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Biology of Sport Apr 2023This double-blind randomised placebo-controlled trial aimed to investigate the effects of α-lactalbumin consumption on sleep quality and quantity in female rugby union...
This double-blind randomised placebo-controlled trial aimed to investigate the effects of α-lactalbumin consumption on sleep quality and quantity in female rugby union athletes during a competition season. Eighteen semi-professional female rugby union players (age 23.8 ± 5.2 y; mean ± SD) wore wrist actigraphy watches for four seven-day blocks corresponding to the pre-season, a home game, a bye week (i.e. no competition game scheduled) and an away game. Participants consumed either an α-lactalbumin (α-LAC), or placebo drink (PLA) every night two hours before bed for the duration of the season. Generalised linear mixed models were used to investigate the effects of the nutritional intervention on sleep variables (total sleep time, sleep efficiency (SE), sleep onset latency (SOL) and wake after sleep onset) over the duration of the season. There was a significant condition by period interaction effect on SOL (p = 0.01). While similar at baseline (23.3 ± 16.3 and 23.2 ± 18.9 min α-LAC and placebo respectively) and for the home game (22.4 ± 17.6 and 19.3 ± 14.9 min α-LAC and placebo respectively), SOL was reduced in the α-LAC group for the bye (11.6 ± 13.4 min) and away game (17.0 ± 11.5 min; p = 0.045). In comparison, SOL remained unchanged in the PLA group (bye 21.2 ± 17.3 and away 22.5 ± 18.5 min). Pre-sleep α-lactalbumin consumption improved SOL in a semi-professional female team-sport cohort. Thus, α-lactalbumin could be utilised by athletes to support sleep during a competitive season.
PubMed: 37077794
DOI: 10.5114/biolsport.2023.116002 -
Journal of Mammary Gland Biology and... Jun 2021Milk is critical for the survival of all mammalian offspring, where its production by a mammary gland is also positively associated with its lactose concentration. A... (Review)
Review
Milk is critical for the survival of all mammalian offspring, where its production by a mammary gland is also positively associated with its lactose concentration. A clearer understanding of the factors that regulate lactose synthesis stands to direct strategies for improving neonatal health while also highlighting opportunities to manipulate and improve milk production and composition. In this review we draw a cross-species comparison of the extra- and intramammary factors that regulate lactose synthesis, with a special focus on humans, dairy animals, and rodents. We outline the various factors known to influence lactose synthesis including diet, hormones, and substrate supply, as well as the intracellular molecular and genetic mechanisms. We also discuss the strengths and limitations of various in vivo and in vitro systems for the study of lactose synthesis, which remains an important research gap.
Topics: Animals; Cattle; Female; Humans; Lactation; Lactose; Mammary Glands, Animal; Mammary Glands, Human; Milk; Rodentia; Species Specificity
PubMed: 34125363
DOI: 10.1007/s10911-021-09491-6 -
Frontiers in Genetics 2022Milk production by dairy cows is sensitive to increased levels of stress hormones such as glucocorticoids (GC) that also regulate the transcription of several genes...
Milk production by dairy cows is sensitive to increased levels of stress hormones such as glucocorticoids (GC) that also regulate the transcription of several genes required for milk synthesis. Whereas previous studies identified that an exogenous GC such as dexamethasone (DEX) transiently suppresses milk yield in several species without any pronounced effect on milk protein or fat percentage, the mechanism underlying this effect has not been established. In this study we sought to establish changes within the mammary glands of non-pregnant dairy cows in their second lactation ( = 3-4; 648-838 kg) following a single dose of exogenous DEX. Changes in the udder were monitored by serial biopsy of alternating quarters, concurrent with quarter-level monitoring of milk yield and composition. Dexamethasone increased serum glucose levels from 12-36 h ( <0 .05), reduced milk yield from 12-48 h ( <0 .05), increased % milk protein content at 24 h post-DEX, and transiently decreased both milk lactose and α-lactalbumin content, while not altering the level of milk fat. After 72 h, all aspects of milk production had returned to pre-treatment levels. Transcriptomic changes in the mammary glands in response to DEX were identified by RNA sequencing followed by differential gene expression analysis. Coincident with the milk yield and composition changes was the differential expression of 519 and 320 genes at 12 and 24 h after DEX (adjusted <0 .05), respectively, with the return of all gene expression to baseline levels by 72 h. Among the transcriptomic changes in response to DEX, there was notable downregulation of elements in the lactose synthesis pathway, specifically and (α-lactalbumin) at 12 h, and sustained downregulation of at 24 h. One gene in the pathway, , was upregulated at 12-24 h post-DEX. This work supports the hypothesis that there is a direct relationship between the response to DEX and the concurrent suppression of milk yield due to the reduced synthesis of α-lactalbumin and lactose by the mammary epithelium. The ability of glucocorticoids to modulate the homeorrhetic requirements for glucose during stressful states concurrent with immune activation bears significance for dairy animals as well as a broad range of lactating mammals.
