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Quinoa, known as the "golden grain" for its high nutritional value, has polysaccharides as one of its sources of important nutrients. However, the biological functions of quinoa polysaccharides remain understudied. In this study, two crude polysaccharide extracts of quinoa (Q-40 and Q-60) were obtained through sequential precipitation with 40% and 60% ethanol, with purities of 58.29% (HPLC) and 62.15% (HPLC) and a protein content of 8.27% and 9.60%, respectively. Monosaccharide analysis revealed that Q-40 contained glucose (Glc), galacturonic acid (GalA), and arabinose (Ara) in a molar ratio of 0.967:0.027:0.006. Q-60 was composed of xylose (xyl), arabinose (Ara), galactose, and galacturonic acid (GalA) with a molar ratio of 0.889:0.036:0.034:0.020. The average molecular weight of Q-40 ranged from 47,484 to 626,488 Da, while Q-60 showed a range of 10,025 to 47,990 Da. Rheological experiments showed that Q-40 exhibited higher viscosity, while Q-60 demonstrated more elastic properties. Remarkably, Q-60 showed potent antioxidant abilities, with scavenging rates of 98.49% for DPPH and 57.5% for ABTS. Antibacterial experiments using the microdilution method revealed that Q-40 inhibited the growth of methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli), while Q-60 specifically inhibited MRSA. At lower concentrations, both polysaccharides inhibited MDA (MD Anderson Cancer Center) cell proliferation, but at higher concentrations, they promoted proliferation. Similar proliferation-promoting effects were observed in HepG2 cells. The research provides important information in the application of quinoa in the food and functional food industries.
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Chenopodium quinoa , Ácidos Hexurónicos , Staphylococcus aureus Resistente a Meticilina , Arabinosa , Escherichia coli , Grano ComestibleRESUMEN
Food coloring plays a vital role in influencing consumers' food choices, imparting vibrant and appealing colors to various food and beverage products. Synthetic food colorants have been the most commonly used coloring agents in the food industry. However, concerns about potential health issues related to synthetic colorants, coupled with increasing consumer demands for food safety and health, have led food manufacturers to explore natural alternatives. Natural pigments not only offer a wide range of colors to food products but also exhibit beneficial bioactive properties. Gardenia yellow pigment is a water-soluble natural pigment with various biological activities, widely present in gardenia fruits. Therefore, this paper aims to delve into Gardenia Yellow Pigment, highlighting its significance as a food colorant. Firstly, a thorough understanding and exploration of various methods for obtaining gardenia yellow pigment. Subsequently, the potential functionality of gardenia yellow pigment was elaborated, especially its excellent antioxidant and neuroprotective properties. Finally, the widespread application trend of gardenia yellow pigment in the food industry was explored, as well as the challenges faced by the future development of gardenia yellow pigment in the field of food and health. Some feasible solutions were proposed, providing valuable references and insights for researchers, food industry professionals, and policy makers.
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Colorantes de Alimentos , Gardenia , Extractos Vegetales , ColorantesRESUMEN
Single-stranded DNA oligonucleotides wrapping on the surface of single-walled carbon nanotubes (SWCNTs), described as DNA corona, are often used as a dispersing agent for SWCNTs. The uneven distribution of DNA corona along SWCNTs is related to the photoelectric properties and the surface activity of SWCNTs. An ionic strength-mediated "DNA corona defects" (DCDs) strategy is proposed to acquire an exposed surface of SWCNTs (accessible surface) as large as possible while maintaining good dispersibility via modulating the conformation of DNA corona. By adjusting the solution ionic strength, the DNA corona phase transitioned from an even-distributed and loose conformation to a locally compact conformation. The resulting enlarged exposed surface of SWCNTs is called DCDs, which provide active sites for molecular adsorption. This strategy is applied for the arrangement of SWCNTs on DNA origami. SWCNTs with ≈11 nm DCD, providing enough space for the adsorption of "capture ssDNA" (≈7 nm width required for 24-nt) extended from DNA origami structures are fabricated. The DCD strategy has potential applications in SWCNT-based optoelectronic devices.
