Evaluation of the osteoprotective potential of whey derived-antioxidative (YVEEL) and angiotensin-converting enzyme inhibitory (YLLF) bioactive peptides in ovariectomised rats

The Osteogenic Potential of Oligopeptides Derived from Black Bean: Insights into Structure-Activity Relationship

Food-derived oligopeptides have emerged as promising natural candidates for antiosteoporosis therapy due to their remarkable osteogenic activity. However, the structure-osteogenic activity relationship of these oligopeptides remains poorly defined. In this study, we investigated for the first time the correlation between the structural characteristics and osteogenic effects of black bean-derived oligopeptides. Among the 70 oligopeptides analyzed, 36, 29, and 30 oligopeptides were found to significantly enhance the proliferation (108.28%-136.78%), differentiation (115.02%-182.41%), and mineralization (110.91%-159.41%) of MC3T3-E1 cells, respectively. Notably, tetrapeptides demonstrated marked efficacy in inducing osteogenesis in vitro, with their mineralization activity significantly correlated with their isoelectric point (pI) values and net charge. Tetrapeptides containing lysine residues, such as KIGT and KGVG, were particularly effective in stimulating osteogenic mineralization. Furthermore, reliable three-dimensional quantitative structure-activity relationship (3D-QSAR) models were successfully established for all of the tetrapeptides. Importantly, the potent osteogenic tetrapeptides were characterized by bulky, electropositive, or hydrogen-bond acceptor groups at the R1 side chain of the N-terminal, along with electronegative or non-hydrogen bond acceptor groups at the R3 position and electronegative or hydrogen-bond acceptor groups at the R4 side chain of the C-terminal. Additionally, network pharmacology analysis highlighted the potential application of these osteogenic tetrapeptides in osteoporosis interventions. In conclusion, our findings demonstrated that the osteogenic activity of black bean-derived oligopeptides is attributed to their specific amino acid composition and structural features, providing novel insights for the efficient discovery and optimization of food-derived osteogenic oligopeptides.

Potential of Kefir-Derived Peptides, Probiotics, and Exopolysaccharides for Osteoporosis Management

PURPOSE OF REVIEW

Osteoporosis is a prevalent skeletal disorder in postmenopausal women and older adults. Kefir has gained attention for its potent antioxidative, anti-inflammatory, and immunomodulatory properties. This review consolidates findings on kefir-derived peptides' interventions in osteoporosis models and evaluates the therapeutic potential of kefir components in preventing osteoporosis, thereby enhancing its application in clinical nutrition strategies for osteoporosis management.

RECENT FINDINGS

Kefir-derived peptides exhibit osteoprotective potential in various animal models of osteoporosis, in which several antioxidative and ACE-inhibitory peptides have been shown to promote osteoblast differentiation and mineralization. In addition, emerging evidence supports the role of kefir-derived probiotics and exopolysaccharides (kefiran) in mitigating bone loss. Kefir holds significant promise in the management of osteoporosis due to its unique composition of bioactive components promoting bone health. While research is still in its early stages, evidence suggests kefir's potential as a natural approach to osteoporosis prevention and management.

Bioactive Milk Peptides as a Nutraceutical Opportunity and Challenges

The biotechnology field has witnessed rapid advancements, leading to the development of numerous proteins and peptides (PPs) for disease management. The production and isolation of bioactive milk peptides (BAPs) involve enzymatic hydrolysis and fermentation, followed by purification through various techniques such as ultrafiltration and chromatography. The nutraceutical potential of bioactive milk peptides has gained significant attention in nutritional research, as these peptides may regulate blood sugar levels, mitigate oxidative stress, improve cardiovascular health, gut health, bone health, and immune responses, and exhibit anticancer properties. However, to enhance BAP bioavailability, the encapsulation method can be used to offer protection against protease degradation and controlled release. This article provides insights into the composition, types, production, isolation, bioavailability, and health benefits of BAPs.

