Pharmacological and Therapeutic Potential of Cucumis callosus: a Novel Nutritional Powerhouse for the Management of Non-communicable Diseases.

Cucumis callosus (Kachri) is an under-exploited fruit of the Cucurbitaceae family, distributed majorly in the arid regions of India in the states of Haryana, Rajasthan, and Gujarat. The fruit is traditionally used by the native people at a small scale by home-level processing. It is a perennial herb that has been shown to possess therapeutic potential in certain disorders. In several studies, the antioxidant, anti-hyperlipidaemic, anti-diabetic, anti-cancerous, anti-microbial, and cardioprotective properties of Kachri have been reported. The fruit has a good nutritional value in terms of high percentages of protein, carbohydrates, essential fatty acids, phenols, and various phytochemicals. Also, gamma radiation treatment has been used on this crop to reduce total bacterial counts (TBC), ensuring safety from pathogens during the storage period of the fruit and its products. These facts lay down a foundation for the development of functional food formulations and nutraceuticals of medicinal value from this functionally rich crop. Processing of traditionally valuable arid region foods into functional foods and products can potentially increase the livelihood and nutritional security of people globally. Therefore, this review focuses on the therapeutic and pharmacological potentials of the Kachri fruit in the management of non-communicable diseases (NCDs) namely, diabetes, cancer, and hyperlipidemia. Graphical abstract of the review.

Controlling Intestinal Infections and Digestive Disorders Using Probiotics.

After consumption, probiotics provide health benefits to the host. Probiotics and their metabolites have therapeutic and nutritional properties that help to alleviate gastrointestinal, neurological, and cardiovascular problems. Probiotics strengthen host immunity through various mechanisms, including improved gut barrier function, receptor site blocking, competitive exclusion of pathogens, and the production of bioactive molecules. Emerging evidence suggests that intestinal bowel diseases can be fatal, but regular probiotic consumption can alleviate disease symptoms. The use and detailed description of the health benefits of probiotics to consumers in terms of reducing intestinal infection, inflammation, and digestive disorders are discussed in this review. The well-designed and controlled studies that examined the use of probiotics to reduce life-threatening activities caused by intestinal bowel diseases are also covered. This review discussed the active principles and potency of probiotics as evidenced by the known effects on host health, in addition to providing information on the mechanism of action.

In Silico Exploration of Metabolically Active Peptides as Potential Therapeutic Agents against Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis (ALS) is regarded as a fatal neurodegenerative disease that is featured by progressive damage of the upper and lower motor neurons. To date, over 45 genes have been found to be connected with ALS pathology. The aim of this work was to computationally identify unique sets of protein hydrolysate peptides that could serve as therapeutic agents against ALS. Computational methods which include target prediction, protein-protein interaction, and peptide-protein molecular docking were used. The results showed that the network of critical ALS-associated genes consists of ATG16L2, SCFD1, VAC15, VEGFA, KEAP1, KIF5A, FIG4, TUBA4A, SIGMAR1, SETX, ANXA11, HNRNPL, NEK1, C9orf72, VCP, RPSA, ATP5B, and SOD1 together with predicted kinases such as AKT1, CDK4, DNAPK, MAPK14, and ERK2 in addition to transcription factors such as MYC, RELA, ZMIZ1, EGR1, TRIM28, and FOXA2. The identified molecular targets of the peptides that support multi-metabolic components in ALS pathogenesis include cyclooxygenase-2, angiotensin I-converting enzyme, dipeptidyl peptidase IV, X-linked inhibitor of apoptosis protein 3, and endothelin receptor ET-A. Overall, the results showed that AGL, APL, AVK, IIW, PVI, and VAY peptides are promising candidates for further study. Future work would be needed to validate the therapeutic properties of these hydrolysate peptides by in vitro and in vivo approaches.

Health benefits of polyphenols: A concise review.