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Nanotubos de Carbono , Nanotubos de Carbono/química , ADN/química , ADN de Cadena Simple , Adsorción , Concentración OsmolarRESUMEN
Tannic acid-based patterning is crucial for its applications in bioengineering, including multifunctional coatings, biosensors, and biochips. However, tannic acid (TA) patterning is challenging owing to the rapid polymerization kinetics of tannins and their strong adhesion towards most surfaces or objects. Herein, we report a strategy for controllable TA nanopatterning based on DNA origami templates. Protruding clustered ssDNA (pcDNA) from DNA origami tiles served as indexes for the selective deposition of TA due to the high flexibility of ssDNA and exposed aromatic bases, which provide active sites for TA-DNA interactions. Next, by exploiting the pH-sensitive degradation of TA polymers, controllable 'erasing' and 'rewriting' of TA nanopatterns were performed. Finally, combining the high adhesion and selective deposition, the TA polymers as a glue modified on the edges of origami tiles directed the reversible association/disassociation of origami multimers. Our strategy provides a simple approach for the controllable nanopatterning of TA, enabling its unique properties to tailor surface patterns for applications in materials science and biomedicine.
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ADN , Polímeros , ADN/químicaRESUMEN
Clanis Bilineata Tingtauica Mell Protein (CBTMP) was a kind of natural full-price protein which has a bright application prospect in the food industry. Since the functional properties of protein can be significantly affected by drying method, this study aims to explore the effect of different drying methods, namely freeze drying (FD), vacuum drying (VD),and hot-air drying (HD) on the structure and functional properties of CBTMP. The results showed that the degree of oxidation of CBTMP was found to be in the following order: HD > VD > FD. Functional characteristics revealed that the CBTMP prepared by VD had relatively high foaming ability (150.24 ± 5.34°C) among three drying methods. However, the stability of emulsion and rheological properties prepared by FD was superior to other samples. Differential scanning calorimeter (DSC) showed CBTMP made by HD had the relatively good thermal stability (Tp = 91.49 ± 0.19 °C), followed by VD and FD. Digestive properties reflected that heating treatment could significantly increase its degree of hydrolysis in vitro. To sum up, the research could provide experimental guidance and theoretical support for the preparation method and utilization of CBTMP.
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Contamination of agricultural products and foods by aflatoxin B1 (AFB1) is becoming a serious global problem, and the presence of AFB1 in edible oil is frequent and has become inevitable, especially in underdeveloped countries and regions. As AFB1 results from a possible degradation of aflatoxins and the interaction of the resulting toxic compound with food components, it could cause chronic disease or severe cancers, increasing morbidity and mortality. Therefore, rapid and reliable detection methods are essential for checking AFB1 occurrence in foodstuffs to ensure food safety. Recently, new biosensor technologies have become a research hotspot due to their characteristics of speed and accuracy. This review describes various technologies such as chromatographic and spectroscopic techniques, ELISA techniques, and biosensing techniques, along with their advantages and weaknesses, for AFB1 control in edible oil and provides new insight into AFB1 detection for future work. Although compared with other technologies, biosensor technology involves the cross integration of multiple technologies, such as spectral technology and new nano materials, and has great potential, some challenges regarding their stability, cost, etc., need further studies.