PubMed: 36561310
DOI: 10.3389/fgene.2022.1072853 -
Nutrients Jan 2020Human milk is rich in nutritional factors, such as alpha-lactalbumin (α-Lac), and important for neonatal development, but nutrient supplementation may be required for...
Human milk is rich in nutritional factors, such as alpha-lactalbumin (α-Lac), and important for neonatal development, but nutrient supplementation may be required for optimal growth. Using a pig model, we hypothesized that α-Lac-enriched whey protein concentrate (WPC) supplementation improves neonatal development. Cesarean-delivered preterm pigs were fed either dilute bovine milk (REF) or REF milk supplemented with WPC with normal (STANDARD-ALPHA) or high (HIGH-ALPHA) α-Lac. Clinical, gut, immune and cognitive endpoints (open field, T-maze) were assessed and tissues collected at Day 19. The growth of STANDARD-ALPHA and HIGH-ALPHA were higher than REF (31 vs. 19 g/kg/d). Most organ weights, gut, immunity and brain variables were similar between WPC groups. HIGH-ALPHA had a higher bone mineral content, colon microbial diversity and an abundance of specific bacteria and microbial metabolites, and tended to show a faster food transit time ( = 0.07). Relative to REF, WPC pigs showed higher relative organ weights, blood amino acids, blood neutrophil function, and microbial metabolites, but lower brush-border enzyme activities and plasma cortisol. Cognition outcomes did not differ among the groups. In conclusion, WPC supplementation of milk improved some growth, gut and immunity parameters in preterm pigs. However, increasing the α-Lac content beyond human milk levels had limited effects on the immature gut and developing brain.
Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Animals, Newborn; Behavior, Animal; Brain; Cognition; Food, Formulated; Gastrointestinal Microbiome; Gestational Age; Immune System; Intestines; Lactalbumin; Nutritional Status; Nutritive Value; Sus scrofa; Whey Proteins
PubMed: 31963562
DOI: 10.3390/nu12010245 -
Foods (Basel, Switzerland) Jan 2024Protein content variation in milk can impact the quality and consistency of dairy products, necessitating access to in-line real time monitoring. Here, we present a...
Protein content variation in milk can impact the quality and consistency of dairy products, necessitating access to in-line real time monitoring. Here, we present a chemometric approach for the qualitative and quantitative monitoring of β-lactoglobulin and α-lactalbumin, using mid-infrared spectroscopy (MIR). In this study, we employed Hotelling T2 and Q-residual for outlier detection, automated preprocessing using nippy, conducted wavenumber selection with genetic algorithms, and evaluated four chemometric models, including partial least squares, support vector regression (SVR), ridge, and logistic regression to accurately predict the concentrations of β-lactoglobulin and α-lactalbumin in milk. For the quantitative analysis of these two whey proteins, SVR performed the best to interpret protein concentration from 197 MIR spectra originating from 42 Cornell University samples of preserved pasteurized modified milk. The R values obtained for β-lactoglobulin and α-lactalbumin using leave one out cross-validation (LOOCV) are 92.8% and 92.7%, respectively, which is the highest correlation reported to date. Our approach introduced a combination of preprocessing automation, genetic algorithm-based wavenumber selection, and used Optuna to optimize the framework for tuning hyperparameters of the chemometric models, resulting in the best chemometric analysis of MIR data to quantitate β-lactoglobulin and α-lactalbumin to date.
PubMed: 38201194
DOI: 10.3390/foods13010166 -
Nutrients Feb 2018Obesity-induced adipose inflammation has been demonstrated to be a key cause of insulin resistance. Peptides derived from bovine α-lactalbumin have been shown to...
