Effects Of Whey Protein Hydrolysate Research Articles

In vitro ACE-inhibitory peptide KGYGGVSLPEW facilitates noradrenaline release from sympathetic nerve terminals: Relationship with the lack of antihypertensive effect on spontaneous hypertensive rats

This study aimed to validate the antihypertensive activity of the angiotensin-converting enzyme (ACE)-inhibitor whey protein hydrolysate (WPH) obtained through the action of proteolytic enzymes from Cynara Cardunculus. The antihypertensive activity of WPH fractions containing peptides with molecular weight below 3kDa (Whey<3kDa) and 1kDa (Whey<1kDa) along with the antihypertensive activity of three potent ACE-inhibitory peptide sequences (DKVGINYW, DAQSAPLRVY and KGYGGVSLPEW), previously identified in WPH, were also investigated. In parallel, the influence of KGYGGVSLPEW (the most potent ACE-inhibitory peptide sequence) on AT1 receptors (a common pharmacological target of antihypertensive therapies beyond ACE), was evaluated. The effect of WPH and fractions (300mg/kg) and peptide sequences (5mg/kg) on systolic, diastolic and mean blood pressure was evaluated by telemetry on spontaneously hypertensive rats (SHR), after single oral administration. Despite their ACE-inhibitory effect in vitro, neither WPH, Whey <3kDa, Whey <1kDa or peptide sequences exhibited antihypertensive activity. In addition, KGYGGVSLPEW was not only devoid of AT1 receptor antagonism but, on the contrary, had a similar effect to that of Ang II by facilitating the noradrenaline release from sympathetic nerve terminals. In vitro ACE blockade does not always correlate with antihypertensive activity and food-derived peptides cannot be classified as antihypertensive agents based exclusively on in vitro assays. The absence of an antihypertensive effect may also be a result of the interaction of these compounds with other components of the systems involved in the blood pressure control.

Effect Of Whey Protein Hydrolysate On Adaptation To Endurance Training In Well-trained Runners

PURPOSE: To compare intake of whey protein hydrolysate (WB) in connection to each exercise session with intake of carbohydrate on adaptation to endurance training in runners. METHODS: 24 well-trained endurance runners (Age 30±9 yrs, VO2max 61±4 ml O2 min-1 kg-1) participated in a block randomized controlled intervention trial including a six weeks running program. Half of the runners ingested WB before (0.3 g kg-1) and WB+carbohydrate (0.3 g protein kg-1 + 1 g carbohydrate kg-1) after each exercise session (PRO). The others ingested isocaloric carbohydrate before and after exercise (CAR). Muscle biopsies were obtained before and after the first training session. Before and two days after the intervention period post-absorptive muscle biopsies were obtained and VO2max and 6k performance were tested. Diet was controlled before tests and four days food diary was obtained in the beginning and end of the intervention period. RESULTS: Improvements were observed in 6k-run performance test (25±1 sec, p<0.01) and VO2max (0.07±0.01 L O2/min, p<0.05) compared to baseline, but no intervention interaction was observed Western plot analysis showed group difference in adaptations in Cyt C (PRO 19±8%, CAR -17±13%, p<0.05). Tendencies towards similar adaption pattern were observed for other mitochondrial targets (VDAC, PHB1, SDHA, intervention interaction p<0.1). mRNA expression of mitochondrial PGC1-α was acutely enhanced after the first running session (0hr post-exercise 339±27% and 2 hr post-exercise 651±25%, p<0.01), but not influenced by intervention beverages. No time or intervention interaction was observed before and after the intervention period in mRNA PGC1-α expression. Daily protein intake excluding intervention beverages was not different between groups. CONCLUSIONS: Ingestion of whey protein hydrolysate before and whey protein hydrolysat plus carbohydrate after each exercise session compared to isocaloric carbohydrate intake did not influence adaptions in 6k performance and VO2max after six weeks of running training. Intake of whey protein seems to have a positive influence on mitochondrial adaptions in well-trained runners and might be beneficial for performance in a longer perspective. Supported by Arla Foods Ingredients Group P/S, Ministry of Culture Committee on Sports Research & Team Denmark.

Hydrophobicity of whey protein hydrolysates enhances the protective effect against oxidative damage on PC 12 cells.

The relationship between hydrophobicity and the protective effect of whey protein hydrolysates (WPHs) against oxidative stress was studied. Whey protein was first hydrolysed by pepsin and trypsin to obtain WPHs. After absorbed by macroporous adsorption resin DA201-C, three fractions named as M20, M40, and M60 were eluted by various concentrations of ethanol. The hydrophobicity showed a trend of increase from M20 to M60. Antioxidant ability test in vitro indicated that all the three components of WPHs displayed reasonably good antioxidant ability. Moreover, with the increase of hydrophobicity, antioxidant ability of WPHs improved significantly. Then rat pheochromocytoma line 12 (PC12) cells oxidative model was built to evaluate the suppression of oxidative stress of three components on PC12 cells induced by H2O2. Morphological alterations, cell viability, apoptosis rate, and intracellular antioxidase system tests all indicated that WPHs exert significant protection on PC cells against H2O2-induced damage. Among them, M60 had the highest protective effect by increasing 19·3% cell survival and reducing 28·6% cell apoptosis. These results suggested hydrophobicity of WPHs was contributing to the antioxidant ability and the protective effect against oxidative damage.

