Soybean β-conglycinin bromelain hydrolysate stimulates cholecystokinin secretion by enteroendocrine STC-1 cells to suppress the appetite of rats under meal-feeding conditions

Exploring the Therapeutic Potential of Bromelain: Applications, Benefits, and Mechanisms

Bromelain is a mixture of proteolytic enzymes primarily extracted from the fruit and stem of the pineapple plant (Ananas comosus). It has a long history of traditional medicinal use in various cultures, particularly in Central and South America, where pineapple is native. This systematic review will delve into the history, structure, chemical properties, and medical indications of bromelain. Bromelain was first isolated and described in the late 19th century by researchers in Europe, who identified its proteolytic properties. Since then, bromelain has gained recognition in both traditional and modern medicine for its potential therapeutic effects.

Peptides with biological and technofunctional properties produced by bromelain hydrolysis of proteins from different sources: A review

Bromelains are cysteine peptidases with endopeptidase action (a subfamily of papains), obtained from different parts of vegetable belonging to the Bromeliaceae family. They have some intrinsic medical activity, but this review is focused on their application (individually or mixed with other proteases) to produce bioactive peptides. When compared to other proteases, perhaps due to the fact that they are commercialized as an extract containing several proteases, the hydrolysates produced by this enzyme tends to have higher bioactivities than other common proteases. The peptides and the intensity of their final properties depend on the substrate protein and reaction conditions, being the degree of hydrolysis a determining parameter (but not always positive or negative). The produced peptides may have diverse activities such as antioxidant, antitumoral, antihypertensive or antimicrobial ones, among others or they may be utilized to improve the organoleptic properties of foods and feeds. Evolution of the use of this enzyme in this application is proposed to be based on a more intense direct application of Bromeliaceae extract, without the cost associated to enzyme purification, and the use of immobilized biocatalysts of the enzyme by simplifying the enzyme recovery and reuse, and also making the sequential hydrolysis using diverse proteases possible.

In vitro gastrointestinal digestion of highland barley protein: identification and characterization of novel bioactive peptides involved in gut cholecystokinin secretion

BACKGROUND

The satiety hormone cholecystokinin (CCK) plays an important role in food intake inhibition. Its secretion is regulated by dietary components. The search for bioactive compounds that induce CCK secretion is currently an active area of research. The objective of this study was to evaluate the ability of highland barley protein digest (HBPD) to stimulate CCK secretion in vitro and in vivo and identify the responsible peptide sequences.

RESULTS

HBPD was prepared by in vitro gastrointestinal digestion model. Peptides of <1000 Da in HBPD accounted for 82%. HBPD was rich in essential amino acids Leu, Phe and Val, but lack in sulfur amino acids Met and Cys. HBPD treatment at a concentration of 5 mg mL-1 significantly stimulated CCK secretion from enteroendocrine STC-1 cells (P < 0.05). Moreover, oral gavage with HBPD in mice significantly increased plasma CCK level. Chromatographic separation was performed to isolate peptide fractions involved in CCK secretion and peptide sequence was determined by ultra-performance liquid chromatography-tandem mass spectrometry. Two novel CCK-releasing peptides, PDLP and YRIVPL, were pointed out for their outstanding CCK secretagogue activity.

CONCLUSION

This study demonstrated for the first time that HBPD had an ability to stimulate CCK secretion in vitro and in vivo and determined the bioactive peptides exerting CCK secretagogue activity in HBPD. © 2023 Society of Chemical Industry.

A comprehensive review on the glucoregulatory properties of food-derived bioactive peptides

Diabetes mellitus, a group of metabolic disorders characterized by persistent hyperglycemia, affects millions of people worldwide and is on the rise. Dietary proteins, from a wide range of food sources, are rich in bioactive peptides with antidiabetic properties. Notable examples include AGFAGDDAPR, a black tea-derived peptide, VRIRLLQRFNKRS, a β-conglycinin-derived peptide, and milk-derived peptide VPP, which have shown antidiabetic effects in diabetic rodent models through variety of pathways including improving beta-cells function, suppression of alpha-cells proliferation, inhibiting food intake, increasing portal cholecystokinin concentration, enhancing insulin signaling and glucose uptake, and ameliorating adipose tissue inflammation. Despite the immense research on glucoregulatory properties of bioactive peptides, incorporation of these bioactive peptides in functional foods or nutraceuticals is widely limited due to the existence of several challenges in the field of peptide research and commercialization. Ongoing research in this field, however, is fundamental to pave the road for this purpose.

