Milk-derived bioactive peptides inhibit human endothelial-monocyte interactions via PPAR-γ dependent regulation of NF-κB

Mulberroside A mitigates intervertebral disc degeneration by inhibiting MAPK and modulating Ppar-γ/NF-κB pathways

BACKGROUND

Intervertebral disc degeneration (IVDD) is a common spine disease with inflammation as its main pathogenesis. Mulberroside A (MA), isolated from herbal medicine, possesses anti-inflammatory characteristics in many diseases. Whereas, there is little exploration of the therapeutic potential of MA on IVDD. This study aimed at the therapeutic potential of MA on IVDD in vivo and in vitro and the mechanism involved.

METHODS

In vitro, western blotting, RT-qPCR, and immunofluorescence analysis were implemented to explore the bioactivity of MA on interleukin-1 beta (IL-1β)-induced inflammation nucleus pulposus cells (NPCs) isolated from Sprague-Dawley male rats. In vivo, X-ray and MRI were applied to measure the morphological changes, and histological staining and immunohistochemistry were employed to investigate the histological changes of intervertebral disc sections on puncture-induced IVDD rat models.

RESULTS

In vitro, MA up-regulated the expression level of anabolic-related proteins (Aggrecan and Collagen II) and decreased catabolic-related proteins (Mmp2, Mmp3, Mmp9, and Mmp13) in IL-1β-induced NPCs. Furthermore, MA inhibits the production of pro-inflammatory factors (Inos, Cox-2, and Il-6) stimulated by IL-1β. Mechanistically, MA inhibited the signal transduction of mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B (NF-κB) pathways in IL-1β-induced NPCs. Moreover, MA might bind to Ppar-γ and then suppress the NF-kB pathway. In vivo experiment illustrated that MA mitigates the IVDD progression in puncture-induced IVDD model. X-ray and MRI images showed MA restore the disc height and T2-weighted signal intensity after puncturing. H&E and Safranin O/Fast Green also showed MA also alleviated morphological changes caused by acupuncture. In addition, MA reversed the expression level of Mmp13, Aggrecan, Collagen II, and Ppar-γ induced in IVDD models.

CONCLUSIONS

MA inhibited degenerative phenotypes in NPCs and alleviated IVDD progression via inhibiting the MAPK and NF-κB pathways; besides, MA suppressed the NF-κB pathway was attributed to activating Ppar-γ, those supported that MA or Ppar-γ might be a potential drug or target for IVDD.

Milk Fat Globule Membrane-Containing Protein Powder Promotes Fitness in Caenorhabditis elegans

Milk-derived peptides and milk fat globule membrane (MFGM) have gained interest as health-promoting food ingredients. However, the mechanisms by which these nutraceuticals modulate the function of biological systems often remain unclear. We utilized Caenorhabditis elegans to elucidate how MFGM-containing protein powder (MProPow), previously used in a clinical trial, affect the physiology of this model organism. Our results demonstrate that MProPow does not affect lifespan but promotes the fitness of the animals. Surprisingly, gene expression analysis revealed that MProPow decreases the expression of genes functioning on innate immunity, which also translates into reduced survival on pathogenic bacteria. One of the innate immunity-associated genes showing reduced expression upon MProPow supplementation is cpr-3, the homolog of human cathepsin B. Interestingly, knockdown of cpr-3 enhances fitness, but not in MProPow-treated animals, suggesting that MProPow contributes to fitness by downregulating the expression of this gene. In summary, this research highlights the value of C. elegans in testing the biological activity of food supplements and nutraceuticals. Furthermore, this study should encourage investigations into whether milk-derived peptides and MFGM mediate their beneficial effects through the modulation of cathepsin B expression in humans.

PPARs in atherosclerosis: The spatial and temporal features from mechanism to druggable targets

BACKGROUND

Atherosclerosis is a chronic and complex disease caused by lipid disorder, inflammation, and other factors. It is closely related to cardiovascular diseases, the chief cause of death globally. Peroxisome proliferator-activated receptors (PPARs) are valuable anti-atherosclerosis targets that showcase multiple roles at different pathological stages of atherosclerosis and for cell types at different tissue sites.

AIM OF REVIEW

Considering the spatial and temporal characteristics of the pathological evolution of atherosclerosis, the roles and pharmacological and clinical studies of PPARs were summarized systematically and updated under different pathological stages and in different vascular cells of atherosclerosis. Moreover, selective PPAR modulators and PPAR-pan agonists can exert their synergistic effects meanwhile reducing the side effects, thereby providing novel insight into future drug development for precise spatial-temporal therapeutic strategy of anti-atherosclerosis targeting PPARs.

KEY SCIENTIFIC

Concepts of Review: Based on the spatial and temporal characteristics of atherosclerosis, we have proposed the importance of stage- and cell type-dependent precision therapy. Initially, PPARs improve endothelial cells' dysfunction by inhibiting inflammation and oxidative stress and then regulate macrophages' lipid metabolism and polarization to improve fatty streak. Finally, PPARs reduce fibrous cap formation by suppressing the proliferation and migration of vascular smooth muscle cells (VSMCs). Therefore, research on the cell type-specific mechanisms of PPARs can provide the foundation for space-time drug treatment. Moreover, pharmacological studies have demonstrated that several drugs or compounds can exert their effects by the activation of PPARs. Selective PPAR modulators (that specifically activate gene subsets of PPARs) can exert tissue and cell-specific effects. Furthermore, the dual- or pan-PPAR agonist could perform a better role in balancing efficacy and side effects. Therefore, research on cells/tissue-specific activation of PPARs and PPAR-pan agonists can provide the basis for precision therapy and drug development of PPARs.

Whey Protein, Vitamins C and E Decrease Interleukin-10 in Chronic Hemodialysis Patients: A Pioneer, Randomized, Double-Blind Pilot Trial

OBJECTIVE

To evaluate the effects of supplementation with whey protein combined with vitamins C and E on inflammatory markers in hemodialysis (HD) patients.

