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In this paper, the influence of different fiber materials on the dynamic splitting mechanical properties of concrete was investigated. Brazil disc dynamic splitting tests were conducted on plain concrete, palm fiber-reinforced concrete, and steel fiber-reinforced concrete specimens using a split Hopkinson pressure bar (SHPB) test device with a 100 mm diameter and a V2512 high-speed digital camera. The Digital Image Correlation (DIC) technique was used to analyze the fracture process and crack propagation behavior of different fiber-reinforced concrete specimens and obtain their dynamic tensile properties and energy dissipation. The experimental results indicate that the addition of fibers can enhance the impact toughness of concrete, reduce the occurrence of failure at the loading end of specimens due to stress concentration, delay the time to failure of specimens, and effectively suppress the expansion of cracks. Steel fibers exhibit a better crack-inhibiting effect on concrete compared to palm fibers. The incident energy for the three types of concrete specimens is roughly the same under the same impact pressure. Compared with plain concrete, the energy absorption rate of palm fiber concrete is decreased, while that of steel fiber concrete is increased. Palm fiber-reinforced concrete and steel fiber-reinforced concrete have lower peak strains than plain concrete under the same loading duration. The addition of steel fibers significantly impedes the internal cracking process of concrete specimens, resulting in a relatively slow growth of damage variables.
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The underlying interplay between physicochemical property and enzymatic hydrolysis of cellulose still remains unclear. The impacts of matrix glycan composition of sugar beet pulp (SBP) on physical structure and saccharification efficiency were emphasized. The results showed that aqueous ammonia (AA) pretreatment could remove the non-cellulosic polysaccharides and destroy the linkage between the pectin and lignin. The cellulose supramolecule was changed significantly after AA pretreatment, in terms of the decline in hardness, gumminess, springiness, thickness and degree of polymerization. Furthermore, vascular cell was exposed and degraded. The highest reducing sugar yield of 355.06 mg/g was obtained from the pretreated SBP (80 °C) with enzyme loading of 30 U/g, which was 1.01 times higher than that of the untreated SBP. This research also supported the idea that recognizing and precisely removing the primary epitopes in cell walls might be an ideal strategy to accomplish the improved enzymatic hydrolysis through mild pretreatment.
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Beta vulgaris , Beta vulgaris/química , Amônia/química , Hidrólise , Açúcares , Celulose/química , Pectinas , Parede Celular , LigninaRESUMO
BACKGROUND: Currently, broad industrial application of laccases is commonly restricted by the high-cost related production. Solid state fermentation (SSF) using agricultural waste is an attractively economic strategy for laccase production, yet its efficiency is low. Pretreatment of cellulosic substrate might be a vital breakpoint to solve the problem in solid state fermentation (SSF). In this study, sodium hydroxide pretreatment was involved to prepare solid substrates from rice straw. Fermentability of solid substrates in terms of carbon resource supply, accessibility and water retention value, and their influence on performance of SSF were analyzed. RESULTS: The results showed that sodium hydroxide pretreatment provided desirable solid substrates with higher enzymatic digestibility and optimal water retention value, which further facilitated the homogeneity of mycelium growth, laccase distribution and nutrition utilization during SSF. The pretreated rice straw (1 h) with diameter less than 0.085 cm gave the maximum laccase production of 2912.34 U/g, which was 7.72 times higher than the control. CONCLUSION: Hence, we proposed that enough balance between nutrition accessibility and structure support was a must for rational design and preparation of solid substrate. Additionally, sodium hydroxide pretreatment of lignocellulosic waste might be an ideal step to enhance the efficiency and lower the production cost in SSF.
