The health benefits of sweet lupin seed flours and isolated proteins

The interest for lupin is continuously growing: one driving force are the numerous studies showing it provides useful health benefits. This review discusses available literature in the area of dyslipidaemia, diabetes, and hypertension prevention, providing hints on the mechanism of action. The addition of lupin protein to the diet of different models of hypercholesterolaemia, such as rat, rabbit, hamster and pig, induce decreases of total and non-HDL cholesterol. The clinical investigations on the cholesterol lowering activity provided controversial results. Those involving hypercholesterolaemic subjects and based on improved lupin foods gave statistically significant total and/or LDL-cholesterol reductions: both protein and fibre are relevant. The moderate hypotensive activity observed in some studies is probably linked to digestion-released ACE-inhibitory peptides. The hypoglycaemic activity, observed in post-prandial studies, is due to gamma-conglutin, a specific protein fraction. All this information suggests that lupin seeds may become a source of ingredients of innovative functional foods

Size and distance estimation in virtual reality

Abstract. Interest in virtual reality (VR) has been on the rise in the recent few years. However, it is difficult to create virtual environments which provide realistic perception of scale for their users. We wanted to study how humans perceive scale in VR and ways to improve VR scale perception. We did a pilot test to see how design choices affect distance and height estimation in VR. For pilot tests we had nine test participants. Based on the experience gathered from the pilot test, we designed the main test. For the main test we had 44 participants. The main test showed similar results for distance estimating as earlier studies. Humans underestimated distances and heights in VR. Having a familiar size object cue, a VR model of a milk carton, next to the object improved height estimations.Koon ja etäisyyden arviointi virtuaalitodellisuudessa. Tiivistelmä. Kiinnostus virtuaalitodellisuuteen (VT) on ollut kasvavaa muutaman viime vuoden aikana. On kuitenkin vaikeaa tehdä virtuaalinen ympäristö, joka luo käyttäjilleen luonnollisen aistimuksen mittakaavasta. Halusimme tutkia, miten ihmiset hahmottavat skaalaa VR:ssä ja kuinka sitä voi parantaa. Teimme pilottitestejä, jotta näkisimme kuinka erilaiset suunnittelupäätökset vaikuttavat etäisyyden ja korkeuden arviointiin virtuaalitodellisuudessa. Pilottitesteissä oli yhdeksän osallistujaa. Pilottitestien pohjalta teimme laajemman testin, jossa hyödynsimme pilottitesteistä saatuja kokemuksia. Laajemmassa testissä oli 44 osallistujaa. Tämä testi tuotti samankaltaisia tuloksia etäisyyden arvioinnissa kuin aikaisemmat tutkimukset. Ihmiset aliarvioivat etäisyyksiä ja korkeuksia virtuaalitodellisuudessa. Kun esineen vieressä oli tunnetun kokoinen esine, maitopurkin virtuaalimalli, korkeuden arviointi parani

Proteomic analysis of sweet algerian apricot kernels ( Prunus armeniaca L.) by combinatorial peptide ligand libraries and LC-MS/MS

An investigation on the proteome of the sweet kernel of apricot, based on equalisation with combinatorial peptide ligand libraries (CPLLs), SDS-PAGE, nLC-ESI-MS/MS, and database search, permitted identifying 175 proteins. Gene ontology analysis indicated that their main molecular functions are in nucleotide binding (20.9 %), hydrolase activities (10.6 %), kinase activities (7 %), and catalytic activity (5.6%). A protein-protein association network analysis using STRING software permitted to build an interactomic map of all detected proteins, characterised by 34 interactions. In order to forecast the potential health benefits deriving from the consumption of these proteins, the two most abundant, i.e. Prunin 1 and 2, were enzymatically digested in silico predicting 10 and 14 peptides, respectively. Searching their sequences in the database BIOPEP, it was possible to suggest a variety of bioactivities, including dipeptidyl peptidase-IV (DPP-IV) and angiotensin converting enzyme I (ACE) inhibition, glucose uptake stimulation and antioxidant properties

Analysis of Narrow-Leaf Lupin Proteins in Lupin-Enriched Pasta by Untargeted and Targeted Mass Spectrometry

The supplementation of different food items with grain legumes and, in particular, with lupin has been demonstrated to provide useful health benefits, especially in the area of cardiovascular disease prevention. In this work, label free quantitative untargeted and targeted approaches based on liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) for investigating the protein profile of three pasta samples containing different percentages of narrow-leaf lupin flour were carried out. The untargeted method permitted the identification of the main acidic globulins (\u3b1-conglutin, \u3b2-conglutin, and \u3b4-conglutin) and the comparison of their profile with raw lupin flour. The targeted method, based on High-performance liquid chromatography electrospray ionization tandem mass spectrometry HPLC-Chip-Multiple Reaction Monitoring (MRM) mode, allowed the quantification of \u3b3-conglutin, the main hypoglycemic component of lupin protein: its concentration was around 2.25 mg/g in sample A, 2.16 mg/g in sample D, and 0.57 mg/g in sample F

Phycobiliproteins from Arthrospira Platensis (Spirulina): A New Source of Peptides with Dipeptidyl Peptidase-IV Inhibitory Activity

Arthrospira platensis (spirulina) is a cyanobacterium, which contains mainly two phycobiliproteins (PBP), i.e., C-phycocyanin (C-PC) and allophycocyanin (APC). In this study, PBP were hydrolyzed using trypsin, and the composition of the hydrolysate was characterized by HPLC-ESI-MS/MS. Furthermore, the potential anti-diabetic activity was assessed by using either biochemical or cellular techniques. Findings suggest that PBP peptides inhibit DPP-IV activity in vitro with a dose-response trend and an IC50 value falling in the range between 0.5 and 1.0 mg/mL. A lower inhibition of the DPP-IV activity expressed by Caco-2 cells was observed, which was explained by a secondary metabolic degradation exerted by the same cells

