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1.
Molecules ; 26(13)2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-34203276

RESUMO

Regioisomers (or positional isomers) of triacylglycerols (TAGs) of milk are known to show differential outcome in relation to human absorption. Quantitation of TAG regioisomers remains a big challenge due to the lack of facile chromatographic separation technique. The feasibility of using fragment ion intensity ratio to determine the ratio of co-eluting AAB/ABA-type regioisomer pairs was confirmed in this study. The ability of C30 stationary phase in resolving interfering TAG isomers was demonstrated for the first time. This allowed us to reveal the complexity of using fragment ion intensity to quantify 1,2-olein-3-palmitin (OOP), 1,3-olein-2-palmitin (OPO), 1,2-olein-3-stearin (OOS), and 1,3-olein-2-stearin (OSO) regioisomers in milk samples. A novel algorithm was proposed to consider the contribution of OPO/OOP and OSO/OOS double bond (DB)-isomers and to eliminate the interference of isobaric ions from other isomers, an aspect overlooked in previous studies. This liquid chromatography-mass spectrometry method that requires no pre-fractioning and a moderate chromatographic separation time of 36 min is simple and, thus, suitable for screening a large number of samples for genetic analysis of this trait. Preliminary results using a small cohort of animals showed that OPO/OOP ratio differs significantly between Jersey and Holstein cows, and a large variation was also observed across individual Holstein cows.


Assuntos
Cruzamento , Leite/metabolismo , Triglicerídeos/metabolismo , Animais , Bovinos , Cromatografia Líquida de Alta Pressão , Feminino , Estereoisomerismo , Triglicerídeos/química , Triglicerídeos/isolamento & purificação
2.
Toxins (Basel) ; 13(6)2021 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-34073628

RESUMO

Hypoglycin A (HGA) originating from soapberry fruits (litchi, and ackee) seeds or seedlings from the sycamore maple (SM) tree (related to Sapindaceae) may cause Jamaican vomiting sickness in humans and atypical myopathy in horses and ruminants. A possible transfer into dairy cow's milk cannot be ruled out since the literature has revealed HGA in the milk of mares and in the offal of captured deer following HGA intoxication. From a study, carried out for another purpose, bulk raw milk samples from four randomly selected dairy farms were available. The cows were pastured in the daytime. A sycamore maple tree was found on the pasture of farm No. 1 only. Bulk milk from the individual tank or milk filling station was sampled in parallels and analyzed for HGA by LC-ESI-MS/MS. Measurable concentrations of HGA occurred only in milk from farm No. 1 and amounted to 120 and 489 nmol/L. Despite low and very variable HGA concentrations, the results indicate that the ingested toxin, once eaten, is transferred into the milk. However, it is unknown how much HGA the individual cow ingested during grazing and what amount was transferred into the bulk milk samples. As a prerequisite for a possible future safety assessment, carry-over studies are needed. Furthermore, the toxins' stability during milk processing should also be investigated as well.


Assuntos
Hipoglicinas/análise , Leite/química , Animais , Bovinos , Feminino , Hipoglicinas/metabolismo , Leite/metabolismo , Projetos Piloto
3.
Molecules ; 26(11)2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-34071375

RESUMO

Milk and colostrum have high biological potential, and due to their natural origin and non-toxicity, they have many uses in cosmetics and dermatology. Research is ongoing on their potential application in other fields of medicine, but there are still few results; most of the published ones are included in this review. These natural products are especially rich in proteins, such as casein, ß-lactoglobulin, α-lactalbumin, lactoferrin, immunoglobulins, lactoperoxidase, lysozyme, and growth factors, and possess various antibacterial, antifungal, antiviral, anticancer, antioxidant, immunomodulatory properties, etc. This review describes the physico-chemical properties of milk and colostrum proteins and the natural functions they perform in the body and compares their composition between animal species (cows, goats, and sheep). The milk- and colostrum-based products can be used in dietary supplementation and for performing immunomodulatory functions; they can enhance the effects of certain drugs and can have a lethal effect on pathogenic microorganisms. Milk products are widely used in the treatment of dermatological diseases for promoting the healing of chronic wounds, hastening tissue regeneration, and the treatment of acne vulgaris or plaque psoriasis. They are also increasingly regarded as active ingredients that can improve the condition of the skin by reducing the number of acne lesions and blackheads, regulating sebum secretion, ameliorating inflammatory changes as well as bestowing a range of moisturizing, protective, toning, smoothing, anti-irritation, whitening, soothing, and antiaging effects.


