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Soil phosphorus (P) availability affects plant growth and distribution. However, it is still unknown how sex-specific variation in functional traits affects plants' P acquisition and soil P transformation. On wet sites, female poplars had a greater specific root length (SRL), and a higher diversity of arbuscular mycorrhizal fungi (AMF) and phosphate-solubilizing bacteria (PSB). Male poplars living on wet sites increased the abundance of AMF and PSB communities and enhanced moderately labile and highly resistant organic P mineralisation via increased phosphatase activity. In contrast, on the dry site, the abundance and diversity of AMF and PSB communities increased in females, enhancing moderately labile and highly resistant organic P mineralisation via elevating phosphatase activities. Males maintained greater SRL and promoted Ca-P mobilisation via the release of root carboxylic acids and rhizosphere acidification on the dry site. The AMF community diversity followed a similar pattern as that of the PSB community when altering the P availability of different-sex plants. Our results indicated that organic P and Ca-P are the major sources of plant-available P in natural P. euphratica forests. Seasonal shifts and geographic locations affected the share of organic and inorganic P pools, and AMF and PSB diversities, ultimately altering sex-specific P acquisition strategies of plants.
Assuntos
Florestas , Micorrizas , Fósforo , Populus , Água , Populus/metabolismo , Populus/fisiologia , Fósforo/metabolismo , Micorrizas/fisiologia , Água/metabolismo , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Solo/química , Microbiologia do Solo , RizosferaRESUMO
Chronic obstructive pulmonary disease (COPD) is a prevalent disease worldwide, mainly caused by cigarette smoking. Maternally expressed gene 3 (MEG3) functions as the lncRNA and is upregulated in COPD patients and human bronchial epithelial cells after fine particulate matter (PM2.5) treatment. However, the molecular mechanism of MEG3 in COPD remains unknown. The expression of MEG3 and miR-218 in COPD tissues and cigarette smoke extract (CSE)-treated 16HBE cells was detected by RT-qPCR. The effects of MEG3 and miR-218 on proliferation and apoptosis in (CSE)-treated 16HBE cells were analyzed by CCK-8 and flow cytometry assay, respectively. The protein levels of inflammatory cytokines (IL-1ß IL-6 and TNF-α) were detected in 16HBE cells by ELISA. MEG3 and miR-218 binding interaction was predicted by LncBase Predicted v.2 and further confirmed by dual luciferase reporter assay and RNA Immunoprecipitation (RIP) assay. MEG3 was upregulated in COPD tissues and inversely related to FEV1%. MEG3 was upregulated in (CSE)-treated 16HBE cells, and knockdown of MEG3 mitigated CSE-repressed proliferation and CSE-triggered apoptosis or inflammation. MiR-218 was demonstrated as a target miRNA of MEG3. MiR-218 was downregulated in COPD tissues and (CSE)-treated or MEG3 overexpressed 16HBE cells. MiR-218 overexpression attenuated CSE-blocked proliferation and CSE-induced apoptosis or inflammation. Deficiency of MEG3 counteracted CSE-blocked proliferation CSE-induced apoptotic rate and inflammatory cytokine (IL-1ß IL-6 and TNF-α) levels, while introduction of anti-miR-218 reversed these effects. MEG3 regulated CSE-inhibited proliferation and CSE-induced apoptosis or inflammation by targeting miR-218, providing a possible therapeutic target for treatment of CSE-induced COPD.