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Aflatoxinas , Técnicas Biosensibles , Aflatoxina B1 , Aflatoxinas/análisis , Técnicas Biosensibles/métodos , Contaminación de Alimentos/análisis , Inocuidad de los AlimentosRESUMEN
In the recent years, edible brown seaweed, Undaria pinnatifida, has presented beneficial effects, which may be correlated with this species containing major bioactive compounds, such as carotenoids, fatty acids, and phytosterols. Marine carotenoid fucoxanthin is abundantly present in edible Undaria pinnatifida and features strong bioactive activities. The stem of Undaria pinnatifida is very hard to gnaw off and cannot be swallowed; therefore, it is usually discarded as waste, making it an environmental issue. Hence, making full use of the waste stem of Undaria pinnatifida is an urgent motivation. The present study aims to explore the optimal preparation technology of fucoxanthin from Undaria pinnatifida stems using supercritical carbon dioxide methods and provides approaches for the extraction and preparation of bioactive compounds from a waste seaweed part. With the comprehensive optimization conditions applied in this study, the experimental yield of fucoxanthin agreed closely with the predicted value by > 99.3%. The potential of α-amylase and glucoamylase to inhibit bioactive compounds was evaluated. The results demonstrated that the inhibition activity (IC50 value) of α-amylase (0.1857 ± 0.0198 µg/ml) and glucoamylase (0.1577 ± 0.0186 µg/ml) varied with extraction conditions due to the different contents of bioactive components in the extract, especially fucoxanthin (22.09 ± 0.69 mg/g extract). Therefore, this study confirmed supercritical fluid extraction technology to be a useful sample preparation method, which can effectively be used to prepare fucoxanthin from waste marine resources. This method can potentially be applied in functional food and related industries.
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Lipid vesicle research is of great significance in the field of biomedicine and great progress has been made in recent years, in which the surface engineering on lipid membranes plays an important role. By introducing new active sites on membrane surface, the physicochemical properties of vesicles are regulated and the biological functions are extended. DNA nanotechnology is an excellent tool for surface engineering of vesicles and has attracted more and more attention. In this Review, the interaction between DNA and lipid membrane is presented. Subsequently, recent advances in the applications of vesicle-surface-engineering based on DNA nanotechnology are highlighted. DNA nanostructures are used to mimic membrane proteins in the system of artificial liposome vesicles. Surface-engineered extracellular vesicles (EVs) based on DNA nanotechnology are applied to achieve non-invasive early screening of diseases with high sensitivity and precision. Finally, challenges and prospects for future development in this field are discussed.
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Nanoestructuras , Nanotecnología , ADN/química , Lípidos , Nanoestructuras/químicaRESUMEN
The main symptoms of diabetes are hyperglycemia and insulin resistance. The inhibition of the starch digestion enzymes could effectively regulate starch digestion and glucose absorption, thereby slowing or treating the symptoms of postprandial hyperglycemia. Herein, we used fucoxanthin isolated from Undaria pinnatifida stems, as α-amylase inhibitor, and monitored the interactions of both biomolecules by using quartz crystal microbalance-admittance (QCM-A) instrument. All the processes of α-amylase hydrolysis of starch were also dynamically tracked by using amylose-immobilized QCM technology. In our work, we found that the kinetic parameter (k off, k on, and k cat) values obtained by the QCM-A analysis were relatively consistent compared to the kinetic parameter values obtained by the conventional Michaelis-Menten analysis. For the inhibitory reactions, the results showed that fucoxanthin significantly reduced the activity of α-amylase in a dose-dependent manner. The QCM-A technology shown to be an excellent approach in obtaining comprehensive and accurate kinetic parameters, thereby providing real and accurate data for kinetic studies. It is helpful to clarify the mechanism of action of fucoxanthin on α-amylase, which further proved the potential of fucoxanthin to improve and treat postprandial hyperglycemia.
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Clanis Bilineata Tingtauica Mell Protein (CBTMP) is a naturally high-quality insect protein resource, while its poor emulsification has limited its application in food industry. In order to change the present situation, in this research, the ultrasonic pretreatment (0 W, 200 W, 400 W, 600 W, and 800 W) method was used to improve the emulsification properties of CBTMP. Results indicated that ultrasound treatment especially at 400 W could significantly change the particle sizes, further increase the content of sulfhydryl group and surface hydrophobicity. The emulsification properties of emulsions were enhanced (from 4.16 ± 1.07 m2/g to 27.62 ± 2.20 m2/g) by sonicated CBTMP solution. Moreover, the physical stability of the emulsions to salt stress and centrifugation treatment was also promoted. Additionally, rheology revealed that a stronger network was formed at 400 W and all samples exhibited frequency-dependent and amplitude-dependent properties. The experiment demonstrated that ultrasound pretreatment was an effective means to improve the emulsification properties of CBTMP and it could provide a promising perspective for the application of CBTMP in food industry.