DESIGN AND METHODS

This was a pioneer, randomized and double-blinded study. Patients were randomized into two groups and stratified by HD frequency. The supplementation group received 20 g of whey protein, 250 mg of vitamin C, and 600 IU of vitamin E; the placebo group, 20 g of rice flour, and microcrystalline cellulose capsules. The interventions were given after HD, 3 times a week, for 8 weeks. The inflammatory markers were assessed: interleukin (IL) IL-12p70, IL-10, IL-6, IL-8, and tumor necrosis factor alpha. For statistical analysis, the χ2 test, Student's t-test, Mann-Whitney test, analysis of variance for repeated two-way measurements, paired t test, and Wilcoxon test were performed. P < .05 was considered statistically significant.

RESULTS

Twenty-three patients completed the study. No significant differences were found in inflammatory markers when comparing the groups postintervention. In the intragroup was a decrease in IL-10 in the supplementation group after 8 weeks (P = .0382). IL-6 tended to decrease by 810.95% in the supplementation group and increased by 732.8% (nonsignificant) in the placebo group.

CONCLUSION

Whey protein combined with vitamins C and E significantly reduced IL-10 in the supplementation group and could be beneficial to reduce IL-6 in HD patients. Future studies are suggested with a larger sample size, different supplementation doses, and longer interventions.

Cell-Penetrating Milk-Derived Peptides with a Non-Inflammatory Profile

Milk-derived peptides are known to confer anti-inflammatory effects. We hypothesised that milk-derived cell-penetrating peptides might modulate inflammation in useful ways. Using computational techniques, we identified and synthesised peptides from the milk protein Alpha-S1-casein that were predicted to be cell-penetrating using a machine learning predictor. We modified the interpretation of the prediction results to consider the effects of histidine. Peptides were then selected for testing to determine their cell penetrability and anti-inflammatory effects using HeLa cells and J774.2 mouse macrophage cell lines. The selected peptides all showed cell penetrating behaviour, as judged using confocal microscopy of fluorescently labelled peptides. None of the peptides had an effect on either the NF-κB transcription factor or TNFα and IL-1β secretion. Thus, the identified milk-derived sequences have the ability to be internalised into the cell without affecting cell homeostatic mechanisms such as NF-κB activation. These peptides are worthy of further investigation for other potential bioactivities or as a naturally derived carrier to promote the cellular internalisation of other active peptides.

PPARγ in Atherosclerotic Endothelial Dysfunction: Regulatory Compounds and PTMs

The formation of atherosclerotic plaques is one of the main sources of cardiovascular disease. In addition to known risk factors such as dyslipidemia, diabetes, obesity, and hypertension, endothelial dysfunction has been shown to play a key role in the formation and progression of atherosclerosis. Peroxisome proliferator-activated receptor-gamma (PPARγ), a transcription factor belonging to the steroid superfamily, is expressed in the aorta and plays a critical role in protecting endothelial function. It thereby serves as a target for treating both diabetes and atherosclerosis. Although many studies have examined endothelial cell disorders in atherosclerosis, the role of PPARγ in endothelial dysfunction is still not well understood. In this review, we summarize the possible mechanisms of action behind PPARγ regulatory compounds and post-translational modifications (PTMs) of PPARγ in the control of endothelial function. We also explore the potential use of endothelial PPARγ-targeted agents in the prevention and treatment of atherosclerosis.

The role of peroxisome proliferator-activated receptor γ in lipid metabolism and inflammation in atherosclerosis

Cardiovascular disease events are the result of functional and structural abnormalities in the arteries and heart. Atherosclerosis is the main cause and pathological basis of cardiovascular diseases. Atherosclerosis is a multifactorial disease associated with dyslipidemia, inflammation, and oxidative stress, among which dyslipidemia and chronic inflammation occur in all processes. Under the influence of lipoproteins, the arterial intima causes inflammation, necrosis, fibrosis, and calcification, leading to plaque formation in specific parts of the artery, which further develops into plaque rupture and secondary thrombosis. Foam cell formation from macrophages is an early event in the development of atherosclerosis. Lipid uptake causes a vascular inflammatory response, and persistent inflammatory infiltration in the lesion area further promotes the development of the disease. Inhibition of macrophage differentiation into foam cell and reduction of the level of proinflammatory factors in macrophages can effectively alleviate the occurrence and development of atherosclerosis. Peroxisome proliferator-activated receptor γ (PPARγ) is a ligand-activated nuclear receptor that plays an important antiatherosclerotic role by regulating triglyceride metabolism, lipid uptake, cholesterol efflux, macrophage polarity, and inhibiting inflammatory signaling pathways. In addition, PPARγ shifts its binding to ligands and co-activators or co-repressors of transcription of target genes through posttranslational modification, thereby affecting the regulation of its downstream target genes. Many ligand agonists have also been developed targeting PPARγ. In this review, we summarized the role of PPARγ in lipid metabolism and inflammation in development of atherosclerosis, the posttranslational regulatory mechanism of PPARγ, and further discusses the value of PPARγ as an antiatherosclerosis target.