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Oryza , Estudos de Viabilidade , Fermentação , Lacase , Hidróxido de Sódio , ÁguaRESUMO
Benzo(a)pyrene (BaP), the earliest and most significant carcinogen among polycyclic aromatic hydrocarbons (PAHs), has been found in foods, tobacco smoke, and automobiles exhaust, etc. Exposure to BaP induced DNA damage directly, or oxidative stress-related damage, resulting in cell apoptosis and carcinogenesis in human respiratory system, digestive system, reproductive system, etc. Moreover, BaP triggered genome-wide epigenetic alterations by methylation, which might cause disturbances in regulation of gene expression, and thereby induced cancer. It has been proved that BaP reduced genome-wide DNA methylation, and activated proto-oncogene by hypomethylation in the promoter region, but silenced tumor suppressor genes by promoter hypermethylation, resulting in cancer initiation and progression. Here we summarized the changes in DNA methylation in BaP exposure, and revealed the methylation of DNA plays a role in cancer development.
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To study the growth rate of different Arthrospira strains, three species of Arthrospira from Ordos alkaline lake, labeled as sp.DD, sp.ER, sp.FB, one species of Arthrospira from Hasu Sea in Hohhot, labeled as sp.HS, another purified strain labeled as sp.QD donated by the Ocean University of China had been collected. The first four need to be further isolated and purified in culture. The growth curves of all strains were plotted. Subsequently, 16S rRNA sequences were amplified and sequenced in an attempt to study taxonomic relationships. The results showed that the growth rate was increased in the first 9 days, and sp.DD had the highest growth rate. Analysis of the sequencing results revealed that sp.HS had 99.79% homology with Arthrospira platensis strain Sp-2, sp.DD had 99.69% homology with Arthrospira platensis FACHB834, sp.QD had 99.54% homology with Arthrospira platensis F3S, sp.ER had 99.79% homology with Arthrospira erdosensis 'Inner Mongolia', sp.FB had 99.74% homology with Arthrospira erdosensis 'Inner Mongolia'. Phylogenetic analysis indicated that sp.HS was closely related to Arthrospira platensis strain Sp-2; sp.DD and sp.QD had a close genetic relationship; sp.ER and sp.FB had a close genetic relationship. In conclusion, these findings provide a theoretical basis for the further development and reproduction of dominant algae species in Inner Mongolia through biological analysis of Arthrospira.
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Spirulina , DNA Bacteriano/genética , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNARESUMO
BACKGROUND: Rubella virus (RV) is the causative agent of rubella or German measles. Although most infections cause only mild self-limited measles-like illness, the infection in pregnant women can cause severe foetal malformation or even miscarriage, especially in the first 3 months of pregnancy. Therefore, it is of great practical significance to establish a simple and sensitive RV detection method. METHODS: The partial epitopes of the E1 and E2 proteins from Rubella Virus were selected as the target sites, the sequence of the selected antigenic sites of the E1 and E2 were linked by a linker. The expression plasmid P6T was constructed by inserting the gene into PET-32A + with a histidine Tag. The P6 protein was induced and expressed in Escherichia coli L21 (DE3) and purified by nickel column affinity. The protein P6 antigen was identified by Western blotting analysis, and an anti-P6 antibody ELISA was established to test known serum samples to evaluate the capability of this method. RESULTS: After purification, the concentration and purity of the protein P6 were 0.283 mg/mL and more than 80%, respectively. Western blotting analysis showed that the protein P6 could react with rubella virus positive serum. By ELISA, 36 negative sera and 58 positive sera were detected. The coincidence rate, specificity and sensitivity of the ELISA were 86.2%, 88.89% and 84.48%, respectively. The P6 ELISA with a kappa coefficient of 0.715, P < 0.05, indicated excellent consistency. CONCLUSIONS: The protein P6 with excellent antigenicity obtained from prokaryotic expression followed by chromatography purification could prove useful for early diagnosis of RV infection.