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Ultrasonido , Animales , Emulsiones , Interacciones Hidrofóbicas e Hidrofílicas , Mariposas Nocturnas , Tamaño de la Partícula , ReologíaRESUMEN
Objective@#To investigate the relationship between breakfast eating frequency and health-risk behavior of high school students in Chongqing, and provide a reference for conducting students to get a good habit of eating breakfast everyday.@*Methods@#A total of 3 283 high school students in Chongqing were selected to participate in a questionnarie by using convenience sampling method. Logistic regression analysis were condueted to analyze the influences made by the unhealty eating behaviors on eating frequency of breakfast.@*Results@#There were 2 064(69.2%) students eating breakfast everyday, 1 219(37.1%) students having no breakfast or eating breakfast sometimes. There were significant differences between different gender, grade, native place, drinking energy drink, smoking, drinking alcohol, gambling, internet addiction students rate of unhealthy breakfast eating frequency(χ2=6.80, 53.97, 8.10, 23.79, 7.89, 16.31, 3.93, 17.96, P<0.05), the males (36.1%) was beyond the females(33.3%), the energy drink drinkers(41.2%) was beyond the non-drinkers(31.7%), the smokers (40.9%) was beyond the non-smokers(34.4%), the alcohol drinkers(40.3%) was beyond the non-drinkers(33.3%), the gamblers(39.7%) was beyond the non-gamblers(34.3%), those having internet addictions (40.0%) was beyond those having no addictions(33.0%). Drinking energy drink(OR=1.32, 95%CI=1.12-1.55), drinking alcohol(OR=1.24, 95%CI=1.02-1.51), internet addiction(OR=1.42, 95%CI=1.19-1.68) were positively correlated with unhealthy breakfast eating frequency of high school students(P<0.05).@*Conclusion@#Social, families and schools should strengthen the guidance of high school students to develop the habit of eating breakfast every day, and advoid the clustering of skipping breakfast and health-risk behaviors.
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Chronic stress has a profound effect on health in both animals and humans. Dexamethasone (Dex), a synthetic glucocorticoid, is used to induce chronic stress in many studies. The impact of chronic stress on epithelial cells of hindgut of ruminants is still unknown. In this study, we investigated the effect of chronic stress induced by long term injection of low dosage of Dex on the colonic epithelium of goats. The results showed that Dex exposure increased the number of TUNEL-positive cells, upregulated caspase-3 and caspase-8 enzyme activity, but decreased protein expression of cell proliferation markers proliferating cell nuclear antigen (PCNA) and Cyclin D2(CCND2). It also activated TLR-4 and NF-κB pathway and increased the transcription levels of vital inflammatory cytokines such as interleukin-10 (IL-10), interleukin-1ß (IL-1ß), and inducible nitric oxide synthase 2 (iNOS2). Chronic stress down-regulated the methylation level of total DNA, suggesting a mechanism for the transcriptional activation of genes, such as claudin-1, claudin-4, ZO-1, and cell cycle-related genes. Taken together, long-term injection of a low dosage of Dex caused damage to the colon epithelium accompanied with the inhibition of cell proliferation and the activation of cell apoptosis and inflammation. However, a general up-regulation of genes expression induced by Dex is due to a lower level of genomic DNA methylation.