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Apoptose , Fumar Cigarros/efeitos adversos , Inflamação/etiologia , MicroRNAs/antagonistas & inibidores , Doença Pulmonar Obstrutiva Crônica/patologia , RNA Longo não Codificante/fisiologia , Linhagem Celular , Proliferação de Células , Citocinas/metabolismo , Humanos , RNA Longo não Codificante/metabolismo , RNA Longo não Codificante/farmacologiaRESUMO
Background: The majority of patients of lung cancer have already lost the chance of surgery at the time of diagnosis. Percutaneous local thermal ablation is a precise minimally invasive technique and a viable alternative to surgical treatment. Compared with radiofrequency ablation and microwave ablation, percutaneous laser ablation for the treatment of lung tumors is less commonly used and reported, especially for primary lung cancer. Case presentation: A 63-year-old male patient with mixed pulmonary nodules selected computed tomography-guided electromagnetic navigation system for percutaneous biopsy and laser ablation therapy. The puncture point was determined through Computed tomography scanning, along with the placement of the electromagnetic navigation system locators. After rapid on-site evaluation and pathological examination of the puncture tissue specimen, the diagnosis of lung adenocarcinoma was confirmed. A 980-nanometer wavelength semiconductor laser fiber was inserted into the appropriate position guided by the electromagnetic navigation system. Subsequently, a power of 7 watt was applied to ablate the tumor for 30 seconds, then pause for 60 seconds before repeating the procedure. Positron emission tomography-Computed tomography examination was performed 1 month after operation, suggesting complete response of the tumor. Conclusion: Here, we present a case of percutaneous laser ablation treatment for primary lung cancer guided by computed tomography-electromagnetic navigation system. As a more precise, shorter duration, impedance-independent, safe and effective minimally invasive thermal ablation method, it is expected to gain wider application and become a novel alternative for surgical treatment.
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Mitochondria are the power source of living cells and implicated in the oxidative metabolism. However, the effect of mitochondria on breeding is usually ignored in conventional research. In this study, the effect of mitochondria on Ganoderma lucidum morphology, yield, and main primary bioactive components was analyzed via structuring and comparing isonuclear alloplasmic strains. The crucial biological pathways were then explored based on the transcriptome. The results showed that isonuclear alloplasmic exhibited difference in mycelial growth rate in potato dextrose agar medium (PDA), basidiospore yield, and polysaccharide and triterpenoid content. Otherwise, mitochondria did not change colony and fruit body morphology, mushroom yield, or mycelial growth rate in solid-state fermentation cultivation material. The transcriptome data of two significant isonuclear alloplasmic strains S1 and S5 revealed that the involvement of differentially expressed genes (DEGs) was mainly in pentose and glucuronate interconversions, starch and sucrose metabolism, and steroid biosynthesis. The result was further confirmed by the other isonuclear alloplasmic strains. The above results further proved that mitochondria could affect the active components of G. lucidum. Our results provide information which will contribute to understanding of mitochondria and will be helpful for breeding improved varieties.
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Several mitogenomes of the genus Ganoderma have been assembled, but intraspecific comparisons of mitogenomes in Ganoderma lingzhi have not been reported. In this study, 19 G. lingzhi mitogenomes were assembled and analyzed combined with three mitogenomes of G. lingzhi from GenBank in term of the characteristics, evolution, and phylogeny. The results showed that the mitogenomes of the G. lingzhi strains are closed circular ranging from 49.23 kb to 68.37 kb. The genetic distance, selective pressure, and base variation indicate that the 14 common protein coding genes were highly conserved. The differences in introns, open reading frames, and repetitive sequences in the mitogenome were the main factors leaded to the variations in mitogenome. The introns were horizontally transferred in mitogenomes, and the differences between introns in the same insertion, which were primarily caused by the repetitive sequence, showed that the introns may be under degeneration. Besides, the frequent insertion and deletion of introns showed an evolutionary rate faster than protein coding genes. Phylogenetic analysis showed that the G. lingzhi strains gathered with high support, and those with the same intron distribution law had closer clustering relationships.
