B), to exert peroxyl scavenging activity (ORAC) and antioxidant action on intestinal cells was studied. B was prepared by solubilisation of seed proteins, with the addition of gums and the application of a pasteurization treatment. The gastrointestinal digests FD and BD showed some differences in the peptide/polypeptide composition. The SGID produced increased ORAC activity for both samples, with some differences in the ORAC of the whole digests BD and FD and of some gel filtration fractions. Bioaccessible fractions (FDdbs and BDdbs) were obtained after treatment with cholestyramine resin to remove bile salts due to their cytotoxicity and oxidative effect. BDdbs presented a greater ORAC potency (IC50: 0.05 ± 0.01 and 0.008 ± 0.004 mg protein/ml for FDdbs and BDdbs, respectively). These fractions showed low cytotoxicity values (measured by LDH release) and produced high intracellular ROS inhibition (around 80 %), increased the SOD activity and the GSH content, with no effect on GPx activity in Caco2-TC7 cells exposed to H2O2. Several fractions with MM < 2.2 kDa presented also these cellular actions; fractions from FD induced higher increases in GSH concentration. Amaranth flour and a processed matrix like the beverage are shown as sources of bioactive peptides with potential cell antioxidant activity.

Release of Bioactive Peptides from Erythrina edulis (Chachafruto) Proteins under Simulated Gastrointestinal Digestion

The estimated and concerning rise in world population over the next few years and the consequent increase in food demand will lead to a deterioration in global food security. To avoid or reduce this world crisis, informed and empowered consumers are turning to sustainable and nutrient-rich foods that substitute animal products, also reducing their associated environmental impact. Moreover, due to the demonstrated influence of diet on the risk of high incidence and mortality of noncommunicable diseases, the current established food pattern is focused on the consumption of foods that have functionality for health. Among these new foods, traditional and underutilized plants are gaining interest as alternative protein sources providing nutritional and biological properties. In this work, the potential of Erythrina edulis (chachafruto) proteins as a source of multifunctional peptides after transit through the gastrointestinal tract has been demonstrated, with antioxidant and immunostimulating effects in both biochemical assays and cell culture. While low molecular weight peptides released during the digestive process were found to be responsible for protection against oxidative stress mediated by their radical scavenging activity, high molecular weight peptides exerted immunostimulating effects by upregulation of immunoresponse-associated biomarkers. The findings of this study support the promising role of chachafruto proteins as a new antioxidant and immunostimulatory ingredient for functional foods and nutraceuticals.

Antioxidant and Immunomodulatory Properties of Chia Protein Hydrolysates in Primary Human Monocyte-Macrophage Plasticity

Chia (Salvia hispanica L.) seed has high potential in the development of functional food due to its protein content with a special amino acid profile. Among the hematopoietic-derived cells, monocytes are endowed with high plasticity, responsible for their pro- and anti-inflammatory function in M1 and M2 phenotype polarization, respectively. Indeed, monocytes are involved in several oxidative- and inflammatory-associated disorders such as cancer, obesity, and cardiovascular and neurodegenerative diseases. This study was designed to investigate the role of chia protein hydrolysates (CPHs) in primary human monocyte–macrophage plasticity response using biochemical, RT-qPCR, and ELISA assays. Our results showed that CPHs reduce ROS and nitrite output, as pro-inflammatory cytokine secretion, and enhance the expression and release of anti-inflammatory cytokines. In addition, CPHs reverse LPS-associated M1 polarization into M2. These findings open new opportunities for developing nutritional strategies with chia as a dietary source of biopeptides to prevent the development and progression of oxidative- and inflammatory-related diseases.

Anticancer activity of protein fractions from chia (Salvia hispanica L.)

Salvia hispanica demonstrated to be a source of protein fractions with anticancer activity. The effect of the protein fractions <1, 1-3, and 3-5 kDa, obtained by ultrafiltration of the S. hispanica hydrolysate, was evaluated on the cellular viability of four cancer cell lines (MCF-7, Caco2, PC-3, and HepG2) and on human fibroblasts (hFB) at different concentrations (0.25, 0.5, 0.75, and 1 mg/ml). The protein fractions did not show cytotoxic effects on hFB. The protein fraction <1 kDa at 1 mg/ml showed the highest statistical effect on the cellular viability of all evaluated cancer lines; thus, its amino acid sequence was analyzed. From the multicriteria decision analysis of the peptide sequences obtained by mass spectrometry, the peptide KLKKNL with potential anticancer activity was selected. In conclusion, protein fractions could represent a therapeutic option for cancer treatment. However, further investigations are necessary to establish conclusive arguments. PRACTICAL APPLICATION: The work of this article is based on the background of the increasing potential of peptides for the treatment of chronic diseases. The results of this study present peptides of low molecular weight, obtained from chia seeds, as a potential adjuvant option for cancer treatment.

