1
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Ishisaka A, Sugimoto R, Marumo H, Doi T, Hamada K, Fujimoto M, Fujiwara N, Yamasaki M, Murakami A. Role of Extracellular Vesicles in Absorption and Functional Mechanisms of Quercetin. Mol Nutr Food Res 2023; 67:e2300225. [PMID: 37672798 DOI: 10.1002/mnfr.202300225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 07/31/2023] [Indexed: 09/08/2023]
Abstract
SCOPE Quercetin (QUE), a phytochemical found in various plant foods, has been shown to have a variety of physiological activities in vivo, though biological sites where it has activities and the mechanisms of transport have not been fully elucidated. METHODS AND RESULTS In the present study, intracellular uptake of QUE into HT-29 human colon adenocarcinoma cells is found to result in spontaneous release of extracellular vesicles (EVs), which are subsequently embedded with QUE. In addition, QUE-embedded EVs are detected in serum of QUE-administered Sprague-Dawley rats. Interestingly, the rate of cellular uptake of QUE-encapsulated EVs (EV-QUE) into RAW264.7 macrophages is markedly higher than that of free QUE. Moreover, EV-QUE suppresses lipopolysaccharide (LPS)-induced nitric oxide at a lower concentration than free QUE. CONCLUSION The present findings suggest that QUE may be embedded in EVs in the gastrointestinal tract, then become absorbed and enter the bloodstream to exhibit biological activities.
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Affiliation(s)
- Akari Ishisaka
- Department of Food Science and Nutrition, School of Human Science and Environment, University of Hyogo, 1-1-12, Shinzaike-Honcho, Himeji, Hyogo, 670-0092, Japan
- Research Institute for Food and Nutritional Sciences, University of Hyogo, 1-1-12, Shinzaike-Honcho, Himeji, Hyogo, 670-0092, Japan
| | - Ryosuke Sugimoto
- Department of Food Science and Nutrition, School of Human Science and Environment, University of Hyogo, 1-1-12, Shinzaike-Honcho, Himeji, Hyogo, 670-0092, Japan
| | - Haruka Marumo
- Department of Food Science and Nutrition, School of Human Science and Environment, University of Hyogo, 1-1-12, Shinzaike-Honcho, Himeji, Hyogo, 670-0092, Japan
| | - Tomoki Doi
- Department of Food Science and Nutrition, School of Human Science and Environment, University of Hyogo, 1-1-12, Shinzaike-Honcho, Himeji, Hyogo, 670-0092, Japan
| | - Kaede Hamada
- Department of Food Science and Nutrition, School of Human Science and Environment, University of Hyogo, 1-1-12, Shinzaike-Honcho, Himeji, Hyogo, 670-0092, Japan
| | - Misa Fujimoto
- Department of Food Science and Nutrition, School of Human Science and Environment, University of Hyogo, 1-1-12, Shinzaike-Honcho, Himeji, Hyogo, 670-0092, Japan
| | - Nao Fujiwara
- Department of Food Science and Nutrition, School of Human Science and Environment, University of Hyogo, 1-1-12, Shinzaike-Honcho, Himeji, Hyogo, 670-0092, Japan
| | - Masao Yamasaki
- Department of Biochemistry and Applied Biosciences, Faculty of Agriculture, University of Miyazaki, Gakuen-kibanadai-nishi-1-1, Miyazaki, 889-2192, Japan
| | - Akira Murakami
- Department of Food Science and Nutrition, School of Human Science and Environment, University of Hyogo, 1-1-12, Shinzaike-Honcho, Himeji, Hyogo, 670-0092, Japan
- Research Institute for Food and Nutritional Sciences, University of Hyogo, 1-1-12, Shinzaike-Honcho, Himeji, Hyogo, 670-0092, Japan
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2
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Fujiwara N, Mukai R, Nishikawa M, Ikushiro S, Murakami A, Ishisaka A. Transfer of quercetin ingested by maternal mice to neonatal mice via breast milk. Biosci Biotechnol Biochem 2023; 87:442-447. [PMID: 36669760 DOI: 10.1093/bbb/zbad007] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 01/12/2023] [Indexed: 01/22/2023]
Abstract
This is the first study that quantified quercetin (QUE) and its 16 metabolites in the breast milk of QUE-fed maternal mice, the plasma and urine of that, and neonatal mice. Interestingly, the QUE aglycone concentration in the milk was much higher than in the plasma of maternal mice, suggesting that QUE may exert biological activity in neonates.
