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Vascular dementia (VaD) is the second most common type of dementia after Alzheimer's disease. In our previous studies, we showed that wheat bran extract (WBE) reduced white matter damage in a rat VaD model and improved memory in a human clinical trial. However, starch gelatinization made the large-scale preparation of WBE difficult. To simplify the manufacturing process and increase efficacy, we attempted to find a decoction containing an optimum ratio of wheat bran, sliced citrus peel, and sliced jujube (WCJ). To find an optimal ratio, the cell survival of C6 (rat glioma) cultured under hypoxic conditions (1% O2) was measured, and apoptosis was assessed. To confirm the efficacies of the optimized WCJ for VaD, pupillary light reflex, white matter damage, and the activation of astrocytes and microglia were assessed in a rat model of bilateral common carotid artery occlusion (BCCAO) causing chronic hypoperfusion. Using a combination of both searching the literature and cell survival experiments, we chose 6:2:1 as the optimal ratio of wheat bran to sliced citrus peel to sliced jujube to prepare WCJ. We showed that phytic acid contained only in wheat bran can be used as an indicator component for the quality control of WCJ. We observed in vitro that the WCJ treatment improved cell survival by reducing apoptosis through an increase in the Bcl-2/Bax ratio. In the BCCAO experiments, the WCJ-supplemented diet prevented astrocytic and microglial activation, mitigated myelin damage in the corpus callosum and optic tract, and, consequently, improved pupillary light reflex at dosages over 100 mg/kg/day. The results suggest that the consumption of WCJ can prevent VaD by reducing white matter damage, and WCJ can be developed as a safe, herbal medicine to prevent VaD.
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Glioblastoma is frequently associated with TP53 mutation, which is linked to a worse prognosis and response to conventional treatments (chemoradiotherapy). Therefore, targeting TP53 is a promising strategy to overcome this poor therapeutic response. Tumor-treating fields (TTFields) are a recently approved treatment for newly diagnosed glioblastoma, which involves direct application of low-intensity, intermediate-frequency alternating electric fields to the tumor, thereby offering a local tumor-killing effect. However, the influence of TP53 mutation status on the effectiveness of TTFields is controversial. Here, we identified the key gene signatures and pathways associated with TTFields in four glioblastoma cell lines varying in TP53 mutation status using gene profiling and functional annotation. Overall, genes associated with the cell cycle, cell death, and immune response were significantly altered by TTFields regardless of TP53 status. TTFields appeared to exert enhanced anti-cancer effects by altering the immune system in the inflammatory environment and regulating cell cycle- and cell death-related genes, but the precise genes influenced vary according to TP53 status. These results should facilitate detailed mechanistic studies on the molecular basis of TTFields to further develop this modality as combination therapy, which can improve the therapeutic effect and minimize side effects of chemoradiotherapy.
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Perfilação da Expressão Gênica , Glioblastoma/genética , Glioblastoma/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Biomarcadores Tumorais , Ciclo Celular/genética , Biologia Computacional/métodos , Regulação Neoplásica da Expressão Gênica , Ontologia Genética , Redes Reguladoras de Genes , Glioblastoma/patologia , Glioblastoma/terapia , Humanos , Estadiamento de Neoplasias , Prognóstico , TranscriptomaRESUMO
The authors wish to make the following corrections to this paper [...].
