RESUMO
This study was conducted to determine the best combination of protein sources in diets for jundiá, based on growth, metabolism, and nutrient deposition. Five protein combinations were tested: casein + fish meal (control), casein + gelatin, casein + albumin, casein + albumin + fish meal, and albumin + fish meal, in diets containing 370 g Kg-1 of crude protein and 13.4 MJ Kg-1 of digestible energy. The fish (9.38 ± 0.12 g) were allocated in a water recirculation system at a density of 3.35 g L-1 per experimental unit and fed until apparent satiety for 40 days with the diets. The fish fed with the control diet had the highest final weight, specific growth rate, protein and feed efficiency ratio, protein retention, and best apparent feed conversion. On the other hand, fish that received casein + albumin and albumin + fish meal diets showed worse results in growth and body protein retention, low trypsin and chymotrypsin activity, and high intestinal amylase activity. Therefore, the combination referred to as control (casein + fish meal) conclusively provides the best rhythm for nutrient digestion and metabolism processes, enabling fish to reach greater growth and retention of body protein with low whole-fish fat content.
Assuntos
Ração Animal , Proteínas Alimentares , Animais , Ração Animal/análise , Proteínas Alimentares/administração & dosagem , Proteínas Alimentares/metabolismo , Caseínas/administração & dosagem , Caseínas/metabolismo , Digestão/fisiologia , Digestão/efeitos dos fármacos , Fenômenos Fisiológicos da Nutrição AnimalRESUMO
Breast milk is known to contain bioactive peptides that are released during digestion, being a major source of bioactive peptides to the new-born, some of which act against invading pathogens. However, the formation of bioactive peptides during digestion of human colostrum remains largely uninvestigated. This study aimed to investigate the formation of peptides during simulated digestion of human colostrum from adult women and to prospect antimicrobial peptides. For this purpose, we used high-resolution MS to monitor the release of peptides during in vitro digestion. Bioinformatics was used for the prospection of antimicrobial activity of peptides. During simulated digestion (oral, gastric and duodenal phases), 2318 peptide sequences derived from 112 precursor proteins were identified. At the end of simulated digestion, casein-derived peptide sequences were the most frequently observed. Among precursors, some proteins were seen for the first time in this study. The resulting peptides were rich in proline, glutamine, valine and leucine residues, providing characteristic traits of antimicrobial peptides. From bioinformatics analysis, seven peptides showed potentially high antimicrobial activity towards bacteria, viruses and fungi, from which the latter was the most prominent predicted activity. Antimicrobial peptides released during digestion may provide a defence platform with controlled release for the new-born.
Assuntos
Anti-Infecciosos , Colostro , Adulto , Gravidez , Humanos , Feminino , Proteólise , Colostro/química , Espectrometria de Massas em Tandem , Peptídeos/química , Leite Humano/metabolismo , Cromatografia Líquida , Caseínas/metabolismo , Peptídeos Antimicrobianos , Proteômica/métodos , Anti-Infecciosos/farmacologia , Anti-Infecciosos/análise , Anti-Infecciosos/metabolismo , DigestãoRESUMO
Early-life adversity, like perinatal protein malnutrition, increases the vulnerability to develop long-term alterations in brain structures and function. This study aimed to determine whether perinatal protein malnutrition predisposes to premature aging in a murine model and to assess the cellular and molecular mechanisms involved. To this end, mouse dams were fed either with a normal (NP, casein 20%) or a low-protein diet (LP, casein 8%) during gestation and lactation. Female offspring were evaluated at 2, 7 and 12 months of age. Positron emission tomography analysis showed alterations in the hippocampal CA3 region and the accessory olfactory bulb of LP mice during aging. Protein malnutrition impaired spatial memory, coinciding with higher levels of reactive oxygen species in the hippocampus and sirt7 upregulation. Protein malnutrition also led to higher senescence-associated ß-galactosidase activity and p21 expression. LP-12-month-old mice showed a higher number of newborn neurons that did not complete the maturation process. The social-odor discrimination in LP mice was impaired along life. In the olfactory bulb of LP mice, the senescence marker p21 was upregulated, coinciding with a downregulation of Sirt2 and Sirt7. Also, LP-12-month-old mice showed a downregulation of catalase and glutathione peroxidase, and LP-2-month-old mice showed a higher number of newborn neurons in the subventricular zone, which then returned to normal values. Our results show that perinatal protein malnutrition causes long-term impairment in cognitive and olfactory skills through an accelerated senescence phenotype accompanied by an increase in oxidative stress and altered sirtuin expression in the hippocampus and olfactory bulb.