Bioactive milk peptides: an updated comprehensive overview and database

Partial digestion of milk proteins leads to the formation of numerous bioactive peptides. Previously, our research team thoroughly examined the decades of existing literature on milk bioactive peptides across species to construct the milk bioactive peptide database (MBPDB). Herein, we provide a comprehensive update to the data within the MBPDB and a review of the current state of research for each functional category from in vitro to animal and clinical studies, including angiotensin-converting enzyme (ACE)-inhibitory, antimicrobial, antioxidant, dipeptidyl peptidase (DPP)-IV inhibitory, opioid, anti-inflammatory, immunomodulatory, calcium absorption and bone health and anticancer activity. This information will help drive future research on the bioactivities of milk peptides.

Whey Protein Hydrolysate Ameliorated High-Fat-Diet Induced Bone Loss via Suppressing Oxidative Stress and Regulating GSK-3β/Nrf2 Signaling Pathway

Long-term hypercaloric intake such as a high-fat diet (HFD) could act as negative regulators on bone remodeling, thereby inducing bone loss and bone microarchitecture destruction. Currently, food-derived natural compounds represent a promising strategy to attenuate HFD-induced bone loss. We previously prepared a whey protein hydrolysate (WPH) with osteogenic capacity. In this study, we continuously isolated and identified an osteogenic and antioxidant octapeptide TPEVDDA from WPH, which significantly promoted the alkaline phosphatase activities on MC3T3-E1 cells and exerted DPPH radical scavenging capacity. We then established an HFD-fed obese mice model with significantly imbalanced redox status and reduced bone mass and further evaluated the effects of different doses of WPH on ameliorating the HFD-induced bone loss and oxidative damages. Results showed that the administration of 2% and 4% WPH for 12 weeks significantly restored perirenal fat mass, improved serum lipid levels, reduced oxidative stress, and promoted the activity of antioxidant enzymes; meanwhile, WPH significantly preserved bone mass and bone mechanical properties, attenuated the degradation of trabecular microstructure, and regulated serum bone metabolism biomarkers. The protein levels of Runx2, Nrf2, and HO-1, as well as the phosphorylation level of GSK-3β in tibias, were notably activated by WPH. Overall, we found that the potential mechanism of WPH on ameliorating the HFD-induced bone loss mainly through its antioxidant and osteogenic capacity by activating Runx2 and GSK-3β/Nrf2 signaling pathway, demonstrating the potential of WPH to be used as a nutritional strategy for obesity and osteoporosis.

Nutritional properties and osteogenic activity of simulated digestion components and peptides from Larimichthys crocea

Fish provides a range of health benefits due to its nutritional and bioactive components. However, the bioactive peptides derived from Larimichthys crocea proteins were not fully investigated, especially the beneficial effects related to bone growth in vitro. In this study, the water extract protein was subjected to the simulated in vitro digestion process, and the osteogenic effect of enzymatic hydrolysate at different digestion stages was evaluated by the proliferation of osteoblast. The protein hydrolyzates of group pepsin treatment for 1 h and pepsin treatment for 2 h showed higher osteogenic activity in vitro. Two peptides including IERGDVVVQDSPSD from pepsin treatment for 1 h and RGDLGIEIPTEK from pepsin treatment for 2 h were identified, which revealed eminent effects in terms of promoting osteoblast proliferation and enhancing ALP activity. Moreover, the available nutrients in the proteins were determined by the molecular weight distribution and free amino acid composition. Those peptides also showed stronger interaction with RGD than integrins. Therefore, the peptides from Larimichthys crocea can be used as an effective ingredient for promoting bone growth in the future.