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Vírus da Rubéola , Rubéola (Sarampo Alemão) , Anticorpos Antivirais , Western Blotting , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Humanos , Imunoglobulina G , Gravidez , Rubéola (Sarampo Alemão)/diagnóstico , Vírus da Rubéola/genéticaRESUMO
Introduction: Tiger nut (TN) is recognized as a high potential plant which can grow in well-drained sandy or loamy soils and provide food nutrients. However, the overground tubers of TN remain unutilized currently, which limits the value-added utilization and large-area cultivation of this plant. Methods: In the present study, the overground tubers of TN were subjected to enzymatic hydrolysis to produce fermentable sugars for biofuels production. Steam explosion (SE) was applied to modify the physical-chemical properties of the overground tubers of TN for enhancing its saccharification. Results and discussion: Results showed that SE broke the linkages of hemicellulose and lignin in the TN substrates and increased cellulose content through removal of hemicellulose. Meanwhile, SE cleaved inner linkages within cellulose molecules, reducing the degree of polymerization by 32.13-77.84%. Cellulose accessibility was significantly improved after SE, which was revealed visibly by the confocal laser scanning microscopy imaging techniques. As a result, enzymatic digestibility of the overground tubers of TN was dramatically enhanced. The cellulose conversion of the SE treated TN substrates reached 38.18-63.97%, which was 2.5-4.2 times higher than that without a SE treatment. Conclusion: Therefore, SE pretreatment promoted saccharification of the overground tubers of TN, which paves the way for value-added valorization of the TN plants.
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BACKGROUND: Tissue heterogeneity significantly influences the overall saccharification efficiency of plant biomass. However, the mechanisms of specific organ or tissue recalcitrance to enzymatic deconstruction are generally complicated and unclear. A multidimensional analysis of the anatomical fraction from 12 corn cultivars was conducted to understand the essence of recalcitrance. RESULTS: The results showed that leaf, leaf sheath, stem pith and stem rind of corn straw exhibited remarkable heterogeneity in chemical composition, physical structure and cell type, which resulted in the different saccharification ratio of cellulose. The high saccharification ratio ranging from 21.47 to 38.96% was in stem pith, whereas the low saccharification ratio ranging from 17.1 to 27.43% was in leaf sheath. High values of lignin, hemicelluloses, degree of polymerization and crystallinity index were critical for the increased recalcitrance, while high value of neutral detergent soluble and pore size generated weak recalcitrance. Interestingly, pore traits of cell wall, especial for microcosmic interface structure, seemed to be a crucial factor that correlated to cellulase adsorption and further affected saccharification. CONCLUSIONS: Highly heterogeneity in cell wall traits influenced the overall saccharification efficiency of biomass. Furthermore, the holistic outlook of cell wall interface was indispensable to understand the recalcitrance and promote the biomass conversion.
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Galectin-3 (Gal-3) can induce T-cell activation and apoptosis and plays a role in tumor immune tolerance. Here, we demonstrate that ginseng pectins selectively inhibit Gal-3-induced T-cell apoptosis, while not affecting T-cell activation. This finding stands in contrast to that from the use of modified citrus pectin (MCP) and potato galactan (P-galactan) that inhibit both. Whereas PKC/ERK and ROS/ERK pathways are involved in both T-cell activation and apoptosis, the Ras/PI3K/Akt pathway is unique to T-cell activation. Ginseng pectins selectively inhibit the ROS/ERK pathway. Using the Sarcomar-180 mouse model in which Gal-3 expression is increased, we found that ginseng pectins (but not MCP or P-galactan) significantly promote T-cell proliferation and IL-2 expression, and inhibit tumor growth by 45%. These in vivo data correlate well with selective effects of pectins on Gal-3-mediated T-cell apoptosis and activation. Our study suggests a novel approach for the development of polysaccharide-based agents that target Gal-3 function.
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Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Galactanos/farmacologia , Galectina 3/metabolismo , Panax/metabolismo , Pectinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Linfócitos T , Animais , Linhagem Celular Tumoral , Humanos , Interleucina-2/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos ICR , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/metabolismoRESUMO
Chemical composition and physical structure of solid substrate have significantly impacts on fermentation performance. The aqueous ammonia was used to pretreat rice straw. Furthermore, the feasibility of pretreatment to improve laccase production was also evaluated in terms of the enzymatic digestibility, chemical structure, physical structure, and laccase production. The results showed that aqueous ammonia pretreatment could modify chemical compositions, destroy rigid structure of the lignocellulosic substrate, increase enzymatic digestibility and change water state, which were beneficial to facilitate the fungus growth and nutrition utilization. Pretreatment of lignocellulosic substrate with aqueous ammonia at 80 °C gave the best effect on laccase production, yielding 172.74 U/g laccase at 14 days, which was 3.4 times higher than that of the control. The aqueous ammonia pretreatment could alternate the physicochemical characteristics of lignocellulosic substrate, resulting in the improved laccase production, which was a promising method that might be explored in solid-state fermentation.