Effect of whey protein hydrolysate on performance and recovery of top-class orienteering runners.

This trial aimed to examine the effect of whey protein hydrolysate intake before and after exercise sessions on endurance performance and recovery in elite orienteers during a training camp. Eighteen elite orienteers participated in a randomized controlled intervention trial during a 1-week training camp (13 exercise sessions). Half of the runners (PRO-CHO) ingested a protein drink before (0.3 g kg(-1)) and a protein-carbohydrate drink after (0.3 g protein kg(-1) and 1 g carbohydrate kg(-1)) each exercise session. The others ingested energy and time-matched carbohydrate drinks (CHO). A 4-km run-test with 20 control points was performed before and on the last day of the intervention. Blood and saliva were obtained in the mornings, before and after run-tests, and after the last training session. During the intervention, questionnaires were fulfilled regarding psychological sense of performance capacity and motivation. PRO-CHO and not CHO improved performance in the 4-km run-test (interaction p < .05). An increase in serum creatine kinase was observed during the week, which was greater in CHO than PRO-CHO (interaction p < .01). Lactate dehydrogenase (p < .001) and cortisol (p = .057) increased during the week, but the change did not differ between groups. Reduction in sense of performance capacity during the intervention was greater in CHO (p < .05) than PRO-CHO. In conclusion, ingestion of whey protein hydrolysate before and after each exercise session improves performance and reduces markers of muscle damage during a strenuous 1-week training camp. The results indicate that protein supplementation in conjunction with each exercise session facilitates the recovery from strenuous training in elite orienteers.

Protective effect of whey protein hydrolysates against oxidative stress in d-galactose-induced ageing rats

The protective effect of whey protein hydrolysate (WPH) against oxidation was studied in d-galactose-induced ageing rats. The rats were divided into a normal group, a d-galactose model group, low-, middle-, and high-dose WPH groups, and an ascorbic acid group. The three WPH groups and the ascorbic acid group also received d-galactose treatment. Administration of WPH significantly increased body weight gain, spleen index and high-density lipoprotein content (P < 0.05) and decreased the triglyceride and low-density lipoprotein contents (P < 0.05) compared with the ageing model group. WPH had a protective effect against d-galactose-induced ageing in rats as shown by the increased activities of superoxide dismutase, catalase and glutathione peroxidase and decrease in the malonaldehyde contents (P < 0.05) in the serum, spleen, liver, and lungs. The protective effect of WPH on d-galactose-induced ageing in rats can be attributed to enhanced antioxidant defences and the elevation of antioxidase activity.

Ameliorative potential of whey protein hydrolysate against paracetamol-induced oxidative stress

The aim of the present study was to validate the antioxidant effect of whey protein hydrolysate (WPH) using a small animal model. Paracetamol is common drug that is safe at therapeutic levels; however, an overdose causes oxidative stress, which may lead to potential hepatic and renal necrosis. The protective effect of WPH against paracetamol-induced hepato-nephrotoxicity in mice was investigated in this study. The WPH was prepared by hydrolyzing ultrafiltered retentate of mozzarella cheese whey with commercial food-grade alcalase; the resulting WPH had substantial in vitro antioxidant activity. Male albino mice were treated with WPH for 4 d [intraperitoneally at 4mg/kg of body weight (BW) per day or orally at 8mg/kg of BW per day] before or after oral administration of paracetamol (300mg/kg of BW) for 2 d. Two control groups were used; the negative control mice were administered water only; the paracetamol group was administered paracetamol at 300mg/kg of BW but received no WPH. Levels of different marker enzymes (glutamate pyruvate transaminase and alkaline phosphatase), creatinine, and blood urea nitrogen were measured in the experimental animal blood sera. The WPH successfully mitigated the increase in the concentration of oxidative biomarkers such as glutathione pyruvate transaminase, alkaline phosphatase, and creatinine, and restored the level of blood urea nitrogen to normal in sera of mice in which oxidative stress was induced with an overdose of paracetamol. Furthermore, the indices of different antioxidant enzymes, such as catalase, superoxide dismutase, and glutathione peroxidase, and lipid peroxidation end-products were determined in liver homogenate. The mice that were given WPH, either intraperitoneally or orally, showed increased activities of antioxidant enzymes and a reduction in thiobarbituric acid reactive substances (TBARS) compared with the paracetamol control group. The protective effect of WPH was less when administered orally than intraperitoneally. We concluded that WPH is the potential protector against paracetamol-induced hepato-nephrotoxicity and can be effectively used in health-promoting foods as a biofunctional ingredient.