Assuntos
Senilidade Prematura , Desnutrição , Gravidez , Camundongos , Animais , Feminino , Memória Espacial , Senilidade Prematura/genética , Caseínas/metabolismo , Estresse Oxidativo , Transtornos da Memória/etiologia , Bulbo Olfatório/fisiologia , Desnutrição/complicações , Desnutrição/metabolismoRESUMO
Social cheating is the exploitation of public goods that are costly metabolites, like exoproteases. Exoprotease exploitation in Pseudomonas aeruginosa has been studied in reference strains. Experimental evolution with reference strains during continuous growth in casein has demonstrated that nonexoprotease producers that are lasR mutants are selected while they behave as social cheaters. However, noncanonical quorum-sensing systems exist in P. aeruginosa strains, which are diverse. In this work, the exploitation of exoproteases in the environmental strain ID4365 was evaluated; ID4365 has a nonsense mutation that precludes expression of LasR. ID4365 produces exoproteases under the control of RhlR, and harbors an inducible prophage. As expected, rhlR mutants of ID4365 behave as social cheaters, and exoprotease-deficient individuals accumulate upon continuous growth in casein. Moreover, in all continuous cultures, population collapses occur. However, this also sometimes happens before cheaters dominate. Interestingly, during growth in casein, ID4565's native prophage is induced, suggesting that the metabolic costs imposed by social cheating may increase its induction, promoting population collapses. Accordingly, lysogenization of the PAO1 lasR mutant with this prophage accelerated its collapse. These findings highlight the influence of temperate phages in social cheating.
Assuntos
Pseudomonas aeruginosa , Percepção de Quorum , Humanos , Percepção de Quorum/genética , Pseudomonas aeruginosa/genética , Caseínas/genética , Caseínas/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Lisogenia , Prófagos/genéticaRESUMO
Cadmium (Cd) is one of the most dangerous heavy metals that exists. A prolonged exposure to Cd causes toxic effects in a variety of tissues, including Central Nervous System (CNS), where it can penetrate the Blood Brain Barrier (BBB). Cd exposure has been linked to neurotoxicity and neurodegenerative diseases. Soy isoflavones have a strong antioxidant capacity, and they have been shown to have positive effects on cognitive function in females. However, the mechanisms underlying Cd neurotoxicity remain completely unresolved. The purpose of this study was to characterize the potential protective effect of a soy-based diet vs. a casein-based diet against Cd toxicity in rat cerebellum. Female Wistar rats were fed with casein (Cas) or soybean (So) as protein sources for 60 days. Simultaneously, half of the animals were administered either 15 ppm of Cadmium (CasCd and SoCd groups) in water or regular tap water as control (Cas and So groups). We analyzed Cd exposure effects on trace elements, oxidative stress, cell death markers, GFAP expression and the histoarchitecture of rat cerebellum. We found that Cd tissue content only augmented in the Cas intoxicated group. Zn, Cu, Mn and Se levels showed modifications among the different diets. Expression of Nrf-2 and the activities of CAT and GPx decreased in Cas and So intoxicated groups,while 3-NT expression increased only in the CasCd group. Morphometry analyses revealed alterations in the purkinje and granular cells morphology, decreased number of granular cells and reduced thickness of the granular layer in Cd-intoxicated rats, whereas no alterations were observed in animals under a So diet. In addition, mRNA expression of apoptotic markers BAX/Bcl-2 ratio and p53 expression increased only in the CasCd group, a finding confirmed by positive TUNEL staining in the cerebellum granule cell layer in the same group. Also, Cd intoxication elicited overexpression of GFAP by astrocytes, which was prevented by soy. White matter alterations were only subtle and characterized by intramyelinic edema in the CasCd group. Overall, these results unmask an irreversible toxic effect of a subchronic Cd intoxication on the cerebellum, and identify a protective role by a soy-based diet with potential as a therapeutic strategy for those individuals exposed to this dangerous environmental contaminant.