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Radiotherapy using high linear energy transfer (LET) radiation results in effectively killing tumor cells while minimizing dose (biological effective) to normal tissues to block toxicity. It is well known that high LET radiation leads to lower cell survival per absorbed dose than low LET radiation. High-linear energy transfer (LET) neutron treatment induces autophagy in tumor cells, but its precise mechanisms in osteosarcoma are unknown. Here, we investigated this mechanism and the underlying signaling pathways. Autophagy induction was examined in gamma-ray-treated KHOS/NP and MG63 osteosarcoma cells along with exposure to high-LET neutrons. The relationship between radiosensitivity and autophagy was assessed by plotting the cell surviving fractions against autophagy levels. Neutron treatment increased autophagy rates in irradiated KHOS/NP and MG63 cells; neutrons with high-LETs showed more effective inhibition than those with lower LET gamma-rays. To determine whether the unfolded protein response and Akt-mTOR pathways triggered autophagy, phosphorylated eIF2α and JNK levels, and phospho-Akt, phosphor-mTOR, and phospho-p70S6 levels were, respectively, investigated. High-LET neutron exposure inhibited Akt phosphorylation and increased Beclin 1 expression during the unfolded protein response, thereby enhancing autophagy. The therapeutic efficacy of high-LET neutron radiation was also assessed in vivo using an orthotopic mouse model. Neutron-irradiated mice showed reduced tumor growth without toxicity relative to gamma-ray-treated mice. The effect of high-LET neutron exposure on the expression of signaling proteins LC3, p-elF2a, and p-JNK was investigated by immunohistochemistry. Tumors in high-LET-neutron radiation-treated mice showed higher apoptosis rates, and neutron exposure significantly elevated LC3 expression, and increased p-elF2a and p-JNK expression levels. Overall, these results demonstrate that autophagy is important in radiosensitivity, cell survival, and cellular resistance against high-LET neutron radiation. This correlation between cellular radiosensitivity and autophagy may be used to predict radiosensitivity in osteosarcoma.
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Autofagia , Nêutrons/uso terapêutico , Osteossarcoma/radioterapia , Resposta a Proteínas não Dobradas , Animais , Linhagem Celular Tumoral , Células Cultivadas , Humanos , Transferência Linear de Energia , MAP Quinase Quinase 4/metabolismo , Camundongos , Proteínas Associadas aos Microtúbulos/metabolismo , Osteossarcoma/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/metabolismoRESUMO
BACKGROUND: Traditional studies of the cardiac proteome have mainly investigated in an animal model by two-dimensional gel electrophoresis (2-DE). However, the results have not been of satisfactory quality for an understanding of the underlying mechanism. Recent quantitative proteomic methods have been improved to overcome these limitations. To comprehensively study the cardiac proteome in a rat model of ischemia-reperfusion (IR), we developed a tandem mass tag (TMT)-based quantitative proteomic strategy. Furthermore, using this strategy, we examined the molecular mechanisms underlying the prevention of myocardial infarction by the intake of Triticum aestivum L. extract (TALE), a representative dietary fiber grain. METHODS: Cardiac proteomes were analyzed by 2-DE as a gel-based approach, and TMT labeling coupled with two-dimensional liquid chromatography (2D-LC) and tandem mass spectrometry (MS/MS) as a non-gel-based quantitative approach. Additionally, gene ontology annotation was conducted by PANTHER database. Several proteins of interest were verified by a Western blot analysis. RESULTS: Total 641 proteins were identified commonly from two independent MS datasets using 2D-LC MS/MS. Among these, we identified 151 IR-related proteins that were differentially expressed between the sham-operation group and IR group, comprising 62 up-regulated proteins and 89 down-regulated proteins. Most of the reduced proteins were involved in metabolic processes. In addition, 57 of the IR-related proteins were affected by TALE intake, representing 25 up-regulated proteins and 32 down-regulated proteins. In particular, TALE intake leads to a switch in metabolism to reduce the loss of high-energy phosphates and the accumulation of harmful catabolites (especially reactive oxygen species (ROS)) and to maintain cytoskeleton balance, leading to a reduction in cardiac IR injury. CONCLUSIONS: Our study provides a comprehensive proteome map of IR-related proteins and potential target proteins and identifies mechanisms implicated in the prevention of myocardial infarction by TALE intake in a rat IR model.