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Affiliation(s)
- Nao Fujiwara
- Department of Food Science and Nutrition, School of Human Science and Environment, University of Hyogo, Himeji, Hyogo, Japan
| | - Rie Mukai
- Department of Food Science, Graduate School of Technology, Industrial and Social Sciences, Tokushima University, Tokushima, Tokushima, Japan
| | - Miyu Nishikawa
- Department of Biotechnology, Faculty of Engineering, Toyama Prefectural University, Imizu, Toyama, Japan
| | - Shinichi Ikushiro
- Department of Biotechnology, Faculty of Engineering, Toyama Prefectural University, Imizu, Toyama, Japan
| | - Akira Murakami
- Department of Food Science and Nutrition, School of Human Science and Environment, University of Hyogo, Himeji, Hyogo, Japan
- Research Institute for Food and Nutritional Sciences, University of Hyogo, Himeji, Hyogo, Japan
| | - Akari Ishisaka
- Department of Food Science and Nutrition, School of Human Science and Environment, University of Hyogo, Himeji, Hyogo, Japan
- Research Institute for Food and Nutritional Sciences, University of Hyogo, Himeji, Hyogo, Japan
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3
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Suihara S, Ishisaka A, Murakami A. (-)-Epigallocatechin-3-O-gallate at a high concentration may induce lipolysis via ATP consumption by activation of stress defense mechanisms. Biosci Biotechnol Biochem 2021; 85:411-420. [PMID: 33604623 DOI: 10.1093/bbb/zbaa056] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 09/30/2020] [Indexed: 01/02/2023]
Abstract
Green tea catechins have thus far been demonstrated to have antiobesity effects in a variety of experimental models. However, upstream molecular events triggering those phenomena remain to be identified. In this study, we found that (-)-epigallocatechin-3-O-gallate (EGCG) promoted lipolysis in lipid-loaded Huh7 human hepatoma cells. Notably, EGCG at a high concentration induced both oxidative stress and protein stress (proteo-stress), leading to activation of stress defense mechanisms, such as mRNA expressions of antioxidant and phase-2 detoxifying enzymes, and heat shock proteins. Furthermore, EGCG decreased the level of intracellular ATP, while glucose uptake from culture media was promoted possibly for energy homeostasis. EGCG also upregulated the expression of adipose triglyceride lipase, and activated AMP-activated protein kinase. Collectively, these results suggest that EGCG induces lipolysis to compensate for ATP reduction derived from activation of stress defense systems against its oxidative and proteo-stress properties.
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Affiliation(s)
- Satoki Suihara
- Department of Food Science and Nutrition, School of Human Science and Environment, University of Hyogo, Himeji, Hyogo, Japan
| | - Akari Ishisaka
- Department of Food Science and Nutrition, School of Human Science and Environment, University of Hyogo, Himeji, Hyogo, Japan.,Research Institute for Food and Nutritional Sciences, University of Hyogo, Himeji, Hyogo, Japan
| | - Akira Murakami
- Department of Food Science and Nutrition, School of Human Science and Environment, University of Hyogo, Himeji, Hyogo, Japan.,Research Institute for Food and Nutritional Sciences, University of Hyogo, Himeji, Hyogo, Japan
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4
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Kato Y, Kawai M, Kawai S, Okano Y, Rokkaku N, Ishisaka A, Murota K, Nakamura T, Nakamura Y, Ikushiro S. Dynamics of the Cellular Metabolism of Leptosperin Found in Manuka Honey. J Agric Food Chem 2019; 67:10853-10862. [PMID: 31496237 DOI: 10.1021/acs.jafc.9b03894] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Leptosperin (methyl syringate β-d-gentiobioside) is abundantly found in manuka honey, which is widely used because of its antibacterial and possible anti-inflammatory activities. The aim of this study was to examine the molecular mechanism underlying the metabolism of leptosperin. Five phytochemicals (leptosperin, methyl syringate (MSYR), glucuronate conjugate of MSYR (MSYR-GA), sulfonate conjugate of MSYR (MSYR-S), and syringic acid (SYR)) were separately incubated with HepG2 and Caco-2 cells. After incubation, we found that the concentration of MSYR decreased, whereas the concentrations of SYR, MSYR-GA, and MSYR-S increased. By profiling with inhibitors and carboxylesterases (CES1, 2), we found that the conversion from MSYR to SYR was mediated by CES1. Lipopolysaccharide-stimulated RAW264.7 cells restored MSYR-GA to MSYR possibly by the secreted β-glucuronidase. All of the mice administered with leptosperin, MSYR, or manuka honey showed higher MSYR (13.84 ± 11.51, 14.29 ± 9.19, or 6.66 ± 2.30 nM) and SYR (1.85 ± 0.66, 6.01 ± 1.20, or 8.16 ± 3.10 nM) levels in the plasma compared with that of the vehicle controls (3.33 ± 1.45 (MSYR) and 1.85 ± 0.66 (SYR) nM). The findings of our study indicate that the unique metabolic pathways of these compounds may account for possible functionalities of manuka honey.
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Affiliation(s)
| | | | | | | | | | | | - Kaeko Murota
- Faculty of Life and Environmental Science , Shimane University , Matsue , Shimane 690-8504 , Japan
| | - Toshiyuki Nakamura
- Graduate School of Environmental and Life Science , Okayama University , Okayama 700-0082 , Japan
| | - Yoshimasa Nakamura
- Graduate School of Environmental and Life Science , Okayama University , Okayama 700-0082 , Japan
| | - Shinichi Ikushiro
- Department of Biotechnology , Toyama Prefectural University , Imizu , Toyama 939-0398 , Japan
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5
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Nakamura T, Hirakawa M, Nakamura Y, Ishisaka A, Kitamoto N, Murakami A, Kato Y. Covalent Modification of Phosphatidylethanolamine by Benzyl Isothiocyanate and the Resultant Generation of Ethanolamine Adduct as Its Metabolite. Chem Res Toxicol 2019; 32:638-644. [PMID: 30735032 DOI: 10.1021/acs.chemrestox.8b00331] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Benzyl isothiocyanate (BITC), a dietary isothiocyanate (ITC) derived from cruciferous vegetables, has anticancer properties. It is believed that the ITC moiety (-N═C═S) that reacts predominantly with thiol compounds plays a central role in triggering the activities resulting from these properties. Recent studies have demonstrated that ITCs also covalently modify amino moieties in a protein. In this study, we examined the chemical reaction between BITC and the aminophospholipid, phosphatidylethanolamine (PE), in the cell membrane or lipoprotein particle. To detect the BITC-modified PE, the bond between ethanolamine (EA) and phosphatidic acid in PE was cleaved using phospholipase D to form the BITC-EA adduct, which was then measured. BITC-EA was detected from the BITC-treated unilamellar liposome and low-density lipoprotein even with only a few micromoles of BITC treatment, suggesting that BITC might react with not only a thiol/amino group of a protein but also an amino moiety of an aminophospholipid. Moreover, after incorporating BITC-PE included in the liposomes into the cultured cells or after direct exposure of BITC to the cells, free BITC-EA was excreted and accumulated in the medium in a time-dependent manner. It indicates that an intracellular enzyme catalyzes the cleavage of BITC-PE to produce BITC-EA. Because the ITC-amine adduct is stable, the ITC-EA adduct could be a promising indicator of ITC exposure in vivo.