Assuntos
Colostro/metabolismo , Cosméticos , Proteínas do Leite/química , Leite/metabolismo , Animais , Antibacterianos/farmacologia , Antifúngicos/farmacologia , Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Antivirais/farmacologia , Caseínas/química , Dermatologia/métodos , Humanos , Imunoglobulinas/química , Fatores Imunológicos/farmacologia , Peptídeos e Proteínas de Sinalização Intercelular/química , Lactalbumina/química , Lactoferrina/química , Lactoglobulinas/química , Lactoperoxidase/química , Muramidase/química , Pele/efeitos dos fármacos , Especificidade da Espécie
4.
Toxins (Basel) ; 13(5)2021 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-34069117

RESUMO

The present study was aimed at investigating the effects of sodium butyrate and sodium ß-hydroxybutyrate on lactation and health of dairy cows fed a high-concentrate (HC) diet. Eighty mid-lactation dairy cows with an average milk yield of 33.75 ± 5.22 kg/d were randomly allocated to four groups (n = 20 per group) and were fed either a low-concentrate (LC) diet, a HC diet, the HC diet with 1% sodium butyrate (HCSB), or the HC diet with 1% sodium ß-hydroxybutyrate (HCHB). The feeding trial lasted for 7 weeks, with a 2-week adaptation period and a 5-week measurement period, and the trial started from 96 ± 13 d in milk. Sodium butyrate supplementation delayed the decline in milk production and improved milk synthesis efficiency and milk fat content. Additionally, it decreased the proinflammatory cytokines and acute phase proteins (APPs) in plasma, the leucocytes in blood, the somatic cell count (SCC) in milk, and the gene expression of pattern recognition receptors (PRRs) and proinflammatory cytokines in the mammary gland, due to decreasing the contents of bacterial cell wall components (lipopolysaccharide, LPS; peptidoglycan, PGN; and lipoteichoic acid, LTA) in the rumen and plasma, compared with the HC diet. Sodium ß-hydroxybutyrate supplementation also improved milk yield, milk synthesis efficiency and milk fat content and partially reduced the adverse effects caused by the HC diet, but it had no effect on decreasing bacterial cell wall components in the rumen and plasma, compared with the HC diet. Collectively, both sodium butyrate and sodium ß-hydroxybutyrate mitigated the negative effects of HC diet on lactation and health of dairy cows, with sodium butyrate being more effective than sodium ß-hydroxybutyrate.


Assuntos
Ácido 3-Hidroxibutírico/farmacologia , Ração Animal/efeitos adversos , Bactérias/isolamento & purificação , Ácido Butírico/farmacologia , Animais , Bovinos , Parede Celular/metabolismo , Dieta/veterinária , Feminino , Lactação , Leite/metabolismo , Rúmen/metabolismo
5.
Food Chem ; 361: 130143, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34051596

RESUMO

We previously observed that sialylated bovine milk oligosaccharides (BMOs) decline in both absolute and relative abundances over the initial stages of bovine lactation, with initial evidence suggesting that this decline occurred due to increased concentrations of unique sulfated BMOs. Since both sulfated and sialylated BMOs have distinct bioactivites, a follow up study was launched in order to more clearly define relative changes in these classes of BMOs over the first week of lactation in dairy cattle. Capillary electrophoresis (CE) and several liquid chromatography mass spectrometry (LC-MS) methods, including a novel multiplexed tandem MS method, were used to profile the BMOs extracted from milk collected from the same 20 Holstein cows at milkings 1, 2, 3, 4, 8, and 14 post-partum. In addition to clearly validating that sulfated and sialylated BMOs exist in direct biosynthetic completion, our study has identified over 170 unique BMOs including 14 unique glucuronic acid-containing trisaccharides.