Peptide Tat(48-60) YVEEL protects against necrotizing enterocolitis through inhibition of toll-like receptor 4-mediated signaling in a phosphatidylinositol 3-kinase/AKT dependent manner

Necrotizing enterocolitis (NEC) is a catastrophic disease largely occurring in preterm infants, and toll-like receptor 4 (TLR4) has been implicated in its pathogenesis. The current therapeutic strategies for NEC are, however, far from optimal. In the present study, a whey-derived antioxidative peptide conjugated with a cell-penetrating TAT [^{Tat (48-60)} YVEEL] was prepared to endow it with enhanced cell uptake capability and bioavailability. The protective effect of ^{Tat (48-60)} YVEEL on experimental NEC was evaluated both in vitro and in vivo. Inhibition of TLR4-mediated signaling by ^{Tat (48-60)} YVEEL was assessed in FHC and IEC-6 enterocytes, neonatal rat model of NEC, and the mechanism underlying this effect was determined. ^{Tat (48-60)} YVEEL significantly inhibited TLR4-mediated expression of pro-inflammatory cytokines, p65 nuclear translocation and restored the impaired enterocyte migration in cultured enterocytes. In addition, ^{Tat (48-60)} YVEEL administration strikingly increased the survival rate, and reduced the severity of NEC in rats through inhibition of TLR4-mediated signaling. These protective effects of ^{Tat (48-60)} YVEEL occurred in a PI3K/AKT dependent manner, as administration of PI3K activator Ys49 abrogated its protective effects. Combined with liposomes, ^{Tat (48-60)} YVEEL demonstrated longer retention in the intestines that better for potential clinical applications. These data demonstrate that ^{Tat (48-60)} YVEEL protects against NEC through inhibition of TLR4-mediated signaling in a PI3K/AKT dependent manner, and offer a potential therapeutic approach to this disease.

A Low-Phenylalanine-Containing Whey Protein Hydrolysate Stimulates Osteogenic Activity through the Activation of p38/Runx2 Signaling in Osteoblast Cells

A phenylalanine (Phe)-restricted diet is indispensable for individuals suffering from phenylketonuria (PKU). Our previous study reported a low-Phe-containing whey protein hydrolysate (LPH) prepared from a selected whey protein hydrolysate (TA2H). This study aimed to investigate the osteogenic activity of LPH and TA2H in MC3T3-E1 preosteoblast cells and explore the underlying mechanism. Results showed that the treatment of TA2H and LPH (at the final concentrations of 100–1000 μg/mL) had a stimulatory effect on the proliferation, differentiation, and mineralization of MC3T3-E1 cells. The LPH of 1000 μg/mL significantly increased cell proliferation (2.15- ± 0.11-fold) and alkaline phosphatase activity (1.22- ± 0.07-fold), promoted the protein and mRNA levels of runt-related transcription factor 2 (Runx2, 2.50- ± 0.14-fold and 2.97- ± 0.23-fold, respectively), enhanced the expression of differentiation biomarkers (type-I collagen, osteocalcin, and osteopontin), increased calcium deposition (1.56- ± 0.08-fold), and upregulated the ratio of osteoprotegerin/receptor activator of nuclear factor-κB ligand. The exploration of signaling pathways indicated that the activated p38-dependent Runx2 signaling contributed to the LPH-induced osteogenesis. These results provided evidence, for the first time, that a prepared low-Phe whey protein hydrolysate positively modulated the activity of osteoblasts through the p38/Runx2 pathway, thereby providing a new osteoinductive protein substitute to make functional PKU food.

Health-Promoting and Therapeutic Attributes of Milk-Derived Bioactive Peptides

Milk-derived bioactive peptides (BAPs) possess several potential attributes in terms of therapeutic capacity and their nutritional value. BAPs from milk proteins can be liberated by bacterial fermentation, in vitro enzymatic hydrolysis, food processing, and gastrointestinal digestion. Previous evidence suggested that milk protein-derived BAPs have numerous health-beneficial characteristics, including anti-cancerous activity, anti-microbial activity, anti-oxidative, anti-hypertensive, lipid-lowering, anti-diabetic, and anti-osteogenic. In this literature overview, we briefly discussed the production of milk protein-derived BAPs and their mechanisms of action. Milk protein-derived BAPs are gaining much interest worldwide due to their immense potential as health-promoting agents. These BAPs are now used to formulate products sold in the market, which reflects their safety as natural compounds. However, enhanced commercialization of milk protein-derived BAPs depends on knowledge of their particular functions/attributes and safety confirmation using human intervention trials. We have summarized the therapeutic potentials of these BAPs based on data from in vivo and in vitro studies.