Plants produce polyphenols, which are considered highly essential functional foods in our diet. They are classified into several groups according to their diverse chemical structures. Flavanoids, lignans, stilbenes, and phenolic acids are the four main families of polyphenols. Several in vivo and in vitro research have been conducted so far to evaluate their health consequences. Polyphenols serve a vital function in the protection of the organism from external stimuli and in eliminating reactive oxygen species (ROS), which are instigators of several illnesses. Polyphenols are present in tea, chocolate, fruits, and vegetables with the potential to positively influence human health. For instance, cocoa flavan-3-ols have been associated with a decreased risk of myocardial infarction, stroke, and diabetes. Polyphenols in the diet also help to improve lipid profiles, blood pressure, insulin resistance, and systemic inflammation. Quercetin, a flavonoid, and resveratrol, a stilbene, have been linked to improved cardiovascular health. Dietary polyphenols potential to elicit therapeutic effects might be attributed, at least in part, to a bidirectional association with the gut microbiome. This is because polyphenols are known to affect the gut microbiome composition in ways that lead to better human health. Specifically, the gut microbiome converts polyphenols into bioactive compounds that have therapeutic effects. In this review, the antioxidant, cytotoxicity, anti-inflammatory, antihypertensive, and anti-diabetic actions of polyphenols are described based on findings from in vivo and in vitro experimental trials. PRACTICAL APPLICATIONS: The non-communicable diseases (NCDs) burden has been increasing worldwide due to the sedentary lifestyle and several other factors such as smoking, junk food, etc. Scientific literature evidence supports the use of plant-based food polyphenols as therapeutic agents that could help to alleviate NCD's burden. Thus, consuming polyphenolic compounds from natural sources could be an effective solution to mitigate NCDs concerns. It is also discussed how natural antioxidants from medicinal plants might help prevent or repair damage caused by free radicals, such as oxidative stress.

Antioxidative, anti-inflammatory, and anticancer properties of the red biopigment extract from Monascus purpureus (MTCC 369).

In this study, the Monascus purpureus (MTCC 369) extracted biopigment produced by solid-state fermentation was evaluated for its therapeutic potential using human prostate LNCaP cells. Antioxidant efficacy of the red biopigment determined using 2,2 diphenyl-1-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid, and ferric reducing antioxidant power assays was found to be 53.16%, 86.27%, and 13.83%, respectively. In addition, expression studies of target gene superoxide dismutase 2 (SOD-2) showed that increasing concentrations (10-50 µg/ml) of the biopigment enhanced its expression from 0.91- to 1.905-fold. An inhibitory effect of 0.424-0.627-fold was observed in the expression of glutathione peroxidase (GPX) with a similar increase in biopigment concentration. Addition of quercetin (positive control) at 50 µg/ml led to 0.295-fold decrease in GPX expression. In contrast, the expression of SOD-2 increased by 1.026-fold in the presence of quercetin. The biopigment also showed an increased serological IL-10 expression (an anti-inflammatory agent) ranging from 1034.58 to 4657.89 pg/ml. Treatment of LNCaP cells with the red biopigment (10-100 µg/ml) resulted in significant (p < .05) reduction (upto 79.86%) in viability and 51.79%-89.86% reduction in cell metabolic activity. Fluorescent microscopy examination of red biopigment-treated cells showed significant inhibition of normal cellular morphology including condensed nuclei, membrane blebbing, and apoptotic bodies, thus confirming its cytotoxic potential. Results of this study revealed that the red biopigment has the potential to modulate the expression of antioxidative and anti-inflammatory markers in addition to being cytotoxic to the LNCaP cancer cells. PRACTICAL APPLICATIONS: These findings indicate that cell treatment with red biopigment has the potential to modulate anti-oxidative, pro-inflammatory and anti-inflammatory genes for therapeutic effects, which is further enhanced by its cytotoxic activity against cancer cells. Considering these cell-based observations, Monascus red biopigment has ample potential as a useful supplement to formulate therapeutic products that delay the development of inflammatory-related diseases and associated complications.

Liposomes loaded with betel leaf (Piper betle L.) ethanolic extract prepared by thin film hydration and ethanol injection methods: Characteristics and antioxidant activities.