Assuntos
Leite/química , Oligossacarídeos/biossíntese , Oligossacarídeos/química , Animais , Bovinos , Cromatografia Líquida , Eletroforese Capilar , Feminino , Ácido Glucurônico/análise , Ácido Glucurônico/química , Ácido Glucurônico/metabolismo , Glicoconjugados/química , Glicoconjugados/metabolismo , Lactação , Espectrometria de Massas , Leite/metabolismo , Ácido N-Acetilneuramínico/análise , Ácido N-Acetilneuramínico/metabolismo , Oligossacarídeos/análise , Oligossacarídeos/metabolismo , Sulfatos/química
6.
J Dairy Sci ; 104(8): 9287-9303, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33934856

RESUMO

Improving feed utilization efficiency in dairy cattle could have positive economic and environmental effects that would support the sustainability of the dairy industry. Identifying key differences in metabolism between high and low feed-efficient animals is vital to enhancing feed conversion efficiency. Therefore, our objectives were (1) to determine whether cows grouped by either high or low feed efficiency have measurable differences in net fat and carbohydrate metabolism that account for differences in heat production (HP), and if so, whether these differences also exists under conditions of feed withdrawal when the effect of feeding on HP is minimized, and (2) to determine whether the abundance of mitochondria in the liver can be related to the high or low feed-efficient groups. Ten dairy cows from a herd of 15 (parity = 2) were retrospectively grouped into either a high (H) or a low (L) feed-efficient group (n = 5 per group) based on weekly energy-corrected milk (ECM) divided by dry mater intake (DMI) from wk 4 through 30 of lactation. Livers were biopsied at wk -4, 2, and 12, and blood was sampled weekly from wk -3 to 12 relative to parturition. Blood was subset to be analyzed for the transition period (wk -3 to 3) and from wk 4 to 12. In wk 5.70 ± 0.82 (mean ± SD) postpartum (PP), cows spent 2 d in respiration chambers (RC), in which CO2, O2, and CH4 gases were measured every 6 min for 24 h. Fatty acid oxidation (FOX), carbohydrate oxidation (COX), metabolic respiratory quotient (RQ), and HP were calculated from gas measurements for 23 h. Cows were fed ad libitum (AD-LIB) on d 1 and had feed withdrawn (RES, restricted diet) on d 2. Additional blood samples were taken at the end of the AD-LIB and RES feeding periods in the RC. During wk 4 to 30 PP, H had greater DMI/kg of metabolic body weight (BW0.75), ECM per kilogram of BW0.75 yield, and ECM/DMI ratio, compared with L, but a lower body condition score between wk 4 and 12 PP. In the RC period, we detected no differences in BW, DMI, or milk yield between groups. We also detected no significant group or group by feeding period interactions for plasma metabolites except for Revised Quantitative Insulin Sensitivity Check Index, which tended to have a group by feeding period interaction. The H group had lower HP and HP per kilogram of BW0.75 compared with L. Additionally, H had lower FOX and FOX per kilogram of BW0.75 compared with L during the AD-LIB period. Methane, CH4 per kilogram of BW0.75, and CH4 per kilogram of milk yield were lower in H compared with L, but, when adjusted for DMI, CH4/DMI did not differ between groups, nor did HP/DMI. Relative mitochondrial DNA copy numbers in the liver were lower in the L than in the H group. These results suggest that lower feed efficiency in dairy cows may result from fewer mitochondria per liver cell as well as a greater whole-body HP, which likely partially results from higher net fat oxidation.


Assuntos
Ração Animal , DNA Mitocondrial , Animais , Bovinos , Variações do Número de Cópias de DNA , Dieta/veterinária , Metabolismo Energético , Feminino , Lactação , Fígado , Leite/metabolismo , Mitocôndrias , Gravidez , Estudos Retrospectivos , Termogênese
7.
Res Vet Sci ; 137: 194-200, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34020334