Obesity-induced adipose inflammation has been demonstrated to be a key cause of insulin resistance. Peptides derived from bovine α-lactalbumin have been shown to inhibit the activities of dipeptidyl peptidase IV (DPP-IV) and angiotensin converting enzyme (ACE), scavenge 2,2'-azinobis [3-ethylbenzothiazoline-6-sulfonate] (ABTS⁺) radical and stimulate glucagon-like peptide-2 secretion. In the present study, the effects of bovine α-lactalbumin hydrolysates (α-LAH) on adipose insulin resistance and inflammation induced by high-fat diet (HFD) were investigated. The insulin resistance model was established by feeding C57BL/6J mice with HFD (60% kcal from fat) for eight weeks. Then, the mice were fed with HFD and bovine α-LAH of different doses (100 mg/kg b.w., 200 mg/kg b.w. and 400 mg/kg b.w.) for another 12 weeks to evaluate its protective effects against HFD-induced insulin resistance. The oral glucose tolerance test (OGTT) and intraperitoneal insulin tolerance test (ipITT) were conducted after intervention with α-LAH for 10 weeks and 11 weeks, respectively. Results showed that bovine α-LAH significantly reduced body weight, blood glucose, serum insulin, and HOMA-IR (homeostatic model assessment of insulin resistance) levels, lowered the area-under-the-curve (AUC) during OGTT and ipITT, and downregulated inflammation-related gene [tumor necrosis factor (TNF)-α, interleukin (IL)-6, monocyte chemoattractant protein (MCP)-1] expression in adipose tissues of HFD-fed C57BL/6J mice. Furthermore, bovine α-LAH also suppressed insulin receptor substrate 1 (IRS-1) serine phosphorylation (Ser307, Ser612), enhanced protein kinase B (known as Akt) phosphorylation, and inhibited the activation of inhibitor of kappaB kinase (IKK) and mitogen activated protein kinase (MAPK) signaling pathways in adipose tissues of HFD-fed C57BL/6J mice. These results suggested that bovine α-LAH could ameliorate adipose insulin resistance and inflammation through IKK and MAPK signaling pathways in HFD-fed C57BL/6J mice.
Topics: Adiposity; Animals; Blood Glucose; Body Weight; Cattle; Chemokine CCL2; Cytokines; Diet, High-Fat; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Gene Expression Regulation; Glucose Tolerance Test; Inflammation; Insulin; Insulin Receptor Substrate Proteins; Insulin Resistance; Lactalbumin; Male; Mice; Mice, Inbred C57BL; Mitogen-Activated Protein Kinases; Peptidyl-Dipeptidase A; Phosphorylation; Protein Hydrolysates; Proto-Oncogene Proteins c-akt
PubMed: 29473848
DOI: 10.3390/nu10020242 -
Molecules (Basel, Switzerland) Oct 2021In complex foods, bioactive secondary plant metabolites (SPM) can bind to food proteins. Especially when being covalently bound, such modifications can alter the...
In complex foods, bioactive secondary plant metabolites (SPM) can bind to food proteins. Especially when being covalently bound, such modifications can alter the structure and, thus, the functional and biological properties of the proteins. Additionally, the bioactivity of the SPM can be affected as well. Consequently, knowledge of the influence of chemical modifications on these properties is particularly important for food processing, food safety, and nutritional physiology. As a model, the molecular structure of conjugates between the bioactive metabolite benzyl isothiocyanate (BITC, a hydrolysis product of the glucosinolate glucotropaeolin) and the whey protein α-lactalbumin (α-LA) was investigated using circular dichroism spectroscopy, anilino-1-naphthalenesulfonic acid fluorescence, and dynamic light scattering. Free amino groups were determined before and after the BITC conjugation. Finally, mass spectrometric analysis of the BITC-α-LA protein hydrolysates was performed. As a result of the chemical modifications, a change in the secondary structure of α-LA and an increase in surface hydrophobicity and hydrodynamic radii were documented. BITC modification at the ε-amino group of certain lysine side chains inhibited tryptic hydrolysis. Furthermore, two BITC-modified amino acids were identified, located at two lysine side chains (K32 and K113) in the amino acid sequence of α-LA.
Topics: Amino Acid Sequence; Animals; Cattle; Circular Dichroism; Food Handling; Food Safety; Humans; Hydrodynamics; Hydrophobic and Hydrophilic Interactions; Isothiocyanates; Lactalbumin; Models, Molecular; Molecular Structure; Peptide Fragments; Protein Stability; Protein Structure, Secondary; Proteolysis; Tandem Mass Spectrometry
PubMed: 34684828
DOI: 10.3390/molecules26206247 -
Journal of Clinical Medicine Dec 2023Type 2 diabetes mellitus (T2DM) is characterized by high blood glucose levels and lipid alterations. Besides pharmacological treatment, lifestyle modifications and...