Bioactive peptides of whey: obtaining, activity, mechanism of action, and further applications

Bioactive peptides derived from diverse food proteins have been part of diverse investigations. Whey is a rich source of proteins and components related to biological activity. It is known that proteins have effects that promote health benefits. Peptides derived from whey proteins are currently widely studied. These bioactive peptides are amino acid sequences that are encrypted within the first structure of proteins, which required hydrolysis for their release. The hydrolysis could be through in vitro or in vivo enzymatic digestion and using microorganisms in fermented systems. The biological activities associated with bio-peptides include immunomodulatory properties, antibacterial, antihypertensive, antioxidant and opioid, etc. These functions are related to general conditions of health or reduced risk of certain chronic illnesses. To determine the suitability of these peptides/ingredients for applications in food technology, clinical studies are required to evaluate their bioavailability, health claims, and safety of them. This review aimed to describe the biological importance of whey proteins according to the incidence in human health, their role as bioactive peptides source, describing methods, and obtaining technics. In addition, the paper exposes biochemical mechanisms during the activity exerted by biopeptides of whey, and their application trends.

Evaluation of the anti-osteoporotic effect of a low-phenylalanine whey protein hydrolysate in an ovariectomized mice model

A phenylalanine (Phe)-restricted diet is indispensable to control the blood Phe for individuals with phenylketonuria (PKU), who are also confronted with progressive bone impairment. Thus, the development of a low-Phe protein substitute that could positively regulate bone metabolism is desired for their bone health. Our previous study reported the preparation of a low-Phe containing whey hydrolysate (LPH) from a selected whey protein hydrolysate (TAH). However, the effect of LPH on the bone status is unknown. In this study, we used an ovariectomized (OVX) mice model to evaluate the anti-osteoporotic potential of oral administration of whey protein concentrate (WPC, protein control), TAH, and LPH on bone physiology and bone metabolism. The results showed that after 12 weeks of treatment, the decreased bone mineral density, the deteriorated trabecular microarchitecture, and the reduced ultimate load due to ovariectomy were significantly attenuated by two whey protein hydrolysates (TAH and LPH); meanwhile, the body weight, uterine weight, bone composition, and the femoral elastic load of OVX mice had not been significantly affected by whey samples. In addition, LPH and TAH dual-regulated bone remodeling in OVX mice through triggering osteogenesis (promoted the expression of runt-related protein 2 (Runx2) and osteoformation markers) and inhibiting osteoresorption as well as inflammation. The modulated mitogen-activated protein kinase signaling and the inhibited nuclear factor κB signaling by LPH and TAH might relate to the dual-regulatory activities on bone. Overall, in the OVX mice model, LPH exerted higher osteoprotective potential than TAH of the same dose by activating the bone formation markers and inhibiting the inflammatory status. The current study demonstrated for the first time the potential use of a low-Phe whey hydrolysate, a protein substitute for PKU individuals, in the prevention of osteoporosis.

Dietary interventions for better management of osteoporosis: An overview

Osteoporosis is a public health concern and a cause of bone loss, increased risk of skeletal fracture, and a heavy economic burden. It is common in postmenopausal women and the elderly and is impacted by dietary factors, lifestyle and some secondary factors. Although many drugs are available for the treatment of osteoporosis, these therapies are accompanied by subsequent side effects. Hence, dietary interventions are highly important to prevent osteoporosis. This review was aimed to provide a comprehensive understanding of the roles of dietary nutrients derived from natural foods and of common dietary patterns in the regulation of osteoporosis. Nutrients from daily diets, such as unsaturated fatty acids, proteins, minerals, peptides, phytoestrogens, and prebiotics, can regulate bone metabolism and reverse bone loss. Meanwhile, these nutrients generally existed in food groups and certain dietary patterns also play critical roles in skeletal health. Appropriate dietary interventions (nutrients and dietary patterns) could be primary and effective strategies to prevent and treat osteoporosis across the lifespan for the consumers and food enterprises.

