Egg white hydrolysate peptides act as antimicrobial and anti-inflammatory agents for acne.

A simple method to generate antibacterial peptides by alkaline hydrolysis of hen egg whites is reported. The method reproducibly generates short peptides with molecular weight of less than 14.4 kDa that exhibit low to no cytotoxicity on RAW 264.7 macrophage cells, but do inhibit the bacterial growth of Cutibacterium acnes (C. acnes), Staphylococcus aureus (S. aureus) and antibiotic-resistant S. aureus (MRSA), while also reducing nitric oxide production from heat-killed C. acnes-treated RAW 264.7 cells. Peptidomics revealed at least thirty peptides within the complex mixture, of which eight were evaluated individually. Three peptides (PK8, EE9 and RP8) were potent anti-inflammation and antibacterial agents, but notably the complex egg white hydrolysate (EWH) was more effective than the individual peptides. Electron microscopy suggests the antibacterial mechanism of both the hydrolysate and the selected peptides is through disruption of the cell membrane of C. acnes. These findings suggest that EWH and EWH-derived peptides are promising candidates for infection and inflammation treatment, particularly in managing acne and combating antibiotic-resistant bacteria like MRSA.

Egg white hydrolysate protects white adipose tissue against metabolic insult in deoxycorticosterone acetate-salt rats.

The purpose of this study was to investigate the effect of an egg white hydrolysate (EWH) to protect white adipose tissue damage from cardiometabolic changes induced by severe hypertension. Male Wistar rats were uninephrectomised and divided: SHAM (weekly subcutaneous vehicle (mineral oil + propylene glycol, 1:1)), SHAM + EWH (subcutaneous vehicle plus EWH via gavage, 1 g/kg per day), DOCA (deoxycorticosterone acetate diluted in vehicle subcutaneously weekly in subsequent doses of 20 mg/kg -1st week, 12 mg/kg - 2­3th week, and 6 mg/kg -4­8th week, respectively, plus 1 % NaCl and 0·2 % KCl in drinking water), and DOCA + EWH. Body weight gain, food and water intake, glucose and lipid metabolism were evaluated. Oxidative stress was assessed by biochemical assay and immunofluorescence for NOX-1, nuclear factor kappa B (NFκB), and caspase-3 in retroperitoneal white adipose tissue (rtWAT). Proinflammatory cytokines (IL-6 and 1ß), CD163+ macrophage infiltration, and immunohistochemistry for TNFα and uncoupling protein-1 were evaluated, as well as histological analysis on rtWAT. Glutathione peroxidase and reductase were also determined in plasma. EWH showed hypocholesterolemic, antioxidant, anti-inflammatory, and anti-apoptotic properties in the arterial hypertension DOCA-salt model. The results demonstrated the presence of functional changes in adipose tissue function by a decrease in macrophage infiltration and in the fluorescence intensity of NFκB, NOX-1, and caspase-3. A reduction of proinflammatory cytokines and restoration of antioxidant enzymatic activity and mitochondrial oxidative damage by reducing uncoupling protein-1 fluorescence intensity were also observed. EWH could be used as a potential alternative therapeutic strategy in the treatment of cardiometabolic complications associated with malignant secondary arterial hypertension.

Egg White Hydrolysate Mitigates Cadmium-induced Neurological Disorders and Oxidative Damage.