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Affiliation(s)
- Toshiyuki Nakamura
- Graduate School of Environmental and Life Science , Okayama University , Okayama 700-0082 , Japan
| | - Miho Hirakawa
- Graduate School of Human Science and Environment , University of Hyogo , Himeji , Hyogo 670-0092 , Japan
| | - Yoshimasa Nakamura
- Graduate School of Environmental and Life Science , Okayama University , Okayama 700-0082 , Japan
| | - Akari Ishisaka
- Graduate School of Human Science and Environment , University of Hyogo , Himeji , Hyogo 670-0092 , Japan.,Research Institute for Food and Nutritional Sciences , University of Hyogo , Himeji , Hyogo 670-0092 , Japan
| | - Noritoshi Kitamoto
- Graduate School of Human Science and Environment , University of Hyogo , Himeji , Hyogo 670-0092 , Japan.,Research Institute for Food and Nutritional Sciences , University of Hyogo , Himeji , Hyogo 670-0092 , Japan
| | - Akira Murakami
- Graduate School of Human Science and Environment , University of Hyogo , Himeji , Hyogo 670-0092 , Japan.,Research Institute for Food and Nutritional Sciences , University of Hyogo , Himeji , Hyogo 670-0092 , Japan
| | - Yoji Kato
- Graduate School of Human Science and Environment , University of Hyogo , Himeji , Hyogo 670-0092 , Japan.,Research Institute for Food and Nutritional Sciences , University of Hyogo , Himeji , Hyogo 670-0092 , Japan
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6
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Takechi R, Alfonso H, Harrison A, Hiramatsu N, Ishisaka A, Tanaka A, Tan L, Lee AH. Assessing self-reported green tea and coffee consumption by food frequency questionnaire and food record and their association with polyphenol biomarkers in Japanese women. Asia Pac J Clin Nutr 2018; 27:460-465. [PMID: 29384336 DOI: 10.6133/apjcn.052017.06] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND AND OBJECTIVES Despite the demonstrated protective effects of green tea and coffee intake against several chronic diseases, finding between studies have not been consistent. One potential reason of this discrepancy is the imprecision in the measurement of tea or coffee consumption using food frequency questionnaire (FFQ) and food record (FR) in epidemiological studies. METHODS AND STUDY DESIGN In a sample of 57 healthy Japanese women, intake of green tea and coffee was estimated by a validated FFQ and a 3-day FR, while their plasma and urine concentrations of polyphenol biomarkers were measured by HPLC. The polyphenols assessed included (-)-epigallocatechin gallate (EGCG), (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC) and (-)- epicatechin (EC), caffeic acid (CA) and chlorogenic acid (CGA). RESULTS Green tea consumption estimated by FFQ and FR showed moderate association, while strong association was detected for coffee consumption. Urinary green tea polyphenol concentrations were moderately-strongly associated with FR-estimated intake, while the associations were weak with FFQ. Similarly, coffee polyphenols in urine were moderately associated with FR-estimated coffee intake, whereas FFQ showed poor correlation. The associations between urinary and plasma polyphenols ranged from moderate to high. CONCLUSIONS The results indicated that firstly, the FFQ tends to overestimate green tea intake. Secondly, the urinary polyphenols are preferred over plasma polyphenols as a potential surrogate marker of the short-term green tea and coffee intake, while their use as an indicator of long-term consumption is not reliable.