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The tropical basidiomycete fungus Phellinus linteus (Mesima) exhibits anti-tumor, anti-angiogenic, and immunomodulatory properties in various cancers including prostate, colon, and lung cancer along with melanoma by, for example, inducing apoptosis or cell cycle arrest. However, whether medina also facilitates treatment of hepatocellular carcinoma (HCC), the third global cause of cancer deaths, remains unknown. Here, we examined its potential as a radiosensitizer in HCC radiotherapy using human HCC Hep3B and HepG2 cell lines and xenograft tumors. Mesima pretreatment significantly enhanced HCC cell radiosensitivity in vitro and the combination of mesima + radiation treatment significantly reduced xenograft tumor growth and size in vivo compared to those with single treatments. Mechanistically, mesima significantly enhanced radiotherapy efficiency by inhibiting tumor cell survival through inducing apoptosis (assessed via annexin V), impairing cell cycle regulation (shown by flow cytometry), and reducing radiation-induced DNA damage repair (measured via γ-H2AX foci). Combination treatment also facilitated autophagic cell death beyond that from single treatments (assessed by quantifying stained acidic vesicular organelles), and diminished tumor cell metastatic potentials (shown by wound and Transwell assays). These findings support the synergistic anti-tumor effects of mesima combined with radiation and suggest scientific evidence for mesima as a radiosensitizer in HCC.
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Morte Celular Autofágica , Basidiomycota/química , Carcinoma Hepatocelular , Neoplasias Hepáticas , Radiossensibilizantes/farmacologia , Animais , Morte Celular Autofágica/efeitos dos fármacos , Morte Celular Autofágica/efeitos da radiação , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/radioterapia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Células Hep G2 , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/radioterapia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas de Neoplasias/biossíntese , Radiossensibilizantes/química , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Colorectal cancer (CRC) is a major cause of mortality that can be treated effectively with chemotherapy and radiotherapy, although resistance to these therapeutic modalities often occurs. Tumor-treating fields (TTFields) can block tumor growth by selectively impairing tumor cell division. In this study, we investigated the mechanism by which 5-fluorouracil (5-FU) sensitizes tumor cells to TTFields. Human HCT116 and SW480 CRC cells were treated with 5-FU and/or TTFields, and characterized in vitro in terms of cell viability, apoptosis through reactive oxygen species production, autophagy, and metastatic potentials. The biological effects of 5-FU and/or TTFields were studied via positron emission tomography and computed tomography on xenograft tumor growth and were confirmed with organoid models of patients. Our results revealed that combination treatment with 5-FU and TTFields increased the efficiency of TTFields therapy in colon cancer cells by downregulating signaling pathways associated with cell proliferation, survival, cell invasion, and migration while upregulating pathways mediating apoptosis and autophagic cell death. The novel mechanistic insights gleaned in this study suggest that combination therapy with TTFields and 5-FU may be effective in treating CRC, although safety and efficacy testing in patients with CRC will need to be performed before this strategy can be implemented clinically for TTF-sensitization.
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Osteosarcoma (OS) originates from osteoid bone tissues and is prone to metastasis, resulting in a high mortality rate. Although several treatments are available for OS, an effective cure does not exist for most patients with advanced OS. Zoledronic acid (ZOL) is a third-generation bisphosphonate that inhibits osteoclast-mediated bone resorption and has shown efficacy in treating bone metastases in patients with various types of solid tumors. Here, we sought to clarify the mechanisms through which ZOL inhibits OS cell proliferation. ZOL treatment inhibited OS cell proliferation, viability, and colony formation. Autophagy inhibition by RNA interference against Beclin-1 or ATG5 inhibited ZOL-induced OS cell death. ZOL induced autophagy by repressing the protein kinase B/mammalian target of rapamycin/p70S6 kinase pathway and extracellular signal-regulated kinase signaling-dependent autophagy in OS cell lines and patient-derived OS cells. Microarrays of miRNA showed that ZOL increased the levels of miR-212-3p, which is known to play an important role in autophagy, in OS in vitro and in vivo systems. Collectively, our data provided mechanistic insight into how increased miR-212-3p through ZOL treatment induces autophagy synergistically in OS cells, providing a preclinical rationale for conducting a broad-scale clinical evaluation of ZOL + miR-212-3p in treating OS.