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Basidiomycota/crescimento & desenvolvimento , Proteínas Fúngicas/biossíntese , Lacase/biossíntese , Lignina , Oryza/química , Fermentação , Hidrólise , Lignina/química , Lignina/metabolismoRESUMO
Acetaminophen (APAP) overdose is the principal cause of drug-induced acute liver failure. 4-hydroxyphenylacetic acid (4-HPA), a major microbiota-derived metabolite of polyphenols, is involved in the antioxidative action. This study seeks to investigate the ability of 4-HPA to protect against APAP-induced hepatotoxicity, as well as the putative mechanisms involved. Mice were treated with 4-HPA (6, 12, or 25 mg/kg) for 3 days, 1 h after the last administration of 4-HPA, a single dose of APAP was intraperitoneally infused for mice. APAP caused a remarkable increase of oxidative stress markers, peroxynitrite formation, and fewer activated phase II enzymes. 4-HPA increased Nrf2 translocation to the nucleus and enhanced the activity of phase II and antioxidant enzymes, and could thereby ameliorate APAP-induced liver injury. Studies reveal that 4-HPA, as an active area of bioactive dietary constituents, could protect the liver against APAP-induced injury, implying that 4-HPA could be a new promising strategy and natural hepatoprotective drug.
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Although pectin-derived polysaccharides can antagonize galectin function in various pathological disorders, the nature of their binding interactions needs to be better defined for developing them as drugs. Moreover, given their relatively large size and complexity, pectin-derived polysaccharides are also useful as model systems to assess inter-polysaccharide and protein-polysaccharide interactions. Here, we investigated interactions between galectin-3 (Gal-3) and pectin-derived polysaccharides: a rhamnogalacturonan (RG) and two homogalacturonans (HGs). BioLayer Interferometry and fluorescence-linked immunosorbent assays indicate that these polysaccharides bind Gal-3 with macroscopic or apparent KD values of 49â nM, 46â µM, and 138â µM, respectively. 15N-1H heteronuclear single quantum coherence (HSQC) NMR studies reveal that these polysaccharides interact primarily with the F-face of the Gal-3 carbohydrate recognition domain. Even though their binding to Gal-3 does not inhibit Gal-3-mediated T-cell apoptosis and only weakly attenuates hemagglutination, their combination in specific proportions increases activity synergistically along with avidity for Gal-3. This suggests that RG and HG polysaccharides act in concert, a proposal supported by polysaccharide particle size measurements and 13C-1H HSQC data. Our model has HG interacting with RG to promote increased avidity of RG for Gal-3, likely by exposing additional lectin-binding sites on the RG. Overall, the present study contributes to our understanding of how complex HG and RG polysaccharides interact with Gal-3.
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Galectina 3/metabolismo , Pectinas/farmacologia , Proteínas Sanguíneas , Galectina 3/química , Galectina 3/genética , Galectinas , Humanos , Células Jurkat , Pectinas/química , Pectinas/genética , Ligação ProteicaRESUMO
Galectin-3 is a galectin with a unique flexible N-terminal tail (NT) connected to the conserved carbohydrate recognition domain (CRD). Galectin-3 is associated with tumor immune tolerance and exhibits an ability to induce T cell apoptosis. We used Jurkat, Jurkat E6-1 and CEM T-cell lines and human peripheral blood mononuclear cells (PBMCs) to investigate the specific roles of the CRD and NT in inducing T cell apoptosis. Galectin-3 triggered sustained extracellular signal-regulated kinase (ERK) phosphorylation that induced apoptosis. ERK was situated upstream of caspase-9 and was independently activated by reactive oxygen species (ROS) and protein kinase C (PKC). The first twelve NT residues had no role in the apoptosis. Residues 13-68 were essential for activating ROS, but did not activate PKC. However, residues 69-110 were required for activation of PKC. An NT fragment and a NT-specific antibody antagonized the apoptosis triggered by full-length galectin-3 further supporting our findings. These findings indicate the CRD and NT play important roles during induction of T cell apoptosis, which suggests their potential as therapeutic targets for reversing cancer immune tolerance.