We aimed to investigate whether the consumption of Egg White Hydrolysate (EWH) acts on nervous system disorders induced by exposure to Cadmium (Cd) in rats. Male Wistar rats were divided into (a) Control (Ct): H2O by gavage for 28 days + H2O (i.p. - 15th - 28th day); (b) Cadmium (Cd): H2O by gavage + CdCl2 - 1 mg/kg/day (i.p. - 15th - 28th day); (c) EWH 14d: EWH 1 g/kg/day by gavage for 14 days + H2O (i.p.- 15th - 28th day); (d) Cd + EWH cotreatment (Cd + EWHco): CdCl2 + EWH for 14 days; (e) EWH 28d: EWH for 28 days; (f) EWHpre + Cd: EWH (1st - 28th day) + CdCl2 (15th - 28th day). At the beginning and the end of treatment, neuromotor performance (Neurological Deficit Scale); motor function (Rota-Rod test); ability to move and explore (Open Field test); thermal sensitivity (Hot Plate test); and state of anxiety (Elevated Maze test) were tested. The antioxidant status in the cerebral cortex and the striatum were biochemically analyzed. Cd induces anxiety, and neuromotor, and thermal sensitivity deficits. EWH consumption prevented anxiety, neuromotor deficits, and alterations in thermal sensitivity, avoiding neuromotor deficits both when the administration was performed before or during Cd exposure. Both modes of administration reduced the levels of reactive species, and the lipid peroxidation increased by Cd and improved the striatum's antioxidant capacity. Pretreatment proved to be beneficial in preventing the reduction of SOD activity in the cortex. EWH could be used as a functional food with antioxidant properties capable of preventing neurological damage induced by Cd.

Cardiovascular Harmful Effects of Recommended Daily Doses (13 µg/kg/day), Tolerable Upper Intake Doses (0.14 mg/kg/day) and Twice the Tolerable Doses (0.28 mg/kg/day) of Copper.

Copper is essential for homeostasis and regulation of body functions, but in excess, it is a cardiovascular risk factor since it increases oxidative stress. The objective of this study was to evaluate the effects of exposure to the recommended daily dose (13 µg/kg/day), upper tolerable dose (0.14 mg/kg/day) and twice the upper tolerable dose (0.28 mg/kg/day) via i.p. over 4 weeks on the vascular reactivity of aortic rings and the contraction of LV papillary muscles of male Wistar rats. It was also determined whether the antioxidant peptide from egg white hydrolysate (EWH) prevents these effects. Copper exposure at the doses evaluated did not change weight gain of male Wistar rats, the reactivity of the aortic rings or the cardiac mass. The dose of 0.13 µg/kg/day did not reduce the force of contraction, but it impaired the time derivatives of force. Doses of 0.14 and 0.28 mg/kg/day reduced the force of contraction, the inotropic response to calcium and isoproterenol, the postrest contraction and the peak and plateau of tetanized contractions. EWH treatment antagonized these effects. These results suggest that copper, even at the dose described as upper tolerable, can impair cardiac contraction without altering vascular reactivity. Antioxidative stress therapy with EWH reversed these harmful effects, suggesting a possible strategy for the amelioration of these effects.

Investigation of the optimal production conditions for egg white hydrolysates and physicochemical characteristics.

This study aimed to investigate the potential of egg white protein hydrolysate (EWH) as a functional food by identifying the optimum production conditions for EWH with response surface methodology (the results of the sensory evaluation were considered as an essential quality indicator). At the same time, its physicochemical and biological activity was also evaluated. The optimal economic production conditions were selected: substrate concentration of 12.5%, enzyme content of 7.5%, and hydrolysis time at 100 min. The degree of hydrolysis (DH %) was 13.51%. In addition, to the better acceptance of the evaluation, it also helps to reduce the production cost of the protein hydrolysate, which is beneficial to future processing and applications. The antioxidant capacity experiments showed that EWH has good antioxidant activity, which presents a dose-dependent relationship. Hence, this study provides a theoretical basis for future research and application of EWH for processing applications, including dietary supplementation. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05708-0.

Application of egg white hydrolysate (EWH) to improve frothing functionality of pasteurized liquid egg in large quantity production.