Three Peptides from Soy Glycinin Modulate Glucose Metabolism in Human Hepatic HepG2 Cells

Ile-Ala-Val-Pro-Gly-Glu-Val-Ala (IAVPGEVA), Ile-Ala-Val-Pro-Thr-Gly-Val-Ala (IAVPTGVA) and Leu-Pro-Tyr-Pro (LPYP), three peptides deriving from soy glycinin hydrolysis, are known to regulate cholesterol metabolism in human hepatic HepG2 cells. We have recently demonstrated that the mechanism of action involves the activation of adenosine monophosphate-activated protein kinase (AMPK). This fact suggested a potential activity of the same peptides on glucose metabolism that prompted us to also investigate this aspect in the same cells. After treatment with IAVPGEVA, IAVPTGVA and LPYP, HepG2 cells were analyzed using a combination of molecular techniques, including western blot analysis, glucose uptake experiments and fluorescence microscopy evaluation. The results showed that these peptides are indeed able to enhance the capacity of HepG2 cells to uptake glucose, via glucose transporter 1 GLUT1 and glucose transporter 4 GLUT4 activation, through the stimulation of protein kinase B Akt and adenosine monophosphate-activated protein kinase AMPK pathways, both involved in glucose metabolism

Potential role of non-soy grain legumes in preventing hypercholesterolemia

Although the health benefits provided by soy protein are known from decades, especially in the area of cholesterol control, non-soy legumes have been only rarely investigated. This is a pity considering the environmental relevance of these seeds: indeed a better knowledge of their beneficial role in the diet may become an important tool to promote their consumption. We summarize here available results either from animal investigations or human trials in the area of hypercholesterolemia prevention. This body of data indicates that a regular consumption of grain legumes is useful for maintaining a correct lipid profile

Two peptides from soy β-conglycinin induce a hypocholesterolemic effect in hepG2 cells by a statin-like mechanism: comparative in vitro and in silico modeling studies

Two peptides from soybean \u3b2-conglycinin, i.e., YVVNPDNDEN (peptide 2) and YVVNPDNNEN (peptide 3), are known to be absorbed by human enterocytes. The former is a fragment of LRVPAGTTFYVVNPDNDENLRMIA (peptide 1), previously shown to increase the low-density lipoprotein (LDL) uptake and degradation in hepatocytes. Research carried out in silico on their interactions with the catalytic site of 3-hydroxy-3-methylglutaryl CoA reductase (HMGCoAR) demonstrated that they behave as competitive inhibitors of HMGCoAR activity with a statin-like mechanism, confirmed by direct inhibition experiments. Research in HepG2 cells aimed at investigating the effects of these peptides on cholesterol metabolism showed that compared to mock treatment peptide 2 at 350 \u3bcM up-regulates the mature SREBP2 protein level by 134.0 \ub1 10.5%, increases the LDLR protein level by 152.0 \ub1 20.0%, and enhances the HMGCoAR protein production by 171 \ub1 29.9%, whereas peptide 3 up-regulates the mature SREBP2 protein level by 158.0 \ub1 9.2%, increases the LDL level 164.0 \ub1 17.9%, and induces a HMGCoAR protein increase by 170 \ub1 50.0%

Biological Characterization of Computationally Designed Analogs of peptide TVFTSWEEYLDWV (Pep2-8) with Increased PCSK9 Antagonistic Activity

The inhibition of the PCSK9/LDLR protein-protein interaction (PPI) is a promising strategy for developing new hypocholesterolemic agents. Recently, new antibodies have been approved for therapy, but the high cost and low patients\u2019 compliance stimulate the development of alternatives. Starting from the structural information available for the complex between PCSK9 and TVFTSWEEYLDWV (Pep2-8) peptide inhibitor and using computational methods, in this work we identified two Pep2-8 analogs as potential inhibitors of the PCSK9/LDLR PPI. Their biological characterization confirmed the theoretical outcomes. Remarkably, the treatment of HepG2 cells with these peptides increased the LDLR protein level on the cellular membrane, with activities that were 100 and 50 times better than the one of Pep2-8 tested at a 50 \u3bcM concentration. Moreover, they were 50 and 5 times more active than Pep2-8 in improving the functional ability of HepG2 cells to uptake extracellular LDL

Lupin protein exerts cholesterol-lowering effects targeting PCSK9: from clinical evidences to elucidation of the in vitro molecular mechanism using HepG2 cells

PCSK9 inhibition is a novel approach for cholesterol reduction because of its crucial pathophysiological role in cholesterol metabolism. This work aimed at evaluating whether lupin protein/peptides may modulate PCSK9 production. Mild hypercholesterolaemic subjects consumed lupin protein or casein (30 g/day) for 4 weeks. The final level of circulating PCSK9, measured by ELISA, was reduced by 8.5% (p = 0.0454) versus baseline value, whereas it remained unchanged in the control group (casein). For investigating the mechanism of action, HepG2 cells were treated with peptic and tryptic peptides from lupin protein: reductions of PCSK9 production and secretion were observed as well as a decrease of hepatic nuclear factor 1-alpha (HNF1-alpha). For the first time, this work provides evidences that lupin protein/peptides may modulate the PCSK9 protein level production and secretion, contributing to explain the beneficial effects observed in animal and human studies and opening a completely new area of investigation on plant proteins