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BACKGROUND/OBJECTIVES: Myocardial infarction (MI) is caused by extensive myocardial damage attributed to the occlusion of coronary arteries. Our previous study in a rat model of ischemia/reperfusion (I/R) demonstrated that administration of arabinoxylan (AX), comprising arabinose and xylose, protects against myocardial injury. In this study, we undertook to investigate whether psyllium seed husk (PSH), a safe dietary fiber containing a high level of AX (> 50%), also imparts protection against myocardial injury in the same rat model. MATERIALS/METHODS: Rats were fed diets supplemented with PSH (1, 10, or 100 mg/kg/d) for 3 d. The rats were then subjected to 30 min ischemia through ligation of the left anterior descending coronary artery, followed by 3 h reperfusion through release of the ligation. The hearts were harvested and cut into four slices. To assess infarct size (IS), an index representing heart damage, the slices were stained with 2,3,5-triphenyltetrazolium chloride (TTC). To elucidate underlying mechanisms, Western blotting was performed for the slices. RESULTS: Supplementation with 10 or 100 mg/kg/d of PSH significantly reduces the IS. PSH supplementation (100 mg/kg/d) tends to reduce caspase-3 generation and increase BCL-2/BAX ratio. PSH supplementation also upregulates the expression of nuclear factor erythroid 2-related factor 2 (NRF2), and its target genes including antioxidant enzymes such as glutathione S-transferase mu 2 (GSTM2) and superoxide dismutase 2 (SOD2). PSH supplementation upregulates some sirtuins (NAD+-dependent deacetylases) including SIRT5 (a mitochondrial sirtuin) and SIRT6 and SIRT7 (nuclear sirtuins). Finally, PSH supplementation upregulates the expression of protein kinase A (PKA), and increases phosphorylated cAMP response element-binding protein (CREB) (pCREB), a target protein of PKA. CONCLUSIONS: The results from this study indicate that PSH consumption reduces myocardial I/R injury in rats by inhibiting the apoptotic cascades through modulation of gene expression of several genes located upstream of apoptosis. Therefore, we believe that PSH can be developed as a functional food that would be beneficial in the prevention of MI.
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Vascular dementia (VaD) develops through a pre-VaD step during which blood vessels narrow due to atherosclerosis attributed to risk factors, including hyperlipidemia. This is followed by a VaD progression step during which inadequate blood supply results in white matter damage and consequent cognitive impairment. Furthermore, administration of arabinoxylan attenuated white matter damage in a rat model of VaD. Thus, we hypothesized that consumption of psyllium seed husk (PSH), containing a high level of arabinoxylan (~60%), could inhibit the VaD progression step. To test this hypothesis, rats were supplemented with PSH at various dosages for 33 days in a model of bilateral common carotid artery occlusion. PSH supplementation decreased astrocytic and microglial activation in the optic tract (opt) and, consequently, attenuated white matter damage in the opt. Attenuation of white matter damage resulted in improvement of pupillary light reflex, an indicator reflecting intactness of the opt. In addition, PSH treatment improved survival of glial cells cultured under hypoxic and glucose-deprived conditions by inhibiting both apoptosis and autophagy. These findings indicate that PSH consumption can inhibit the VaD progression step through a decrease of white matter damage. Therefore, these results support our hypothesis that PSH consumption prevents VaD due to the high arabinoxylan content in the rat model. PSH consumption has already been shown to reduce risk factors, thereby inhibiting the pre-VaD step. Consequently, PSH consumption can contribute to the prevention of VaD by inhibiting both the pre-VaD and VaD progression steps. In conclusion, our rat study suggests that PSH might be a candidate to explore its use in clinical studies to reduce VaD.