Sterilized Liquid Eggs (SLE) are convenient for the baking process by minimizing the food safety risks of fresh eggs. Although these advantages were encouraging, the thermal effects of the pasteurization process had a negative impact on the functionality of the egg whites, thus making them unattractive to the food industry. Therefore, our previous study found that adding 1-5% egg white hydrolysate (EWH) contributed to the foaminess and stability in SLE. This primary purpose of this study was to confirm the feasibility of applying the optimum concentration of EWH for simultaneous evaluation and shelf life for batch production of SLE. The physical characteristics of the foam were analyzed by adding 1 ± 0.2% of EWH to SLE, and it was found that the foam with 1% EWH had better stability (low drainage), better viscosity, and similar distribution of foam bubbles size in the microstructure. No Salmonella infection has been found during the shelf life of 7 days. In addition, the highest overall acceptability has obtained using the large quantity produced SLE with 1% EWH to produce spoon cookies, followed by sensory evaluation. The cross-sectional height of the cookie and the distribution of holes in the structure were in line with those of the non-sterilized liquid egg white (NSLE). Hence, adding 1% EWH was found to the optimum concentration, which provides good foaming performance and stability of SLE. This study conveys a positive assessment to SLE producers and potential users, as it will increase their profitability economically while meeting the market challenges.

ROS Suppression by Egg White Hydrolysate in DOCA-Salt Rats-An Alternative Tool against Vascular Dysfunction in Severe Hypertension.

This study aimed to evaluate the potential for lowering blood pressure and beneficial effects on mesenteric resistance arteries (MRA) and conductance vessels (aorta) produced by dietary supplementation of an egg white hydrolysate (EWH) in rats with severe hypertension induced by deoxycorticosterone plus salt treatment (DOCA-salt), as well as the underlying mechanisms involved. The DOCA-salt model presented higher blood pressure, which was significantly reduced by EWH. The impaired acetylcholine-induced relaxation and eNOS expression observed in MRA and aorta from DOCA-salt rats was ameliorated by EWH. This effect on vessels (MRA and aorta) was related to the antioxidant effect of EWH, since hydrolysate intake prevented the NF-κB/TNFα inflammatory pathway and NADPH oxidase-induced reactive oxygen species (ROS) generation, as well as the mitochondrial source of ROS in MRA. At the plasma level, EWH blocked the higher ROS and MDA generation by DOCA-salt treatment, without altering the antioxidant marker. In conclusion, EWH demonstrated an antihypertensive effect in a model of severe hypertension. This effect could be related to its endothelium-dependent vasodilator properties mediated by an ameliorated vessel's redox imbalance and inflammatory state.

Production of egg white hydrolysate by digestion with pineapple bromelain: optimization, evaluation and antioxidant activity study.

Chicken egg white is known to be an excellent source of good quality proteins to make hydrolysate with potential bioactive properties. Enzymatic digestion is a well-known method to produce protein hydrolysates; however, the type of enzyme determines the bioactive potential of the protein hydrolysates due to difference in their catalytic specificity. In this study, process optimization, production and evaluation of whole egg white protein hydrolysate (WEWPH) using pineapple bromelain through the Box-Behnken design were carried out. The design experiment (r 2 = 0.9557) displayed a significant (p < 0.01) effect of pH of egg white (9.0), hydrolysis time (24 h), and enzyme/substrate ratio (3.2 unit/g substrate) on hydrolysis and to form bioactive WEWPH. Antioxidant activity of the WEWPH was confirmed by DPPH radical scavenging assay. Gel filtration chromatography, SDS-PAGE and FTIR spectroscopy analysis of WEWPH revealed the digestion of egg white and the integrity of WEWPH in terms of secondary structure. The WEWPH exhibited strong scavenging activities of DPPH (EC50 = 238.3 µg/ml), ABTS ABTS (EC50 = 54.9 µg/ml), peroxyl (EC50 = 391.6 µg/ml) and superoxide radicals. The WEWPH also displayed reducing power and singlet oxygen quenching activity. These results reveal that the bioactive WEWPH could be a promising ingredient in health food and nutraceuticals. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-021-05188-0.

Improvement of Foaming Characteristics and Stability of Sterilized Liquid Egg with Egg White Hydrolysate (EWH).

