A metabolomics approach for investigating urinary and plasma changes in spontaneously hypertensive rats (SHR) fed with chicken skin protein hydrolysates diets

Valorization of Chicken Slaughterhouse Byproducts to Obtain Antihypertensive Peptides

Hypertension (HTN) is the leading cause of premature deaths worldwide and the main preventable risk factor for cardiovascular diseases. Therefore, there is a current need for new therapeutics to manage this condition. In this regard, protein hydrolysates containing antihypertensive bioactive peptides are of increasing interest. Thus, agri-food industry byproducts have emerged as a valuable source to obtain these hydrolysates as they are rich in proteins and inexpensive. Among these, byproducts from animal origin stand out as they are abundantly generated worldwide. Hence, this review is focused on evaluating the potential role of chicken slaughterhouse byproducts as a source of peptides for managing HTN. Several of these byproducts such as blood, bones, skins, and especially, chicken feet have been used to obtain protein hydrolysates with angiotensin-converting enzyme (ACE)-inhibitory activity and blood pressure-lowering effects. An increase in levels of endogenous antioxidant compounds, a reduction in ACE activity, and an improvement of HTN-associated endothelial dysfunction were the mechanisms underlying their effects. However, most of these studies were carried out in animal models, and further clinical studies are needed in order to confirm these antihypertensive properties. This would increase the value of these byproducts, contributing to the circular economy model of slaughterhouses.

Health effects of peptides obtained from hydrolysed chicken by-products by the action of Bromelia pinguin and B. karatas proteases in Wistar rats induced with metabolic syndrome

Metabolic syndrome (MS) is considered a major public health problem because it is associated with the development of cardiovascular disease and type 2 diabetes. Bioactive peptides can play an important role in the prevention and treatment of MS. The possible health effects of peptides obtained from hydrolysed chicken by-products (CH) by the action of plant proteases from Bromelia pinguin (BP), B. karatas (BK), and bromelain (BRO) were evaluated in a model of induced MS. Thirty male Wistar rats were randomised into the following groups: (1) standard diet (STD); (2) induction of MS with a hypercaloric diet (MS+CH); (3) CH-BP 200 mg CH/kg; (4) CH-BK 200 mg CH/kg; (5) CH-BRO 200 mg CH/kg; and (6) carnosine (CAR) 50 mg of carnosine/kg of body weight. The CH decreased the glucose levels (p < 0.05) and improved the lipid profile (p < 0.05) in the serum of the groups with induced MS. Liver lesions were attenuated with a decrease in hepatic enzymatic activities (p < 0.05), and the accumulation of lipid inclusions in the liver decreased. The data showed that CH and the use of proteases to obtain peptides with health effects could be a good therapeutic alternative for individuals with MS.

Bioactivity of peptides obtained from poultry by-products: A review

The production and consumption of poultry products (chicken, duck, and turkey) are continually growing throughout the world, leading to the generation of thousands of tons of organic by-products, which may be important sources of bioactive peptides. The bioactive peptides isolated from poultry by-products have biological properties that can be useful in the prevention of different metabolic diseases and hence, their consumption could be beneficial for human health. Such peptides can be used as nutraceuticals, and their inclusion as active components of functional food products is increasingly gaining attention. The aim of this review was to present the investigations of the biological effect of the peptides obtained from different poultry by-products and the possible mechanisms of action underlying these effects.

Antihypertensive effect and underlying mechanism of tripeptide NCW on spontaneously hypertensive rats using metabolomics analysis

Tripeptide NCW identified in our previous study displayed a strong ACE inhibitory activity, but whether it has any antihypertensive effect in vivo remains unknown. Thus, in this study, we aimed to investigate the protective effects of tripeptide NCW in spontaneously hypertensive rats (SHRs) and to further figure out the serum metabolic profiling variations due to its oral administration via UPLC-Q-TOF-MS/MS-based metabolomics analysis to clarify the underlying hypotensive mechanism. After three weeks of oral administration, the tripeptide NCW-treated group (NCW/SHR group, 80 mg per kg BW per d) showed significantly reduced systolic and diastolic blood pressure by 48.08 ± 3.84 mmHg and 48.92 ± 5.77 mmHg, respectively. Additionally, a total of 25 blood pressure-related metabolites were identified as being significantly changed in SHRs given tripeptide NCW after three weeks. These 25 metabolites might be biomarkers that indicated that the tripeptide NCW exhibits antihypertensive activity via regulating bile acid metabolism, lipid metabolism, amino acid metabolism, purinergic signaling, pantothenate and CoA biosynthesis, and the citrate cycle. Collectively, tripeptide NCW has a protective effect on SHRs associated with serum metabolite abnormalities.