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Apoptose , Carboidratos , Galectina 3/metabolismo , Domínios e Motivos de Interação entre Proteínas , Linfócitos T/metabolismo , Apoptose/imunologia , Carboidratos/química , Caspase 9/metabolismo , Linhagem Celular Tumoral , Galectina 3/química , Humanos , Antígenos Comuns de Leucócito/metabolismo , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fosforilação , Proteína Quinase C/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Linfócitos T/imunologiaRESUMO
BACKGROUND: In Chinese folk medicine, Corni fructus (C. fructus) has traditionally been used to improve liver function, although the mechanism underlying its activity remains unclear. The aim of the present study was to evaluate the protective effects of wild C. fructus methanolic extract against acute alcoholic liver injury. METHODS: Alcohol was administered to mice for three consecutive days, either alone or in combination with C. fructus methanolic extract (50, 100, or 200â mg/kg body weight/d). Serum and liver tissue were collected from the animals and subjected to biochemical and histopathological analyses. RESULTS: C. fructus signiï¬cantly alleviated alcohol-induced liver injury by reducing serum alanine aminotransferase, aspartate aminotransferase, and thiobarbituric acid reactive species, inhibiting hydroxyl radicals (â¢OH), and increasing total superoxide dismutase, glutathione peroxidase, and glutathione in the liver (P < 0.05). In addition, the C. fructus treatment inhibited the expression and activity of cytochrome P450 2E1 (P < 0.05). CONCLUSIONS: C. fructus could be a promising natural substance for ameliorating acute alcohol-induced oxidative stress and hepatic injury.
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Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Cornus/química , Metanol/química , Extratos Vegetais/uso terapêutico , Alanina Transaminase/metabolismo , Animais , Antioxidantes/metabolismo , Aspartato Aminotransferases/metabolismo , Citocromo P-450 CYP2E1/metabolismo , Feminino , Glutationa/metabolismo , Glutationa Peroxidase , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/lesões , Fígado/metabolismo , Malondialdeído/metabolismo , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Superóxido DismutaseRESUMO
As a member of the galectin family of animal lectins, galectin-12 is preferentially expressed in adipocytes and leukocytes. In adipocytes, galectin-12 is associated with lipid droplets and regulates lipid metabolism and energy balance, whereas its role in leukocytes is not clear. Analysis of galectin-12 expression in a public data set of acute myeloid leukemia (AML) samples revealed that it is selectively overexpressed in the M3 subtype, which is also known as acute promyelocytic leukemia (APL). To investigate the role of galectin-12 in APL cells, we manipulated its expression in the APL cell line, NB4, and measured resultant effects on all-trans-retinoic acid (ATRA)-induced granulocytic differentiation. With a doxycycline-inducible gene knockdown system, we found that suppression of galectin-12 promoted ATRA-induced neutrophil differentiation but inhibited lipid droplet formation. Our results indicate that overexpression of galectin-12 contributes to a differentiation block in APL cells, and suppression of galectin-12 facilitates granulocytic differentiation. Furthermore, these data suggest that lipogenesis and other aspects of myeloid differentiation can be differentially regulated. Taken together, these findings suggest that galectin-12 may be a target for treatment of the ATRA-resistant subset of APL.