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Apoptosis/efectos de los fármacos , Colon/patología , Dexametasona/efectos adversos , Células Epiteliales/metabolismo , Cabras/metabolismo , Inflamación/metabolismo , Inflamación/patología , Receptor Toll-Like 4/metabolismo , Animales , Ciclo Celular/efectos de los fármacos , Ciclo Celular/genética , Citocinas/genética , Citocinas/metabolismo , Metilación de ADN/efectos de los fármacos , Metilación de ADN/genética , Células Epiteliales/efectos de los fármacos , Células Epiteliales/patología , Regulación de la Expresión Génica/efectos de los fármacos , Inflamación/genética , Mediadores de Inflamación/metabolismo , Masculino , FN-kappa B/metabolismo , Regiones Promotoras Genéticas/genética , Transducción de Señal/efectos de los fármacos , Uniones Estrechas/efectos de los fármacos , Uniones Estrechas/metabolismoRESUMEN
BACKGROUND: Dexamethasone (Dex), an artificially synthetic cortisol substitute, is commonly used as an anti-inflammatory drug, and is also employed to mimic the stress state experimentally. It is well known that chronic stress disturbs the gut microbiota community and digestive functions. However, no relevant studies have been conducted in ruminants. RESULTS: In this study, a low dosage of Dex (0.2 mg/kg body weight, Dex group, n = 5) was consecutively injected intramuscularly for 21 days to simulate chronic stress in growing goats. Goats were injected with saline (0.2 mg/kg body weight) as the control group (Con, n = 5). Dex-treated goats showed a higher number of white blood cells and blood glucose levels (p < 0.01), but lower dry matter intake (DMI) and body weight (p < 0.01) than those of saline-injected goats. Plasma cortisol concentration decreased significantly in response to the Dex injection compared to the control (p < 0.05). The Dex treatment did not change most ruminal volatile fatty acid (VFAs) concentrations before the morning feeding after 1-21 days of treatment (p > 0.05); however, ruminal VFA concentrations decreased dramatically 2, 4, 6, and 8 h after the morning feeding on day 21 of the Dex injections. In this study, chronic Dex exposure did not alter the community structure of microbes or methanogenes in the rumen, caecum, or colonic digesta. Only Prevotella increased on days 7 and 14 of Dex treatment, but decreased on day 21, and Methanosphaera was the only genus of methanogene that decreased. CONCLUSIONS: Our results suggest that chronic Dex exposure retards growth by decreasing DMI, which may be mediated by higher levels of blood glucose and lower ruminal VFA production. Microbiota in the digestive tract was highly resistant to chronic Dex exposure.
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Bacterias/efectos de los fármacos , Bacterias/crecimiento & desarrollo , Dexametasona/administración & dosificación , Microbioma Gastrointestinal/efectos de los fármacos , Tracto Gastrointestinal/microbiología , Cabras/microbiología , Animales , Bacterias/genética , Bacterias/metabolismo , Glucemia/metabolismo , Ácidos Grasos Volátiles/metabolismo , Tracto Gastrointestinal/efectos de los fármacos , Tracto Gastrointestinal/metabolismo , Cabras/sangre , Hidrocortisona/sangre , MasculinoRESUMEN
The aim of this study was to investigate the effects of dexamethasone (DEX) on zinc metabolism in goats. In this study, 10 goats were randomly divided into two groups. One group was injected with dexamethasone (Dex group) and the other group was injected with saline (Con group). Dex treatment significantly decreased hepatic zinc levels (p < .01) and increased Zn transporters 1 (ZNT-1) expression (p < .05). The concentration of zinc in the cecal and colonic contents was significantly increased (p < .05). However, zinc levels were increased only in the colon tissues (p < .05) but not in the cecal tissues (p > .05). A dramatic increase in Zrt-, Irt-related proteins 14 (ZIP-14) expression (p < .05) following Dex treatment was also observed and likely induced the elevated zinc levels in the colon, and a significant reduction in Zip-14 methylation (p < .05) may be responsible for the observed increase in Zip-14 expression. Together, these results indicate that Dex influences zinc homeostasis by increasing hepatic ZNT-1 and colonic ZIP-14 expression. Additionally, these results provide valuable information for the clinical application of Dex.