Assuntos
Cádmio , Oligoelementos , Ratos , Feminino , Animais , Cádmio/farmacologia , Glycine max , Oligoelementos/farmacologia , Ratos Wistar , Caseínas/metabolismo , Caseínas/farmacologia , Antioxidantes/farmacologia , Dieta , Estresse Oxidativo , HomeostaseRESUMO
We aimed to evaluate the incidence of unstable non-acid milk (UNAM) in cows fed either sugarcane or corn silage. Second, we aimed to evaluate the effect of daily variation (d 1 to 4) and alcohol grades (72, 78, and 80%) on UNAM incidence. The experiment was conducted as a split-plot crossover design, with 2 periods and 2 roughage types (sugarcane or corn silage). Thirteen multiparous Holstein cows with an average of 281 ± 29 d in milk were randomly distributed into 2 diets. Individual blood (analysis of total proteins, albumin, urea, calcium, phosphorus, magnesium, iron, chloride, glucose, and lactate) and milk samples (analysis of protein, fat, lactose and total solids, somatic cell count, and characterization of the protein profile) were collected during the last 4 d of each period. For UNAM identification, the alcohol test was conducted in milk samples at 4°C; specifically, if the sample presented the formation of clots, this would be noted as positive for UNAM. In addition, the Dornic acidity analysis was performed in the same samples to evaluate the true milk acidity. The use of sugarcane and higher degrees of alcohol were associated with increased UNAM. We observed no daily variation in UNAM. Nevertheless, we found no roughage type effect on the variables most commonly associated with UNAM, such as changes in salts in the casein micelle and, consequently, the zeta potential and the κ-casein (CN) fraction. The Pearson correlation analysis showed that the zeta potential and the concentrations of αS2-CN, blood ionic calcium, lactate, and glucose increased as the incidence of UNAM increased, showing a positive correlation among these variables. In contrast, the concentrations of lactose, phosphorus, and potassium decreased as UNAM increased, presenting a negative correlation. This study brought important discoveries to unveil why cows manifest UNAM. For instance, higher alcohol grades and cows fed with sugarcane had increased the incidence of UNAM. Additionally, animals with a higher incidence of UNAM (sugarcane-fed cows) were related to increased ionic calcium and glucose and changes in milk protein profile, with lower levels of BSA, ß-CN, and α-lactalbumin and greater αS1-CN content, all of which were correlated with UNAM. Nonetheless, this trial also provides evidence for the need for further studies to better understand the physiological mechanisms that directly affect the stability of milk protein.