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Galectinas/fisiologia , Leucemia Promielocítica Aguda/patologia , Lipogênese/fisiologia , Mielopoese/efeitos dos fármacos , Proteínas de Neoplasias/fisiologia , Neutrófilos/patologia , Linhagem Celular Tumoral , Galectinas/genética , Técnicas de Silenciamento de Genes , Humanos , Leucemia Promielocítica Aguda/metabolismo , Lipídeos/biossíntese , PPAR gama/biossíntese , PPAR gama/genética , Espécies Reativas de Oxigênio/metabolismo , Explosão Respiratória , Tretinoína/farmacologiaRESUMO
Galectin-12, a member of the galectin family of ß-galactoside-binding animal lectins, is preferentially expressed in adipocytes and required for adipocyte differentiation in vitro. This protein was recently found to regulate lipolysis, whole body adiposity, and glucose homeostasis in vivo. Here we identify VPS13C, a member of the VPS13 family of vacuolar protein sorting-associated proteins highly conserved throughout eukaryotic evolution, as a major galectin-12-binding protein. VPS13C is upregulated during adipocyte differentiation, and is required for galectin-12 protein stability. Knockdown of Vps13c markedly reduces the steady-state levels of galectin-12 by promoting its degradation through primarily the lysosomal pathway, and impairs adipocyte differentiation. Our studies also suggest that VPS13C may have a broader role in protein quality control. The regulation of galectin-12 stability by VPS13C could potentially be exploited for therapeutic intervention of obesity and related metabolic diseases.
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Adipogenia/genética , Galectinas/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas/metabolismo , Células 3T3-L1 , Animais , Galectinas/genética , Camundongos , Proteínas do Tecido Nervoso/genética , Estabilidade Proteica , Proteínas/genética , Proteínas de Transporte VesicularRESUMO
1. Acetaminophen (APAP) overdose leads to severe hepatotoxicity. 3,4-dihydroxyphenylacetic acid (DOPAC) is a scarcely studied microbiota-derived metabolite of quercetin. The aim of this study was to determine the protective effect of DOPAC against APAP-induced liver injury. 2. Mice were treated intragastrically with DOPAC (10, 20 or 50 mg/kg) for 3 days before APAP (300 mg/kg) injection. APAP alone caused increase in serum aminotransferase levels and changes in hepatic histopathology. APAP also promoted oxidative stress by increasing lipid peroxidation and decreasing anti-oxidant enzyme activities. These events led to hepatocellular necrosis and reduced liver function. DOPAC increased nuclear factor erythroid 2-related factor 2 (Nrf-2) translocation to the nucleus and enhanced the expression of phase II enzymes and anti-oxidant enzymes, and thereby reduced APAP hepatotoxicity and enhanced anti-oxidant ability. 3. Our data provide evidence that DOPAC protected the liver against APAP-induced injury, which is involved in Nrf-2 activation, implying that DOPAC can be considered as a potential natural hepatoprotective agent.
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Ácido 3,4-Di-Hidroxifenilacético/farmacologia , Substâncias Protetoras/farmacologia , Quercetina/metabolismo , Acetaminofen , Animais , Doença Hepática Induzida por Substâncias e Drogas , Camundongos , Microbiota , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacosRESUMO
Cytochrome P450 (CYP) 2E1 is an important enzyme involved in the metabolism of many endogenous and exogenous compounds. It is essential to evaluate the expression of CYP2E1 in the studies of drug-drug interactions and the screening of drugs, natural products, and foodstuffs. The present work is a feasibility study on the development of immunoassays using a specific and sensitive chicken-sourced anti-CYP2E1 IgY antibody. Cloning, expression, and purification of a recombinant CYP2E1 (mice origin) protein were carried out. Anti-CYP2E1 IgY antibodies were generated by immunizing white Leghorn chickens with purified recombinant CYP2E1 protein and were purified by immune affinity chromatography. The IgY titer attained a peak level (≥1:128,000) after the fifth booster injection. For evaluation of the expression of CYP2E1 in different herbal treatment samples, the mice were treated by oral gavage for 3 days with alcohol (50% 15 mL/kg), acetaminophen (APAP, 300 mg/kg), Cornus officinalis extract (100 mg/kg), Alhagi-honey extract (100 mg/kg), Apocynum venetum extract (100 mg/kg), hyperoside (50 mg/kg), isoquercetin (50 mg/kg), 4-hydroxyphenylacetic acid (50 mg/kg), 3-hydroxyphenylacetic acid (50 mg/kg), and 3,4-hydroxyphenylacetic acid (50 mg/kg). The expression of CYP2E1 was determined by Western blot analysis, immunohistochemistry, ELISA, and immunomagnetic beads (IMBs) using anti-CYP2E1 IgY in liver tissue. The results showed that C. officinalis extract, Alhagi-honey extract, A. venetum extract, hyperoside, isoquercetin, and their xenobiotics 4-hydroxyphenylacetic acid, 3-hydroxyphenylacetic acid, and 3,4-hydroxyphenylacetic acid significantly decreased CYP2E1 levels. Alcohol and APAP treatments significantly increased CYP2E1 levels as analyzed with Western blot analysis, immunohistochemistry, and ELISA. The IMB method is suitable for large-scale screening, and it is a rapid screening (20 min) that uses a portable magnet and has no professional requirements for the operator, which makes it useful for on-the-spot analysis. Considering these results, the anti-CYP2E1 IgY could be applied as a novel research tool in screening for the CYP2E1 inhibitor/enhancer.