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Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Colon/metabolismo , Dexametasona/efectos adversos , Cabras/metabolismo , Hígado/metabolismo , Zinc/metabolismo , Animales , Expresión Génica/efectos de los fármacos , MasculinoRESUMEN
Chronic stress severely threatens the welfare and health of animals and humans. In order to study the effects of chronic stress on metabolism, de novo transcriptome sequencing was used to generate the expressed sequence tag dataset for the goat, using nextgeneration sequencing technology. For this study, consecutive dexamethasone (Dex) injection was used in 10 healthy male goats (body weight 25⯱â¯1.0â¯kg) to mimic chronic stress. Ten male goats were randomly assigned into two groups, one group was injected intramuscularly with the same volume of saline as control (Con) group, and another (Dex) group was injected intramuscularly with 0.2â¯mg/kg Dex for 21â¯days. To elucidate the resulting changes in genes, transcriptome profiling of liver was conducted by analysing samples from three goats of each group using RNA-Seq. A total of 137 differentially expressed genes (DEGs) were identified between Con group and Dex group. GO classification showed rhythmic process and hormone secretion in term cellular, and chemoattractant activity in term molecular function had noticeable differences in the proportion between DEGs and all genes. By mapping the DEGs to the COG database, we found that general function prediction only, energy production and conversion, and amino acid transport and metabolism were the most frequently represented functional clusters. We mapped the unigenes to the KEGG pathway database and found most annotated genes were involved in the AMPK signalling pathway as well as pathways in cancer and insulin signalling pathway. Via KEGG enrichment analysis, we found the DEGs were significantly enriched in insulin signalling pathway, AMPK signalling pathway and adipocytokine signalling pathway. In addition, these pathways have close relationship with metabolism, which resulted in metabolic changes in which the identified DEGs may play important roles. These results provide valuable information for further research on the complex molecular mechanisms of dexamethasone in goats and will provide a foundation for future studies.
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Dexametasona/efectos adversos , Perfilación de la Expresión Génica/métodos , Cabras/genética , Hígado/química , Redes y Vías Metabólicas/efectos de los fármacos , Adenilato Quinasa/genética , Animales , Dexametasona/administración & dosificación , Perfilación de la Expresión Génica/veterinaria , Regulación de la Expresión Génica/efectos de los fármacos , Redes Reguladoras de Genes/efectos de los fármacos , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Secuenciación de Nucleótidos de Alto Rendimiento/veterinaria , Inyecciones Intramusculares , Hígado/efectos de los fármacos , Masculino , Distribución Aleatoria , Análisis de Secuencia de ARN/métodos , Análisis de Secuencia de ARN/veterinariaRESUMEN
AIMS: The quorum-sensing molecule N(3oxododecanoyl)lhomoserine lactone (C12-HSL), produced by the Gram negative human pathogenic bacterium Pseudomonas aeruginosa, modulates mammalian cell behavior. Our previous findings suggested that C12-HSL rapidly decreases viability and induces apoptosis in LS174T goblet cells. MAIN METHODS: In this study, the effects of 100⯵M C12-HSL on mitochondrial function and cell proliferation in LS174T cells treated for 4â¯h were evaluated by real-time PCR, enzyme-linked immunosorbent assay (ELISA) and flow cytometry. KEY FINDINGS: The results showed that the activities of mitochondrial respiratory chain complexes IV and V were significantly increased (Pâ¯<â¯0.05) in LS174T cells after C12-HSL treatment, with elevated intracellular ATP generation (Pâ¯<â¯0.05). Flow cytometry analysis revealed significantly increased intracellular Ca2+ levels (Pâ¯<â¯0.05), as well as disrupted mitochondrial activity and cell cycle arrest upon C12-HSL treatment. Apoptosis and cell proliferation related genes showed markedly altered expression levels (Pâ¯<â¯0.05) in LS174T cells after C12-HSL treatment. Moreover, the paraoxonase 2 (PON2) inhibitor TQ416 (1⯵M) remarkably reversed the above C12-HSL associated effects in LS174T cells. SIGNIFICANCE: These findings indicated that C12-HSL alters mitochondrial energy production and function, and inhibits cell proliferation in LS174T cells, with PON2 involvement.