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Affiliation(s)
- Ryusuke Takechi
- Curtin Health Innovation Research Institute, Curtin University, Western Australia, Australia. .,School of Public Health, Faculty of Health Sciences, Curtin University, Western Australia, Australia.,Nutrition Clinic, Kagawa Nutrition University, Tokyo, Japan
| | - Helman Alfonso
- School of Public Health, Faculty of Health Sciences, Curtin University, Western Australia, Australia
| | - Amy Harrison
- School of Public Health, Faculty of Health Sciences, Curtin University, Western Australia, Australia
| | - Naoko Hiramatsu
- School of Human Science and Environment, University of Hyogo, Himeji, Japan
| | - Akari Ishisaka
- School of Human Science and Environment, University of Hyogo, Himeji, Japan
| | - Akira Tanaka
- Nutrition Clinic, Kagawa Nutrition University, Tokyo, Japan
| | - La'Belle Tan
- School of Public Health, Faculty of Health Sciences, Curtin University, Western Australia, Australia
| | - Andy H Lee
- School of Public Health, Faculty of Health Sciences, Curtin University, Western Australia, Australia
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7
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Ishisaka A, Ikushiro S, Takeuchi M, Araki Y, Juri M, Yoshiki Y, Kawai Y, Niwa T, Kitamoto N, Sakaki T, Ishikawa H, Kato Y. In vivo absorption and metabolism of leptosperin and methyl syringate, abundantly present in manuka honey. Mol Nutr Food Res 2017; 61. [DOI: 10.1002/mnfr.201700122] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Revised: 03/31/2017] [Accepted: 04/10/2017] [Indexed: 11/05/2022]
Affiliation(s)
- Akari Ishisaka
- School of Human Science and Environment; University of Hyogo; Himeji Hyogo Japan
- Research Institute for Food and Nutritional Sciences; University of Hyogo; Himeji Hyogo Japan
| | - Shinichi Ikushiro
- Department of Biotechnology; Toyama Prefectural University; Imizu Toyama Japan
| | - Mie Takeuchi
- School of Human Science and Environment; University of Hyogo; Himeji Hyogo Japan
| | - Yukako Araki
- School of Human Science and Environment; University of Hyogo; Himeji Hyogo Japan
| | - Maki Juri
- School of Human Science and Environment; University of Hyogo; Himeji Hyogo Japan
| | - Yui Yoshiki
- School of Human Science and Environment; University of Hyogo; Himeji Hyogo Japan
| | - Yoshichika Kawai
- Department of Food Science; Graduate School of Biomedical Sciences; Tokushima University; Tokushima Tokushima Japan
| | - Toshio Niwa
- Faculty of Health and Nutrition; Shubun University; Ichinomiya Aichi Japan
| | - Noritoshi Kitamoto
- School of Human Science and Environment; University of Hyogo; Himeji Hyogo Japan
- Research Institute for Food and Nutritional Sciences; University of Hyogo; Himeji Hyogo Japan
| | - Toshiyuki Sakaki
- Department of Biotechnology; Toyama Prefectural University; Imizu Toyama Japan
| | | | - Yoji Kato
- School of Human Science and Environment; University of Hyogo; Himeji Hyogo Japan
- Research Institute for Food and Nutritional Sciences; University of Hyogo; Himeji Hyogo Japan
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8
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Kato Y, Oki K, Suga N, Ono S, Ishisaka A, Miura Y, Kanazawa S, Naito M, Kitamoto N, Kettle AJ. A novel quinone derived from 5-hydroxyindoleacetic acid reacts with protein: Possible participation of oxidation of serotonin and its metabolite in the development of atherosclerosis. Free Radic Biol Med 2016; 101:500-510. [PMID: 27856348 DOI: 10.1016/j.freeradbiomed.2016.11.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 11/09/2016] [Accepted: 11/13/2016] [Indexed: 02/05/2023]
Abstract
The modification of 5-hydroxyindoleacetic acid (5HIAA) by myeloperoxidase with a xanthine oxidase system was investigated by chromatographic analyses. Two major products were identified as a dimer and quinone (indoleacetate dione) of 5HIAA. The formation of a quinone moiety was also confirmed by chemical trapping with o-phenylenediamine. In the presence of N-acetyl-cysteine (NAC), a quinone-NAC adduct was formed. When glyceraldehyde 3-phosphate dehydrogenase was exposed to the myeloperoxidase system with 5HIAA, quinone adducts were formed on the protein molecule. A monoclonal antibody was prepared using a quinone-modified protein as an immunogen to immunochemically detect the quinone on a protein. The established antibody recognized the quinone-NAC adduct, quinone-modified poly-L-lysine, and quinone-modified low-density lipoprotein. Quinone-modified proteins in human atherosclerotic lesions were immunohistochemically observed using the established antibody to the quinone and also a monoclonal antibody to tryptamine dione-modified protein, suggesting an occurrence of in vivo oxidation of serotonin and 5HIAA, accompanied by covalent adduction to biomolecules.
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Affiliation(s)
- Yoji Kato
- Graduate School of Human Science and Environment, University of Hyogo, Himeji, Hyogo, Japan.
| | - Kota Oki
- Graduate School of Human Science and Environment, University of Hyogo, Himeji, Hyogo, Japan
| | - Naoko Suga
- Graduate School of Human Science and Environment, University of Hyogo, Himeji, Hyogo, Japan
| | - Shigeki Ono
- Graduate School of Human Science and Environment, University of Hyogo, Himeji, Hyogo, Japan
| | - Akari Ishisaka
- Graduate School of Human Science and Environment, University of Hyogo, Himeji, Hyogo, Japan
| | - Yoko Miura
- Department of Molecular and Cellular Biology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
| | - Satoshi Kanazawa
- Department of Molecular and Cellular Biology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
| | - Michitaka Naito
- Division of Nutrition & Health, School and Graduate School of Life Studies, Sugiyama Jogakuen University, Nagoya, Aichi, Japan
| | - Noritoshi Kitamoto
- Graduate School of Human Science and Environment, University of Hyogo, Himeji, Hyogo, Japan
| | - Anthony J Kettle
- Centre for Free Radical Research, Department of Pathology, University of Otago, Christchurch, New Zealand
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9
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Kato Y, Fujinaka R, Juri M, Yoshiki Y, Ishisaka A, Kitamoto N, Nitta Y, Ishikawa H. Characterization of a Monoclonal Antibody against Syringate Derivatives: Application of Immunochemical Detection of Methyl Syringate in Honey. J Agric Food Chem 2016; 64:6495-6501. [PMID: 27477590 DOI: 10.1021/acs.jafc.6b01328] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Syringic acid is one of the key skeletal structures of plant-derived chemicals. The derivatives of syringic acid have certain biological functions. In this study, a monoclonal antibody to syringic acid-based phytochemicals was prepared and characterized. The obtained antibody reacted with methyl syringate, syringic acid, and leonurine. Methyl syringate is a characteristic compound found in manuka honey, other honey varieties, and plants. Manuka honey was fractionated using HPLC, and the reactivity of the fractions with the antibody was examined. The antibody reacted with the fraction in which methyl syringate was eluted. The amount of methyl syringate in honeys as estimated by ELISA using the antibody had a good linearity compared with that estimated by HPLC. These results suggest that the antibody is applicable for the immunochemical detection of syringic acid derivatives in plants and foods.