Qihuang Zhuyu Formula Attenuates Atherosclerosis via Targeting PPARγ to Regulate Cholesterol Efflux and Endothelial Cell Inflammation

At present, due to the limitations of drug therapy targets for atherosclerosis, some patients fail to achieve satisfactory efficacy. Cholesterol efflux dysfunction and endothelial cell inflammation are considered to be important factors in the development of atherosclerosis. Peroxisome proliferator-activated receptor gamma (PPARγ), a promising therapeutic target for atherosclerosis, plays a dual role in regulating cholesterol efflux and endothelial cell inflammation. However, the use of PPARγ agonist in clinical practice is greatly limited as it could lead to water and sodium retention and hence result in congestive heart failure. Qihuang Zhuyu Formula (QHZYF) is a hospital preparation of Jiangsu Province Hospital of Chinese Medicine which has definite effect in the treatment of atherosclerosis, but its pharmacological mechanism has not been clear. In this study, we successfully predicted that QHZYF might regulate cholesterol efflux and endothelial inflammation via targeting PPARγ-mediated PPARγ/LXRα/ABCA1-ABCG1 and PPARγ/NF-κB p65 pathways by using UPLC-Q-TOF/MS, network pharmacology, bioinformatics analysis, and molecular docking technology. Subsequently, we confirmed in vivo that QHZYF could attenuate atherosclerosis in ApoE-/- mice and regulate the expression levels of related molecules in PPARγ/LXRα/ABCA1-ABCG1 and PPARγ/NF-κB p65 pathways of ApoE-/- mice and C57BL/6 wild-type mice. Finally, in in vitro experiments, we found that QHZYF could reduce lipid content and increase cholesterol efflux rate of RAW 264.7 cells, inhibit the inflammatory response of HUVECs, and regulate the expression levels of related molecules in the two pathways. In addition, the above effects of QHZYF were significantly weakened after PPARγ knockdown in the two kinds of cells. In conclusion, our study revealed that QHZYF attenuates atherosclerosis via targeting PPARγ-mediated PPARγ/LXRα/ABCA1-ABCG1 and PPARγ/NF-κB p65 pathways to regulate cholesterol efflux and endothelial cell inflammation. More importantly, our study offers a promising complementary and alternative therapy which is expected to make up for the limitation of current drug treatment methods and provide a valuable reference for new drugs development in the future.

The Enteric Glia and Its Modulation by the Endocannabinoid System, a New Target for Cannabinoid-Based Nutraceuticals?

The enteric nervous system (ENS) is a part of the autonomic nervous system that intrinsically innervates the gastrointestinal (GI) tract. Whereas enteric neurons have been deeply studied, the enteric glial cells (EGCs) have received less attention. However, these are immune-competent cells that contribute to the maintenance of the GI tract homeostasis through supporting epithelial integrity, providing neuroprotection, and influencing the GI motor function and sensation. The endogenous cannabinoid system (ECS) includes endogenous classical cannabinoids (anandamide, 2-arachidonoylglycerol), cannabinoid-like ligands (oleoylethanolamide (OEA) and palmitoylethanolamide (PEA)), enzymes involved in their metabolism (FAAH, MAGL, COX-2) and classical (CB1 and CB2) and non-classical (TRPV1, GPR55, PPAR) receptors. The ECS participates in many processes crucial for the proper functioning of the GI tract, in which the EGCs are involved. Thus, the modulation of the EGCs through the ECS might be beneficial to treat some dysfunctions of the GI tract. This review explores the role of EGCs and ECS on the GI tract functions and dysfunctions, and the current knowledge about how EGCs may be modulated by the ECS components, as possible new targets for cannabinoids and cannabinoid-like molecules, particularly those with potential nutraceutical use.

Peptides, Exopolysaccharides, and Short-Chain Fatty Acids from Fermented Milk and Perspectives on Inflammatory Bowel Diseases

Crohn's disease and ulcerative colitis are characterized by chronic inflammatory processes and an imbalanced immune response along the gastrointestinal (GI) tract. Pharmacological treatments have been widely used, although their long-term application has adverse side effects. On the other hand, milks fermented with specific lactic acid bacteria (LAB) have been shown to be useful as alternative or complementary aids. Many metabolites such as peptides, exopolysaccharides, and short-chain fatty acids are produced during milk fermentation. These components have been shown to change the pH of the gastrointestinal lumen, aid intestine mucosal recovery, modulate the microbiota, and reduce the inflammatory response (innate and adaptive immune system), both in vitro and in vivo. Therefore, the objective of the present review is to describe how these bioactive compounds from fermented milk by specific LAB can decrease the deleterious symptoms of inflammatory bowel disease.

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.

A raising dawn of pentoxifylline in management of inflammatory disorders in Covid-19

The existing pandemic viral infection caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) leads to coronavirus disease 2019 (Covid-19). SARS-CoV-2 exploits angiotensin-converting enzyme 2 (ACE2) as an entry-point into affected cells and down-regulation of ACE2 by this virus triggers the release of pro-inflammatory cytokines and up-regulation of angiotensin II. These changes may lead to hypercytokinemia and the development of cytokine storm with the development of acute lung injury and acute respiratory distress syndrome. Different repurposed had been in use in the management of Covid-19, one of these agents is pentoxifylline (PTX) which has anti-inflammatory and antioxidant properties. Therefore, the objective of the present mini-review is to highlight the potential role of PTX in Covid-19 regarding its anti-inflammatory and antioxidant effects. PTX is a non-selective phosphodiesterase inhibitor that increases intracellular cyclic adenosine monophosphate which stimulates protein kinase A and inhibits leukotriene and tumor necrosis factor. PTX has antiviral, anti-inflammatory and immunomodulatory effects, thus it may attenuate SARS-CoV-2-induced hyperinflammation and related complications. As well, PTX can reduce hyper-viscosity and coagulopathy in Covid-19 through increasing red blood cell deformability and inhibition of platelet aggregations. In conclusion, PTX is a non-selective phosphodiesterase drug, that has anti-inflammatory and antioxidant effects thereby can reduce SARS-CoV-2 infection-hyperinflammation and oxidative stress. Besides, PTX improves red blood cells (RBCs) deformability and reduces blood viscosity so can mitigate Covid-19-induced hyper-viscosity and RBCs hyper-aggregation which is linked with the development of coagulopathy. Taken together, PTX seems to be an effective agent against Covid-19 severity.