Betel leaf ethanolic extract (BLEE), which was dechlorophyllized by sedimentation process was loaded in liposomes at 1 and 2% (w/v) concentrations using two different methods, namely thin film hydration (TF) and ethanol injection (EI) methods. Liposomes loaded with 1% BLEE and prepared by TF method (BLEE/L-T1) had the smallest particle size and paler color than BLEE/L-E1, BLEE/L-E2, and BLEE/L-T2 (p < .05). BLEE/L-T1 also showed strong stability as judged by its lowest zeta potential and polydispersity index. The highest encapsulation efficiency (EE) and lowest releasing efficiency (RE) were also found with BLEE/L-T1. No significant difference (p > .05) in the antioxidant activities was detected between the BLEE-loaded liposomes and BLEE solutions, indicating that encapsulation had no adverse effect on BLEE antioxidant potency. BLEE/L-T1 showed higher antioxidant stability than unencapsulated BLEE at the equivalent amount based on EE (BLEE/U-T1) during in vitro gastrointestinal tract digestion system. Therefore, BLEE/L-T1 could be an efficient delivery system for improving stability of antioxidant activities of BLEE. PRACTICAL APPLICATIONS: Despite the many benefits of betel leaf ethanolic extract, it still has some distinctive odor and slightly greenish color as well as instability induced by environment factors, which can limit applications in foods. Encapsulation of the betel extract in liposomes can be a good approach to mask its undesirable color and odor and to augment its antioxidant stability. Liposomal technology can be used to load betel leaf extract. However, different methods have been implemented to prepare liposomes that exhibit varying encapsulation efficacy as well as bioactivities. Thin film hydration method was shown to yield the liposome with better physical characteristics, higher encapsulation efficiency, slower release, and higher antioxidant stability than the ethanol injection method. Therefore, the thin film hydration method could be adopted to prepare stable liposomes loaded with betel leaf extract that possess antioxidant activity suitable for food applications.

Functional Characterization of Mung Bean Meal Protein-Derived Antioxidant Peptides.

The aim of this work was to characterize the antioxidant properties of some of the peptides present in bromelain mung bean meal protein hydrolysate (MMPH). The MMPH was subjected to two rounds of bioassay-guided reversed-phase HPLC separation followed by peptide identification in the most potent fractions using tandem mass spectrometry. Twelve antioxidant peptides, namely, HC, CGN, LAN, CTN, LAF, CSGD, MMGW, QFAAD, ERF, EYW, FLQL, and QFAW were identified and assayed for antioxidant properties. CTN, HC, CGN, and CSGD were the most potent (p < 0.05) DPPH radical scavengers with EC50 values of 0.30, 0.29, 0.28, and 0.30 mg/mL, respectively, which are lower than the 0.03 mg/mL obtained for reduced glutathione (GSH). CTN, HC, CGN, and CSGD exhibited the most potent (p < 0.05) scavenging activities against hydroxyl and superoxide radicals with EC50 values that are similar to those of GSH. The cysteine-containing peptides also had stronger ferric reducing antioxidant power and metal chelation activity than peptides devoid of cysteine. In contrast, MMGW, ERF, and EYW had poor radical scavenging and metal chelation activities. We conclude that the availability of the sulfhydryl group may have enhanced antioxidant potency while the presence of bulky groups such phenylalanine and tryptophan had an opposite effect.

Chemical composition and in vitro antioxidant properties of water-soluble extracts obtained from Bangladesh vegetables.