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Affiliation(s)
| | | | | | | | | | | | - Yoko Nitta
- Department of Nutritional Science, Faculty of Health and Welfare Science, Okayama Prefectural University , 111 Kuboki, Soja-shi, Okayama 719-1197, Japan
| | - Hirohito Ishikawa
- Healthcare Systems, Company, Ltd. , 2-22-8 Chikusa-ku, Nagoya, Aichi 464-0858, Japan
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10
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Nuka E, Tomono S, Ishisaka A, Kato Y, Miyoshi N, Kawai Y. Metal-catalyzed oxidation of 2-alkenals generates genotoxic 4-oxo-2-alkenals during lipid peroxidation. Biosci Biotechnol Biochem 2016; 80:2007-13. [PMID: 27281652 DOI: 10.1080/09168451.2016.1191334] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Lipid peroxidation products react with cellular molecules, such as DNA bases, to form covalent adducts, which are associated with aging and disease processes. Since lipid peroxidation is a complex process and occurs in multiple stages, there might be yet unknown reaction pathways. Here, we analyzed comprehensively 2'-deoxyguanosine (dG) adducts with oxidized arachidonic acid using liquid chromatography-tandem mass spectrometry and found the formation of 7-(2-oxo-hexyl)-etheno-dG as one of the major unidentified adducts. The formation of this adduct was reproduced in the reaction of dG with 2-octenal and predominantly with 4-oxo-2-octenal (OOE). We also found that other 2-alkenals (with five or more carbons) generate corresponding 4-oxo-2-alkenal-type adducts. Importantly, it was found that transition metals enhanced the oxidation of C4-position of 2-octenal, leading to the formation of OOE-dG adduct. These findings demonstrated a new pathway for the formation of 4-oxo-2-alkenals during lipid peroxidation and might provide a mechanism for metal-catalyzed genotoxicity.
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Affiliation(s)
- Erika Nuka
- a Departmentof Food Science , Institute of Biomedical Sciences, TokushimaUniversity Graduate School , Tokushima , Japan
| | - Susumu Tomono
- b Laboratory of Longevity Biochemistry, Graduate School of Integrated Pharmaceutical and Nutritional Sciences, Graduate Program in Food and Nutritional Sciences , University of Shizuoka , Shizuoka , Japan
| | - Akari Ishisaka
- c Research Institute for Food and Nutritional Sciences , University of Hyogo , Himeji , Japan
| | - Yoji Kato
- c Research Institute for Food and Nutritional Sciences , University of Hyogo , Himeji , Japan
| | - Noriyuki Miyoshi
- b Laboratory of Longevity Biochemistry, Graduate School of Integrated Pharmaceutical and Nutritional Sciences, Graduate Program in Food and Nutritional Sciences , University of Shizuoka , Shizuoka , Japan
| | - Yoshichika Kawai
- a Departmentof Food Science , Institute of Biomedical Sciences, TokushimaUniversity Graduate School , Tokushima , Japan
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11
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Lee AH, Tan L', Hiramatsu N, Ishisaka A, Alfonso H, Tanaka A, Uemura N, Fujiwara Y, Takechi R. Plasma concentrations of coffee polyphenols and plasma biomarkers of diabetes risk in healthy Japanese women. Nutr Diabetes 2016; 6:e212. [PMID: 27270110 PMCID: PMC4931312 DOI: 10.1038/nutd.2016.19] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Revised: 02/13/2016] [Accepted: 04/27/2016] [Indexed: 01/29/2023] Open
Abstract
Coffee consumption has been reported to reduce the risk of type 2 diabetes in experimental and epidemiological studies. This anti-diabetic effect of coffee may be attributed to its high content in polyphenols especially caffeic acid and chlorogenic acid. However, the association between plasma coffee polyphenols and diabetic risks has never been investigated in the literature. In this study, fasting plasma samples were collected from 57 generally healthy females aged 38-73 (mean 52, s.d. 8) years recruited in Himeji, Japan. The concentrations of plasma coffee polyphenols were determined by liquid chromatography coupled with mass tandem spectrometer. Diabetes biomarkers in the plasma/serum samples were analysed by a commercial diagnostic laboratory. Statistical associations were assessed using Spearman's correlation coefficients. The results showed that plasma chlorogenic acid exhibited negative associations with fasting blood glucose, glycated hemoglobin and C-reactive protein, whereas plasma total coffee polyphenol and plasma caffeic acid were weakly associated with these biomarkers. Our preliminary data support previous findings that coffee polyphenols have anti-diabetic effects but further replications with large samples of both genders are recommended.