Therapeutic peptides of Mucuna pruriens L.: Anti-genotoxic molecules against human hepatocellular carcinoma and hepatitis C virus

To assist the development of new therapeutic strategies for several disorders, biologically active peptides/proteins obtained from plant sources can be considered. Current study expected to determine the biological activities of peptide fractions of Mucuna pruriens against hepatocellular carcinoma cell lines (HepG2/ADM, HepG2, SMMC-7721, and QGY-7703), as well as normal cell line to prove their selectivity. Moreover, anti-genotoxicity and antiviral activity against the hepatitis C virus (HCV) were assessed. The methods of this study were to isolate the peptides of M. pruriens and hydrolysate fractionation via fractionated pepsin-pancreatin hydrolysates by ultrafiltration/high-performance ultrafiltration cell, identify anti-hepatoma activity of peptide fractions human liver cancer and normal cells by (3-(4,5-dimethylthiazole-2-yl)-2,5-biphenyl tetrazolium bromide) (MTT) assay, determine anti-HCV, and assess anti-genotoxic effect of peptide fractions against damage that induced via alkylating agent methyl methanesulphonate in human mononuclear cells. The results showed that the fraction 5-10 kDa has been reported to exhibit significant cytotoxic activity against HepG2 and QGY-7703. It was proven that both of 5-10 and >10 kDa fractions are active against HCV. The cytotoxic concentration (CC50) of 5-10 kDa against the cell line was 703.04 ± 5.21 µg/ml. Anti-genotoxic activities of the peptide fractions were evaluated as mean values for the analyzed comet images. In this regard, the highest activity of protecting DNA damages was observed by the peptide fraction of 5-10 kDa. This study revealed the potential ability of peptide fractions of M. pruriens for the treatment of liver cancer, HCV, and high activities of protecting DNA damages.

Neuroprotective Effect Of Peptide Fractions from Chia (Salvia hispanica) on H2O2-Induced Oxidative Stress-Mediated Neuronal Damage on N1E-115 Cell Line

Neurodegenerative diseases (ND) affect around a billion people worldwide. Oxidative stress plays a critical role in the activation of neuronal death mechanisms, implicated in the ND etiology. In the present research, the neuroprotective effect of the S. hispanica protein derivatives is evaluated, on neuronal cells N1E-115, after the damage induction with H₂O₂. From the protein-rich fraction of S. hispanica, three peptide fractions were obtained (3-5, 1-3 y < 1 kDa) and its neuroprotective effect on neuronal cells N1E-115 was evaluated, through the antioxidant pathway. In the toxicity assay, the peptide fractions showed viability greater than 90%. When N1E-115 cells were incubated with 100 µM H₂O₂, fractions 1-3 and < 1 kDa, presented cell viability of 66.64% ± 3.2 and 67.32% ± 2.8, respectively. Fractions 1-3 and < 1 kDa reduced by 41.73% ± 3.2 and 40.87% ± 2.8, respectively, the ROS production compared to the control, without significant statistical difference between both fractions (p < 0.05), while F3-5 kDa, only reduced the ROS production by 21.95% ± 2.4. The protective effect observed in the < 3 kDa fractions could be associated with its antioxidant activity, which represents an important study target.

Neuroprotective effect from Salvia hispanica peptide fractions on pro-inflammatory modulation of HMC3 microglial cells

Neuroinflammation plays a critical role in the neurodegenerative disease's development, where microglia's act an important role in the mechanisms of response to neuronal damage. In the present research, the neuroprotective effect from Salvia hispanica peptide fractions on the proinflammatory modulation on HMC3 microglial cells was evaluated. From the enzymatic hydrolysis of a protein-rich fraction from S. hispanica seeds, three peptide fractions (<1, 1-3 and 3-5 kDa) were obtained, from which its neuroprotective and anti-inflammatory effect was determined on the production of proinflammatory mediators on HMC3 cells. The F1-3 kDa exhibited the greatest protective effect (79.04%), associated with the decrease in ROS cell production (51.3 ± 2.3%). Likewise, F1-3 kDa at 50 µg/ml, presented the highest reduction percentages of NO (33.1 ± 2.30%), TNFα (26.4 ± 1.1%) and IL6 (17.36 ± 1.6%). F1-3 kDa exhibited a neuroprotective effect in HMC3 cells associated with its antioxidant and anti-inflammatory effect. PRACTICAL APPLICATIONS: Currently, neurodegenerative diseases represent a global health problem, so the search for bioactive compounds with neuroprotective effect is useful in the prevention and treatment of this group of diseases. Peptide research with an effect on the proinflammatory and prooxidant mediator's reduction presents a potential application in the functional food's development aimed at the treatment of chronic diseases, that have oxidative stress and inflammation as their etiological factor. The present research adds to the scientific evidence of the potential benefits of bioactive peptides obtained from chia seeds. The results correlate with the main health benefits of whole chia seed in humans, such as antioxidant, anti-inflammatory, hypoglycemic and hypotensive capacity. This relationship is associated with the protein and peptide composition of chia, which increases its added value as food.

Studies on vascular response to full superantigens and superantigen derived peptides: Possible production of novel superantigen variants with less vasodilation effect for tolerable cancer immunotherapy

Superantigens (SAgs) are a class of antigens that cause non-specific activation of T-cells resulting in polyclonal T cell activation and massive cytokine release and causing symptoms similar to sepsis, e.g. hypotension and subsequent hyporeactivity. We investigated the direct effect of SAgs on vascular tone using two recombinant SAgs, SEA and SPEA. The roles of Nitric Oxide (NO) and potentially hyperpolarization, which is dependent on the K⁺ channel activation, were also explored. The data show that SEA and SPEA have direct vasodilatory effects that were in part NO-dependent, but completely dependent on activation of K⁺ channels. Our work also identified the functional regions of one of the superantigens, SPEA, that are involved in causing the vasodilation and possible hypotension. A series of 20 overlapping peptides, spanning the entire sequence of SPEA, were designed and synthesized. The vascular response of each peptide was measured, and the active peptides were identified. Our results implicate the regions, (61-100), (101-140) and (181-220) which cause the vasodilation and possible hypotension effects of SPEA. The data also shows that the peptide 181-220 exert the highest vasodilation effect. This work therefore, demonstrates the direct effect of SAgs on vascular tone and identify the active region causing this vasodilation. We propose that these three peptides could be effective novel antihypertensive drugs. We also overexpressed, in E.coli, four superantigens from codon optimized genes.