A pasteurized liquid egg leads to protein denaturation and degradation of processing properties, whereas non-pasteurized eggs may have food safety risks. If the negative impact of the pasteurization process on liquid eggs can be reduced, for example, the loss of stability and foamability, companies will be willing to purchase pasteurized eggs, thereby reducing food safety risks. Therefore, in this study, specific hydrolyzation conditions were used to produce egg white hydrolysate (EWH) with a lower molecular mass of amino acid and peptide fragments, and the effects of various concentration of EWH refilling on pasteurized liquid egg properties were investigated. The results showed that up to 30.1% of EWH was hydrolyzed by protease A and papain. Adding 1% (w/w) EWH can improve the negative charge potential value, surface tension, viscosity, and weight loss analysis of the sample. In addition, the cake structure and the appearance was acceptable to consumers. Therefore, to ensure its efficient use in the baking industry and considering the cost and stability, 1% (w/w) EWH was chosen as the best concentration.

Antioxidant Properties of Egg White Hydrolysate Prevent Mercury-Induced Vascular Damage in Resistance Arteries.

Aim: We investigated the antioxidant protective power of egg white hydrolysate (EWH) against the vascular damage induced by mercury chloride (HgCl2) exposure in resistance arteries. Methods: Male Wistar rats received for 60 days: (I) intramuscular injections (i.m.) of saline and tap water by gavage - Untreated group; (II) 4.6 µg/kg of HgCl2 i.m. for the first dose and subsequent doses of 0.07 µg/kg/day and tap water by gavage - HgCl2 group; (III) saline i.m. and 1 g/kg/day of EWH by gavage - EWH group, or (IV) the combination of the HgCl2 i.m. and EWH by gavage - EWH + HgCl2 group. Blood pressure (BP) was indirectly measured and dose-response curves to acetylcholine (ACh), sodium nitroprusside (SNP), and noradrenaline (NE) were assessed in mesenteric resistance arteries (MRA), as in situ production of superoxide anion, nitric oxide (NO) release, vascular reactive oxygen species (ROS), lipid peroxidation, and antioxidant status. Results: Egg white hydrolysate prevented the elevation in BP and the vascular dysfunction after HgCl2 exposure; restored the NO-mediated endothelial modulation and inhibited the oxidative stress and inflammatory pathways induced by HgCl2. Conclusion: Egg white hydrolysate seems to be a useful functional food to prevent HgCl2-induced vascular toxic effects in MRA.

Purification and identification of angiotensin II type I receptor downregulating peptide from egg white hydrolysate.

The vasoconstricting effect of angiotensin II (Ang II) is mediated by Ang II type I receptor (AT1R); blocking or blunting AT1R is a key strategy for the development of antihypertensive drugs. Our previous study showed that the blood pressure lowering the activity of egg white hydrolysate (EWH) in spontaneously hypertensive rats was due to the downregulation of aortic AT1R expression, which promoted us to further identify the AT1R downregulating peptides in the present study. The protein expression of AT1R in a rat aortic vascular smooth muscle cell line A7r5 cells was used for the activity test. The hydrolysate was fractionated stepwise by C18 Sep-Pack cartridge and reverse-phase chromatography, and the peptide sequences were characterized by LC-MS/MS. Peptides including ITKPNDVYS, VVGSAEAGVDAAS, AVHAAHAEINEAGRE, AGREVVGSAEAGVD, and VVGSAEAGVD, were identified. ITKPNDVYS showed the most potent peptide for lowering the level of AT1R in A7r5 cells. These results suggested that ITKPNDVYS is the responsible peptide for lowering the AT1R level in EWH. PRACTICAL APPLICATIONS: A new peptide ITKPNDVYS was identified as a downregulator of AT1R from egg white hydrolysate, which provides a new approach for the development of food protein-derived antihypertensive peptides as nutraceuticals or functional food ingredients.

Egg white hydrolysate enhances insulin sensitivity in high-fat diet-induced insulin-resistant rats via Akt activation.