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Affiliation(s)
- A H Lee
- School of Public Health, Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia
| | - L 'b Tan
- School of Public Health, Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia
| | - N Hiramatsu
- School of Human Science and Environment, University of Hyogo, Himeji, Japan
| | - A Ishisaka
- School of Human Science and Environment, University of Hyogo, Himeji, Japan
| | - H Alfonso
- School of Public Health, Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia
| | - A Tanaka
- Nutrition Clinic, Kagawa Nutrition University, Tokyo, Japan
| | - N Uemura
- School of Human Science and Environment, University of Hyogo, Himeji, Japan
| | - Y Fujiwara
- School of Human Science and Environment, University of Hyogo, Himeji, Japan
| | - R Takechi
- School of Public Health, Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia.,Nutrition Clinic, Kagawa Nutrition University, Tokyo, Japan.,Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia, Australia
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12
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Takechi R, Alfonso H, Hiramatsu N, Ishisaka A, Tanaka A, Tan L, Lee AH. Elevated plasma and urinary concentrations of green tea catechins associated with improved plasma lipid profile in healthy Japanese women. Nutr Res 2016; 36:220-6. [DOI: 10.1016/j.nutres.2015.11.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Revised: 11/13/2015] [Accepted: 11/16/2015] [Indexed: 01/05/2023]
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Kawabata K, Mukai R, Ishisaka A. Quercetin and related polyphenols: new insights and implications for their bioactivity and bioavailability. Food Funct 2015; 6:1399-417. [DOI: 10.1039/c4fo01178c] [Citation(s) in RCA: 187] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The physiological functions and mechanisms of action of quercetin and its related polyphenols are highlighted, including their effects on brain, blood vessels, muscle, and intestinal microflora.
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Affiliation(s)
- Kyuichi Kawabata
- Department of Bioscience
- Fukui Prefectural University
- Eiheiji-cho, Yoshida-gun, Fukui 910-1195
- Japan
| | - Rie Mukai
- Department of Food Science
- Institute of Health Biosciences
- The University of Tokushima Graduate School
- Tokushima 770-8503
- Japan
| | - Akari Ishisaka
- School of Human Science and Environment
- University of Hyogo
- Himeji 670-0092
- Japan
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Kato Y, Araki Y, Juri M, Fujinaka R, Ishisaka A, Kitamoto N, Nitta Y, Niwa T, Takimoto Y. Immunochemical authentication of manuka honey using a monoclonal antibody specific to a glycoside of methyl syringate. J Agric Food Chem 2014; 62:10672-10678. [PMID: 25310890 DOI: 10.1021/jf503464a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Leptosperin, a novel glycoside of methyl syringate, is exclusively present in manuka honey derived from the Leptospermum species Leptospermum scoparium. Quantification of leptosperin might thus be applicable for authentication of honey. The concentration of leptosperin has high linearity with antibacterial activity. We established a monoclonal antibody to leptosperin and characterized the antibody in detail by a competitive enzyme-linked immunosorbent assay (ELISA), comparing the results with those of the high-performance liquid chromatography (HPLC) method for validation. The antigen in manuka honey was confirmed as leptosperin by HPLC fractionation with quantitation by an ELISA. Leptosperin contents of 50 honey samples were analyzed by an established ELISA, which can handle 20 samples (duplicate) on one 96-well plate. Significant coincidence with the chemical quantitation was observed. Immunochemical quantitation of leptosperin would be an economical and facile method for the possible authentication of manuka honey, allowing many honey samples to be processed and analyzed by an ELISA simultaneously.
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Affiliation(s)
- Yoji Kato
- School of Human Science and Environment and ‡Research Institute for Food and Nutritional Sciences, University of Hyogo , Himeji, Hyogo 670-0092, Japan
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15
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Kato Y, Fujinaka R, Ishisaka A, Nitta Y, Kitamoto N, Takimoto Y. Plausible authentication of manuka honey and related products by measuring leptosperin with methyl syringate. J Agric Food Chem 2014; 62:6400-6407. [PMID: 24941263 DOI: 10.1021/jf501475h] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Manuka honey, obtained from Leptospermum scoparium flowers in New Zealand, has strong antibacterial properties. In this study, plausible authentication of the manuka honey was inspected by measuring leptosperin, methyl syringate 4-O-β-D-gentiobiose, along with methyl syringate. Despite a gradual decrease in methyl syringate content over 30 days at 50 °C, even at moderate 37 °C, leptosperin remained stable. A considerable correlation between nonperoxide antibacterial activity and leptosperin content was observed in 20 certified manuka honey samples. Leptosperin and methyl syringate in manuka honey and related products were analyzed using HPLC connected with mass spectrometry. One noncertified brand displayed significant variations in the leptosperin and methyl syringate contents between two samples obtained from different regions. Therefore, certification is clearly required to protect consumers from disguised and/or low-quality honey. Because leptosperin is stable during storage and specific to manuka honey, its measurement may be applicable for manuka honey authentication.
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Affiliation(s)
- Yoji Kato
- School of Human Science and Environment, and ‡Research Institute for Food and Nutritional Sciences, University of Hyogo , Hyogo, Japan
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Ishisaka A, Mukai R, Terao J, Shibata N, Kawai Y. Specific localization of quercetin-3-O-glucuronide in human brain. Arch Biochem Biophys 2014; 557:11-7. [PMID: 24893148 DOI: 10.1016/j.abb.2014.05.025] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 05/13/2014] [Accepted: 05/26/2014] [Indexed: 01/05/2023]
Abstract
In recent years, many papers have suggested that dietary flavonoids may exert beneficial effects in the brain tissue for the protection of neurons against oxidative stress and inflammation. However, the bioavailability of flavonoids across the blood-brain barrier and the localization in the brain remain controversial. Thus, we examined the localization of quercetin-3-O-glucuronide (Q3GA), a major phase-II metabolite of quercetin, in the human brain tissues with or without cerebral infarction by immunohistochemical staining using anti-Q3GA antibody. A significant immunoreactivity was observed in the epithelial cells of the choroid plexus, which constitute the structural basis of the blood-cerebrospinal fluid (CSF) barrier, and in the foamy macrophages of recent infarcts. The cellular accumulation of Q3GA was also reproduced in vitro in macrophage-like RAW264, microglial MG6, and brain capillary endothelial RBEC1. It is of interest that a common feature of these cell lines is the deconjugation of Q3GA, resulting in the cellular accumulation of non-conjugated quercetin and the methylated forms. We then examined the anti-inflammatory activity of Q3GA and the deconjugated forms in the lipopolysaccharide-stimulated macrophage cells and revealed that the deconjugated forms (quercetin and a methylated form isorhamnetin), but not Q3GA itself, exhibited inhibitory effects on the inflammatory responses through attenuation of the c-Jun N-terminal kinase pathway. These results suggested that a quercetin glucuronide can pass through the blood-brain barrier, perhaps the CSF barrier, accumulate in specific types of cells, such as macrophages, and act as anti-inflammatory agents in the brain through deconjugation into the bioactive non-conjugated forms.