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4-Butirolactona/análogos & derivados , Células Caliciformes/efectos de los fármacos , Homoserina/análogos & derivados , Intestinos/citología , Intestinos/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Percepción de Quorum/efectos de los fármacos , 4-Butirolactona/farmacología , Adenosina Trifosfato/biosíntesis , Apoptosis/efectos de los fármacos , Arildialquilfosfatasa/antagonistas & inhibidores , Calcio/metabolismo , Proliferación Celular/efectos de los fármacos , Transporte de Electrón/efectos de los fármacos , Homoserina/farmacología , HumanosRESUMEN
BACKGROUND: Dexamethasone (Dex), a synthetic glucocorticoid, is among the most commonly used drugs worldwide in animals and humans as an anti-inflammatory and immunosuppressive agent. GC has profound effects on plasma glucose level and other metabolic conditions. However, the effect of prolonged use of Dex on glucose metabolism in ruminants is still unclear. RESULTS: Ten goats were randomly assigned to two groups: the control goats were injected with saline, and the Dex-treated goats were intramuscularly injected daily for 21 d with 0.2 mg/kg Dex. The results showed that plasma glucose and insulin concentrations were significantly increased after Dex administration (P < 0.05). Additionally, the content of hepatic glycogen was also markedly increased in Dex-treated goats (P < 0.01), while the content of glycogen in dorsal longissimus was unchanged by Dex (P > 0.05). The expression of several key genes, involved in blood glucose regulation, was detected by real-time PCR in the small intestine, skeletal muscle and liver. The expression of glucose transporter type 2 (GLUT2), sodium-glucose transporter 1 (SGLT1) and sodium-potassium ATPase (Na-K/ATPase) in the small intestine were generally increased by Dex, and GLUT2 mRNA expression was significantly up-regulated (P < 0.05). In liver, the expression of genes involved in gluconeogenesis including glucose-6-phosphatase catalytic subunit (G6PC), cytosolic form of phosphoenolpyruvate carboxykinase (PCK1) and pyruvate carboxylase (PC), were significantly down-regulated by Dex. However, the protein expression levels of PCK1 & PCK2 were significantly increased by Dex, suggesting a post-transcriptional regulation. In dorsal longissimus, the mRNA expression of genes associated with gluconeogenesis and the insulin signaling pathway were generally up-regulated by Dex, but the mRNA expression of two markers of muscle atrophy, namely F-box protein 32 (FBXO32/Atrogin1) and muscle RING-finger protein 1 (MuRF1), was not altered by Dex. CONCLUSIONS: Taken together, these results indicate that chronic administration of a low dosage of Dex induces hyperglycemia mainly through gluconeogenesis activation in the goat liver.
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Chronic stress seriously threatens welfare and health in animals and humans. Consecutive dexamethasone (Dex) injection was used to mimic chronic stress previously. In order to investigate the effect of chronic stress on hepatic lipids metabolism, in this study, 10 healthy male goats were randomly allocated into two groups, one received a consecutive injection of Dex via intramuscularly for 3â¯weeks (Dex group), the other received the same volume of saline as the control group (Con group). Hepatic health and triglyceride (TG) metabolism were analyzed and compared between two groups. The data showed that a significant decrease of TG in plasma and the liver was significantly decreased by Dex (Pâ¯<â¯.05), while the hepatic nonesterified fatty acid (NEFA) concentration was increased compared to the Con group (Pâ¯<â¯.05). Consistent with the decrease of TG level, the activity of hepatic lipoprotein lipase (LPL) and hepatic lipase (HL) enzymes activities were significantly enhanced by Dex. Real-time PCR results showed that the mRNA expression of sterol regulatory element binding transcription factor 1 (SREBP-1), acyl-CoA dehydrogenase long chain (ACADL) and acyl-CoA synthetase bubblegum family member 1 (ACSBG1) genes in liver was significantly up-regulated by chronic Dex injection (Pâ¯<â¯.05), whereas perilipin 2 (PLIN2) and adipose triglyceride lipase (ATGL) mRNA expression was significantly decreased by Dex (Pâ¯<â¯.05). In addition, no obvious damages were observed in the liver in both Con and Dex groups demonstrating by the sirius red staining, HE staining as well as several biochemical parameters related to the functional status of hepatocytes. Our data indicate that chronic Dex exposure decreases TG levels in the circulation and the liver through activating lipolysis and inhibiting lipogenesis without causing hepatic damages in the growing goats.