RESUMO

BACKGROUND: Fat metabolism is a complex process regulated by a number of factors. Adiponectin receptor 1 (ADIPOR1) gene takes active part in lipid metabolism. Although, there have been some researches indicating that ADIPOR1 could influence the milk fat metabolism through targeting some factors, little is known about the effect of ADIPOR1 on goat milk fat metabolism. To investigate the regulatory role of ADIPOR1 on milk fat metabolism in GMECs, we analysed overexpression in the presence and absence of AdipoRon (50 µM) and examined knockdown using siRNA. Using RT-qPCR, we assessed ADIPOR1 mRNA expressions among different lactation stages in goat mammary gland and the expression of six genes that regulate milk fat metabolism in GMECs. RESULTS: ADIPOR1 mRNA expression level was higher during the various lactation stages, except dry-off period. Knockdown and overexpression results revealed a significant decrease and increase in mRNA expression of ADIPOR1 and genes considered: SREBF1, ACACA, FASN, SCD, ATGL, and HSL, respectively. Treatment of GMECs with AdipoRon 50 µM resulted in a significant (p < 0.05) increase in the mRNA expression of all measured genes, except SREBF1. CONCLUSION: Overall, ADIPOR1 plays a central role in regulating the transcription of several genes involved in milk fat metabolism.


Assuntos
Gorduras/metabolismo , Cabras/genética , Cabras/metabolismo , Metabolismo dos Lipídeos/genética , Glândulas Mamárias Animais/metabolismo , Leite/metabolismo , Receptores de Adiponectina/genética , Animais , Contagem de Células/veterinária , Células Epiteliais/metabolismo , Feminino , Regulação da Expressão Gênica , Lactação/metabolismo , RNA Mensageiro , RNA Interferente Pequeno/metabolismo , Receptores de Adiponectina/metabolismo
8.
FASEB J ; 35(5): e21455, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33913197

RESUMO

Mammal's milk is an abundantly foremost source of proteins, lipids, and micronutrients for human nutrition and health. Understanding the molecular mechanisms underlying synthesis of milk components provides practical benefits to improve the milk quality via systematic breeding program in mammals. Through RNAi with EEF1D in primary bovine mammary epithelial cells, we phenotypically observed aberrant formation of cytoplasmic lipid droplets and significantly decreased milk triglyceride level by 37.7%, and exploited the mechanisms by which EEF1D regulated milk lipid synthesis via insulin (PI3K-Akt), AMPK, and PPAR pathways. In the EEF1D CRISPR/Cas9 knockout mice, incompletely developed mammary glands at 9th day postpartum with small or unformed lumens, and significantly decreased triglyceride concentration in milk by 23.4% were observed, as well as the same gene expression alterations in the three pathways. For dairy cattle, we identified a critical regulatory mutation modifying EEF1D transcription activity, which interpreted 7% of the genetic variances of milk lipid yield and percentage. Our findings highlight the significance of EEF1D in mammary gland development and milk lipid synthesis in mammals.


Assuntos
Lipídeos/biossíntese , Lipogênese , Glândulas Mamárias Animais/metabolismo , Leite/metabolismo , Fator 1 de Elongação de Peptídeos/fisiologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Células Epiteliais/metabolismo , Feminino , Regulação da Expressão Gênica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética
9.
Food Chem ; 356: 129692, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-33819791

RESUMO

To increase milk production, antibiotics are administered to animals to provide weight gain and to prevent or treat diseases. The inappropriate use of these substances can lead to antibiotic resistance and allergic reactions and toxic effects to milk consumers. We describe the development of a simple, fast, portable, and low-cost microfluidic paper-based analytical device (µPAD) to quantify sulfonamides in milk using the inhibition of the colorimetric reaction between carbonic anhydrase (CA) and 4-nitrophenyl acetate. The main advantages presented by the µPAD include reproducible batch production, simple application, and precise analysis without previous treatment. The µPAD displayed good linearity (R2 ≥ 0.986) in a wide range of sulfonamides in milk (2.5 to 40.0 µmol L-1), being selective for the drugs even in a highly complex matrix. We expect that this device allows in situ monitoring of milk quality, reducing the prejudicial conditions associated with high concentrations of sulfonamides in milk.