Assuntos
Ganoderma , Genoma Mitocondrial , Genoma Mitocondrial/genética , Filogenia , Evolução Molecular , Ganoderma/genética , Íntrons/genéticaRESUMO
Most conventional chemotherapeutics indiscriminately kill both cancerous and healthy cells and cause toxic side effects, limiting the maximum tolerated dose and thereby compromising therapeutic efficacy. To address this challenge, here dual-targeting intelligent DNA guided missile (GM)-integrated nanospacecraft (NSC) (abbreviated as GM-NSC) is demonstrated for staged chemotherapeutic drug delivery exclusively into cancer cells and then mitochondria (not into healthy cells). GM-NSC is essentially a core/shell nanocomposite composed of gold nanoparticles (AuNPs) surrounded by a high-density multilayer DNA crown that is self-assembled from DNA tetrahedral units (DNA Tetra) in a highly ordered manner. Each tetrahedral structural unit is equipped with three functional components: a cancer cell-targeting aptamer pointing toward the outside environment, a hidden mitochondria-targeting triphenylphosphonium (TPP), and an explosive bolt (E-bolt). GM-NSC can remain intact in fetal bovine serum solution over 12 h and has 53-fold improved systemic stability. Each GM-NSC accommodates 1250 anticancer doxorubicin (Dox), achieving a 48-63-fold improved drug payload capacity. When systemically administrated into a tumor-bearing xenograft murine model, Dox-loaded GM-NSC enters into tumor sites with 18-fold improved specificity followed by autonomous separation of GMs from the NSC core and specific mitochondrial accumulation due to the explosion of E-bolt upon stimuli of endogenous miRNAs. About 80% of Dox uptaken is transferred into mitochondria and induces mitochondria-mediated apoptosis. As a result, the growth of malignant tumor is almost 100% inhibited without detectable toxicity to healthy tissues. Due to the desirable systemic stability, good biocompatibility, high cargo loading capability, satisfactory in vivo biodistribution, and therapeutic efficacy without adverse effects, intelligible GM-NSC is expected to become an alternative drug delivery system for precision cancer therapy.
Assuntos
Nanopartículas Metálicas , MicroRNAs , Nanopartículas , Neoplasias , Animais , Linhagem Celular Tumoral , DNA , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Sistemas de Liberação de Medicamentos , Ouro , Humanos , Camundongos , Nanopartículas/química , Neoplasias/tratamento farmacológico , Soroalbumina Bovina , Distribuição TecidualRESUMO
OBJECTIVES: Cuffed endotracheal intubation and stent implantation were employed to simulate two types of benign airway stenosis and further to analysis the different features between them from trachecscopic characteristics, gross anatomy to histopathological changes. In addition, our study explored the therapeutic effect of mitomycin C at different concentrations on granulation tissue caused by stent implantation in order to provide a new therapeutic strategy for clinical treatment of benign airway stenosis. METHODS: Twelve beagle dogs were randomly divided into four groups, with three dogs in each group. Group A: Three beagle dogs were intubated through oral trachea after general anesthesia and cuff pressure maintained at 200 mmHg for 24 h. Group B, Group C and Group D: endotracheal coated self-expanding metal stents were placed after general anesthesia under the guidance of bronchoscope. On the Day7 after stent implantation, Group B, as control group, was injected phosphate buffer solution of 1 ml into granulation tissue at the end of stent; Group C was injected mitomycin C of 1 ml at 0.4 mg/ml and Group D was injected mitomycin C of 1 ml at 0.8 mg/ml into granulation tissue at the end of metal airway stent respectively, the same method as Group B. Bronchoscopy was used to observe tracheal lumen on the seventh day, fourteenth day and twenty-first day after modeling and pathological changes were examined on twenty-first day. RESULTS: Two models of benign airway stenosis can be established by cuffed endotracheal intubation and stent implantation. There was tracheal rupture in the trachea cartiage ring in the cuffed endotracheal intubation group, but was't in stent implantation group. Histopathological characteristics were different between cuffed endotracheal intubation and stent implantation groups. In stent placement groups, we found that the stenosis degree of mitomycin C at 0.4 mg/ml was approximately 19%-32%, mitomycin C at 0.8 mg/ml was approximately 16%-21% and the control group was approximately 36%-47%. CONCLUSION: The two models of canine benign tracheal stenosis induced by cuffed endotracheal intubation and stent implantation are relatively simple, reliable and reproducible and have different characteristics. Mitomycin C could inhibit proliferation of granulation tissue and attenuate the degree of airway stenosis caused by stent implantation.