Agents that block the renin-angiotensin system (RAS) improve glucoregulation in the metabolic syndrome disorder. We evaluated the effects of egg white hydrolysate (EWH), previously shown to modulate the protein abundance of RAS component in vivo, on glucose homeostasis in diet-induced insulin-resistant rats. Sprague-Dawley rats were fed a high-fat diet (HFD) for 6 weeks to induce insulin resistance. They were then randomly divided into four groups receiving HFD or HFD supplemented with different concentrations of EWH (1, 2 and 4 %) for another 6 weeks in the first trial. In the second trial, insulin-resistant rats were divided into two groups receiving only HFD or HFD+4 % EWH for 6 weeks. Glucose homeostasis was assessed by oral glucose tolerance and insulin tolerance tests. Insulin signalling and protein abundance of RAS components, gluconeogenesis enzymes and PPARγ were evaluated in muscle, fat and liver. Adipocyte morphology and inflammatory markers were evaluated. In vivo administration of EWH increased insulin sensitivity, improved oral glucose tolerance (P < 0·0001) and reduced systemic inflammation (P < 0·05). EWH potentiated insulin-induced Akt phosphorylation in muscle (P = 0·0341) and adipose tissue (P = 0·0276), but minimal differences in the protein abundance of tissue RAS components between the EWH and control groups were observed. EWH treatment also reduced adipocyte size (P = 0·0383) and increased PPARγ2 protein abundance (P = 0·0237). EWH treatment yielded positive effects on the inflammatory profile, glucose tolerance, insulin sensitivity and adipocyte differentiation in HFD-induced insulin resistance rats. The involvement of local RAS activity requires further investigation.

Egg white hydrolysate improves fatigue due to short-term swimming load test in mice.

We studied the effect of egg white hydrolysate (EWH) on swimming endurance in mice. 7-week-old male ddY mice (28-30 g) were divided into three groups and fed an AIN-93G diet supplemented with casein (n = 8), EWH (n = 7), or egg white protein (EWP, n = 8) for 14 days. From day 11, the mice underwent a swimming test daily with a weight load equivalent to 10% of their body weight, and the lengths of time they swam were recorded. Blood was sampled for testing on the last day of the study. We observed that increases in the swimming duration through day 14 were significantly greater in the EWH group than in the casein group (p = 0.049). As a factor underlying this, the hexanoyl-lysine level in blood was confirmed to be decreased in the former group (p = 0.013). These findings indicate that consumption of EWH extended the swimming duration and suggest the mechanistic involvement of an antifatigue effect mediated by its antioxidant activity.

Optimization and Scale-Up Preparation of Egg White Hydrolysate with Angiotensin I Converting Enzyme Inhibitory Activity.

Angiotensin I converting enzyme (ACE) plays an important role in regulation of blood pressure as it converts angiotensin I into angiotensin II (a potent vasoconstrictor). Food protein-derived ACE inhibitory peptides have been considered as a safer alternative to antihypertensive drugs. In our previous study, three ACE inhibitory peptides were characterized from egg white ovotransferrin and their antihypertensive activity has been validated in spontaneously hypertensive rats. However, it is too costly to prepare these peptides from purified egg white ovotransferrin. The aims of the study were to determine the feasibility of preparing these peptides using egg white and then to optimize the conditions of preparing egg white hydrolysate. Taguchi's method was used to design experiments for optimization, which was established as follows: substrate %, pH of thermoase, time of thermoase digestion, ratio of pepsin to substrate, pH of pepsin, temperature of pepsin, and time of pepsin digestion were 7.5%, pH 8, 90 min, 1%, pH 2.5, 55 °C, and 180 min, respectively. The ACE inhibitory activity (IC50 value) and peptide yield obtained under optimal condition were 30 ± 2 µg/mL and 77.5% ± 0.3%, respectively, which were comparable to the predicted values. Hydrolysate prepared at 150 L reactor showed comparable activity but low peptide yield. Results of this study demonstrated the feasibility of using egg white protein as the starting material to prepare a functional ingredient with potent ACE inhibitory activity.

Pepsin Egg White Hydrolysate Improves Glucose Metabolism Complications Related to Metabolic Syndrome in Zucker Fatty Rats.