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Isquemia Encefálica/complicações , Demência Vascular/prevenção & controle , Psyllium/farmacologia , Substância Branca/efeitos dos fármacos , Animais , Doença Crônica , Demência Vascular/etiologia , Modelos Animais de Doenças , Masculino , Psyllium/administração & dosagem , Ratos , Ratos Sprague-DawleyRESUMO
We have previously shown that supplementation of wheat with hot-water extract reduces myocardial injury by inhibiting apoptosis in a rat model of myocardial infarction (MI). Arabinogalactan-peptide (AGP), a cell wall polysaccharide of wheat, was also responsible for the protection. However, the underlying mechanisms were not elucidated. In this study, we investigated the underlying mechanisms for how AGP supplementation reduces myocardial injury. First, we isolated highly pure AGP from all-purpose wheat flour. We supplemented rats with AGP at a dose of 100 mg/kg/d for 3 days, and subjected the rats to ischemia (30 min) through ligation of the left anterior descending coronary artery followed by reperfusion (3 h) through a release of the ligation. Supplementation with AGP significantly reduced the infarct size in the heart. In addition, AGP intake inhibited the apoptotic cascade, determined through decreased mitogen-activated protein kinases (p38 and c-Jun N-terminal kinase) phosphorylation, decreased Bcl-2-associated X protein/B-cell lymphoma ratios, and decreased generation of nicked DNA, which was confirmed through western blotting and terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling staining. These findings indicate that AGP intake can protect against myocardial injury. Traditionally, consumption of dietary fiber such as AGP has been shown to reduce MI risk by inhibiting preocclusion steps through reducing risk factors. Our findings suggest that AGP intake can also reduce MI risk by inhibiting postocclusion steps. This study describes a better dietary recommendation and new prevention strategy for reducing MI risk through regular consumption of wheat rich in AGP.
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BACKGROUND/OBJECTIVES: Vascular dementia (VaD) caused by reduced blood supply to the brain manifests as white matter lesions accompanying demyelination and glial activation. We previously showed that arabinoxylan consisting of arabinose and xylose, and arabinose itself attenuated white matter injury in a rat model of VaD. Here, we investigated whether larch arabinogalactan (LAG) consisting of arabinose and galactose could also reduce white matter injury. MATERIALS/METHODS: We used a rat model of bilateral common carotid artery occlusion (BCCAO), in which the bilateral common carotid arteries were exposed and ligated permanently with silk sutures. The rats were fed a modified AIN-93G diet supplemented with LAG (100 mg/kg/day) for 5 days before and 4 weeks after being subjected to BCCAO. Four weeks after BCCAO, the pupillary light reflex (PLR) was measured to assess functional consequences of injury in the corpus callosum (cc). Additionally, Luxol fast blue staining and immunohistochemical staining were conducted to assess white matter injury, and astrocytic and microglial activation, respectively. RESULTS: We showed that white matter injury in the the cc and optic tract (opt) was attenuated in rats fed diet supplemented with LAG. Functional consequences of injury reduction in the opt manifested as improved PLR. Overall, these findings indicate that LAG intake protects against white matter injury through inhibition of glial activation. CONCLUSIONS: The results of this study support our hypothesis that cell wall polysaccharides consisting of arabinose are effective at protecting white matter injury, regardless of their origin. Moreover, LAG has the potential for development as a functional food to prevent vascular dementia.
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The development of coronary heart disease can be divided into preocclusion and postocclusion steps. We previously showed that cell wall polysaccharides consisting of a high content of arabinose and/or xylose, such as apple pectin, protected against myocardial injury by inhibiting postocclusion steps. We hypothesized that xyloglucan, another apple cell wall polysaccharide that consists of a high content of xylose, might also show myocardial protection. To test the hypothesis, rats were supplemented with either tamarind xyloglucan (TXG) (1, 10, and 100 mg/kg per day) or cotton cellulose (CCL) (100mg/kg per day) for 3 days. Then, rats underwent 30 minutes of ischemia followed by 3 hours of reperfusion. Supplementation with TXG at a dosage greater than 10mg/kg per day significantly reduced the infarct size (IS), whereas supplementation with CCL at 100mg/kg per day did not reduce IS. TXG supplementation up-regulated the expression of myoglobin and fatty acid-binding protein, both of which are known to be involved in apoptosis and ATP generation. Indeed, TXG supplementation inhibited apoptosis through decrease in p38 and JNK phosphorylation, increase in Bcl-2/Bax ratio, inhibition in the conversion of procaspase-3 to cleaved caspase-3, and decrease in the generation of DNA nicks. From these results, we demonstrated that xyloglucan in apple can protect against myocardial injury by inhibiting apoptosis and improving energy metabolism. Therefore, apple xyloglucan and pectin contribute to the known beneficial effects of apple in reducing the risk of coronary heart disease by blocking postocclusion steps through apoptosis inhibition. In addition, this study demonstrates the feasibility of developing TXG as a cardioprotectant.