Assuntos
Saccharum , Silagem , Feminino , Bovinos , Animais , Silagem/análise , Zea mays/metabolismo , Saccharum/metabolismo , Caseínas/metabolismo , Lactose/metabolismo , Lactação/fisiologia , Lactalbumina/metabolismo , Micelas , Incidência , Magnésio/metabolismo , Cálcio/metabolismo , Sais/metabolismo , Cloretos/metabolismo , Grão Comestível/química , Proteínas do Leite/análise , Fósforo/metabolismo , Glucose/metabolismo , Ureia/metabolismo , Lactatos/análise , Potássio/metabolismo , Ferro , Rúmen/metabolismoRESUMO
The study aimed to explore the in vitro digestion of a myoglobin diet and its relationship with the gut microbiota and intestinal barrier at two feeding time points. The in vitro study indicated that myoglobin diets had a higher α-helix content and lower digestibility. The particle sizes of the digested myoglobin diets were higher but their zeta potential values were lower than those of a casein diet. C57BL/6J mice were fed with a casein diet incorporated with 0, 0.38%, 1.13% and 3.39% myoglobin for 3 and 8 weeks. With the increase of the myoglobin content, the relative abundance of Akkermansia muciniphila increased significantly. Moreover, the content of short chain fatty acids tended to increase and then decrease as the myoglobin content increased at 3 weeks. Furthermore, the low-myoglobin diet upregulated the gene expression involved in colonic mucin and tight junction proteins by increasing the proportion of beneficial microbiota. However, the high-myoglobin diet had adverse effects.
Assuntos
Microbioma Gastrointestinal , Mucosa Intestinal , Mioglobina , Animais , Caseínas/metabolismo , Dieta , Dieta Hiperlipídica , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Muco/metabolismo , Mioglobina/administração & dosagem , VerrucomicrobiaRESUMO
OBJECTIVE: This work aims to evaluate the effects of enzyme concentration, pH, temperature and time course degree of hydrolysis (DH) of papain regarding further development of pharmaceutical and cosmetic formulations. METHODS: The hydrolysis of casein, collagen, keratin and porcine skin at pH and temperature ranges of the human skin was evaluated. Also, low contact times of enzyme-substrate were studied. The incorporation of 3mM of cysteine improved the caseinolytic (PU), collagenolytic (CU) and keratinolytic (KU) activities of papain. RESULTS: In general, the increase from 0.1 to 1.0 or 2.0 mgmL-1 of papain improved PU, CU and KU. When 2.0 mgmL-1 of papain was used, the highest DH of casein, collagen and keratin was obtained at 240min (14%, 35% and 6% respectively). The decrease in pH and temperature reduced all proteolytic activities, but papain maintained at least 50% and 40% of its activity at 26°C and pH 4.5 respectively. Scanning electron micrographs of the surface of the skin showed that papain application had exfoliating activity. CONCLUSION: This preformulation study demonstrated that papain concentration, time of application and pH of the product should be evaluated when developing a product to promote the hydrolysis of the proteins of the skin.
OBJECTIF: Ce travail vise à évaluer les effets de la concentration d'enzyme, du pH, de la température et du degré d'hydrolyse (DH) de la papaïne concernant le développement ultérieur de formulations pharmaceutiques et cosmétiques. MÉTHODES: L'hydrolyse de la caséine, du collagène, de la kératine et de la peau porcine à des plages de pH et de température de la peau humaine a été évaluée. De plus, des faibles temps de contact enzyme-substrat ont été étudiés. L'incorporation de 3mM de cystéine a amélioré les activités caséinolytiques (PU), collagénolytiques (CU) et kératinolytiques (KU) de la papaïne. RÉSULTATS: En général, l'augmentation de 0,1 à 1,0 ou 2,0 mg.mL−1 de papaïne a amélioré la PU, la CU et la KU. Lorsque 2,0 mg mL−1 de papaïne ont été utilisés, les DH les plus élevées de caséine, de collagène et de kératine ont été obtenues à 240 min (14, 35 et 6 %, respectivement). La diminution du pH et de la température a réduit toutes les activités protéolytiques, mais la papaïne a maintenu au moins 50 et 40 % de son activité à 26 °C et pH 4,5, respectivement. Des micrographies obtenues par microscopie électronique à balayage de la surface de la peau ont montré que l'application de la papaïne avait une activité exfoliante. CONCLUSION: Cette étude de pré-formulation a démontré que la concentration de papaïne, le temps d'application et le pH du produit doivent être évalués lors du développement d'un produit pour favoriser l'hydrolyse des protéines de la peau.