Type 2 diabetes mellitus (T2DM) is characterized by high blood glucose levels and lipid alterations. Besides pharmacological treatment, lifestyle modifications and nutraceuticals can be used to manage glucose and lipid profiles, which is crucial for preventing, or avoiding, serious consequences associated with the condition. This randomized controlled clinical trial on 75 patients with T2DM evaluated the effects of a combination of myo-inositol and d-chiro-inositol (40:1), α-lactalbumin, Gymnema sylvestre, and zinc on glucose and lipid profile. The intention-to-treat analysis displayed no significant differences in glucose parameters between the groups; however, the study group displayed reduced levels of total cholesterol ( = 0.01) and LDL ( = 0.03) after 3 months of supplementation. A subgroup analysis involving patients who did not modify their antidiabetic therapy, after 6 months displayed improved levels of total cholesterol ( = 0.03) and LDL ( = 0.04) in the study group versus placebo, along with a greater body weight reduction ( = 0.03) after 3 months. Furthermore, within the study group, levels of HDL ( = 0.03) and triglycerides ( = 0.04) improved after 3 months. These findings support supplementation with myo-inositol and d-chiro-inositol (40:1), α-lactalbumin, Gymnema sylvestre, and zinc as an adjuvant and safe strategy to manage the lipid profiles of patients with T2DM.
PubMed: 38137721
DOI: 10.3390/jcm12247650 -
Scientific Reports Aug 2017Whey protein promotes weight loss and improves diabetic control, however, less is known of its bioactive components that produce such benefits. We compared the effects...
Whey protein promotes weight loss and improves diabetic control, however, less is known of its bioactive components that produce such benefits. We compared the effects of normal protein (control) diet with high protein diets containing whey, or its fractions lactalbumin and lactoferrin, on energy balance and metabolism. Diet-induced obese rats were randomized to isocaloric diets: Control, Whey, Lactalbumin, Lactoferrin, or pair-fed to lactoferrin. Whey and lactalbumin produced transient hypophagia, whereas lactoferrin caused prolonged hypophagia; the hypophagia was likely due to decreased preference. Lactalbumin decreased weight and fat gain. Notably, lactoferrin produced sustained weight and fat loss, and attenuated the reduction in energy expenditure associated with calorie restriction. Lactalbumin and lactoferrin decreased plasma leptin and insulin, and lactalbumin increased peptide YY. Whey, lactalbumin and lactoferrin improved glucose clearance partly through differential upregulation of glucoregulatory transcripts in the liver and skeletal muscle. Interestingly, lactalbumin and lactoferrin decreased hepatic lipidosis partly through downregulation of lipogenic and/or upregulation of β-oxidation transcripts, and differentially modulated cecal bacterial populations. Our findings demonstrate that protein quantity and quality are important for improving energy balance. Dietary lactalbumin and lactoferrin improved energy balance and metabolism, and decreased adiposity, with the effects of lactoferrin being partly independent of caloric intake.
Topics: Adiposity; Animals; Body Weight; Diet; Energy Intake; Energy Metabolism; Insulin; Lactalbumin; Lactoferrin; Leptin; Male; Obesity; Peptide YY; Rats; Whey Proteins
PubMed: 28855697
DOI: 10.1038/s41598-017-09781-2 -
Journal of Dairy Science Dec 2020Camel milk has unique physical, nutritional, and technological properties when compared with other milks, especially bovine. Because proteins confer many of the... (Comparative Study)
Comparative Study
Camel milk has unique physical, nutritional, and technological properties when compared with other milks, especially bovine. Because proteins confer many of the properties of milk and its products, this study aimed to determine the proteins of camel milk, their correlations, and relative distribution. Raw milk samples were collected from 103 dromedary camels in the morning and evening. Capillary electrophoresis results showed wide variation in the concentrations (g/L) of proteins between samples as follows: α-lactalbumin, 0.3 to 2.9; α-casein, 2.4 to 10.3; α-casein, 0.3 to 3.9; β-casein, 5.5 to 29.0; κ-casein, 0.1 to 2.4; unknown casein protein 1, 0.0 to 3.4; and unknown casein protein 2, 0.0 to 4.6. The range in percent composition of the 4 caseins were as follows: α, 12.7 to 35.3; α, 1.8 to 20.8; β, 42.3 to 77.4; and κ, 0.6 to 17.4. The relative proportion of α-, α-, β-, and κ-caseins in camel milk (26:4:67:3, wt/wt) differed from that of bovine milk (38:10:36:12, wt/wt). This difference might explain the dissimilarity between the 2 milks with respect to technical and nutritional properties.
Topics: Animals; Camelus; Caseins; Cattle; Electrophoresis, Capillary; Lactalbumin; Milk; Milk Proteins; Nutritive Value; Species Specificity
PubMed: 33069408
DOI: 10.3168/jds.2020-19122