Assuntos
Traqueia , Estenose Traqueal , Animais , Cães , Constrição Patológica/complicações , Intubação Intratraqueal/efeitos adversos , Intubação Intratraqueal/métodos , Mitomicina/farmacologia , Mitomicina/uso terapêutico , Ruptura/complicações , Ruptura/tratamento farmacológico , Ruptura/patologia , Stents/efeitos adversos , Traqueia/patologia , Estenose Traqueal/etiologia , Estenose Traqueal/terapiaRESUMO
Chronic obstructive pulmonary disease (COPD) is a type of respiratory disease. The dysregulation of long non-coding RNA (lncRNA) taurine upregulated gene 1 (TUG1) has been reported in diverse diseases. This study aimed to explore the functions and mechanism of TUG1 in COPD. The levels of TUG1 and BRD4 were significantly up-regulated, and the level of miR-34c was apparently down-regulated in COPD patients or CSE-treated BEAS-2B cells. TUG1 was verified to sponge to miR-34c, and BRD4 was validated as a target of miR-34c. TUG1 depletion or miR-34c overexpression promoted cell proliferation but restrained apoptosis, inflammatory response in CSE-treated BEAS-2B cells. MiR-34c inhibitor mitigated the inhibitory effect on cell proliferation and the promotion effects on cell apoptosis, inflammatory response in CSE-treated BEAS-2B cells induced by TUG1 silencing. Mechanistically, TUG1 modulated BRD4 expression in CSE-treated BEAS-2B cells by sponging miR-34c. TUG1 modulated BRD4 to regulate cell proliferation, cell apoptosis and inflammatory response in CSE-treated BEAS-2B cells by sponging miR-34c.
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Pleurotus pulmonarius, a member of the Pleurotaceae family in Basidiomycota, is an edible, economically important mushroom in most Asian countries. In this study, the complete mitochondrial genomes (mtDNA) of three P. pulmonarius strains - two monokaryotic commercial (J1-13 and ZA3) and one wild (X1-15) - were sequenced and analyzed. In ZA3 and X1-15, the mtDNA molecule was found to be a single circle of 68,305 bp and 73,435 bp, respectively. Both strains contain 14 core protein-coding genes and two ribosomal RNA (rRNA) subunit genes. The ZA3 strain has 22 transfer RNA (tRNA) genes and nine introns: eight in cytochrome c oxidase subunit 1 (coxl), and one in the rRNA large subunit (rnl). Monokaryotic J1-13 and ZA3 mtDNAs were found to be similar in their structure. However, the wild strain X1-15 contains 25 tRNA genes and only seven introns in coxl. Open reading frames (ORFs) of ZA3/J1-13 and X1-15 encode LAGLIDADG, ribosomal protein S3, and DNA polymerase II. In addition, mtDNA inheritance in J1-13, ZA3, and X1-15 was also studied. Results showed that the mtDNA inheritance pattern was uniparental and closely related to dikaryotic hyphal location with respect to the parent. Results also show that mtDNA inheritance is influenced by both the parental nuclear genome and mitogenome in the zone of contact between two compatible parents. In summary, this analysis provides valuable information and a basis for further studies to improve our understanding of the inheritance of fungal mtDNA.
Assuntos
Genoma Mitocondrial , Padrões de Herança , Pleurotus/genética , DNA Mitocondrial , Genoma Fúngico , FilogeniaRESUMO
Ganoderma lucidum is a medicinal mushroom that has been widely used in East Asia for the treatment of various diseases. The pharmacological activity of this fungus is primarily attributable to the polysaccharides and triterpenoids. In this study, to obtain the fruit bodies with improved content of active constituents, we examined the effect of salicylic acid (SA) and calcium ion on the biosynthesis of polysaccharides and triterpenoids by spraying the chemicals during the fruiting. To explore the underlying mechanisms for the variation, the transcripts of related genes involved in the polysaccharide and triterpenoid biosynthesis were measured. Results showed that Ca2+ had no effect on production of polysaccharides and triterpenoids, whereas SA increased triterpenoid content by 23.32%, compared to the control, but it had little influence on polysaccharide production. Interestingly, the combined induction increased polysaccharide and triterpenoid content by 9.02% and 13.61%, respectively, compared to the control. Under Ca2+ induction, the transcript of ugp gene in the polysaccharide biosynthetic pathway up-regulated in all three stages (mycelium, primordium, and fruit body), while pgm and gls gave no response in the mycelium and primordium stages, and up-regulated in the fruit body stage. Differently, six key triterpenoid biosynthetic genes including hmgr, hmgs, mvd, fps, sqs, and ls did not respond to the induction. In the case of SA and combined induction, pgm and ugp were up-regulated in all three stages, while gls showed an increased expression in the primordium stage and no response in other stages. The six triterpenoid biosynthetic genes were up-regulated in all three stages. The present study provides a useful approach to producing G. lucidum fruit bodies with high polysaccharide and triterpenoid content. This is important to the G. lucidum industry.