Camel whey protein hydrolysates induced G2/M cellcycle arrest in human colorectal carcinoma

Camel milk has been gaining immmense importance due to high nutritious value and medicinal properties. Peptides from milk proteins is gaining popularity in various therapeutics including human cancer. The study was aimed to investigate the anti-cancerous and anti-inflammatory properties of camel whey protein hydrolysates (CWPHs). CWPHs were generated at three temperatures (30 ℃, 37 ℃, and 45 ℃), two hydrolysis timepoints (120 and 360 min) and with three different enzyme concentrations (0.5, 1 and 2 %). CWPHs demonstrated an increase in anti-inflammatory effect between 732.50 (P-6.1) and 3779.16 (P-2.1) µg Dicolfenac Sodium Equivalent (DSE)/mg protein. CWPHs (P-4.3 & 5.2) inhibited growth of human colon carcinoma cells (HCT116) with an IC50 value of 231 and 221 μg/ml, respectively. P-4.3 induced G2/M cell cycle arrest and modulated the expression of Cdk1, p-Cdk1, Cyclin B1, p-histone H3, p21 and p53. Docking of two peptides (AHLEQVLLR and ALPNIDPPTVER) from CWPHs (P-4.3) identified Polo like kinase 1 as a potential target, which strongly supports our in vitro data and provides an encouraging insight into developing a novel peptide-based anticancer formulation. These results suggest that the active component, CWPHs (P-4.3), can be further studied and modeled to form a small molecule anti-cancerous therapy.

Milk‑derived hexapeptide PGPIPN prevents and attenuates acute alcoholic liver injury in mice by reducing endoplasmic reticulum stress

Bioactive peptides are an emerging area of biomedical research in the study of numerous human diseases, including acute alcoholic liver injury (AALI). To study the role and mechanism of the milk-derived hexapeptide Pro-Gly-Pro-Ile-Pro-Asn (PGPIPN) in preventing and reducing AALI, the present study established a mouse model of AALI. PGPIPN was used as a therapeutic drug, and glutathione (GSH) was used as a positive control. The body and liver weights of mice were measured, and the liver indexes were calculated to observe mice health. The pathological morphology of liver tissues stained with hematoxylin and eosin were examined to analyze hepatic injury, and hepatocyte apoptosis was measured with a TUNEL assay. The concentrations or activities of alanine aminotransferase (ALT), aspartate aminotransferase, tumor necrosis factor-α, interleukin (IL)-1β, IL-6, triglyceride, total cholesterol, malondialdehyde, superoxide dismutase and GSH peroxidase (GSH-PX) were detected in serum and/or liver homogenates. The 78 kDa glucose-regulated protein (GRP78), protein kinase R-like (PKR) endoplasmic reticulum kinase (PERK), phosphorylated (p)-PERK, eukaryotic initiation factor 2α (eIF-2α), p-eIF-2α, inositol-requiring enzyme 1α (IRE-1α), spliced X-box binding protein 1 (XBP-1s), C/EBP homologous protein (CHOP), caspase-3 and cleaved caspase-3 proteins associated with endoplasmic reticulum stress in hepatocytes were assessed by western blotting, and RNA levels of XBP-1s, CHOP and caspase-3 genes were assessed by reverse transcription-quantitative PCR. The results suggested that PGPIPN attenuated alcoholic hepatocyte damage in animal models and reduced hepatocyte oxidative stress in a dose-dependent manner. Moreover, PGPIPN reduced endoplasmic reticulum stress by regulating the expression levels of p-PERK, p-eIF-2α, XBP-1s, CHOP, caspase-3 and cleaved caspase-3. Collectively, the present results indicated that PGPIPN, as a potential therapeutic drug for AALI, exerted a protective effect on the liver and could reduce liver damage.

Association of Dairy Product Consumption with Metabolic and Inflammatory Biomarkers in Adolescents: A Cross-Sectional Analysis from the LabMed Study

This study aimed to investigate the association between dairy product consumption and metabolic and inflammatory biomarkers in Portuguese adolescents, and whether the association differed by weight status. A cross-sectional study was conducted during the school year 2011/2012 with 412 Portuguese adolescents (52.4% girls) in 7th and 10th grade (aged 12 to 18 years old). The World Health Organization cutoffs were used to categorize adolescents as non-overweight (NW) or overweight (OW). Blood samples were collected to analyze C-reactive protein (CRP), interleukin-6 (IL-6), leptin, and adiponectin. Dairy product intake was evaluated using a food frequency questionnaire. Participants were divided by tertiles according to the amount of dairy product consumed. The associations between dairy product consumption with metabolic and inflammatory biomarkers were evaluated using generalized linear regression models with logarithmic link and gamma distribution and adjusted for potential confounders. The majority of adolescents were NW (67.2%). NW adolescents had lower IL-6, CRP, and leptin concentration than their counterparts (p < 0.05, for all comparisons). Higher levels of total dairy product and milk intake were inversely associated with IL-6 (P for trend <0.05, for all) in NW adolescents, but not in OW adolescents. NW adolescents in the second tertile of yogurt consumption had lower level of IL-6 compared to those in the first tertile (p = 0.004). Our results suggest an inverse association between total dairy product and milk intake and serum concentrations of IL-6 only among NW adolescents.

Characterization of unique metabolites in γ-aminobutyric acid-rich cheese by metabolome analysis using liquid chromatography-mass spectrometry

Fermented dairy products comprise many functional components. Our previous study using fermented milk showed that the γ-aminobutyric acid (GABA)-producing Lactococcus lactis 01-7 strain can produce unique metabolites such as antihypertensive peptides, whereas this study was designed to find the unique metabolites in GABA-rich cheese using the 01-7 strain. Metabolites between cheese ripening with the non-GABA-producing L. lactis 01-1 strain (control) and GABA-rich cheese ripening with a mixture of 01-1 and 01-7 strains were compared. GABA and ornithine were detected in GABA-rich cheese using an amino acid analyzer and citrate was detected in the control cheese using HPLC. Metabolome analysis using LC-MS showed that peptides with unknown function and those with antihypertensive activity were higher in the GABA-rich cheese than in the control cheese. Further analysis of the amount of the YLGY derivatives showed that the amount of YL in the GABA-rich cheese was lower than that in the control. PRACTICAL APPLICATIONS: Clarification of metabolites in cheese contributes to the improvement of cheese ripening, thereby providing consumers with unique cheese with good nutritional and functional characteristics. The use of the 01-7 strain as a cheese starter might provide a functional cheese with antihypertensive-, antioxidative-, and anxiolytic-like activities.