Metabolic Profiling and Metabolites Fingerprints in Human Hypertension: Discovery and Potential

Early detection of pathogenesis through biomarkers holds the key to controlling hypertension and preventing cardiovascular complications. Metabolomics profiling acts as a potent and high throughput tool offering new insights on disease pathogenesis and potential in the early diagnosis of clinical hypertension with a tremendous translational promise. This review summarizes the latest progress of metabolomics and metabolites fingerprints and mainly discusses the current trends in the application in clinical hypertension. We also discussed the associated mechanisms and pathways involved in hypertension's pathogenesis and explored related research challenges and future perspectives. The information will improve our understanding of the development of hypertension and inspire the clinical application of metabolomics in hypertension and its associated cardiovascular complications.

Effect of Revtech thermal processing on volatile organic compounds and chemical characteristics of split yellow pea (Pisum sativum L.) flour

Yellow pea (Pisumsativum L.) is an economically rich source of nutrients with health-promoting effects. However, the consumption of pea ingredients is minimal due to their off-flavor characteristics. The present study investigated the effect of Revtech heat treatment on the chemical profile and volatile compounds in split yellow pea flour. Revtech treatment (RT) was applied at 140°C with a residence time of 4 min in dry condition (RT 0%) and in the presence of 10% steam (RT 10%). Both thermal treatments resulted in a significant reduction (p < 0.05) in lipoxygenase activity and the concentration of key beany-related odors such as heptanal, (E)-2-heptenal, 1-octen-3-ol, octanal, and (E)-2-octenal. In addition, RT 10% resulted in a significant reduction in pentanal, 1-penten-3-ol, hexanal, and 1-hexanol compared to untreated flour. The content of known precursors of lipoxygenase such as linoleic and linolenic acids was found in higher concentrations in heat-treated flours, indicating the efficacy of Revtech technology in minimizing the degradation of polyunsaturated fatty acids. No significant changes in the amino acid composition or the 29 selected phenolic compounds in pea flours were observed with Revtech processing except for two compounds, caffeic acid and gallocatechin, which were found at higher concentrations in RT 0%. PRACTICAL APPLICATION: Thermal processing of split yellow pea flours at 140°C using Revtech technology successfully decreased the concentrations of volatile compounds responsible for beany off-flavor while improving the nutritional quality of studied yellow pea flours. These results provide valuable information to the food industry for developing novel pulse-based products with enhanced sensory characteristics.

Activity and bioavailability of food protein-derived angiotensin-I-converting enzyme-inhibitory peptides

Angiotensin-I-converting enzyme (ACE) inhibitory peptides are able to inhibit the activity of ACE, which is the key enzymatic factor mediating systemic hypertension. ACE-inhibitory peptides can be obtained from edible proteins and have the function of antihypertension. The amino acid sequences and the secondary structures of ACE-inhibitory peptides determine the inhibitory activities and stability. The resistance of ACE-inhibitory peptides to digestive enzymes and peptidase affect their antihypertensive bioactivity in vivo. In this paper, the mechanism of ACE-inhibition, sources of the inhibitory peptides, structure-activity relationships, stability during digestion, absorption and transportation of ACE-inhibitory peptides, and consumption of ACE-inhibitory peptides are reviewed, which provide guidance to the development of new functional foods and production of antihypertensive nutraceuticals and pharmaceuticals.

Metabolomics profiling in hypertension and blood pressure regulation: a review

Hypertension is a chronic health condition in which blood pressure is usually elevated beyond normal levels. It can progress with serious complications if left undetected and untreated. Incidence of hypertension is on the increase worldwide with debilitating consequences on the health systems of many countries. It is a multifactorial disorder that requires a multi-pronged approach to address it. One such approach is the use of metabolomics or metabolite profiling to understand its underlying cause and possibly control it. Changes in metabolites profiles have been used to accurately predict so many disease conditions in addition to identifying possible biomarkers and pathways associated in their pathogenicity. This will enable their early detection, diagnosis and treatment as well as likely complications that may arise and also assist in development of biomarkers for clinical uses. The objective of this review therefore is to present some of the current knowledge on the application of metabolomics profiling in hypertension and blood pressure control.

Investigation of low molecular weight peptides (<1 kDa) in chicken meat and their contribution to meat flavor formation

BACKGROUND

Low molecular weight peptides (LMWPs) (<1 kDa) generated in meat during chilled conditioning can act as flavor precursors in the Maillard reaction with a potential contribution to key volatile organic compound (VOC) formation upon heating. Liquid chromatography/quadrupole time-of-flight mass spectrometry (LC/QTOF-MS) successfully detected 44 LMWPs in chicken breast and thigh muscles stored at 4 °C for up to 6 days. Carnosine (350 mg per 100 g), glutathione (GSH, 20 mg per 100 g) (concentrations based on reported values in the literature) and cysteine glycine (Cys Gly, 5 mg per 100 g) (concentration based on results from LC/QTOF-MS) were used in model systems containing ribose (25 mg per 100 g). The three model systems were heated at 180 °C for 2 h at pH 6.3. VOCs were measured by simultaneous distillation solvent extraction/gas chromatography/mass spectrometry.