The aim of this study was to evaluate the nutritional value and antioxidant properties of aqueous extracts of some Bangladesh vegetables using fruits of ash gourd, bitter gourd, brinjal, okra, ridge gourd, snake gourd, and leaves of Indian spinach, kangkong, and stem amaranth. Proximate composition showed that the dried extracts were composed mainly of crude protein (14.6%-46.7%) and non-fibre carbohydrates (26.4%-53.5%). With the exception of stem amaranth, all the extracts had >40% DPPH radical scavenging ability at 0.5 mg/ml. In contrast metal chelation was lower, except in Indian spinach with ~46%. The ferric reducing antioxidant power (FRAP) was highest for the kangkong (10.9 mM Fe3+ reduced), which is similar to the 9.9 mM for butylated hydroxytoluene (BHT). All the extracts suppressed linoleic acid oxidation better than BHT within the first 5 days of the incubation period. We conclude that the Indian spinach, kangkong, and okra could be considered as the most promising sources of antioxidant compounds. PRACTICAL APPLICATIONS: Vegetables are commonly consumed as part of a regular diet but the high water and fiber contents usually mean that large quantities are required to provide long-term health benefits. Therefore, in this work, aqueous extracts of nine Bangladesh vegetables were prepared to provide a more concentrated form of nutrients and bioactive compounds. The extracts had strong nutritional value based on the high contents of crude protein, potassium, iron, and non-fibre carbohydrates. The high content of polyphenolic compounds in the extracts can also provide health benefits, which was demonstrated through strong free radical scavenging, metal chelation, ferric iron reduction, and inhibition of linoleic acid oxidation. These vegetable extracts have the potential to be used as sources of bioactive compounds to prevent or treat non-communicable diseases that are associated with high oxidative stress.

Red Beetroot Betalains: Perspectives on Extraction, Processing, and Potential Health Benefits.

In recent years, red beetroot has received a growing interest due to its abundant source of bioactive compounds, particularly betalains. Red beetroot betalains have great potential as a functional food ingredient employed in the food and medical industry due to their diverse health-promoting effects. Betalains from red beetroot are natural pigments, which mainly include either yellow-orange betaxanthins or red-violet betacyanins. However, betalains are quite sensitive toward heat, pH, light, and oxygen, which leads to the poor stability during processing and storage. Therefore, it is necessary to comprehend the impacts of the processing approaches on betalains. In this review, the effective extraction and processing methods of betalains from red beetroot were emphatically reviewed. Furthermore, a variety of recently reported bioactivities of beetroot betalains were also summarized. The present work can provide a comprehensive review on both conventional and innovative extraction techniques, processing methods, and the stability of betalains.

Stability of tuna trypsin-loaded alginate-chitosan beads in acidic stomach fluid and the release of active enzyme in a simulated intestinal tract environment.

Encapsulation properties of trypsin from tonggol tuna (Thunnus tonggol) spleen using different materials including alginate (AG), low and high molecular weight chitosan (LC and HC, respectively), and soy lecithin (SL) were studied. The highest encapsulation efficiency and greatest relative activity were found in AG/LC beads after simulated gastric phase (p < .05). AG/LC encapsulated trypsin was used in simulated in vitro gastrointestinal tract for hydrolysis of sodium caseinate, soy protein isolate and fish mince, in which all protein samples were hydrolyzed as indicated by the increased α-amino group content (p < .05). Higher degradation was attained when beads containing trypsin were added. When AG/LC beads packed in blister pack were stored for 8 weeks at refrigerated temperature, a 26% decrease in activity occurred. Therefore, encapsulated tonggol tuna spleen trypsin can be prepared using AG/LC to withstand structural breakdown in stomach, but be released as an active protease within intestinal tract. PRACTICAL APPLICATION: Spleen from tonggol tuna is a by-product, which can be used as a source of trypsin, a proteolytic enzyme. The trypsin that was encapsulated within alginate and low molecular weight chitosan beads was released in the intestinal phase and was retained proteolytic activity. Therefore, this encapsulated trypsin can be packaged in capsules and taken as a supplement to aid protein digestion in the gastrointestinal tract, especially for people that need such digestive aids.

A double-blind, randomized, crossover trial protocol of whole hemp seed protein and hemp seed protein hydrolysate consumption for hypertension.