Postprandial Effects of a Proprietary Milk Protein Hydrolysate Containing Bioactive Peptides in Prediabetic Subjects

Milk proteins have been hypothesized to protect against type 2 diabetes (T2DM) by beneficially modulating glycemic response, predominantly in the postprandial status. This potential is, amongst others, attributed to the high content of whey proteins, which are commonly a product of cheese production. However, native whey has received substantial attention due to its higher leucine content, and its postprandial glycemic effect has not been assessed thus far in prediabetes. In the present study, the impact of a milk protein hydrolysate of native whey origin with alpha-glucosidase inhibiting properties was determined in prediabetics in a randomized, cross-over trial. Subjects received a single dose of placebo or low- or high-dosed milk protein hydrolysate prior to a challenge meal high in carbohydrates. Concentration-time curves of glucose and insulin were assessed. Incremental areas under the curve (iAUC) of glucose as the primary outcome were significantly reduced by low-dosed milk peptides compared to placebo (p = 0.0472), and a minor insulinotropic effect was seen. A longer intervention period with the low-dosed product did not strengthen glucose response but significantly reduced HbA1c values (p = 0.0244). In conclusion, the current milk protein hydrolysate of native whey origin has the potential to modulate postprandial hyperglycemia and hence may contribute in reducing the future risk of developing T2DM.

Preparation, Bioavailability, and Mechanism of Emerging Activities of Ile-Pro-Pro and Val-Pro-Pro

Ile-Pro-Pro and Val-Pro-Pro are two most well-known food-derived bioactive peptides, initially identified as inhibitors of angiotensin I-converting enzyme (ACE) from a sample of sour milk. These two peptides were identified in fermented and enzymatic hydrolyzed cow and non-cow (that is, goat, sheep, buffalo, yak, camel, mare, and donkey) milk, as well as sourdough prepared from wheat, rye, and malt. Similar to other bioactive peptides, bioavailability of these peptides is low (about 0.1%), reaching picomolar concentration in human plasma; they showed blood pressure lowering activity in animals and in human, via improved endothelial function, activation of ACE2, and anti-inflammatory property. Emerging bioactivities of these two peptides toward against metabolic syndrome and bone-protection received limited attention, but may open up new applications of these peptides as functional food ingredients. Further studies are warranted to determine the best source as well as to identify novel enzymes (particularly from traditional fermented milk products) to improve the efficiency of production, to characterize possible peptide receptors using a combination of omics technology with molecular methods to understand if these two peptides act as signal-like molecules, to improve their bioavailability, and to explore new applications based on emerging bioactivities.

Minor compounds from virgin olive oil attenuate LPS-induced inflammation via visfatin-related gene modulation on primary human monocytes

We have analyzed the effects of minor compounds found in the unsaponifiable fraction (UF) and in the phenolic fraction (PF) of virgin olive oil (VOO) on LPS-induced inflammatory response via visfatin modulation in human monocytes. For this purpose, monocytes were incubated with UF and PF at different concentrations and the pro-inflammatory stimulus LPS for 24 hr; squalene (SQ) and hydroxytyrosol (HTyr), the main components in UF and PF, respectively, were also used. The relative expression of both pro-inflammatory and anti-inflammatory genes, as well as other genes related to the NAD+-biosynthetic pathway was evaluated by RT-qPCR; and the secretion of some of these markers was assessed by ELISA procedures. We found that UF, SQ, PF, and HTyr prevented from LPS-induced dysfunctional gene expression and secretion via visfatin-related gene modulation in human monocytes. These findings unveil a potential beneficial role for minor compounds of VOO in the prevention of inflammatory-disorders. PRACTICAL APPLICATION: In this project, potential health benefits of VOO micronutrients (unsaponifiable and phenolic compounds) were confirmed through anti-inflammatory assays. Our results reveal new interesting researching goals concerning nutrition by considering the role of bioactive VOO compounds in the prevention and progress of diseases related to inflammation.

1,8-Cineole Ameliorates LPS-Induced Vascular Endothelium Dysfunction in Mice via PPAR-γ Dependent Regulation of NF-κB

1,8-Cineole (eucalyptol), a monoterpene, has been widely reported for the anti-inflammatory effects. Our previous data confirmed that 1,8-cineole ameliorated the inflammatory phenotype of human umbilical vein endothelial cells (HUVECs) by mediating NF-κB expression in vitro. At present, we investigated the protection effects of 1,8-cineole on vascular endothelium in lipopolysaccharide (LPS)-induced acute inflammatory injury mice and the potential mechanisms involved in the protection in HUVECs. Results from enzyme linked immunosorbent assays revealed that 1,8-cineole suppressed the secretion of interleukin (IL)-6 and IL-8 and increased the expression of IL-10 in the serum of LPS-induced mice. 1,8-Cineole reduced the inflammatory infiltration and the expression of vascular cell adhesion molecular 1 (VCAM-1) in the sections of thoracic aorta in LPS-induced acute inflammatory mice. Western blotting indicated that 1,8-cineole significantly decreased the phosphorylation of NF-κB p65 and increased the expression of PPAR-γ in the thoracic aorta tissue. 1,8-Cineole increased the expression of PPAR-γ in LPS-induced HUVECs. 1,8-Cineole and rosiglitazone reduced the protein and mRNA levels of VCAM-1, E-selectin, IL-6, and IL-8 in LPS-induced HUVECs, which could be reversed by the action of GW9662 (inhibitor of PPAR-γ). 1,8-Cineole and rosiglitazone blocked the LPS-induced IκBα degradation and NF-κB p65 nucleus translocation, which could be reversed by the pretreatment of GW9662 or silence of PPAR-γ gene. In conclusion, 1,8-cineole attenuated LPS-induced vascular endothelial cells injury via PPAR-γ dependent modulation of NF-κB.