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Polissacarídeos/metabolismo , Reishi/metabolismo , Transdução de Sinais , Triterpenos/metabolismo , Cálcio/farmacologia , Cromatografia Líquida de Alta Pressão , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Polissacarídeos/análise , RNA Fúngico/isolamento & purificação , RNA Fúngico/metabolismo , Reishi/química , Reishi/crescimento & desenvolvimento , Ácido Salicílico/farmacologia , Transdução de Sinais/efeitos dos fármacos , Triterpenos/análise , Regulação para Cima/efeitos dos fármacosRESUMO
Dysregulation of glucose metabolism is a primary hallmark of metabolic disease (i.e., diabetes, obesity, etc.). Complementary nonpharmaceutical strategies are needed to prevent and/or ameliorate dysregulation of glucose metabolism and prevent progression from normoglycemia to prediabetes and type 2 diabetes across the lifespan. Cocoa compounds, particularly the procyanidins, have shown promise for improving insulin sensitivity and blood glucose homeostasis. However, the molecular mechanisms by which cocoa procyanidins exert these functions remain poorly understood. Furthermore, cocoa procyanidins exhibit size diversity, and evidence suggests that procyanidin bioactivity and size may be related. Here, we show that a procyanidin-rich cocoa extract elicits an antidiabetic effect by stimulating glycogen synthesis and glucose uptake, independent of insulin. Cocoa procyanidins did not appear to act via stimulation of AMPK or CaMKII activities. Additionally, in the presence of insulin, glycogen synthesis and AKT phosphorylation were affected. These mechanisms of action are most pronounced in response to oligomeric and polymeric procyanidins. These results demonstrate (1) specific mechanisms by which cocoa procyanidins improve glucose utilization in skeletal muscle and (2) that larger procyanidins appear to possess enhanced activities. These mechanistic insights suggest specific strategies and biological contexts that may be exploited to maximize the antidiabetic benefits of cocoa procyanidins.
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Cacau/química , Insulina/metabolismo , Fibras Musculares Esqueléticas/efeitos dos fármacos , Proantocianidinas/farmacologia , Índice de Massa Corporal , Células Cultivadas , Glucose/metabolismo , Glicogênio/metabolismo , Humanos , Hipoglicemiantes/farmacologia , Resistência à Insulina , Masculino , Peso Molecular , Fibras Musculares Esqueléticas/metabolismo , Extratos Vegetais/farmacologiaRESUMO
A hallmark of type 2 diabetes (T2D) is ß-cell dysfunction and the eventual loss of functional ß-cell mass. Therefore, mechanisms that improve or preserve ß-cell function could be used to improve the quality of life of individuals with T2D. Studies have shown that monomeric, oligomeric and polymeric cocoa flavanols have different effects on obesity, insulin resistance and glucose tolerance. We hypothesized that these cocoa flavanols may have beneficial effects on ß-cell function. INS-1 832/13-derived ß-cells and primary rat islets cultured with a monomeric catechin-rich cocoa flavanol fraction demonstrated enhanced glucose-stimulated insulin secretion, while cells cultured with total cocoa extract and with oligomeric or polymeric procyanidin-rich fraction demonstrated no improvement. The increased glucose-stimulated insulin secretion in the presence of the monomeric catechin-rich fraction corresponded with enhanced mitochondrial respiration, suggesting improvements in ß-cell fuel utilization. Mitochondrial complex III, IV and V components are up-regulated after culture with the monomer-rich fraction, corresponding with increased cellular ATP production. The monomer-rich fraction improved cellular redox state and increased glutathione concentration, which corresponds with nuclear factor, erythroid 2 like 2 (Nrf2) nuclear localization and expression of Nrf2 target genes including nuclear respiratory factor 1 (Nrf1) and GA binding protein transcription factor alpha subunit (GABPA), essential genes for increasing mitochondrial function. We propose a model by which monomeric cocoa catechins improve the cellular redox state, resulting in Nrf2 nuclear migration and up-regulation of genes critical for mitochondrial respiration, glucose-stimulated insulin secretion and ultimately improved ß-cell function. These results suggest a mechanism by which monomeric cocoa catechins exert their effects as an effective complementary strategy to benefit T2D patients.