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Apoptose/efeitos dos fármacos , Cardiotônicos , Metabolismo Energético/efeitos dos fármacos , Glucanos/administração & dosagem , Infarto do Miocárdio/patologia , Xilanos/administração & dosagem , Animais , Caspase 3/metabolismo , Parede Celular/química , Dieta , Modelos Animais de Doenças , Frutas/química , Marcação In Situ das Extremidades Cortadas , Masculino , Malus , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Miocárdio/química , Miocárdio/patologia , Pectinas/administração & dosagem , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/análise , Ratos , Ratos Sprague-Dawley , Tamarindus , Proteína X Associada a bcl-2RESUMO
We reported previously that supplementation with apple pectin, a dietary fiber, reduced myocardial injury in a rat model of ischemia-reperfusion. In this study, we further investigated an arabinogalactan, one of the constituent polysaccharides of pectin, to determine which domains comprising pectin were responsible for the protection. In a rat model of 30-min ischemia followed by 3-h reperfusion, supplementation with larch arabinogalactan (LAG) over 50 mg/kg/day significantly reduced infarct size. Reverse transcription polymerase chain reaction (RT-PCR), immunohistochemistry, and immunoblot analyses showed that intake of LAG blocked the steps involved in apoptotic cascades through downregulation of gelsolin gene expression at the protein (Gelsolin) level, inhibition of p38 phosphorylation in mitogen-activated protein kinase (MAPK) pathways, decreased bax/bcl-2 ratio at the protein (Bax/Bcl-2) level, which was correlated with the ratio at the mRNA level, inhibition of the conversion of Procaspase protein to Caspase-3 protein, and consequently a decrease in apoptotic cells. In addition, the intake of LAG reduced the hif1-α gene expression at the protein (HIF1-α) level. These findings suggest that arabinogalactan is an active component of pectin for reducing myocardial injury by inhibiting apoptosis in postocclusion steps, possibly indicating that arabinogalactan can be developed as a cardioprotectant to prevent myocardial injury.
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Apoptose/efeitos dos fármacos , Galactanos/administração & dosagem , Larix/química , Isquemia Miocárdica/tratamento farmacológico , Extratos Vegetais/administração & dosagem , Animais , Caspase 3/genética , Caspase 3/metabolismo , Modelos Animais de Doenças , Humanos , Masculino , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Isquemia Miocárdica/genética , Isquemia Miocárdica/metabolismo , Isquemia Miocárdica/fisiopatologia , Fosforilação , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos , Ratos Sprague-Dawley , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismoRESUMO
Many cohort studies have shown that consumption of diets containing a higher composition of foods derived from plants reduces mortality from coronary heart disease (CHD). Here, we examined the active components of a plant-based diet and the underlying mechanisms that reduce the risk of CHD using three rat models and a quantitative proteomics approach. In a short-term myocardial infarction (MI) model, intake of wheat extract (WE), the representative cardioprotectant identified by screening approximately 4,000 samples, reduced myocardial injury by inhibiting apoptosis, enhancing ATP production, and maintaining protein homeostasis. In long-term post-MI models, this myocardial protection resulted in ameliorating adverse left-ventricular remodelling, which is a predictor of heart failure. Among the wheat components, arabinose and xylose were identified as active components responsible for the observed efficacy of WE, which was administered via ingestion and tail-vein injections. Finally, the food components of plant-based diets that contained cell wall polysaccharides rich in arabinose, xylose, and possibly fucose were found to confer protection against myocardial injury. These results show for the first time that specific monosaccharides found in the cell wall polysaccharides in plant-based diets can act as active ingredients that reduce CHD by inhibiting postocclusion steps, including MI and heart failure.