RESULTS

Of 33 VOCs detected, 26 were significantly different (P ≤ 0.05) between the three peptides. The majority of nitrogen-containing volatiles, pyrazines and pyridines, dominated the carnosine mixture, while sulfur-containing VOCs dominated the GSH and Cys Gly peptide mixtures.

CONCLUSION

Known key aroma compounds such as thiazole (meaty), 2-methyl-3-furanthiol (beef and meat), 2-furfurylthiol (roasted), dihydro-2-methyl-3(2H)-thiophenone (meaty), 2-acetylthiazole (meaty and roasted) and pyrazine (meaty) were detected under conditions specific to aged and thermally treated chicken, suggesting a potential contribution to the overall sensory quality of cooked meat. © 2018 Society of Chemical Industry.

Food protein-derived renin-inhibitory peptides: in vitro and in vivo properties

Renin catalyzes the rate-determining step in the renin-angiotensin-aldosterone system that regulates mammalian blood pressure by converting angiotensinogen to angiotensin I (Ang I). Excessive plasma levels of Ang I is a causative factor in hypertension development. Therefore, inhibition of renin activity can lower blood pressure and provide relief from clinical symptoms associated with hypertension. Synthetic compounds are currently the most used group of renin inhibitors; however, only aliskiren is approved as a drug for hypertension treatment. But some negative side effects are associated with aliskiren therapy, which have necessitated the search for alternative natural compounds such as food protein-derived renin-inhibitory peptides with blood pressure-reducing effects. This paper is a concise review of the currently known sources and methods of production of renin-inhibitory peptides including their potential in vitro and in vivo extent of renin inhibition. PRACTICAL APPLICATIONS: Hypertension is a major human chronic disease that leads to severe cardiovascular impairment and ultimately death if not managed properly. Current therapeutic approach to hypertension management involves the use of drugs that inhibit excessive activities of renin and angiotensin converting enzyme (ACE), the two main enzymes that control mammalian blood pressure. Since renin catalyzes a single reaction that is the rate-determining step in the renin-angiotensin system, inhibition of this enzyme activity could be a highly effective strategy for controlling blood pressure without severe negative side effects. However, therapeutic control of renin activity remains difficult with only one approved drug. Some food protein-derived peptides have been found to inhibit renin activity inhibition, which could offer a drug-free treatment for hypertension. Therefore, this review provides a summary of recent developments in the advances and efficacy testing of renin-inhibitory peptides.

Dose-Related Antihypertensive Properties and the Corresponding Mechanisms of a Chicken Foot Hydrolysate in Hypertensive Rats

The antihypertensive properties of different doses of a chicken foot hydrolysate, Hpp11 and the mechanisms involved in this effect were investigated. Spontaneously hypertensive rats (SHR) were administered water, Captopril (50 mg/kg) or Hpp11 at different doses (25, 55 and 85 mg/kg), and the systolic blood pressure (SBP) was recorded. The SBP of normotensive Wistar-Kyoto (WKY) rats administered water or Hpp11 was also recorded. Additionally, plasmatic angiotensin-converting enzyme (ACE) activity was determined in the SHR administered Hpp11. Moreover, the relaxation caused by Hpp11 in isolated aortic rings from Sprague-Dawley rats was evaluated. Hpp11 exhibited antihypertensive activity at doses of 55 and 85 mg/kg, with maximum activity 6 h post-administration. At this time, no differences were found between these doses and Captopril. Initial SBP values of 55 and 85 mg/kg were recovered 24 or 8 h post-administration, respectively, 55 mg/kg being the most effective dose. At this dose, a reduction in the plasmatic ACE activity in the SHR was found. However, Hpp11 did not relax the aortic ring preparations. Therefore, ACE inhibition could be the mechanism underlying Hpp11 antihypertensive effect. Remarkably, Hpp11 did not modify SBP in WKY rats, showing that the decreased SBP effect is specific to the hypertensive state.

Analysis of Urine Composition in Type II Diabetic Mice after Intervention Therapy Using Holothurian Polypeptides

Hydrolysates and peptide fractions (PF) obtained from sea cucumber with commercial enzyme were studied on the hyperglycemic and renal protective effects on db/db rats using urine metabolomics. Compared with the control group the polypeptides from the two species could significantly reduce the urine glucose and urea. We also tried to address the compositions of highly expressed urinary proteins using a proteomics approach. They were serum albumins, AMBP proteins, negative trypsin, elastase, and urinary protein, GAPDH, a receptor of urokinase-type plasminogen activator (uPAR), and Ig kappa chain C region. We used the electronic nose to quickly detect changes in the volatile substances in mice urine after holothurian polypeptides (HPP) fed, and the results show it can identify the difference between treatment groups with the control group without overlapping. The protein express mechanism of HPP treating diabetes was discussed, and we suggested these two peptides with the hypoglycemic and renal protective activity might be utilized as nutraceuticals.