The purpose of this study was to evaluate the effect of the administration of two egg white hydrolysates on glucose metabolism complications related to Metabolic Syndrome (MS) in Zucker fatty rats (ZFR). ZFR were given 750 mg/kg/day of egg white hydrolyzed with pepsin (HEW1) or with aminopeptidase (HEW2) for 12 weeks in their drinking water or just water. Zucker lean rats (ZLR), which received water, were used as a control. The presence of tactile allodynia, which is a sign of peripheral neuropathy, was assessed. Blood samples and pancreas were collected to determine the effect of the hydrolysates on glucose metabolism. The intake of HEW1 significantly lowered plasma insulin levels and improved the quantitative indexes of insulin resistance, insulin sensitivity, and pancreatic ß-cell functionality (HOMA-IR, HOMA-ß, and QUICKI, respectively), but non-significant changes were observed in group treated with HEW2. Compared to ZLR, ZFR showed tactile allodynia, but the consumption of both hydrolysates significantly increased mechanical sensitivity in ZFR. In conclusion, HEW1 pepsin could improve the glucose metabolism abnormalities associated with MS in obese Zucker rats.

Egg white-derived peptides prevent cardiovascular disorders induced by mercury in rats: Role of angiotensin-converting enzyme (ACE) and NADPH oxidase.

The study aimed to investigate the effects of egg white hydrolysate (EWH) on vascular disorders induced by mercury (Hg). For this, male Wistar rats were treated for 60days: Untreated (saline, i.m.); Mercury (HgCl2, i.m., 1st dose 4.6µg/kg, subsequent doses 0.07µg/kg/day); Hydrolysate (EWH, gavage, 1g/kg/day); Hydrolysate-Mercury. Systolic (SBP) and diastolic (DBP) blood pressure measurement and vascular reactivity experiments in aorta were performed. We analyzed endothelial dependent and independent vasodilator responses and vasoconstrictor response to phenylephrine (Phe) in absence and presence of endothelium, a NOS inhibitor, a NADPH oxidase inhibitor, the superoxide dismutase, a non-selective COX inhibitor, a selective COX-2 inhibitor, an AT-1 receptors blocker. In situ superoxide anion production, SOD-1, NOX-4, p22phox, COX-2 and AT-1 mRNA levels and NOX-1 protein expression were performed in aorta while the determination of angiotensin converting enzyme (ACE) activity was measured in plasma. As results, EWH prevented the increase in SBP and Phe responses and the endothelial dysfunction elicited by Hg, which was related to decreased ACE activity and NOX activation by EWH and, subsequently, alleviated ROS production and improved NO bioavailability in aorta. In conclusion, EWH could be considered as alternative or complementary treatment tools for Hg-induced cardiovascular damage.

Egg White Hydrolysate Improves Glucose Tolerance in Type-2 Diabetic NSY Mice.

We have previously reported that chicken egg white (EW) and low-allergenic EW hydrolysate (EWH) suppressed ectopic fat accumulation and improved serum glucose and insulin levels. In this study, the dietary effects of EW and EWH on glucose tolerance were investigated in different ways to clarify the effect of EW and EWH on intestinal glucose absorption. Type 2 diabetic Nagoya-Shibata-Yasuda mice were divided into four groups: a low-fat and low-sucrose casein-based diet group (NL); high-fat and high-sucrose (HFS) casein-based diet group (NH); HFS EW-based diet group (NE); and HFS EWH-based diet group (NEH). Mice were fed their respective diets for 8 wk. At the end of the 6th and 7th week, an oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) were respectively conducted in experiment A. At the end of the 7th week, an intraperitoneal glucose tolerance test (ipGTT) was conducted in experiment B. In experiment A, the plasma glucose level was suppressed in the NE group during both OGTT and ITT, and suppressed in the NEH group during OGTT, but not during ITT. In experiment B, the plasma glucose level was similarly suppressed in the NEH group during ipGTT, but the suppressive effect was weakened compared to OGTT. Plasma insulin level was lower in the NE and NEH groups in both experiments. Fecal triacylglycerol excretion was increased in the NE and NEH groups in experiment A and liver triacylglycerol content was suppressed in the NE group in experiment B. These findings suggested that in addition to improving fat metabolism, EWH improves glucose tolerance via mechanisms related and unrelated to small intestinal function.

Ameliorative effects of egg white hydrolysate on recognition memory impairments associated with chronic exposure to low mercury concentration.