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Parede Celular/metabolismo , Dieta , Modelos Animais de Doenças , Monossacarídeos/metabolismo , Infarto do Miocárdio/metabolismo , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Extratos Vegetais/administração & dosagem , Polissacarídeos/metabolismo , Triticum/química , Animais , Apoptose , Masculino , Traumatismo por Reperfusão Miocárdica/patologia , Proteômica , Ratos , Ratos Sprague-Dawley , Remodelação VentricularRESUMO
Vascular dementia is characterized by white matter lesions involving the demyelination and activation of astrocytes and microglia. In a previous study, we showed that the supernatant of a laboratory-scale, hot water extract of ground whole wheat (TALE) attenuated white matter injury and astrocytic activation in a rat model of bilateral common carotid artery occlusion (BCCAO). In the present study, we made several modifications to the hot water extraction process to remove starch and enable large-scale production. We used wheat bran (WB), which contains less starch, instead of ground whole wheat. In addition, we removed starch granules with a decanter before hot water extraction. The final product, wheat bran extract (WBE), contained 2.42% arabinose, a surrogate marker of arabinoxylan, which is an active constituent of WBE. Supplementation of the rat model of BCCAO with WBE (400 mg/kg/day) for 33 days attenuated white matter injury, which was assessed by Luxol Fast Blue staining, in the corpus callosum (cc) and optic tract (opt) regions. Attenuation of white matter injury in the opt region was accompanied by improvement of the pupillary light reflex. Immunochemical staining revealed that supplementation with WBE reduced astrocytic activation in the cc and opt regions and reduced microglial activation in the opt region. These findings indicate that supplementation with WBE is effective at attenuating white matter injury accompanied by the inhibition of astrocytic and microglial activation. Therefore, extracts from WB, a cheap by-product of wheat milling, can be developed as a nutraceutical to prevent vascular dementia, a disease for which there is no approved pharmaceutical treatment.
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Intakes of apple and its products are shown to reduce the risk of coronary heart disease by delaying occlusion of coronary arteries. In our previous study, we showed that apple pectin protected against myocardial injury by prohibiting apoptotic cascades in a rat model of ischemia/reperfusion. Thus, we hypothesized that water-extracted apple, into which apple pectin was released from the cell wall, might exhibit the same efficacy as apple pectin. To test this hypothesis, we fed rats either cold water- (400 mg kg(-1) d(-1)) or hot water-extracted apples (HWEA; 40, 100, and 400 mg kg(-1) d(-1)). Three days later, the rats were subjected to myocardial injuries by ligating the left anterior descending coronary artery (30 minutes), and subsequently, the heart (3 hours) reperfused by releasing the ligation. Only the rats that were supplemented with HWEA (400 mg kg(-1) d(-1)) showed significant reductions in infarct size, which was 28.5% smaller than that of the control group. This infarct size reduction could be partly attributed to the prevention of steps leading to apoptosis. These steps are manifested by a higher Bcl-2/Bax ratio, lower procaspase-3 conversion to caspase-3, and inhibition of DNA nick generation, which reflects the extent of apoptosis. The findings indicate that HWEA supplementation reduces myocardial injury by inhibiting apoptosis under ischemia/reperfusion conditions. In conclusion, this study suggests that apple intake, specifically boiled apple, might reduce the risk of coronary heart disease by inhibiting postocclusion steps, such as myocardial injury after artery occlusion, as well as preocclusion steps, such as atherosclerotic plaque formation.