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Affiliation(s)
- Akari Ishisaka
- School of Human Science and Environment, University of Hyogo, Himeji 670-0092, Japan
| | - Rie Mukai
- Department of Food Science, Graduate School of Nutrition and Biosciences, The University of Tokushima, Tokushima 770-8503, Japan
| | - Junji Terao
- Department of Food Science, Graduate School of Nutrition and Biosciences, The University of Tokushima, Tokushima 770-8503, Japan
| | - Noriyuki Shibata
- Department of Pathology, Tokyo Women's Medical University, Tokyo 162-8666, Japan
| | - Yoshichika Kawai
- Laboratory of Food and Biodynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.
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Ishisaka A, Kawabata K, Miki S, Shiba Y, Minekawa S, Nishikawa T, Mukai R, Terao J, Kawai Y. Mitochondrial dysfunction leads to deconjugation of quercetin glucuronides in inflammatory macrophages. PLoS One 2013; 8:e80843. [PMID: 24260490 PMCID: PMC3834324 DOI: 10.1371/journal.pone.0080843] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Accepted: 10/16/2013] [Indexed: 01/09/2023] Open
Abstract
Dietary flavonoids, such as quercetin, have long been recognized to protect blood vessels from atherogenic inflammation by yet unknown mechanisms. We have previously discovered the specific localization of quercetin-3-O-glucuronide (Q3GA), a phase II metabolite of quercetin, in macrophage cells in the human atherosclerotic lesions, but the biological significance is poorly understood. We have now demonstrated the molecular basis of the interaction between quercetin glucuronides and macrophages, leading to deconjugation of the glucuronides into the active aglycone. In vitro experiments showed that Q3GA was bound to the cell surface proteins of macrophages through anion binding and was readily deconjugated into the aglycone. It is of interest that the macrophage-mediated deconjugation of Q3GA was significantly enhanced upon inflammatory activation by lipopolysaccharide (LPS). Zymography and immunoblotting analysis revealed that β-glucuronidase is the major enzyme responsible for the deglucuronidation, whereas the secretion rate was not affected after LPS treatment. We found that extracellular acidification, which is required for the activity of β-glucuronidase, was significantly induced upon LPS treatment and was due to the increased lactate secretion associated with mitochondrial dysfunction. In addition, the β-glucuronidase secretion, which is triggered by intracellular calcium ions, was also induced by mitochondria dysfunction characterized using antimycin-A (a mitochondrial inhibitor) and siRNA-knockdown of Atg7 (an essential gene for autophagy). The deconjugated aglycone, quercetin, acts as an anti-inflammatory agent in the stimulated macrophages by inhibiting the c-Jun N-terminal kinase activation, whereas Q3GA acts only in the presence of extracellular β-glucuronidase activity. Finally, we demonstrated the deconjugation of quercetin glucuronides including the sulfoglucuronides in vivo in the spleen of mice challenged with LPS. These results showed that mitochondrial dysfunction plays a crucial role in the deconjugation of quercetin glucuronides in macrophages. Collectively, this study contributes to clarifying the mechanism responsible for the anti-inflammatory activity of dietary flavonoids within the inflammation sites.