BACKGROUND: Primary hypertension accounts for almost 95% of all cases of high blood pressure and is a major modifiable risk factor for cardiovascular diseases. Lifestyle interventions have been shown to prevent hypertension. One of the prominent potential therapeutic lifestyle strategies to prevent or manage hypertension is increasing dietary protein as a macronutrient or as bioactive peptides. An emerging plant-based protein source that may have anti-hypertensive properties is hemp seed. METHODS/DESIGN: A randomized, double-blind, crossover clinical trial will be conducted on 35 hypertensive participants aged 18-75 years, with a BMI between 18.5 and 40 kg/m2, systolic blood pressure (SBP) between 130 and 160 mmHg and diastolic blood pressure (DBP) ≤ 110 mmHg. The trial will be conducted for a period of 22 weeks and will consist of three treatment periods of 6 weeks, separated by 2-week washout periods. The treatments will be consumed twice a day and consist of 25 g casein, hemp seed protein (HSP), or HSP plus HSP hydrolysate (HSP+). The primary outcome of this trial is 24-h SBP, measured on the first day of first phase and the last day of each phase. Office-measured blood pressure, pulse-wave velocity and augmentation index and anthropometrics will be determined at the first and last days of each period. Also, body composition will be assessed by dual x-ray absorptiometry (DXA) scan on the first day of the first phase and within the last 2 days of each treatment period. Blood samples will be collected on the first and last 2 days of each treatment phase whereas urine samples will be collected on the first day of the first phase plus the last day of each phase to be analyzed for specific biomarkers. DISCUSSION: This trial protocol is designed to evaluate the hypotensive potential of consuming whole HSP, and HSP+, in comparison to casein protein. This study will be the first trial investigating the potential anti-hypertensive benefit of dietary hemp protein plus bioactive peptide consumption in humans. TRIAL REGISTRATION: National Clinical Trial (NCT), ID: NCT03508895. Registered on 28 June 2018. Retrospectively registered on the publicly accessible Registry Databank at ClinicalTrials.gov (http://ClinicalTrials.gov).

In situ oxidation of canola meal sinapic acid by horseradish peroxidase (type II) and tyrosinase.

The enzymatic oxidation of sinapic acid catalyzed by horseradish peroxidase (HRP) or tyrosinase was investigated using model systems, which contained the pure compound or canola meal. Spectrophotometric scanning of pure sinapic acid solution in the presence of HRP (0.2 U) or tyrosinase (40.3 U) showed continuous decreases in absorbance at 304 nm over a period of 90 and 60 min, respectively. HPLC analyses of enzymatic end products, obtained by the catalysis with HRP or tyrosinase, indicated the presence of two main compounds (1 and 2). After alkaline hydrolysis of canola meal, sinapic acid that was released from sinapine was also converted to compounds 1 and 2 by HRP or tyrosinase. Enzyme reaction kinetics results indicate that the catalytic efficiency (CE = 0.538), reaction velocity (Vmax  = 5.67 ∆A/h), and Michaelis-Menten constant (Km  = 926.64 µM) of HRP are significantly higher than those of tyrosinase (CE = 0.041, Vmax  = 0.41 ∆A/h, Km  = 173.03 µM) at 50-250 µM pure sinapic acid concentrations. PRACTICAL APPLICATIONS: Canola meal contains a large amount of sinapine, which is the choline ester of sinapic acid, a strong antioxidant compound. However, the oxidation or decarboxylation products of sinapic acid could add value by increasing the level of electron-dense carboxylic and carbonyl compounds. In this study, enzymatic treatment of alkaline-hydrolyzed canola meal with horseradish peroxidase (HRP) and tyrosinase was investigated and shown to be suitable for converting sinapic acid into oxidized compounds. Therefore, the enzymatic treatment is a potential application for value-added processing of canola meal.

Polyphenol composition and antioxidant properties of vegetable leaf-fortified bread.

The aim of this work was to determine the antioxidant properties of aqueous extracts of vegetable leaf-fortified bread as well as estimate the contents of polyphenolic compounds. Enriched bread was produced from wheat flour fortified at 1, 2, and 3% (w/w) with dried leafy vegetable powders from Amaranthus viridis, Solanum macrocarpon, and Telfairia occidentalis. Gallic acid was the most abundant soluble polyphenol in the control bread and the content in the control bread was significantly higher (p < 0.05) than in all the fortified bread samples. Fortification of bread especially at 3% level resulted in significantly (p < 0.05) higher concentrations of other polyphenols (myricetin, catechin, quercetin, and rutin) compared to the control bread. The fortified bread extracts had significantly (p < 0.05) more effective antioxidants than the control for DPPH radical scavenging activity, ferric iron reducing antioxidant power, metal chelation, and inhibition of linoleic acid peroxidation. PRACTICAL APPLICATIONS: Bread is one of the consumed foods and could be used as a suitable carrier of bioactive compounds. Leafy vegetables contain high levels of polyphenols that could provide beneficial effects by contributing to improved health status of consumers. Therefore, incorporation of leafy vegetables into leavened bread could provide a means of enhancing polyphenol consumption. In this work, we showed that soluble polyphenols were enriched in vegetable-fortified bread. The polyphenol-rich extracts of the fortified bread demonstrated better free radical scavenging and inhibition of unsaturated fatty acid oxidation activities than the regular bread. Therefore, regular consumption of vegetable leaf-fortified bread could lead to reduced oxidative stress and associated chronic diseases in human beings. The vegetable leaf fortification could also serve as a suitable means of enhancing the shelf life of wheat bread.