Different Temperature Treatments of Millet Grains Affect the Biological Activity of Protein Hydrolyzates and Peptide Fractions

The objective of this study was to analyze millet protein hydrolyzates and peptide fractions with molecular mass under 3.0 kDa obtained from grains treated with different temperature values as inhibitors of angiotensin-converting enzyme (ACE), α-amylase, and α-glucosidase activity. The protein fractions were hydrolyzed in vitro in gastrointestinal conditions and the highest degree of hydrolysis was noted for globulin 7S obtained from control grains (98.33%). All samples were characterized by a high peptide bioaccessibility index, which was 23.89 for peptides obtained from globulin 11S after treatment with 100 °C. The highest peptide bioavailability index was noted for peptides obtained from globulin 11S after the treatment with 65 °C (2.12). The highest potential metabolic syndrome inhibitory effect was determined for peptide fractions obtained from the prolamin control (IC50 for ACE and α-amylase was 0.42 and 0.11 mg/mL, respectively) and after the 100 °C treatment (IC50 for ACE and α-glucosidase was 0.33 and 0.12 mg/mL, respectively) and from globulin 11S after the 65 °C treatment (IC50 0.38 and 0.05 for ACE and α-glucosidase, respectively). The effect of these samples on endothelial cell HECa10 was determined. The sequences of potential inhibitory peptides were identified as GEHGGAGMGGGQFQPV, EQGFLPGPEESGR, RLARAGLAQ, YGNPVGGVGH, and GNPVGGVGHGTTGT.

Design and synthesis of biotinylated cardiac glycosides for probing Nur77 protein inducting pathway

The orphan nuclear receptor Nur77 (also known as TR3 or nerve growth factor-induced clone B NGFI-B) functions as a nuclear transcription factor in the regulation of target gene expression and plays a critical role in the regulation of differentiation, proliferation, apoptosis, and survival of many different cell types. Recent studies demonstrate that Nur77 also involves many important physiological and pathological processes including cancer, inflammation and immunity, cardiovascular diseases, and bone diseases. Our previous studies showed that cardiac glycosides could induce the expression of Nur77 protein and its translocation from the nucleus to the cytoplasm and subsequent targeting to mitochondria, leading to apoptosis of cancer cells. In order to probe the Nur77 protein inducting pathway, we designed and synthesized a series of novel biotinylated cardiac glycosides from β-Antiarin and α-Antiarin, two typical cardiac glycosides from the plant of Antiaris toxicaria. The induction of Nur77 protein expression of these biotinylated cardiac glycosides and their inhibitory effects on NIH-H460 cancer cell proliferation were evaluated. Results displayed that some biotinylated cardiac glycosides could significantly induce the expression of Nur77 protein comparable with their parent compounds β-Antiarin and α-Antiarin. Also, their streptavidin binding activities were evaluated. Among them, biotinylated cardiac glycosides P4b and P5a exhibited significant effect on the induction of Nur77 expression along with high binding capacity with streptavidin, suggesting that they can be used as probes for probing Nur77 protein inducting pathway.

The roles of PPARs in human diseases

Peroxisome proliferator-activated receptors (PPARs), as members of nuclear hormone receptor superfamily, can be activated by binding natural or synthetic ligands. The use of related ligands has revealed many potential roles for PPARs in the pathogenesis of some human metabolic disorders and inflammatory-related disease. Based on the previous studies, this review primarily concluded the current progress of knowledge regarding the specific biological activity of PPARs in cancers, atherosclerosis, and type 2 diabetes mellitus, providing a foundation for the potential therapeutic use of PPAR ligands in human diseases.

Identification of New Anti-inflammatory Peptides from Zein Hydrolysate after Simulated Gastrointestinal Digestion and Transport in Caco-2 Cells

Chronic inflammation is an underlying contributor to various chronic diseases. The objectives of this study were to investigate the anti-inflammatory activity of zein hydrolysate after simulated gastrointestinal digestion and Caco-2 cell absorption and to identify novel anti-inflammatory peptides after transport across Caco-2 cells. Three zein hydrolysates were prepared and further digested using gastrointestinal proteases; their transports were studied in Caco-2 cells. Anti-inflammatory activity was studied in endothelial EA.hy926 cells. Three zein hydrolysates and their digests significantly decreased the expression of tumor necrosis factor-α (TNF-α) induced pro-inflammatory vascular cell adhesion molecule-1 (VCAM-1) by 37.3-66.0%. Eleven novel peptides with 5-9 amino acid residues were sequenced; three peptides showed strong anti-inflammatory activity by inhibiting the VCAM-1 by 54-38.9% and intercellular cell adhesion molecule-1 (ICAM-1) by 36.5-28.6% at 0.2 mM. A new approach to identify novel anti-inflammatory peptides that could survive gastrointestinal digestion and absorption was developed.