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Pectin has been shown to inhibit the actions of galectin-3, a ß-galactoside-binding protein associated with cancer progression. The structural features of pectin involved in this activity remain unclear. We investigated the effects of different ginseng pectins on galectin-3 action. The rhamnogalacturonan I-rich pectin fragment, RG-I-4, potently inhibited galectin-3-mediated hemagglutination, cancer cell adhesion and homotypic aggregation, and binding of galectin-3 to T-cells. RG-I-4 specifically bound to the carbohydrate recognition domain of galectin-3 with a dissociation constant of 22.2 nm, which was determined by surface plasmon resonance analysis. The structure-activity relationship of RG-I-4 was investigated by modifying the structure through various enzymatic and chemical methods followed by activity tests. The results showed that (a) galactan side chains were essential to the activity of RG-I-4, whereas arabinan side chains positively or negatively regulated the activity depending on their location within the RG-I-4 molecule. (b) The activity of galactan chain was proportional to its length up to 4 Gal residues and largely unchanged thereafter. (c) The majority of galactan side chains in RG-I-4 were short with low activities. (d) The high activity of RG-I-4 resulted from the cooperative action of these side chains. (e) The backbone of the molecule was very important to RG-I-4 activity, possibly by maintaining a structural conformation of the whole molecule. (f) The isolated backbone could bind galectin-3, which was insensitive to lactose treatment. The novel discovery that the side chains and backbone play distinct roles in regulating RG-I-4 activity is valuable for producing highly active pectin-based galectin-3 inhibitors.
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Galectina 3/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias/metabolismo , Panax/química , Pectinas , Proteínas Sanguíneas , Configuração de Carboidratos , Adesão Celular/efeitos dos fármacos , Galectina 3/antagonistas & inibidores , Galectinas , Humanos , Células Jurkat , Proteínas de Neoplasias/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Pectinas/química , Pectinas/farmacologia , Relação Estrutura-AtividadeRESUMO
High temperature and pH modification could produce functional pectins. In this study, high temperature-modified (HTCP) and pH-modified (MCP) citrus pectins were prepared for studying their anti-tumor activities in eight cancer cell lines and a mouse Sarcoma-180 (S-180) tumor model. HTCP inhibited the proliferation of these cancer cells and induced a caspase-3-dependent cell apoptosis and cell cycle arrest at G2/M phase. It also inhibited the growth of S-180 tumor to 49% of the control at the dose of 200 mg kg(-1) d(-1) and extended the survival time of the tumor-bearing mice. MCP had no anti-proliferative effects on these cancer cells and no anti-tumor effect in the mouse model. The anti-tumor activity of HTCP in the mouse tumor model was not correlated with immunomodulation and galectin-3 inhibition, but correlated well with proliferation inhibition. HTCP might be exploited as a functional food for cancer prevention and/or treatment.