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Catequina/análogos & derivados , Chocolate , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Mitocôndrias/enzimologia , Fosforilação Oxidativa , Extratos Vegetais/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Catequina/química , Catequina/isolamento & purificação , Catequina/metabolismo , Linhagem Celular , Suplementos Nutricionais/análise , Complexo III da Cadeia de Transporte de Elétrons/química , Complexo III da Cadeia de Transporte de Elétrons/genética , Complexo III da Cadeia de Transporte de Elétrons/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/química , Complexo IV da Cadeia de Transporte de Elétrons/genética , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Indução Enzimática , Glucose/metabolismo , Hipoglicemiantes/análise , Hipoglicemiantes/química , Hipoglicemiantes/isolamento & purificação , Hipoglicemiantes/metabolismo , Secreção de Insulina , Células Secretoras de Insulina/citologia , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/metabolismo , Masculino , Mitocôndrias/metabolismo , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Ratos Wistar , Técnicas de Cultura de TecidosRESUMO
Polyphenol profiles and in vitro digestive enzyme inhibitory activities were compared between cocoa extracts from unfermented beans (UB), fermented beans (FB), unfermented liquor (UL), and fermented liquor (FL). Total polyphenols, total flavanols, and individual flavanols were significantly different between UB/FB and UL/FL. All extracts effectively inhibited α-glucosidase (lowest IC50 = 90.0 µg/mL, UL) and moderately inhibited α-amylase (lowest IC50 = 183 µg/mL, FL) and lipase (lowest IC25 = 65.5 µg/mL, FB). Our data suggest that fermentation does not reduce α-glucosidase inhibition, while roasting may enhance inhibition. For α-amylase, both fermentation and roasting improved inhibition. Finally, for lipase, both fermentation and roasting attenuated inhibition. Conclusive correlations between inhibition and mDP, total polyphenol, and flavanol contents were not found. Our data suggest that enzyme inhibition activities of cocoa are not uniformly reduced by polyphenol/flavanol losses during fermentation and roasting. This paradigm-challenging finding suggests other cocoa constituents, potentially formed during processing, contribute to digestive enzyme inhibition.
Assuntos
Cacau/química , Inibidores Enzimáticos/química , Flavonoides/metabolismo , Bactérias/metabolismo , Cacau/metabolismo , Cacau/microbiologia , Culinária , Digestão , Inibidores Enzimáticos/metabolismo , Fermentação , Flavonoides/química , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/metabolismo , Temperatura Alta , Humanos , Cinética , Sementes/química , Sementes/metabolismo , Sementes/microbiologia , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/química , alfa-Amilases/metabolismo , alfa-Glucosidases/química , alfa-Glucosidases/metabolismoRESUMO
Antioxidant activities of Ampelopsis grossedentata extract (EXT) and its major component dihydromyricetin (DHM) were analysed and compared with BHA in two model systems, soybean oil and cooked ground beef. Oxidation of soybean oil samples was measured using peroxide value, anisidine value, headspace volatiles and headspace oxygen content. TBARS (thiobarbituric acid reactive substances) test was used to measure the oxidation of cooked beef. DHM was more potent than BHA in preventing soybean oil oxidation. EXT was not as effective as BHA or DHM in soybean oil. In cooked beef, all three antioxidants significantly lowered oxidation compared to control, but there were no differences between the three. Mechanisms and potentials of EXT and DHM as natural food antioxidants need to be studied on a case-by-case basis.