Assuntos
Anidrases Carbônicas/química , Colorimetria/métodos , Leite/química , Papel , Sulfonamidas/química , Animais , Anidrases Carbônicas/metabolismo , Bovinos , Colorimetria/instrumentação , Concentração de Íons de Hidrogênio , Técnicas Analíticas Microfluídicas , Leite/metabolismo , Nitrofenóis/química , Nitrofenóis/metabolismo , Sulfonamidas/metabolismo
10.
Toxins (Basel) ; 13(3)2021 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-33799569

RESUMO

Aflatoxin M1 (AFM1) is a hydroxylated metabolite of aflatoxin B1 (AFB1) that can be excreted in milk of cows after consuming contaminated feed. The aim of this study consisted of a field monitoring to assess the contamination levels of AFB1 in 60 feed samples from two feeding systems for high-yielding dairy cows and of AFM1 in the corresponding raw milk samples. The aflatoxins were analyzed by in-house validated methods based on high-performance liquid chromatography (HPLC) with fluorescence detection. AFB1 was detected in 55% of feed samples (mean 0.61 µg/kg, with 2 samples exceeding the European Union (EU) maximum level set at 5 µg/kg), with greater incidence and concentration in compound feed than in unifeed rations (p < 0.05). AFM1 was detected in 38.3% milk samples (mean 12.6 ng/kg, with 5 samples exceeding the EU maximum level set at 50 ng/kg), with a higher occurrence in milk of cows fed compound feed, as well as in spring milk compared to that produced in winter. The overall transfer ratio of aflatoxins from feed to milk was 3.22%, being higher in cows fed with compound feed and in spring milkings. In a selection of positive matched samples (n = 22), the ratio AFM1/AFB1 exceeded the European Food Safety Authority (EFSA) estimated 6% threshold for high-yielding dairy cows.


Assuntos
Aflatoxina B1/metabolismo , Aflatoxina M1/metabolismo , Ração Animal/microbiologia , Monitoramento Biológico , Microbiologia de Alimentos , Fungos/metabolismo , Leite/metabolismo , Aflatoxina B1/toxicidade , Aflatoxina M1/toxicidade , Criação de Animais Domésticos , Animais , Bovinos , Cromatografia Líquida de Alta Pressão , Indústria de Laticínios , Feminino , Espectrometria de Fluorescência
11.
J Agric Food Chem ; 69(15): 4490-4500, 2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33826315

RESUMO

The quality of milk is inseparable from its milk components, and fatty acid content is a key factor affecting the quality of milk. In this study, the miRNA and mRNA profiles of the bovine mammary gland tissue during the dry period and the peak lactation period were determined through high-throughput sequencing. In total, 72 miRNA-mRNA regulatory pathways were screened, including miR-128/PPARGC1A regulatory pathways. miR-128 can directly target PPARGC1A and inhibit its expression. In addition, the study also observed that there was a miR-128 binding site in the sequence of the circular RNA circ11103, and circ11103 significantly reduced the expression of miR-128. circ11103 upregulated the triglyceride levels in bovine mammary epithelial cells (BMECs) and increased the contents of unsaturated fatty acids. However, miR-128 decreased triglyceride and cholesterol levels in BMECs. This study aims to analyze the mechanism governing the regulatory effect of circ11103 on milk fat metabolism, which provides new insights into improving milk quality.


Assuntos
MicroRNAs , Leite , Animais , Bovinos , Células Epiteliais/metabolismo , Ácidos Graxos/metabolismo , Feminino , Lactação , Metabolismo dos Lipídeos/genética , Glândulas Mamárias Animais/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Leite/metabolismo
12.
Food Chem ; 355: 129443, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33799265

RESUMO

Here, a facile hydrothermal method was used to synthesize highly photoluminescent N-doped carbon dots, and the quantum yields reached 97.1%. Then, a label-free immunosensor based on the inner filter effect of carbon dots was developed for ultrasensitive detection of aflatoxin M1 residues in milk. The detection limit was 0.0186 ng/mL (equivalents to 18.10 ng/kg), which satisfied the most stringent maximum tolerable limit value of 25 ng/kg. Besides, the immunosensor showed a good linear relationship from 0.003 ng/mL to 0.81 ng/mL, and the average recoveries ranged from 79.6% to 112.5% for spiked milk samples, with relative standard deviations ranging from 6.7% to 13.3%. Compared with other immunoassays, the inner filter effect-based immunosensor incorporating fluorescent detection into conventional enzymatic cascade amplification systems and could be a reliable on-site screening method for aflatoxin M1 residue analysis.


