Etude du potentiel antioxydant de quatre fractions obtenues par ultrafiltration membranaire d’hydrolysats de protéines de fenugrec (Trigonella foenumgraecum) [Antioxidant properties of ultrafiltration membrane fractions obtained from fenugreek (Trigonella foenum-graecum) proteins hydrolysates]

Introduction. Vu leur richesse en protéines, les légumineuses peuvent cons-tituer une source potentielle de biopeptides. Ces derniers peuvent être libérés des pro-téines par une hydrolyse enzymatique contrôlée. Les hydrolysats, ainsi obtenus, sont formés d’un mélange de peptides. Objectif. Cette étude vise à évaluer, in vitro, l’activité antioxydante d’hydrolysats protéiques de fenugrec et de leurs fractions. Matériel et méthodes. Les protéines sont purifiées à partir de la farine de fenugrec délipidée, par précipitation au point isoélectrique. Ces protéines sont ensuite hydrolysées par deux enzymes : l’Espérase et la Purafect. Les hydrolysats obtenus (PFHE et PFHP, respective-ment pour protéines de fenugrec hydrolysées avec Espérase et Purafect) sont alors frac-tionnés par ultrafiltration membranaire aux seuils de coupure moléculaire 30, 10 et 5 kDa. Les propriétés antioxydantes de chaque fraction ont été évaluées par la détermi-nation de la capacité de piégeage du diphénylpicrylhydrazyl et du pouvoir de réduction de l’ion ferrique. Résultats. Les PFHE montrent des propriétés antioxydantes supérieures à celles enregistrées avec les PFHP. Les activités antioxydantes des deux hydrolysats varient d’une fraction à une autre, avec de meilleures activités enregistrées avec les fractions 30 kDa. Les fractions ont montré des propriétés antioxy-dantes inférieures ou égales à celles des hydrolysats. Conclusion. Les hydrolysats de protéines de fenugrec possèdent des propriétés antioxydantes. Par ailleurs, ces proprié-tés ne sont pas significativement améliorées après fractionnement

Effets de deux hydrolysats de protéines de poisson (Sardina pilchardus et Sardinella aurita) sur le transport inverse du cholestérol et le statut redox, chez le rat soumis à un régime enrichi en cholestérol |Effects of two fish protein hydrolysates (Sardina pilchardus and Sardinella aurita) on reverse cholesterol transport and redox status, in rat fed a cholesterol-enriched diet]

Introduction. Several studies have reported that marine peptides have antioxidant effect. However, few have focused on their cholesterol-lowering effect. Objective. The purpose of this study was to evaluate the effects of sardine (Sardina pilchardus ) and sardinelle (Sardinella aurita) protein hydrolysates on reverse cholesterol transport, and antioxidant status, in rat fed a cholesterol-enriched diet. Materials and methods. Eighteen male Wistar rats (350±15g) were divided into three groups, and fed 20% casein and 1% cholesterol for 15 days. During this period, two groups received by gavage sardine protein hydrolysates (HPS) or sardinelle (HPA) solution. The 3rd group received water (GC). Results. Cholesterolemia was 1.7-fold lower in hydrolysates fed groups. The lecithin: cholesterol acyltransferase (LCAT) activity was respectively, 1.7- and 1.6-fold higher in HPS and HPA groups. Phospholipids values of high density lipoprotein (PL-HDL ) were 1.4-fold lower in HPS compared with GC group. Cholesteryl esters amounts of HDL (CE-HDL ) were respectively, 1.7- and 1.5-fold higher in HPS and HPA groups. Liver and muscle thiobarbituric acid reactive substances (TBARS) were respectively reduced by 68% and 29% in HPS and 48.5% and 63.6% in HPA group. Superoxide dismutase (SOD) activity was increased by 32% in liver and 78% in muscle of HPA. Conclusion. It seems that HPS and HPA act favorably on reverse cholesterol transport, and improve oxidative stress, in rat fed cholesterol- enriched diet

Protein Hydrolysates from Fenugreek (<i>Trigonella foenum graecum</i>) as Nutraceutical Molecules in Colon Cancer Treatment

The application of plant extracts for therapeutic purposes has been used in traditional medicine since the plants are a source of a great variety of chemical compounds that possess biological activity. Actually, the effect of these extracts on diseases such as cancer is being widely studied. Colorectal adenocarcinoma is one of the main causes of cancer related to death and the second most prevalent carcinoma in Western countries. The aim of this work is to study the possible effect of two fenugreek (Trigonella foenum graecum) protein hydrolysates on treatment and progression of colorectal cancer. Fenugreek proteins from seeds were hydrolysed by using two enzymes separately, which are named Purafect and Esperase, and were then tested on differentiated and undifferentiated human colonic adenocarcinoma Caco2/TC7 cells. Both hydrolysates did not affect the growth of differentiated cells, while they caused a decrease in undifferentiated cell proliferation by early apoptosis and cell cycle arrest in phase G1. This was triggered by a mitochondrial membrane permeabilization, cytochrome C release to cytoplasm, and caspase-3 activation. In addition, the hydrolysates of fenugreek proteins displayed antioxidant activity since they reduce the intracellular levels of ROS. These findings suggest that fenugreek protein hydrolysates could be used as nutraceutical molecules in colorectal cancer treatment

Combined biocatalytic conversion of smooth hound viscera: Protein hydrolysates elaboration and assessment of their antioxidant, anti-ACE and antibacterial activities

The aim of this study was to investigate the antioxidant, anti-ACE and antibacterial activities of smooth hound viscera hydrolysates (SHVHs). Viscera, as by-product, were hydrolyzed with crude alkaline protease extract from the same species, three commercial proteases and a combination endogenous and exogenous preparations. Hydrolysates showed different degrees of hydrolysis and the digestion with endogenous enzymes in combination with commercial proteases was found to enhance protein hydrolysis. The resulting SHVHs had high protein content (70.89%–89.06%) and they were mainly constituted by Gly, Glu and Gln, while Tau was the major free amino acid. In addition, they contained high amounts of UMP, Uridine, GMP and Guanosine, while undigested proteins were mainly rich in IMP and Xanthine. Furthermore, SHVHs showed different molecular mass distribution and RP-HPLC profiles proving their molecular mass and hydrophilic/hydrophobic peptide heterogeneity. All the SHVHs exhibited antioxidant activity, in terms of radical-scavenging activity, reducing power, metal chelating activity, β-carotene protection, lipid peroxidation inhibition and DNA breakage assay, and it was found that a medium degree of hydrolysis was appropriate to obtain hydrolysates with good antioxidant capacity. In addition, the SHVHs antioxidant activity was improved after simulated gastrointestinal digestion. Besides their antibacterial effect against several Gram-positive and Gram-negative bacteria, all the hydrolysates showed varying degrees of ACE inhibitory activities and the highest one was achieved by the Purafect hydrolysate (IC50 = 75 μg/mL). The overall data suggested that the SHVHs could be used as potential source of natural antioxidant, antimicrobial and anti-ACE peptides to formulate functional foods.Funded by the Ministry of Higher Education and Scientific Research, Tunisia. Emerging Research Group Grant from Generalitat Valenciana in Spain (GV/2015/138) and JAEDOC-CSIC postdoctoral contract of L.M. cofounded by the European Social Found are acknowledged.Peer reviewe