Anti-allergic activity of mung bean (Vigna radiata (L.) Wilczek) protein hydrolysates produced by enzymatic hydrolysis using non-gastrointestinal and gastrointestinal enzymes.

Mung bean seed is a well-known plant protein consumed in Asian countries but the protein is usually retrieved as a waste product during starch production. This study investigated the anti-allergic property of mung bean protein hydrolysates (MBPH) produced by enzymatic hydrolysis using non-gastrointestinal (non-GI), GI and a combination of non-GI+GI enzymes. The hydrolysates were investigated for any anti-allergic property by detecting the amount of ß-hexosaminidase released in RBL-2H3 cells, and complemented with the MTT assay to show cell viability. It was found that MBPH hydrolyzed by a combination of flavourzyme (non-GI enzyme) and pancreatin (GI enzyme) exhibited the highest anti-allergic activity (135.61%), followed by those produced with alcalase, a non-GI enzyme (121.74%) and 80.32% for pancreatin (GI enzyme). Minimal toxicity (<30%) of all hydrolysates on RBL-2H3 cells line was observed. The results suggest that MBPH can potentially serve as a hypoallergenic food ingredient or supplement. PRACTICAL APPLICATIONS: Mung bean (Vigna radiata L. (Wilczek)) is also known as "green gram" and it is an excellent source of protein. The major mung bean storage proteins are the globulin, albumin and legumin, which are also referred to as legume allergens. Our study showed that mung bean peptides obtained after enzymatic hydrolysis influenced ß-hexosaminidase inhibition without any toxic effect on RBL-2H3 cells. This indicates that mung bean allergenicity can be reduced after enzymatic hydrolysis and the protein hydrolysates could be as a hypoallergic food, ingredient, supplement and/or protein substitute in the formulation of food products.

Structural and functional properties of food protein-derived antioxidant peptides.

The aim of this work is to provide a timely examination of the structure-activity relationship of antioxidative peptides. The main production approach involves enzymatic hydrolysis of animal and plant proteins to produce protein hydrolyzates, which can be further processed by membrane ultrafiltration into size-based peptide fractions. The hydrolyzates and peptide fractions can also be subjected to separation by column chromatography to obtain pure peptides. Although the structural basis for enhanced antioxidant activity varies, protein hydrolyzates and peptide fractions that contain largely low molecular weight peptides have generally been shown to be potent antioxidants. In addition to having hydrophobic amino acids such as Leu or Val in their N-terminal regions, protein hydrolyzates, and peptides containing the nucleophilic sulfur-containing amino acid residues (Cys and Met), aromatic amino acid residues (Phe, Trp, and Tyr) and/or the imidazole ring-containing His have been generally found to possess strong antioxidant properties. PRACTICAL APPLICATIONS: High levels of reactive oxygen species (ROS) in addition to the presence of metal cations can lead to oxidative stress, which promotes reactions that cause destruction of critical cellular biopolymers, such as proteins, lipids, and nucleic acids. Oxidative stress could be due to insufficient levels of natural cellular antioxidants, which enables accumulation of ROS to toxic levels. A proposed approach to ameliorating oxidative stress is the provision of exogenous peptides that can be consumed to complement cellular antioxidants. Food protein-derived peptides consist of amino acids joined by peptides bonds just like glutathione, a very powerful natural cellular antioxidant. Therefore, this review provides a timely summary of the in vitro and in vivo reactions impacted by antioxidant peptides and the postulated mechanisms of action, which could aid development of potent antioxidant agents. The review also serves as a resource material for identifying novel antioxidant peptide sources for the formulation of functional foods and nutraceuticals.