Assuntos
Caseínas , Papaína , Animais , Humanos , Caseínas/metabolismo , Colágeno/metabolismo , Queratinas , Papaína/metabolismo , SuínosRESUMO
Obesity is mainly caused by excess energy intake and physical inactivity, and the number of overweight/obese individuals has been steadily increasing for decades. Previous studies showed that rodents fed westernized diets exhibit endocrine pancreas deterioration and a range of metabolic disorders. This study evaluated the effects of moderated aerobic treadmill exercise training on pancreatic islet cell viability and function in mice consuming a high-fat and sucrose diet. In the present study, 60-day-old male C57BL/6J mice were divided into four groups: control (C), fed a standard diet AIN-93M (3.83 kcal/g; 70% carbohydrate (cornstarch and dextrinized starch were chosen as the major source of carbohydrate for the AIN-93 diet. In addition, a small amount of sucrose), 20% protein (casein), and 10% fat (soybean) with no training (i.e., sedentary); C + training (CTR, fed the standard diet with eight weeks of exercise; high-fat diet + sucrose (HFDS), fed a high fat and sucrose diet (5.2 kcal/g; 20% carbohydrate (cornstarch and dextrinized starch were chosen as the major source of carbohydrate), 20% protein (casein), 60% fat (Lard was chosen as the major source of fat and a small amount of soybean) + 20% sucrose diluted in drinking water with no training; and HFDS + training (HFDSTR). After eight weeks, the HFDS mice displayed increased body weight (P<0.001) and epididymal, inguinal and retroperitoneal adipose tissue mass (P<0.01). These mice also presented insulin resistance (P<0.01), glucose intolerance (P<0.001), impaired glucose-stimulated insulin secretion (GSIS) and were less responsive to the physiological net ROS production induced by glucose stimulus. The HFDS group's pancreatic islet cells were 38% less viable and 59% more apoptotic than those from the C group (P<0.05). The HFDSTR improved glucose tolerance, body mass, insulin sensitivity and GSIS (P<0.05). Furthermore, HFDSTR mice had 53% more viable isolated pancreatic islets cells and 29% fewer apoptotic cells than the HFDS group (P<0.01). Thus, exercise training may slow down and/or prevent adverse metabolic effects associated with consuming a westernized diet.
Assuntos
Resistência à Insulina , Ilhotas Pancreáticas , Animais , Caseínas/metabolismo , Dieta Hiperlipídica/efeitos adversos , Glucose/metabolismo , Insulina/metabolismo , Resistência à Insulina/fisiologia , Ilhotas Pancreáticas/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/metabolismo , Obesidade/prevenção & controle , Amido , Sacarose/metabolismoRESUMO
This work aimed to evaluate the effect of carbonylation induced by tetracyclines, ß-lactams, fluoroquinolones, and pyrethroids in caseins of bovine origin on their immunoreactivity and allergenicity. Using a spectrophotometric method, ELISA, dot-blot, and an IgE-mediated milk allergy mouse model, we confirmed that antibiotics and pesticides at their maximum residue limit, promoted the in vitro carbonylation of caseins (among 5.0 ± 0.01 and 67.5 ± 0.70 nmol of carbonyl/mg of protein); furthermore, carbonylations greater than 19 nmol significantly increase the in vitro IgE immunoreactivity of caseins (average OD among 0.63-1.50) regarding the negative control (average OD: 0.56). On the other hand, sensitized mice exposed to oxidized caseins showed increased clinical scores (2-5), positive skin tests, and footpad swelling (0.28-0.59 mm) compared to the negative control (1-2; negative skin tests; 0.1 mm, respectively), denoting increased allergenicity. These results suggest that casein carbonylation increases their IgE immunoreactivity and allergenicity, a fact that could be explained by the resistance to the digestion promoted by carbonylation and by conformational changes in the random coil casein structure, which can expose cryptic epitopes or neoepitopes.