Protective effect of whey protein hydrolysates against hydrogen peroxide-induced oxidative stress on PC12 cells

The protective effect of whey protein hydrolysates (WPHs) against H(2)O(2)-induced oxidative damage on rat pheochromocytoma line 12 (PC12) cells was studied. Whey protein was hydrolyzed by pepsin and trypsin and purified by macrospore absorption resins. PC12 cells were pretreated with WPHs (from 369 to 1,980Da) at different concentrations for 2h, then washed and incubated with 100μM H(2)O(2) in the presence of WPHs for another 24h. With 100-400μg WPH/ml the viable cells increased by 20-30% when incubated with H(2)O(2) suggesting that they may play a role as antioxidant in foods.

Hypertension-attenuating effect of whey protein hydrolysate on spontaneously hypertensive rats

The angiotensin I-converting enzyme (ACE)-inhibitory activity and antihypertensive effect of whey protein hydrolysate (WPH) after single oral administration (short term) or continuous administration for 20 d (long term) were investigated. In the case of short term administration, the systolic and diastolic blood pressure of spontaneously hypertensive rats (SHRs) in captopril and WPH-supplemented groups significantly decreased from 6 to 8 h post-administration compared to the negative control group. In the case of long term administration, WPH supplementation lowered the blood pressure and affected the heart rate of SHRs in a dose-dependent manner, the lowest systolic blood pressure was obtained at the dose of 240 mg WPH/kg b.w. Furthermore, the ACE activity in plasma, lung, kidney and abdominal aorta of the WPH-administered groups decreased in a dose-related manner, and was significantly lower than that of the negative control group. These results suggest that WPH with an ACE-inhibitory activity could potentially suppress the development of hypertension in SHRs.

Anti-inflammatory activities of enzymatic (alcalase) hydrolysate of a whey protein concentrate

This study was designed to evaluate the anti-inflammatory effects of whey protein hydrolysate (WPH) in mice. Hydrolysis for this experiment was conducted in a pH-stat at 20% degree of hydrolysis. Carrageenan-induced paw edema, peritonitis induced by lipopolysaccharide (LPS) and acetic acid-induced writhing were tested to investigate anti-inflammatory activity. Overall, WPH inhibited carrageenan-induced mice paw edema significantly with doses of 30 mg/kg (p < 0.001), 100 mg/kg (p < 0.01) and 300 mg/kg (p < 0.001) at 3 h post carrageenan. The inhibitory values of edema were 60.34, 39.65 and 68.96%, respectively. After 4 h and an intraperitoneal injection of LPS (100 μg/kg), WPH further inhibited leukocyte recruitment to the peritoneal cavity of mice at a dose of 300 mg/kg (p < 0.05). In a number of the writhing episodes, WPH reduced contortions using a dose of 300 mg/kg. These results indicate that the hydrolysate obtained by treatment with alcalase demonstrated anti-inflammatory activity in the experimental models. All the anti-inflammatory actions obtained were also suggested to be due the presence of glutamine. Key words : Whey protein, proteases, hydrolysate, anti-inflammatory activity, mice.

Effect of whey protein hydrolysates produced by various enzymes on H2O2 induced DNA damage in human leukocytes

Effect of whey protein hydrolysates produced by various enzymes on H2O2 induced DNA damage in human leukocytes

Tumor-Protective and Tumor-Promoting Actions of Dietary Whey Proteins in an N-Methyl-N-Nitrosourea Model of Rat Mammary Carcinogenesis

: The mammary tumor-protective effects of dietary factors are considered to be mediated by multiple signaling pathways, consistent with the heterogeneous nature of the disease and the distinct genetic profiles of tumors arising from diverse mammary cell populations. In a 7,12-dimethylbenz(a)anthracene-induced model of carcinogenesis, we showed previously that female Sprague-Dawley rats exposed to AIN-93G diet containing whey protein hydrolysate (WPH) beginning at gestation Day 4 had reduced tumor incidence than those exposed to diet containing casein (CAS), due partly to increased mammary differentiation and reduced activity of phase I metabolic enzymes. Here, we evaluated the tumor-protective effects of these same dietary proteins to the direct-acting carcinogen N-methyl-N-nitrosourea (NMU). We found that lifetime exposure to WPH, relative to CAS, decreased mammary tumor incidence and prolonged the appearance of tumors in NMU-treated female rats, with no corresponding effects on tumor multiplicity. At 115 days post-NMU, histologically normal mammary glands from WPH-fed tumor-bearing rats had increased gene expression for the tumor suppressor BRCA1 and the differentiation marker κ-casein than those of CAS-fed tumor-bearing rats. Tumor-bearing rats from the WPH group had more advanced tumors, with a greater incidence of invasive ductal carcinoma than ductal carcinoma in situ and higher serum Cpeptide levels than corresponding rats fed CAS. WPH-fed tumor-bearing rats were also heavier after NMU administration than CAS tumor-bearing rats, although no correlation was noted between body weight and C-peptide levels for either diet group. Results demonstrate the context-dependent tumor-protective and tumor-promoting effects of WPH; provide support for distinct signaling pathways underlying dietary effects on development of mammary carcinoma; and raise provocative questions on the role of diet in altering the prognosis of existing breast tumors.