Assuntos
Aflatoxina M1/análise , Imunoensaio/métodos , Leite/química , Pontos Quânticos/química , Animais , Carbono/química , Limite de Detecção , Leite/metabolismo
13.
Food Chem ; 356: 129659, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-33812186

RESUMO

Oxytetracycline (OTC), one of the largely used antibiotic in veterinary practice has been banned due to its potential side effects. Development of a field applicable and affordable kit to detect OTC will help to eliminate such milk from human consumption. An aptamer has been designed (27 nt; Kd = 29.2 ± 19.4 nM) through rational truncation. OTC interacts with this aptamer in G rich regions as confirmed by molecular modelling and circular dichroism spectroscopy. To develop a lateral flow based aptasensor, OTC was conjugated with a 7 kDa carrier protein to immobilize onto the nitrocellulose membrane. Using 0.125 µM aptamer-gold conjugate, assay could visually detects upto 5 ng/mL of OTC in spiked milk within 10 mins [Limit of quantitation (LOQ)-0.254 ± 1.62 ng/mL; permissible limit 100 ng/mL]. It showed no cross reactivity with components of milk and data correlated with analysis done through HPLC.


Assuntos
Antibacterianos/análise , Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Leite/química , Oxitetraciclina/análise , Animais , Proteínas de Transporte/química , Ouro/química , Limite de Detecção , Nanopartículas Metálicas/química , Leite/metabolismo , Sistemas Automatizados de Assistência Junto ao Leito
14.
Biomed Res Int ; 2021: 3653157, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33829059

RESUMO

PPARGC1A gene plays an important role in the activation of various important hormone receptors and transcriptional factors involved in the regulation of adaptive thermogenesis, gluconeogenesis, fiber-type switching in skeletal muscle, mitochondrial biogenesis, and adipogenesis, regulating the reproduction and proposed as a candidate gene for milk-related traits in cattle. This study identified polymorphisms in the PPARGC1A gene in Italian Mediterranean buffaloes and their associations to milk production and quality traits (lactation length, peak milk yield, fat and protein yield, and percentage). As a result, a total of seven SNPs (g.-78A>G, g.224651G>C, g.286986G>A, g.304050G>A, g.325647G>A, g.325817T>C, and g.325997G>A) were identified by DNA pooled sequencing. Analysis of productivity traits within the genotyped animals revealed that the g.286986G>A located at intron 4 was associated with milk production traits, but the g.325817T>C had no association with milk production. Polymorphisms in g.-78A>G was associated with peak milk yield and milk yield, while g.304050G>A and g.325997 G>A were associated with both milk yield and protein percentage. Our findings suggest that polymorphisms in the buffalo PPARGC1A gene are associated with milk production traits and can be used as a candidate gene for milk traits and marker-assisted selection in the buffalo breeding program.


Assuntos
Búfalos/genética , Estudos de Associação Genética , Leite/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Polimorfismo de Nucleotídeo Único/genética , Característica Quantitativa Herdável , Animais , Frequência do Gene/genética , Itália
15.
Food Chem ; 356: 129658, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-33838604

RESUMO

A novel fluorescent probe (RA), based on the rosamine skeleton bearing acrylate group, has been reasonably designed and prepared, which employed an addition-cyclization-elimination sequence reaction mechanism to detect cysteine. RA displayed rapid response to cysteine within 1.5 min, and exhibited satisfactory selectivity for cysteine over H2S, glutathione (Glu), and homocysteine (Hcy), due to the formation of seven-membered lactam favored kinetically. Fluorescence ratio was utilized to detect cysteine from 6.0 to 20.0 µM with a detection limit of 0.29 µM. More, RA was used to monitor cysteine in BSA, water, milk, milk powder, cabbage, radish, apple, and pear.


Assuntos
Cisteína/análise , Corantes Fluorescentes/química , Compostos Heterocíclicos com 3 Anéis/química , Leite/química , Plantas/química , Rodaminas/química , Soroalbumina Bovina/química , Espectrometria de Fluorescência/métodos , Água/química , Animais , Brassica/química , Brassica/metabolismo , Glutationa/química , Homocisteína/química , Limite de Detecção , Malus/química , Malus/metabolismo , Leite/metabolismo , Plantas/metabolismo , Pyrus/química , Pyrus/metabolismo , Raphanus/química , Raphanus/metabolismo
16.
J Dairy Sci ; 104(5): 5601-5616, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33663838