Explorative Screening of Bioactivities Generated by Plant-Based Proteins after In Vitro Static Gastrointestinal Digestion

The gastrointestinal digestion of food proteins can generate peptides with a wide range of biological activities. In this study, we screened various potential bioactivities generated by plant-based proteins. Whey protein as an animal protein reference, five grades of pea protein, two grades of wheat protein, and potato, fava bean, and oat proteins were submitted to in vitro SGID. They were then tested in vitro for several bioactivities including measures on: (1) energy homeostasis through their ability to modulate intestinal hormone secretion, to inhibit DPP-IV activity, and to interact with opioid receptors; (2) anti-hypertensive properties through their ability to inhibit ACE activity; (3) anti-inflammatory properties in Caco-2 cells; (4) antioxidant properties through their ability to inhibit production of reactive oxygen species (ROS). Protein intestinal digestions were able to stimulate intestinal hormone secretion by enteroendocrine cells, to inhibit DPP-IV and ACE activities, to bind opioid receptors, and surprisingly, to decrease production of ROS. Neither pro- nor anti-inflammatory effects have been highlighted and some proteins lost their pro-inflammatory potential after digestion. The best candidates were pea, potato, and fava bean proteins.

Soybean protein-derived peptide nutriment increases negative nitrogen balance in burn injury-induced inflammatory stress response in aged rats through the modulation of white blood cells and immune factors

BACKGROUND

As an important nutrient, soybean protein-derived peptides (SPP) affect the immune function of animals.

OBJECTIVE

This study describes the effects of nutrient supplementation with SPP on the negative nitrogen balance in the burn injury-induced inflammatory response of aged rats.

DESIGN

Soybean protein isolate (SPI) was hydrolyzed to obtain SPP. A negative nitrogen-balance aged rat model and a major full-thickness 30% total body surface area (TBSA) burn-injury rat model were utilized.

RESULTS

The results show that SPP can increase the speed and ability of inflammatory stress by adjusting white blood cell counts. Soybean protein-derived peptides significantly increased serum immunoglobulin M (IgM), immunoglobulin G (IgG) and immunoglobulin A (IgA) levels; significantly decreased serum interleukin-1 beta (IL-β), tumor necrosis factor-alpha (TNF-α) and regulated upon activation normal T-cell expressed and secreted (RANTES) levels. These results give conclusive evidence that SPP has a significantly positive effect in improving the immune function on the condition of negative nitrogen balance with burn-injury, and reducing excessive inflammation.

CONCLUSIONS

Nutrient supplementation of SPP can, therefore, be used as an adjuvant treatment to inhibit the development and severity of inflammatory reactions caused by burns, providing a novel therapy for the treatment and positive prognosis of burn patients.

Induction of CCK and GLP-1 release in enteroendocrine cells by egg white peptides generated during gastrointestinal digestion

The effect of dietary protein on the induction of intestinal hormones is recognised. However, little is known about the nature of the digestion products involved in this intestinal signalling. Our aim was to characterise egg white protein digestion products and study their ability to induce CCK and GLP-1 release in enteroendocrine STC-1 cells. Intestinal digests triggered GLP-1 release at a higher rate than gastric digests. Peptides, but not free amino acids, showed a potent GLP-1 secretagogue effect, while proteins only had a modest effect. CCK was released in response to peptides and free amino acids but not proteins. Two hydrophobic negatively charged peptides triggered CCK release, while the highest GLP-1 response was found with a hydrophobic positively charged peptide, pointing to the involvement of different receptors or active sites. Identifying peptide sequences and receptors involved in hormonal secretion could open up new ways to control food intake and glucose metabolism.

Trypsin inhibitors: promising candidate satietogenic proteins as complementary treatment for obesity and metabolic disorders?

The increase in non-communicable chronic diseases has aroused interest in the research of adjuvants to the classic forms of treatments. Obesity and metabolic syndrome are the main targets of confrontation because they relate directly to other chronic diseases. In this context, trypsin inhibitors, molecules with wide heterologous application, appear as possibilities in the treatment of overweight and obesity due to the action on satiety related mechanisms, mainly in the modulation of satiety hormones, such as cholecystokinin. In addition, trypsin inhibitors have the ability to also act on some biochemical parameters related to these diseases, thus, emerging as potential candidates and promising molecules in the treatment of the obesity and metabolic syndrome. Thus, the present article proposes to approach, through a systematic literature review, the advantages, disadvantages and viabilities for the use of trypsin inhibitors directed to the treatment of overweight and obesity.

Whole flour and protein hydrolysate from common beans reduce the inflammation in BALB/c mice fed with high fat high cholesterol diet

Common bean (Phaseolus vulgaris L.) is a source of bioactive peptides, but little is known about its effects on hypercholesterolemia, oxidative stress, and the inflammatory process. Therefore, the aim of this study was to evaluate the effect of whole flour and bean protein hydrolysate of common bean variety Carioca on inflammation and oxidative stress in BALB/c mice. Four experimental groups were included in the study: standard diet (SD), high fat high cholesterol diet (HFC), high fat high cholesterol diet and whole bean flour (HFC-F); and high fat high cholesterol diet and bean protein hydrolysate (HFC-PH). Animals fed with bean protein hydrolysate showed lower weight gain and food intake. Animals fed with whole bean flour showed lower alanine aminotransferase and low-density lipoprotein cholesterol levels than animals fed with bean protein hydrolysate. SOD mRNA was lower in HFC, HFC-F and HFC-PH groups whereas SOD concentration was higher in HFC-F and HFC-PH groups. HSP72 mRNA expression was lower in the HFC-F group in relation to HFC-PH. IL-10 and PPARα mRNA expression was lower in HFC-F and HFC-PH groups in comparison with SD. The whole bean flour and bean protein hydrolysate reduced inflammation and the risk factors for cardiovascular diseases in BALB/c mice.