Renal cell carcinoma alters endothelial receptor expression responsible for leukocyte adhesion

Renal cell carcinoma (RCC) escapes immune recognition. To elaborate the escape strategy the influence of RCC cells on endothelial receptor expression and endothelial leukocyte adhesion was evaluated. Human umbilical vein endothelial cells (HUVEC) were co-cultured with the RCC cell line, Caki-1, with and without tumor necrosis factor (TNF)-alpha. Intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), endothelial (E)-selectin, standard and variants (V) of CD44 were then analysed in HUVEC, using flow cytometry and Western blot analysis. To determine which components are responsible for HUVEC-Caki-1 interaction causing receptor alteration, Caki-1 membrane fragments versus cell culture supernatant were applied to HUVECS. Adhesion of peripheral blood lymphocytes (PBL) and polymorphonuclear neutrophils (PMN) to endothelium was evaluated by co-culture adhesion assays. Relevance of endothelial receptor expression for adhesion to endothelium was determined by receptor blockage. Co-culture of RCC and HUVECs resulted in a significant increase in endothelial ICAM-1, VCAM-1, E-selectin, CD44 V3 and V7 expression. Previous stimulation of HUVECs with TNF-alpha and co-cultivation with Caki-1 resulted in further elevation of endothelial CD44 V3 and V7 expression, whereas ICAM-1, VCAM-1 and E-selectin expression were significantly diminished. Since Caki-1 membrane fragments also caused these alterations, but cell culture supernatant did not, cell-cell contact may be responsible for this process. Blocking ICAM-1, VCAM-1, E-selectin or CD44 with respective antibodies led to a significant decrease in PBL and PMN adhesion to endothelium. Thus, exposing HUVEC to Caki-1 results in significant alteration of endothelial receptor expression and subsequent endothelial attachment of PBL and PMN.

Alternative foaming agents for topical treatment of ulcerative colitis

Approximately 907,000 Americans currently suffer from ulcerative colitis, a condition characterized by inflammation of the large intestine or rectum. Treatment of this disease often includes anti-inflammatory medication or immunosuppressants. Here foams are an attractive delivery platform, offering relatively high bioavailability, low systemic exposure, and improved patient comfort. However, the surfactants that generate these foams may adversely affect the diseased mucosa. Therefore, this project evaluated two alternative surfactants for use in topical drug delivery platforms: sodium caseinate and l-α-phosphatidylcholine. Both were compared to the biocompatible surfactant Pluronic^® F-127 using stability and density tests, and biocompatibility tests performed on mini-guts. Sodium caseinate foams were less stable but denser than Pluronic^® foams; however, they exhibited an unexpectedly low shelf-life. l-α-phosphatidylcholine was an unsuccessful primary foaming agent owing to poor foamability at low concentrations. Mini-gut growth rates were not significantly altered by surfactants, while morphology and an MTT assay identified Pluronic^® as the most biocompatible surfactant at higher concentrations. These results clarify the possible challenges that the tested surfactants may present in topical delivery platforms and show the relevance of permeability to tissue-surfactant interaction tests. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1448-1456, 2018.

Protective effects of pioglitazone on vascular endothelial cell dysfunction induced by high glucose via inhibition of IKKα/β–NFκB signaling mediated by PPARγ in vitro

PIO, a synthetic ligand for PPARγ, is used clinically to treat T2DM. However, little is known about its protective effects on endothelium and the underlying mechanisms. In this study, we sought to investigate the protective effects of PIO on endothelium and its probable mechanisms: 95% confluent wild type (WT) HUVECs and PPARγLow-HUVECs that we first injured with HG (33 mmol·L–1) were first pretreated with 10 μmol·L–1 of GW9662 for 30 min, and then treated the cells with different concentrations of PIO (5, 10, or 20 μmol·L–1) for 24 h. Finally, we measured the levels of NO, ET1, TNFα, and IL6 in the cell culture supernatant. These cells were then used to determine cell viability, caspase3 activity, the levels of IKKα/β mRNA, IKKα/β, and NFκB-p65. Severe dysfunction and activation of IKKα/β–NFκB signaling occurred after we exposed HUVECs to HG. Conversely, treatment with PIO significantly attenuated the dysfunction and the activation of IKKα/β–NFκB signaling induced by HG in a dose-dependent manner. Moreover, the protective effects of PIO were completely abrogated by GW9662 or down-regulation of PPARγ. Taken together, the results indicate that PIO protects HUVECs against the HG-induced dysfunction through the inhibition of IKKα/β–NFκB signaling mediated by PPARγ.

Modulation of the biomarkers of inflammation and oxidative stress by ruminant trans fatty acids and dairy proteins in vascular endothelial cells (HUVEC)

This study aimed to determine whether dairy macronutrients alter markers of inflammation and oxidative stress in endothelial cells. Human endothelial cells (HUVEC) were treated with ruminant trans fatty acids (rTFA), either trans-vaccenic acid (tVA) or trans-palmitoleic acid (tPA), whey protein hydrolysate, leucine or combinations of rTFA and dairy protein compounds. Industrial TFA elaidic acid (EA) was also investigated and compared with rTFA. Inflammatory prostaglandins (PG) and F₂-isoprostanes (F₂-isoP) isomers, markers of oxidative stress, were assessed in cell supernatants by LC-MS/MS. Both tVA and tPA, as well as whey protein hydrolysate, decreased TNFα-induced PG excretion. Combinations of rTFA and dairy protein compounds decreased inflammation to a similar extent than rTFA alone. EA increased class VI F₂-isoP isomers, whereas tVA mostly raised class III isomers. In summary, rTFA decreased inflammatory markers and increased oxidative stress markers in endothelial cells. Combinations of rTFA with whey proteins or leucine showed no additive effect.

Therapeutic hexapeptide (PGPIPN) prevents and cures alcoholic fatty liver disease by affecting the expressions of genes related with lipid metabolism and oxidative stress

PGPIPN is a therapeutic hexapeptide derived from bovine β-casein. Here we investigated the role and mechanism of this peptide on alcoholic fatty liver disease (AFLD). We took human hepatic cell line LO2 and hepatocellular carcinoma cell line HepG2 to establish the models of steatosis hepatocyte induced by alcohol, taken PGPIPN as pharmacological intervention. And we also established the model of AFLD mice, taken PGPIPN as therapeutic drug and glutathione (GSH) as positive control. We assayed the biochemical materials related to liver injury, lipid metabolism and oxidation, and observed morphology change and fat accumulation of hepatocyte. The gene expressions and/or activities related to liver injury, lipid metabolism and oxidation, such as ACC, PPAR-γ, CHOP and Caspase-3, were assessed by real time PCR and western blot. Our results showed PGPIPN alleviated hepatic steatosis in both model cells and AFLD model mice. PGPIPN can effectively reduce the lipid accumulation and oxidative stress of hepatocyte in a dose-dependent manner. PGPIPN alleviated alcohol-induced cell steatosis and injuries by regulating the gene expressions and/or activities of ACC, PPAR-γ, CHOP and Caspase-3. Our results demonstrated PGPIPN had the protective and therapeutic effect on AFLD, which may serve as a potential therapeutic agent for AFLD.