Milk proteins and their derived peptides on bone health: Biological functions, mechanisms, and prospects

Bone is a dynamic organ under constant metabolism (or remodeling), where a delicate balance between bone resorption and bone formation is maintained. Disruption of this coordinated bone remodeling results in bone diseases, such as osteoporosis, the most common bone disorder characterized by decreased bone mineral density and microarchitectural deterioration. Epidemiological and clinical evidence support that consumption of dairy products is beneficial for bone health; this benefit is often attributed to the presence of calcium, the physiological contributions of milk proteins on bone metabolism, however, are underestimated. Emerging evidence highlighted that not only milk proteins (including individual milk proteins) but also their derived peptides positively regulate bone remodeling and attenuate bone loss, via the regulation of cellular markers and signaling of osteoblasts and osteoclasts. This article aims to review current knowledge about the roles of milk proteins, with an emphasis on individual milk proteins, bioactive peptides derived from milk proteins, and effect of milk processing in particular fermentation, on bone metabolism, to highlight the potential uses of milk proteins in the prevention and treatment of osteoporosis, and, to discuss the knowledge gap and to recommend future research directions.

Kefir Peptides Prevent Estrogen Deficiency-Induced Bone Loss and Modulate the Structure of the Gut Microbiota in Ovariectomized Mice

Osteoporosis is a major skeletal disease associated with estrogen deficiency in postmenopausal women. Kefir-fermented peptides (KPs) are bioactive peptides with health-promoting benefits that are produced from the degradation of dairy milk proteins by the probiotic microflora in kefir grains. This study aimed to evaluate the effects of KPs on osteoporosis prevention and the modulation of the composition of the gut microbiota in ovariectomized (OVX) mice. OVX mice receiving an 8-week oral gavage of 100 mg of KPs and 100 mg of KPs + 10 mg Ca exhibited lower trabecular separation (Tb. Sp), and higher bone mineral density (BMD), trabecular number (Tb. N) and bone volume (BV/TV), than OVX groups receiving Ca alone and untreated mice, and these effects were also reflected in bones with better mechanical properties of strength and fracture toughness. The gut microbiota of the cecal contents was examined by 16S rDNA amplicon sequencing. α-Diversity analysis indicated that the gut microbiota of OVX mice was enriched more than that of sham mice, but the diversity was not changed significantly. Treatment with KPs caused increased microbiota richness and diversity in OVX mice compared with those in sham mice. The microbiota composition changed markedly in OVX mice compared with that in sham mice. Following the oral administration of KPs for 8 weeks, the abundances of Alloprevotella, Anaerostipes, Parasutterella, Romboutsia, Ruminococcus_1 and Streptococcus genera were restored to levels close to those in the sham group. However, the correlation of these bacterial populations with bone metabolism needs further investigation. Taken together, KPs prevent menopausal osteoporosis and mildly modulate the structure of the gut microbiota in OVX mice.

Technical integrative approaches to cheese whey valorization towards sustainable environment

Whey, a byproduct of cheese production, is often treated as an industrial dairy waste. A large volume of this product is disposed of annually due to inadequate bioconversion approaches. With its high pollutant load, disposal without pretreatment has raised a lot of environmental concerns alerting the need to seek optimal methods for adequately extracting and utilizing its organic content. In recent years, several techniques for whey valorization have emerged which may serve as interventionary measures against its environmental effects after disposal. In this review, we discuss five major approaches, by which whey can be converted into eco-friendly products, to significantly cut whey wastage. The approaches to whey valorization are therefore examined under the following perspectives: whey as a raw material for the production of bioethanol and prebiotic oligosaccharides via β-galactosidase and microbe catalyzed reactions, for the production of refined lactose as an excipient for pharmaceutical purposes, and the clinical significance of whey hydrolysates and their antifungal activity in food processing.