Hydrolyzed collagen from porcine lipase-defatted seabass skin: Antioxidant, fibroblast cell proliferation, and collagen production activities.

Defatting of seabass skins using porcine pancreas lipase (PPL) at 25 or 50 units/g dry matter) for 1-3 hr at 30ºC was investigated. Treatment of seabass skin with PPL (25 unit/g dry matter) for 3 hr removed 83.81% lipids when compared to 57.27% using isopropanol. Hydrolysis of PPL-treated skin by papain (0.3 unit/g dry matter) (PPL-papain-3 process) at 40ºC for 90 min provided hydrolyzed collagen (HC) with higher yield, α-amino group content, ferric-reducing antioxidant power, and metal chelating activity than other treatments (p < 0.05). There was no difference in fishy odor between HC from PPL-papain-2 and PPL-papain-3 processes (p > 0.05). All the HC (50-250 µg/ml) samples stimulated L929 fibroblast cell proliferation and also induced collagen production in a dose-dependent manner. Also, all HC contained peptides with molecular weight of 406-11,860 Da. Gly and imino acids were dominant amino acids in HC prepared with PPL-papain-3 process. PRACTICAL APPLICATIONS: Seabass skin is a potential raw material for the production of hydrolyzed collagen (HC). However, seabass skin contains a large amount of lipids, including polyunsaturated fatty acids. These unsaturated lipids are oxidized during processing, particularly during hydrolysis at high temperature. This leads to the development of undesirable odor, especially fishy odor. Therefore, seabass skin defatting is an important step for improving the quality of the resulting HC. The use of lipase is an alternative method that can be used to remove lipids in skins without using solvents. HC from defatted skins will contain bioactive peptides and therefore, can be used as a food supplement or for skin nourishment.

Antihypertensive properties of tilapia (Oreochromis spp.) frame and skin enzymatic protein hydrolysates.

Proteins from tilapia frame and skin can potentially be precursors of antihypertensive peptides according to the result of BIOPEP analyses. The aim was to generate peptides with inhibitory effects against angiotensin-converting enzyme (ACE) and renin from tilapia frame and skin protein isolates (FPI and SPI). The most active hydrolysate was then tested for blood pressure-lowering ability in spontaneously hypertensive rats (SHRs). Tilapia frame and skin protein hydrolysates (FPHs and SPHs) were respectively produced from FPI and SPI hydrolysis using pepsin, papain, or bromelain. The ACE-inhibitory activities of tilapia protein hydrolysates with varying degree of hydrolysis (DH) were evaluated. In order to enhance the activity, the hydrolysate was fractionated into four fractions (<1 kDa, 1-3 kDa, 3-5 kDa, and 5-10 kDa) and the one with the greatest ability to inhibit in vitro ACE and renin activities was subjected to oral administration (100 mg/kg body weight) to SHRs. Systolic and diastolic blood pressure (SBP and DBP), mean arterial pressure (MAP), and heart rates (HR) were subsequently measured within 24 h. The pepsin-hydrolyzed FPH (FPHPe) with the highest DH (23%) possessed the strongest ACE-inhibitory activity (IC50: 0.57 mg/mL). Its <1 kDa ultrafiltration fraction (FPHPe1) suppressed both ACE (IC50: 0.41 mg/mL) and renin activities more effectively than larger peptides. In addition, FPHPe1 significantly (p < 0.05) reduced SBP (maximum -33 mmHg), DBP (maximum -24 mmHg), MAP (maximum -28 mmHg), and HR (maximum -58 beats) in SHRs. FPHPe1 showed both in vitro and in vivo antihypertensive effects, which suggest tilapia processing coproducts may be valuable protein raw materials for producing antihypertensive peptides.

Structural and Antihypertensive Properties of Enzymatic Hemp Seed Protein Hydrolysates.