Peroxisome proliferator-activated receptor γ agonist suppresses mast cell maturation and induces apoptosis

Peroxisome proliferator-activated receptor gamma (PPAR γ), is important in the immunoregulation of the allergic response. Mast cells are the most important inflammatory cells in immediate hypersensitivity and allergic diseases. However, there is limited information regarding the effects of PPAR γ on mast cell maturation. In the present study, mouse bone marrow-derived mast cells (BMMCs) were cultured in interleukin (IL)-3 and stem cell factor (SCF), in the presence or absence of the PPAR γ agonist, pioglitazone (PIO). The expression levels of the tyrosine kinase receptor CD117 and the high affinity IgE receptor FcεRI α, were assessed by flow cytometry, cell viability was assessed by Alamar-Blue assay and histamine release was determined by measuring the activity of β-hexosaminidase. IL-3 and SCF are required for the development of mast cells in vitro. PIO dose-dependently inhibited the expression of CD117 and FcεRI α, and the maturation of BMMCs. Treatment with PIO additionally inhibited the formation of granules and reduced the expression of β-hexosaminidase. In addition, reverse transcription-polymerase chain reaction analysis revealed that BMMCs treated with PIO expressed a lower level of mast cell protease (MCP)-6 mRNA and PIO treatment enhanced the level of PPAR γ mRNA. Furthermore, PIO induced mast cell progenitor apoptosis. PPAR γ agonists may maintain mast cell homeostasis by inhibiting maturation of their precursors. The inhibitory effects of PPAR γ agonists include suppression of the activation of mast cells and a decrease in mast cell function in the inflammatory response. Therefore, PPAR γ agonists may serve as effective anti-inflammatory reagents in the treatment of allergic reactions.

Milk-derived bioactive peptides and their health promoting effects: a potential role in atherosclerosis

Bioactive peptides derived from milk proteins are food components that, in addition to their nutritional value, retain many biological properties and have therapeutic effects in several health disorders, including cardiovascular disease. Amongst these, atherosclerosis is the underlying cause of heart attack and strokes. It is a progressive dyslipidaemic and inflammatory disease where accumulation of oxidized lipids and inflammatory cells leads to the formation of an atherosclerotic plaque in the vessel wall. Milk-derived bioactive peptides can be released during gastrointestinal digestion, food processing or by enzymatic and bacterial fermentation and are considered to promote diverse beneficial effects such as lipid lowering, antihypertensive, immnomodulating, anti-inflammatory and antithrombotic effects. In this review, an overview of the diverse biological effects of these compounds is given, particularly focusing on their beneficial properties on cardiovascular disease and proposing novel mechanisms of action responsible for their bioactivity. Attempts to prevent cardiovascular diseases target modifications of several risk factors such as high blood pressure, obesity, high blood concentrations of lipids or insulin resistance. Milk-derived bioactive peptides are a source of health-enhancing components and the potential health benefit of these compounds has a growing commercial potential. Consequently, they have been incorporated as ingredients in functional foods, as dietary supplements and as pharmaceuticals to promote health and reduce risk of chronic diseases.

Rice protein hydrolysates (RPHs) inhibit the LPS-stimulated inflammatory response and phagocytosis in RAW264.7 macrophages by regulating the NF-κB signaling pathway

Different RPH components inhibit LPS-induced NO and TNF-α production. RPHs-C-7-3 inhibits the expression of pro-inflammatory expression. RPHs-C-7-3 suppresses the LPS-stimulated phagocytic ability. RPHs-C-7-3 regulates the nuclear translocation of p65.

Effect of valsartan on ACAT-1 and PPAR-γ expression in intima with carotid artery endothelial balloon injury in rabbit

OBJECTIVE

To study the effect of valsartan on ACAT-1 and PPAR-γ expression after vascular endothelial balloon injury in intimal hyperplasia process.

METHODS

24 male New Zealand white rabbits were randomly divided into three groups with 8 in each group.

CONTROL GROUP

rabbits were fed with normal diet; Balloon injury group: rabbits were fed with 0.5% cholesterol, 5% lard rabbit feed; balloon injury + valsartan group, rabbits were fed with 0.5% cholesterol, 5% lard rabbit feed added with 10 mg/(kg.d) valsartan gavage. RT-PCR and Western blotting method were used to detect the carotid ACAT-1, PPAR-γ mRNA and protein expression after 8 weeks of feeding.

RESULTS

In carotid artery balloon injury group, vascular smooth muscle cells (VSMC) proliferation and intimal hyperplasia were significantly higher 14 d after endothelial injury. In 14 days valsartan treatment group VSMC proliferation and intimal hyperplasia were lighter than the surgery group. Compared with the control group, ACAT-1, PPAR-γ mRNA and protein were significantly increased in balloon injury group and valsartan group (P < 0.01 or P < 0.05); the expression of ACAT-1 mRNA and protein were significantly lower in valsartan group and balloon injury group (P < 0.01 or P < 0.05). The expression of PPAR-γ mRNA and protein in valsartan group expression was significantly higher than that in the balloon injury group (P < 0.05). The expression level of ACAT-1 and PPAR-γ mRNA in balloon injury group and valsartan group showed negative correlation (P < 0.05).

CONCLUSION

The expression of ACAT-1, PPAR-γ mRNA and protein content were significantly increased in intimal hyperplasia process after vascular endothelial balloon injury. The effect of valsartan suppressed intimal hyperplasia correlated with the expression of down-regulated ACAT-1 and up-regulated PPAR-γ.