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Affiliation(s)
- Akari Ishisaka
- Faculty of Food Culture, Department of Nutrition, Kurashiki Sakuyo University, Kurashiki, Japan
| | - Kyuichi Kawabata
- Department of Bioscience, Faculty of Biotechnology, Fukui Prefectural University, Fukui, Japan
| | - Satomi Miki
- Department of Food Science, Graduate School of Nutrition and Biosciences, The University of Tokushima, Tokushima, Japan
| | - Yuko Shiba
- Department of Food Science, Graduate School of Nutrition and Biosciences, The University of Tokushima, Tokushima, Japan
| | - Shoko Minekawa
- Department of Food Science, Graduate School of Nutrition and Biosciences, The University of Tokushima, Tokushima, Japan
| | - Tomomi Nishikawa
- Department of Food Science, Graduate School of Nutrition and Biosciences, The University of Tokushima, Tokushima, Japan
| | - Rie Mukai
- Department of Food Science, Graduate School of Nutrition and Biosciences, The University of Tokushima, Tokushima, Japan
| | - Junji Terao
- Department of Food Science, Graduate School of Nutrition and Biosciences, The University of Tokushima, Tokushima, Japan
| | - Yoshichika Kawai
- Laboratory of Food and Biodynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
- * E-mail:
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Mukai R, Kawabata K, Otsuka S, Ishisaka A, Kawai Y, Ji ZS, Tsuboi H, Terao J. Effect of quercetin and its glucuronide metabolite upon 6-hydorxydopamine-induced oxidative damage in Neuro-2a cells. Free Radic Res 2012; 46:1019-28. [DOI: 10.3109/10715762.2012.673720] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Ishisaka A, Ichikawa S, Sakakibara H, Piskula MK, Nakamura T, Kato Y, Ito M, Miyamoto KI, Tsuji A, Kawai Y, Terao J. Accumulation of orally administered quercetin in brain tissue and its antioxidative effects in rats. Free Radic Biol Med 2011; 51:1329-36. [PMID: 21741473 DOI: 10.1016/j.freeradbiomed.2011.06.017] [Citation(s) in RCA: 177] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Revised: 06/04/2011] [Accepted: 06/09/2011] [Indexed: 01/01/2023]
Abstract
Quercetin is widely distributed in vegetables and herbs and has been suggested to act as a neuroprotective agent. Here, we demonstrate that quercetin can accumulate enough to exert biological activity in rat brain tissues. Homogenates of perfused rat brain without detectable hemoglobin contaminants were treated with β-glucuronidase/sulfatase and the released quercetin and its methylated form were analyzed using high-performance liquid chromatography (HPLC) with three different detection methods. Both quercetin and the methylated form were detected in the brain of quercetin-administered rats using HPLC-UV and HPLC with electrochemical detection and were further identified using HPLC-tandem mass spectrometry. Oral administration of quercetin (50mg/kg body wt) attenuated the increased oxidative stress in the hippocampus and striatum of rats exposed to chronic forced swimming. The possible transport of quercetin derivatives into the brain tissue was reproduced in vitro by using a rat brain capillary endothelial cell line, a model of the blood-brain barrier. These results show that quercetin could be a potent nutrient that can access the brain and protect it from disorders associated with oxidative stress.
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Affiliation(s)
- Akari Ishisaka
- Department of Food Science, Graduate School of Nutrition and Biosciences, University of Tokushima, Tokushima, Japan
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Kawai Y, Ishisaka A, Saito S, Uchida K, Shibata N, Kobayashi M, Fukuchi Y, Naito M, Terao J. Immunochemical detection of flavonoid glycosides: Development, specificity, and application of novel monoclonal antibodies. Arch Biochem Biophys 2008; 476:124-32. [DOI: 10.1016/j.abb.2008.01.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2007] [Accepted: 01/14/2008] [Indexed: 11/15/2022]
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Shiba Y, Kinoshita T, Chuman H, Taketani Y, Takeda E, Kato Y, Naito M, Kawabata K, Ishisaka A, Terao J, Kawai Y. Flavonoids as substrates and inhibitors of myeloperoxidase: molecular actions of aglycone and metabolites. Chem Res Toxicol 2008; 21:1600-9. [PMID: 18620432 DOI: 10.1021/tx8000835] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Myeloperoxidase (MPO), secreted by activated neutrophils and macrophages at the site of inflammation, may be implicated in the oxidation of protein/lipoprotein during the development of cardiovascular diseases. Flavonoids have been suggested to act as antioxidative and anti-inflammatory agents in vivo; however, their molecular actions have not yet been fully understood. In this study, we examined the molecular basis of the inhibitory effects of dietary flavonoids, such as quercetin, and their metabolites on the catalytic reaction of MPO using a combination of biological assays and theoretical calculation studies. Immunohistochemical staining showed that a quercetin metabolite was colocalized with macrophages, MPO, and dityrosine, an MPO-derived oxidation product of tyrosine, in human atherosclerotic aorta. Quercetin and the plasma metabolites inhibited the formation of dityrosine catalyzed by the MPO enzyme and HL-60 cells in a dose-dependent manner. Spectrometric analysis indicated that quercetin might act as a cosubstrate of MPO resulting in the formation of the oxidized quercetin. Quantitative structure-activity relationship studies showed that the inhibitory actions of flavonoids strongly depended not only on radical scavenging activity but also on hydrophobicity (log P). The requirement of a set of hydroxyl groups at the 3, 5, and 4'-positions and C2-C3 double bond was suggested for the inhibitory effect. The binding of quercetin and the metabolites to a hydrophobic region at the entrance to the distal heme pocket of MPO was also proposed by a computer docking simulation. The current study provides the structure-activity relationships for flavonoids as the anti-inflammatory dietary constituents targeting the MPO-derived oxidative reactions in vivo.
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Affiliation(s)
- Yuko Shiba
- Department of Food Science, Graduate School of Nutrition and Biosciences, The University of Tokushima, Tokushima 770-8503, Japan
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Ishisaka A, Kawagoe M. Examination of the time-water content superposition on the dynamic viscoelasticity of moistened polyamide 6 and epoxy. J Appl Polym Sci 2004. [DOI: 10.1002/app.20465] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Uehara ES, Farris M, Morelli PT, Ishisaka A. 'Eloquent chaos' in the oral discourse of killing fields survivors: an exploration of atrocity and narrativization. Cult Med Psychiatry 2001; 25:29-61. [PMID: 11270665 DOI: 10.1023/a:1005606014694] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
If "narrative" implies a form of discourse in which sequenced events are meaningfully connected, an "anti-narrative" is a chaotic discourse form "of time without sequence, telling without mediation, and speaking about oneself without being fully able to reflect on oneself" (Frank 1995: 98). This paper examines narratives and anti-narratives in the oral discourses of survivors of the Cambodian killing fields. Through an extended analysis of two cases, we demonstrate the internal logic and "eloquence" of anti-narratives--i.e., the ways in which anti-narrative patterns vividly express and reveal a survivor's complex and continuing experience of atrocity.
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