RESUMO

Increasing the supply of metabolizable protein (MP) and improving its AA profile may attenuate body protein mobilization in fresh cows and lead to increased milk production. Increasing the concentration of rumen-undegradable protein (RUP) to increase MP supply and replacing RUP sources from forages instead of nonforage fiber sources may further decrease tissue mobilization if it improves dry matter intake (DMI). Our objective was to determine whether increasing MP concentrations and improving the AA profile at the expense of either nonforage or forage fiber (fNDF) would affect MP balance and empty body (EB) composition (measured using the urea dilution method) in early postpartum dairy cows of different parities. In a randomized block design, 40 primigravid [77 ± 1.5 kg of EB crude protein (CP) at 8 ± 0.6 d before calving] and 40 multigravid (92 ± 1.6 kg of EB CP at 5 ± 0.6 d before calving) Holsteins were blocked by calving date and fed a common prepartum diet (11.5% CP). After calving to 25 d in milk (DIM), cows were fed 1 of 4 diets: (1) a diet deficient in MP meeting 87% of MP requirements (DMP, 17% CP, 24% fNDF), (2) 104% of MP requirements using primarily soy protein to make MP adequate (AMP, 20% CP, 24% fNDF), (3) 110% of MP requirements using a blend of proteins and rumen-protected (RP) AA to make MP adequate (Blend, 20% CP, 24% fNDF), or (4) a diet similar to Blend but substituting added RUP for fNDF rather than nonforage NDF (Blend-fNDF, 20% CP, 19% fNDF). Blend was formulated to have a RUP supply with a similar AA profile to that of casein. Cows were fed a common diet (16.3% CP) from 26 to 50 DIM. Calculated MP balance (supply - requirements) was less than zero for DMP and Blend-fNDF from 1 to 4 wk of lactation (WOL), whereas that for AMP was positive from 1 to 4 WOL and that for Blend was close to zero from 3 to 4 WOL. Daily MP balance was greater from 5 to 7 WOL for DMP compared with AMP and Blend (100 vs. 22 g/d). From -7 to 7 d relative to calving, losses of EB CP were greater for DMP than for AMP and Blend (-121 vs. average of 11 g/d). From 7 to 25 DIM, cows fed AMP (-139 g/d) and Blend-fNDF (-147 g/d) lost EB CP but cows fed Blend (-8 g/d) maintained EB CP. Increased DMI for Blend versus AMP led to reduced losses of EB lipid in primiparous cows from 7 to 25 d relative to calving (-1.0 vs. -1.3 kg/d of EB lipid), whereas lipid mobilization was similar in multiparous cows (average -1.1 kg of EB lipid/d). By 50 DIM, EB lipid and CP were similar across treatments and parities (average 60.2 kg of EB lipid and 81.6 kg of EB CP). Overall, feeding fresh cows a high MP diet with a balanced AA profile improved DMI and attenuated EB CP mobilization, which could partly explain positive carryover effects on milk production for multiparous cows and reduced lipid mobilization for primiparous cows.


Assuntos
Aminoácidos , Dieta Rica em Proteínas , Aminoácidos/metabolismo , Animais , Composição Corporal , Bovinos , Dieta/veterinária , Dieta Rica em Proteínas/veterinária , Proteínas na Dieta/metabolismo , Feminino , Lactação , Leite/metabolismo , Rúmen/metabolismo
17.
Nutrients ; 13(2)2021 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-33668674

RESUMO

Cheddar cheese is a protein-dense whole food and high in leucine content. However, no information is known about the acute blood amino acid kinetics and protein anabolic effects in skeletal muscle in healthy adults. Therefore, we conducted a crossover study in which men and women (n = 24; ~27 years, ~23 kg/m2) consumed cheese (20 g protein) or an isonitrogenous amount of milk. Blood and skeletal muscle biopsies were taken before and during the post absorptive period following ingestion. We evaluated circulating essential and non-essential amino acids, insulin, and free fatty acids and examined skeletal muscle anabolism by mTORC1 cellular localization, intracellular signaling, and ribosomal profiling. We found that cheese ingestion had a slower yet more sustained branched-chain amino acid circulation appearance over the postprandial period peaking at ~120 min. Cheese also modestly stimulated mTORC1 signaling and increased membrane localization. Using ribosomal profiling we found that, though both milk and cheese stimulated a muscle anabolic program associated with mTORC1 signaling that was more evident with milk, mTORC1 signaling persisted with cheese while also inducing a lower insulinogenic response. We conclude that Cheddar cheese induced a sustained blood amino acid and moderate muscle mTORC1 response yet had a lower glycemic profile compared to milk.