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Apoptose/efeitos dos fármacos , Malus/química , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Extratos Vegetais/administração & dosagem , Animais , Caspase 3/genética , Caspase 3/metabolismo , Modelos Animais de Doenças , Masculino , Pectinas/administração & dosagem , Pectinas/química , Extratos Vegetais/química , Ratos , Ratos Sprague-Dawley , Temperatura , Água , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismoRESUMO
BACKGROUND/OBJECTIVE: Myocardial cell death due to occlusion of the coronary arteries leads to myocardial infarction, a subset of coronary heart disease (CHD). Dietary fiber is known to be associated with a reduced risk of CHD, the underlying mechanisms of which were suggested to delay the onset of occlusion by ameliorating risk factors. In this study, we tested a hypothesis that a beneficial role of dietary fiber could arise from protection of myocardial cells against ischemic injury, manifested after occlusion of the arteries. MATERIALS/METHODS: Three days after rats were fed apple pectin (AP) (with 10, 40, 100, and 400 mg/kg/day), myocardial ischemic injury was induced by 30 min-ligation of the left anterior descending coronary artery, followed by 3 hr-reperfusion. The area at risk and infarct area were evaluated using Evans blue dye and 2,3,5-triphenyltetrazolium chloride (TTC) staining, respectively. DNA nicks reflecting the extent of myocardial apoptosis were assessed by TUNEL assay. Levels of cleaved caspase-3, Bcl-2, and Bax were assessed by immunohistochemistry. RESULTS: Supplementation of AP (with 100 and 400 mg/kg/day) resulted in significantly attenuated infarct size (IS) (ratio of infarct area to area at risk) by 21.9 and 22.4%, respectively, in the AP-treated group, compared with that in the control group. This attenuation in IS showed correlation with improvement in biomarkers involved in the apoptotic cascades: reduction of apoptotic cells, inhibition of conversion of procaspase-3 to caspase-3, and increase of Bcl-2/Bax ratio, a determinant of cell fate. CONCLUSIONS: The findings indicate that supplementation of AP results in amelioration of myocardial infarction by inhibition of apoptosis. Thus, the current study suggests that intake of dietary fiber reduces the risk of CHD, not only by blocking steps leading to occlusion, but also by protecting against ischemic injury caused by occlusion of the arteries.
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Ischemic stroke is caused by brain injury due to prolonged ischemia by occlusion of cerebral arteries. In this study, we isolated active compounds from an ethanol extract of Aurantii Immatri Pericarpium (HY5356). We first showed by DNA fragmentation assay that HY5356 improved human hepatocellular carcinoma cells (HepG2) under hypoxic conditions by inhibiting apoptosis. When HY5356 was fractionated with dichloromethane (MC), ethyl acetate (EA) and n-butanol (BU), the MC fraction improved cell viability at the lowest concentration (100 µg/ml). Intraperitoneal injection of HY5356 (200 mg/kg) or the MC fraction (200 mg/kg) to rats prior to occlusion attenuated brain injury significantly in a rat model of ischemia-reperfusion. Adopting cell viability under hypoxic conditions as an activity screening system, we isolated nobiletin and tangeretin as active compounds. The results suggest that intake of Aurantii Immatri Pericarpium containing nobiletin and tangeretin as active compounds might be beneficial for preventing ischemic stroke.
Assuntos
Isquemia Encefálica/cirurgia , Citrus/química , Flavonas/administração & dosagem , Extratos Vegetais/administração & dosagem , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Isquemia Encefálica/complicações , Fragmentação do DNA/efeitos dos fármacos , Modelos Animais de Doenças , Flavonas/química , Frutas/química , Células Hep G2 , Humanos , Masculino , Extratos Vegetais/química , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/fisiopatologiaRESUMO
Interruption or prolonged reduction and subsequent restoration of blood flow into the kidney triggers the generation of a burst of reactive oxygen species (ROS), leading to injury in the tubular epithelial cells. In this study, we determined whether methanol extract of goat's-beard (Aruncus dioicus) (extract) could prevent this ischemia/re-perfusion injury. When in vitro radical scavenging activity of the extract was measured using a DPPH radical quenching assay, the extract displayed slightly lower activity than ascorbic acid. One hour after administration of the extract (400 mg/kg) by intraperitoneal injection in rats, renal ischemia/reperfusion injury was generated by clamping the left renal artery for forty minutes, followed by 24 hr restoration of blood circulation. Prior to clamping the left renal artery, the right renal artery was removed. Compared with the vehicle-treated group, pre-treatment with the extract significantly reduced the tubular epithelial cell injury by 37% in the outer medulla region, and consequently reduced serum creatinine concentration by 39%. Reduction in the cell injury was mediated by attenuation of Bax/Bcl-2 ratio, inhibition of caspase-3 activation from procaspase-3, and subsequent reduction in the number of apoptotic cells. Thus, goat's-beard (Aruncus dioicus) might be developed as a prophylactic agent to prevent acute kidney injury.