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Ampelopsis/química , Antioxidantes/química , Flavonóis/química , Carne/análise , Óleo de Soja/química , Ampelopsis/metabolismo , Animais , Hidroxianisol Butilado/química , Bovinos , Cromatografia Líquida de Alta Pressão , Flavonóis/análise , Oxirredução , Fenóis/análise , Extratos Vegetais/química , Óleo de Soja/metabolismoRESUMO
Procyanidins are available in the diet from sources such as cocoa and grapes. Procyanidins are unique in that they are comprised of repeating monomeric units and can exist in various degrees of polymerization. The degree of polymerization plays a role in determining the biological activities of procyanidins. However, generalizations cannot be made regarding the correlation between procyanidin structure and bioactivity because the size-activity relationship appears to be system dependent. Our aim was to screen fractions of procyanidins with differing degrees of polymerization in vitro for anti-inflammatory activities in models of colonic inflammation. Monomeric, oligomeric and polymeric cocoa procyanidin fractions were screened using cell models of disrupted membrane integrity and inflammation in human colon cells. High-molecular-weight polymeric procyanidins were the most effective at preserving membrane integrity and reducing secretion of interleukin-8 in response to inflammatory stimuli. Conversely, oligomeric procyanidins appeared to be the least effective. These results suggest that polymeric cocoa procyanidins may be the most effective for preventing loss of gut barrier function and epithelial inflammation, which are critical steps in the pathogenesis of metabolic endotoxemia, inflammatory bowel disease and colon cancer. Therefore, further investigations of the potential health-protective benefits of cocoa procyanidins with distinct degrees of polymerization, particularly high-molecular-weight procyanidins, are warranted.
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Anti-Inflamatórios/farmacologia , Biflavonoides/farmacologia , Cacau/química , Catequina/farmacologia , Colo/efeitos dos fármacos , Inflamação/tratamento farmacológico , Proantocianidinas/farmacologia , Células CACO-2 , Cromatografia Líquida de Alta Pressão , Colo/metabolismo , Células HT29 , Humanos , Interleucina-8/metabolismo , Peso Molecular , Permeabilidade , Extratos Vegetais/farmacologiaRESUMO
Metabolism of flavanols (catechins, procyanidins) by gut microbiota has been extensively characterized. Comparatively little is known about accumulation of flavanols and their metabolites in the colon tissues, particularly during chronic exposure to low doses. Mice were fed low doses of cocoa flavanols for 12 weeks. Supplementation of the control diet with flavanols did not increase colonic tissue accumulation of flavanols nor microbial metabolites versus control. The type of cocoa flavanols did not affect colonic tissue accumulation of native flavanols or metabolites. Total phenolic content of the diets indicated that these results are not explained by background levels of undetected phenolics in the control diet. This is the longest known chronic flavanol feeding study to examine colonic tissue accumulation. Vast differences appear to exist between acute high doses and chronic low doses, to which gut microbiota and epithelium adapt. These results indicate that the fate of flavanols in the colon during chronic exposure is not fully understood.
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Bactérias/metabolismo , Cacau/metabolismo , Catequina/metabolismo , Colo/metabolismo , Microbiota , Extratos Vegetais/metabolismo , Proantocianidinas/metabolismo , Ração Animal/análise , Animais , Bactérias/isolamento & purificação , Colo/microbiologia , Suplementos Nutricionais/análise , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
There is interest in the potential of cocoa flavanols, including monomers and procyanidins, to prevent obesity and type-2 diabetes. Fermentation and processing of cocoa beans influence the qualitative and quantitative profiles of individual cocoa constituents. Little is known regarding how different cocoa flavanols contribute to inhibition of obesity and type-2 diabetes. The objective of this study was to compare the impacts of long-term dietary exposure to cocoa flavanol monomers, oligomers, and polymers on the effects of high-fat feeding. Mice were fed a high-fat diet supplemented with either a cocoa flavanol extract or a flavanol fraction enriched with monomeric, oligomeric, or polymeric procyanidins for 12 weeks. The oligomer-rich fraction proved to be most effective in preventing weight gain, fat mass, impaired glucose tolerance, and insulin resistance in this model. This is the first long-term feeding study to examine the relative activities of cocoa constituents on diet-induced obesity and insulin resistance.