Effect of probiotic cultures on the angiotensin converting enzyme inhibitory activity of whey-based fermented beverages

Fermented whey-based beverages were elaborated using commercial probiotics cultures (CHR HANSEN): BCT-1®, ABT-4®, ABC where A: Lactobacillus acidophilus, B: Bifidobacterium animalis subsp. lactis, C: Lactobacillus paracasei subsp. paracasei and T: Streptococccus thermophiles. Three treatments were prepared with these probiotics cultures and a treatment without cultures added as a control. All beverage were maintained at 4 °C and evaluated during their shelf life at 0, 7, 14 and 21 days. The variables analyzed were peptide concentration, proteolysis, ACE-inhibitory activity and, peptide and aromatic amino acid profiles. Principal component analysis (PCA) was conducted to assess the relationship between these variables. All whey-based fermented beverages added with probiotics presented ACE inhibitory activity (22-100%). However, whey-based beverage without probiotics added had the highest ACE inhibitory activity (100%), and it was maintained during its shelf life. Fermented beverage with ABT-4® culture had an ACE inhibitory activity from 80 to 100% during its shelf life. Thus can be attributed to the release of peptides during processing. Meanwhile, significative correlations were observed between variables varying this depending on the treatment, both, in magnitude and in direct or inverse direction (0.684-0.986). The ACE inhibitory activity was correlated to proteolysis and peptide and aromatic amino acids profiles. And, the IC₅₀ was observed in the range of 0.01-0.055 mg/mL.

Phosvitin Derived Phospho-Peptides Show Better Osteogenic Potential than Intact Phosvitin in MC3T3-E1 Osteoblastic Cells

Phosphorylated proteins from food sources have been investigated as regulators of bone formation with potential benefits in treating osteoporosis. Egg, a cheap and nutritious food, is also the source of various proteins and bioactive peptides with applications in human health. Egg yolk is rich in phosvitin, the most phosphorylated protein in nature. Phosvitin has been shown to improve bone health in experimental animals, although the molecular mechanisms and its specific effects on bone-forming osteoblastic cells are incompletely understood. Previous work in our group has identified pancreatin-generated phosvitin phospho-peptides (PPP) as a potential source for bioactive peptides. Given this background, we examined the roles of both phosvitin and PPP in the function of osteoblastic cells. Our results demonstrated their potential to improve bone health by promoting osteoblast differentiation and proliferation, suppressing osteoclast recruitment and the deposition of extracellular matrix, although PPP appeared to demonstrate superior osteogenic functions compared to phosvitin alone.

Repertoire of Structure-Activity-Based Novel Modified Peptides Elicits Enhanced Osteogenic Potential

Biologically active peptides in milk proteins can be used as effective dietary supplements for management of bone-associated issues including osteoporosis. A bioactive peptide derived from milk, viz. VLPVPQK/PepC, has been validated previously from our lab for its osteoanabolic action. In this study, we report 14 novel variants of PepC, designed in silico, based on the structure-activity relationship, aiming to enhance its osteogenic effect that holds tremendous therapeutic utility for bone-related injuries. PepC was computationally modified at seven positions of its original sequence, resulting in 14 modified synthetic peptides for functional predictions and in vitro assessment by comparative analysis of modified peptides by PepC for improved ability in osteogenic functional assays (proliferation potential, antioxidant ability, gene and protein expression, cytotoxic effect, bone mineralization) using calvarial osteoblasts. For most peptides with the highest Peptide7 response relative to PepC (p < 0.05), enhanced osteoanabolic response was observed. Further observations on Peptide7 have therefore been investigated in depth (qPCR, immunoblotting, LCMS/MS, and PCA analysis). Peptide7 displayed a rise in the expression of osteogenes (Osterix, Opg, Bmp2, and Runx2, p < 0.05) and protein (Runx2 and Bmp2, p < 0.05). Besides, LCMS/MS findings suggest Peptide7 escapes intestinal peptidases degradation. Experimental evidence supports an improved osteological reaction to newly modified peptides and hence exploitation in the preparation of functional foods or supplements.