The aim of this work was to produce antihypertensive protein hydrolysates through different forms of enzymatic hydrolysis (2% pepsin, 4% pepsin, 1% alcalase, 2% alcalase, 2% papain, and 2% pepsin + pancreatin) of hemp seed proteins (HSP). The hemp seed protein hydrolysates (HPHs) were tested for in vitro inhibitions of renin and angiotensin-converting enzyme (ACE), two of the enzymes that regulate human blood pressure. The HPHs were then administered orally (200 mg/kg body weight) to spontaneously hypertensive rats and systolic blood pressure (SBP)-lowering effects measured over a 24 h period. Size exclusion chromatography mainly showed a 300-9560 Da peptide size range for the HPHs, while amino acid composition data had the 2% pepsin HPH with the highest cysteine content. Fluorescence spectroscopy revealed higher fluorescence intensities for the peptides when compared to the unhydrolyzed hemp seed protein. Overall, the 1% alcalase HPH was the most effective (p < 0.05) SBP-reducing agent (-32.5 ± 0.7 mmHg after 4 h), while the pepsin HPHs produced longer-lasting effects (-23.0 ± 1.4 mmHg after 24 h). We conclude that an optimized combination of the fast-acting HPH (1% alcalase) with the longer-lasting HPHs (2% and 4% pepsin) could provide daily effective SBP reductions.

Thermoase-derived flaxseed protein hydrolysates and membrane ultrafiltration peptide fractions have systolic blood pressure-lowering effects in spontaneously hypertensive rats.

Thermoase-digested flaxseed protein hydrolysate (FPH) samples and ultrafiltration membrane-separated peptide fractions were initially evaluated for in vitro inhibition of angiotensin I-converting enzyme (ACE) and renin activities. The two most active FPH samples and their corresponding peptide fractions were subsequently tested for in vivo antihypertensive activity in spontaneously hypertensive rats (SHR). The FPH produced with 3% thermoase digestion showed the highest ACE- and renin-inhibitory activities. Whereas membrane ultrafiltration resulted in significant (p < 0.05) increases in ACE inhibition by the <1 and 1-3 kDa peptides, only a marginal improvement in renin-inhibitory activity was observed for virtually all the samples after membrane ultrafiltration. The FPH samples and membrane fractions were also effective in lowering systolic blood pressure (SBP) in SHR with the largest effect occurring after oral administration (200 mg/kg body weight) of the 1-3 kDa peptide fraction of the 2.5% FPH and the 3-5 kDa fraction of the 3% FPH. Such potent SBP-lowering capacity indicates the potential of flaxseed protein-derived bioactive peptides as ingredients for the formulation of antihypertensive functional foods and nutraceuticals.

Potential of a renin inhibitory peptide from the red seaweed Palmaria palmata as a functional food ingredient following confirmation and characterization of a hypotensive effect in spontaneously hypertensive rats.

This work examined the resistance of the renin inhibitory, tridecapeptide IRLIIVLMPILMA derived previously from a Palmaria palmata papain hydrolysate, during gastrointestinal (GI) transit. Following simulated GI digestion, breakdown products were identified using mass spectrometry analysis and the known renin and angiotensin I converting enzyme inhibitory dipeptide IR was identified. In vivo animal studies using spontaneously hypertensive rats (SHRs) were used to confirm the antihypertensive effects of both the tridecapeptide IRLIIVLMPILMA and the seaweed protein hydrolysate from which this peptide was isolated. After 24 h, the SHR group fed the P. palmata protein hydrolysate recorded a drop of 34 mm Hg in systolic blood pressure (SBP) from 187 (±0.25) to 153 (± 0.64) mm Hg SBP, while the group fed the tridecapeptide IRLIIVLMPLIMA presented a drop of 33 mm Hg in blood pressure from 187 (±0.95) to 154 (±0.94) mm Hg SBP compared to the SBP recorded at time zero. The results of this study indicate that the seaweed protein derived hydrolysate has potential for use as antihypertensive agents and that the tridecapeptide is cleaved and activated to the dipeptide IR when it travels through the GI tract. Both the hydrolysate and peptide reduced SHR blood pressure when administered orally over a 24 h period.