Functional significance of bioactive peptides derived from soybean

Biologically active peptides play an important role in metabolic regulation and modulation. Several studies have shown that during gastrointestinal digestion, food processing and microbial proteolysis of various animals and plant proteins, small peptides can be released which possess biofunctional properties. These peptides are to prove potential health-enhancing nutraceutical for food and pharmaceutical applications. The beneficial health effects of bioactive peptides may be several like antihypertensive, antioxidative, antiobesity, immunomodulatory, antidiabetic, hypocholesterolemic and anticancer. Soybeans, one of the most abundant plant sources of dietary protein, contain 36-56% of protein. Recent studies showed that soy milk, an aqueous extract of soybean, and its fermented product have great biological properties and are a good source of bioactive peptides. This review focuses on bioactive peptides derived from soybean; we illustrate their production and biofunctional attributes.

Increased consumption of salmon during pregnancy partly prevents the decline of some plasma essential amino acid concentrations in pregnant women

BACKGROUND & AIMS

Oily fish is a good source of n-3 long-chain polyunsaturated fatty acids. Since these fatty acids may change efficiency of amino acid (AA) absorption, we determined whether increased salmon consumption influences plasma AA concentrations in pregnant women and their newborns.

METHODS

Pregnant women were randomly allocated to remain on their habitual diet (n = 61; control group) or to consume two 150 g farmed salmon portions per week from 20 weeks pregnancy until birth (n = 62; salmon group). Plasma AA concentrations were determined in women at w20, w34 and w38 of pregnancy and in umbilical cord at delivery.

RESULTS

Concentrations of arginine, valine, leucine and lysine were affected by both time of pregnancy and salmon intake (p < 0.05), with a smaller gestation-associated decrease in the salmon group. Total essential AA concentrations were similar in both groups at w20, but at w38 were higher in salmon group (p < 0.05). Cord plasma AA concentrations, higher than in maternal plasma (p < 0.01), were similar in the two groups (p > 0.05).

CONCLUSIONS

Two portions/wk of oily fish increased plasma essential AA concentrations during pregnancy and could contribute to a maternal health benefit. Two portions/wk of salmon did not affect plasma AA concentrations in the newborn.

CLINICAL TRIALS IDENTIFIER

NCT00801502.

Suppressive effect on food intake of a potato extract (Potein®) involving cholecystokinin release in rats

We have recently reported that oral gavage of a potato extract (Potein®) suppressed the food intake in rats. The satiating effect of the potato extract was compared in the present study to other protein sources, and the involvement of endogenous cholecystokinin (CCK) secretion was examined. Food consumption was measured in 18-h fasted rats after oral gavage of the potato extract or other protein sources. The CCK-releasing activity of the potato extract was then examined in anesthetized rats with a portal cannula. Oral gavage of the potato extract reduced the food intake in the rats, the effect being greater than with casein and a soybean β-conglycinin hydrolysate. The suppressive effect on appetite of the potato extract was attenuated by treating with a CCK-receptor antagonist (devazepide). The portal CCK concentration was increased after a duodenal administration of the potato extract to anesthetized rats. These results indicate that the potato extract suppressed the food intake in rats through CCK secretion.

Screening of soy and milk protein hydrolysates for their ability to activate the CCK1 receptor

The cholecystokinin receptor-type 1 (CCK1R) is a G-protein coupled receptor localized in the animal gastrointestinal tract. Receptor activation by the natural peptide ligand CCK leads to a feeling of satiety. In this study, hydrolysates from soy and milk proteins were evaluated for their potential to activate the CCK1R, assuming that bioactive peptides with a satiogenic effect can be used as an effective therapeutic strategy for obesity. Different protein hydrolysates were screened with a cell-based bioassay, which relies on the generation of a fluorescent signal upon receptor activation. Fluorescence was monitored using a fluorescence plate reader and confocal microscopy. Results from the fluorescence plate reader were biased by background autofluorescence of the protein hydrolysate matrices, which makes the fluorescence plate reader inappropriate for the evaluation of complex formulations. Measurements with the confocal microscope resulted in reliable and specific results. The latter approach showed that the gastrointestinal digested 7S fraction of soy protein demonstrates CCK1R activity.