The study aimed to investigate whether the Egg White Hydrolysate (EWH) is able to prevent the recognition memory disorders associated with long-term Hg exposure in rats. For this, male Wistar rats were treated for 60 days with: a) Untreated: saline solution (i.m.); b) Hydrolysate: EWH (1 g/kg/day, gavage); c) Mercury: HgCl2 (1st dose 4.6 µg/kg, subsequent doses 0.07 µg/kg/day, i.m.); d) Hydrolysate-Mercury. Object recognition memory test was performed to verify Short (STM) and Long-Term Memory (LTM) and Open Field, Plus Maze and Tail Flick tests were performed as control for behavioural experiments. Reactive Oxygen Species (ROS) in the hippocampus were determined by the dichlorofluorescein diacetate (DCFH-DA) method, malondialdehyde (MDA) levels by TBARS, antioxidant power by FRAP assay and total Hg concentration by atomic fluorescence spectrometry. We confirm that the STM and LTM were impaired in adult rats exposed to Hg at low concentrations, which may be related to the increased metal deposition, ROS production and subsequent oxidative damage in the hippocampus. In addition, we demonstrated for the first time that EWH treatment is able to prevent memory impairment induced by Hg exposure, reducing Hg content and ROS production in the hippocampus. In conclusion, EWH prevents memory impairments induced by chronic exposure to low doses of Hg. These findings may represent a good public health strategy since they indicate that EWH is a promising candidate as a new natural therapy for heavy metal intoxication.

Egg white hydrolysate promotes neuroprotection for neuropathic disorders induced by chronic exposure to low concentrations of mercury.

This study aims to investigate whether the egg white hydrolysate (EWH) acts on the neuropathic disorders associated with long-term Mercury (Hg) exposure in rats. 8- week-old male Wistar rats were treated for 60 days with: a) Control - saline solution (i.m.); b) Mercury - HgCl2 (1st dose 4.6µg/kg, subsequent doses 0.07µg/kg/day, i.m.); c) Hydrolysate - EWH (1g/kg/day, gavage); d) Mercury and Hydrolysate. Mechanical allodynia was assessed using Von Frey Hairs test; heat hyperalgesia by the plantar test; catalepsy by a modification of the "ring test" and spontaneous locomotor activity by a photocell activity chambers. Analyses were performed at 0, 30 and 60 days of treatment. Brain and plasma MDA, plasma NPSH and TNF-α determination and skin immunohistochemistry were performed at 60 days. Hg induced a reduction in mechanical sensitivity threshold at 30 and 60 days and in thermal sensitivity threshold at 60 days. At the end of treatment catalepsy was developed, but there was not significant alteration in spontaneous locomotor activity. Hg also increased brain and plasma MDA, plasma NPSH and TNF-α levels and the number of Merkel cell-neurite complex in the skin. EWH prevented the development of mechanical allodynia, thermal hyperalgesia and catalepsy induced by Hg and the increase in MDA concentration in brain and plasma and in the number of Merkel cell-neurite complex in the skin. In conclusion, EWH promotes neuroprotection against the toxic effects caused by Hg, demonstrating a beneficial therapeutic potential.

Increased muscular triglyceride content and hyperglycemia in Goto-Kakizaki rat are decreased by egg white hydrolysate.

We investigated the fat metabolic characteristics in non-obese and diabetic Goto-Kakizaki (GK) rat and the effects of dietary egg white hydrolysate (EWH) on glucose and fat metabolism. Wistar (W) and GK (G) rats were placed into dietary casein (WC and GC) or EWH (WE and GE) group, and fed their respective diet for six weeks. Triglyceride (TG) content and stearoyl-CoA desaturase (SCD) indices in the soleus muscle were higher in the GC group than WC group in parallel with worsening serum glucose metabolic parameters. The glucose metabolic parameters were significantly improved in the GE group. The TG accumulation and SCD indices in the soleus muscle were also significantly lower in the GE group than in the GC group. In conclusion, dietary EWH not only improved glucose metabolism but also reduced both TG accumulation and SCD indices in the soleus muscle of GK rat.