Assuntos
Aminoácidos/sangue , Queijo , Ingestão de Alimentos/fisiologia , Músculo Esquelético/metabolismo , Adulto , Animais , Biópsia , Estudos Cross-Over , Ácidos Graxos não Esterificados/sangue , Feminino , Voluntários Saudáveis , Humanos , Insulina/sangue , Leucina/metabolismo , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Leite/metabolismo , Período Pós-Prandial , Ribossomos/metabolismo , Transdução de Sinais
18.
Carbohydr Polym ; 259: 117734, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33673995

RESUMO

Oligosaccharides are one of the most important components in mammalian milk. Milk oligosaccharides can promote colonization of gut microbiota and protect newborns from infections. The diversity and structures of MOs differ among mammalian species. MOs in human and farm animals have been well-documented. However, the knowledge on MOs in rat and mouse have been very limited even though they are the most-widely used models for studies of human physiology and disease. Herein, we use a high-sensitivity online solid-phase extraction and HILIC coupled with electrospray tandem mass spectrometry to analyze the acidic MOs in rat and mouse. Among the fifteen MOs identified, twelve were reported for the first time in rat and mouse together with two novel sulphated oligosaccharides. The complete list of acidic oligosaccharides present in rat and mouse milk is the baseline information of these animals and should contribute to biological/biomedical studies using rats and mice as models.


Assuntos
Leite/metabolismo , Oligossacarídeos/análise , Espectrometria de Massas por Ionização por Electrospray , Animais , Cromatografia Líquida de Alta Pressão , Interações Hidrofóbicas e Hidrofílicas , Camundongos , Oligossacarídeos/isolamento & purificação , Ratos , Extração em Fase Sólida
19.
Food Funct ; 12(6): 2760-2771, 2021 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-33683238

RESUMO

This study investigated the behavior of nano-sized particles of hydroxyapatite (nHA) during dynamic in vitro gastrointestinal digestion, alone or dispersed within skim milk. The dissolution and the structural changes of nHA were investigated by analyzing the dissolution of calcium and using transmission electron microscopy and X-ray diffraction. The dissolution of nHA during gastric digestion involved a rapid early stage and a much slower later stage. It was incomplete by the end of gastric digestion, both with and without milk. However, there was no sign of nHA recrystallization in the intestinal phase. X-ray diffraction analysis of digesta showed the breakdown of the crystalline structure of nHA and the formation of potentially new calcium phosphate phases during digestion. Skim milk formed a structural clot and significantly retarded the dissolution of nHA during gastric digestion. Possible mechanisms leading to the incomplete dissolution of nHA and the matrix effect of milk are discussed.


Assuntos
Digestão/fisiologia , Durapatita , Leite , Nanopartículas , Animais , Cálcio/metabolismo , Durapatita/química , Durapatita/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Leite/química , Leite/metabolismo , Modelos Biológicos , Nanopartículas/química , Nanopartículas/metabolismo , Estômago/fisiologia
20.
Genes (Basel) ; 12(2)2021 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-33562534

RESUMO

The mammary gland undergoes important anatomical and physiological changes from embryogenesis through puberty, pregnancy, lactation and involution. These steps are under the control of a complex network of molecular factors, in which epigenetic mechanisms play a role that is increasingly well described. Recently, studies investigating epigenetic modifications and their impacts on gene expression in the mammary gland have been performed at different physiological stages and in different mammary cell types. This has led to the establishment of a role for epigenetic marks in milk component biosynthesis. This review aims to summarize the available knowledge regarding the involvement of the four main molecular mechanisms in epigenetics: DNA methylation, histone modifications, polycomb protein activity and non-coding RNA functions.


Assuntos
Metilação de DNA/genética , Epigênese Genética/genética , Lactação/genética , Glândulas Mamárias Animais/metabolismo , Animais , Feminino , Humanos , Glândulas Mamárias Animais/crescimento & desenvolvimento , Leite/metabolismo , Gravidez
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