この博士論文は内容の要約のみの公開（または一部非公開）になっています筑波大学 (University of Tsukuba)201

Oritani Yukihiro

織谷 幸太

筑波大学University of Tsukuba博士（生物科学）Doctor of Philosophy in Biological Science2017この博士論文は内容の要約のみの公開（または一部非公開）になっていますdoctoral thesi

Oritani, Yukihiro

193583

織谷, 幸太

Tsukuba Repository  (Tulips-R)

Studies on the Absorption and BiologicalActivities of Polyphenols with Catechol Groups著者 Oritani Yukihiro内容記述 この博士論文は内容の要約のみの公開（または一部非公開）になっていますyear 2018その他のタイトル カテコール構造を持つポリフェノールの吸収と生理活性に関する研究学位授与大学 筑波大学 (University of Tsukuba)学位授与年度 2017報告番号 12102甲第8565号URL http://hdl.handle.net/2241/00152265       Studies on the Absorption and Biological Activities of Polyphenols with Catechol Groups     January 2018    Yukihiro ORITANI     Studies on the Absorption and Biological Activities of Polyphenols with Catechol Groups     A Dissertation Submitted to the Graduate School of Life and Environmental Sciences, the University of Tsukuba in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Biological Science (Doctoral Program in Biological Sciences)    Yukihiro ORITANI  i  Table of Contents  Abstract.....................................................................................................................1 Abbreviations............................................................................................................3 General Introduction................................................................................................4 Chapter 1 Comparison of (-)-Epigallocatechin-3-O-gallate (EGCG) and O-Methyl-EGCG Bioavailability in Rats Summary............................................................................................................7 Introduction.......................................................................................................8 Materials and Methods....................................................................................10 Results...............................................................................................................17 Discussion..........................................................................................................26 Chapter 2 Absorption and Metabolism of Piceatannol in Rats Summary............................................................................................................31 Introduction.......................................................................................................32 Materials and Methods....................................................................................35 ii  Results................................................................................................................43 Discussion...........................................................................................................53 Chapter 3 Enhanced Glucose Tolerance by Intravascularly Administered Piceatannol in Freely Moving Healthy Rats Summary.............................................................................................................58 Introduction........................................................................................................59 Materials and Methods......................................................................................61 Results.................................................................................................................66 Discussion............................................................................................................76 General Discussion.....................................................................................................81 Acknowledgements.....................................................................................................83 References..................................................................................................................84   1  Abstract Various kinds of polyphenols with catechol groups are broadly found in food and they are daily consumed by human. Furthermore, there are numerous reports that polyphenols have various beneficial bioactivities to human health. However, it is still unclear how much polyphenols with catechol group are absorbed after oral administration and contribute to express the bioactivities in vivo. In this study, I focused my interest on the absorption and bioactivities of polyphenols with catechol groups, piceatannol, (-)-Epigallocatechin-3-O-gallate (EGCG) and their analogs. I have investigated and evaluated their oral absorption in rats, and the effect on the glucose tolerance by these polyphenols. These experiments revealed that the methylation on catechol group of EGCG remarkably change the pharmacokinetics by affecting absorption and the distribution volume. Further, it was clarified that the absorption of piceatannol, which have a catechol group, is superior to that of resveratrol, which have no catechol group. These results suggested the presence of catechol group have impact on absorption, and on the strength of bioactivity in vivo. My results also demonstrated that, on the process of absorption, piceatannol was metabolized to isorhapontigenin. Isorhapontigenin is a piceatannol analog which is methylated at the position of catechol group. Further, only piceatannol have enhanced glucose tolerance of rats, but  2  Isorhapontigenin have not. These findings indicated that methylation on catechol group of piceatannol may attenuates its bioactivity. My results showed that the modifications of catechol groups in polyphenols affects the strength of their bioactivities thorough the various steps after oral administration such as absorption, distribution and activities itself. These knowledges may help to predict the absorption and bioactivities on the basis of polyphenolic structure.               3  Abbreviations ANOVA          analysis of variance AUCs           the areas under the concentration–time curves  BW           body weight C0           speculated concentration at 0 h COMT           catechol-O-methyl transferase ECD           electrochemical detector EDTA           ethylenediaminetetraacetic acid  EGCG           (-)-Epigallocatechin-3-O-gallate EGCG3′′Me    (-)-Epigallocatechin-3-O-(3-O-methyl)gallate EGCG4′′Me    (-)-Epigallocatechin-3-O-(4-O-methyl)gallate iv           intravenously LOD           the limit of detection  LOQ           the limit of quantitation  po           per os T1/2           the half-lives UFLC           ultra-fast liquid chromatography Vd           apparent distribution volume of central compartment  4  General Introduction Various phenolic compounds are included in the food as secondary metabolites of the plants[1]. Especially, phenolic compounds which have plural hydroxyl groups are generally called “polyphenols”. Polyphenols have various functional molecular groups. Catechol group is one of the groups having some functions. Catechol group consist of a benzene ring and two hydroxyl groups next to each other, and it has strong antioxidant activity [1, 2]. Antioxidant activity, capacity to scavenge active oxygen, is known to be important to prevent various chronic diseases [3]. On the other hands, catechol group is also known to be methylated by catechol-O-methyl transferase (COMT) [1, 4]. COMT is broadly expressed in various organs [5, 6] and is related to the metabolism of catecholamine, catechol estrogen and polyphenols with catechol groups. Even though the metabolism of endogenous catechol, catecholamine and catechol estrogen, is well documented, the metabolism and absorption of many polyphenols with catechol groups are unclear. One of the reasons of that is that the skeletal structure of polyphenols has multiplicity and are classified various types in the point of molecular weight and fat solubility. These properties are not negligible to consider absorption and pharmacokinetics in vivo, because the efficacies of absorption were generally dependent on its molecular weight and fat solubility and other factors [7].   5  On the basis of their skeletal structures, polyphenols can be classified flavonoid, stilbenoid, phenylpropanoid and others [1, 8]. In almost polyphenol classes, polyphenols with catechol group are found, and there are numerous studies for bioactivities and health benefits of intake of these polyphenols. For instance, improvements of the lipid metabolism [9], remove of the active oxygen [10, 11], anti-allergic effect [12], and enhancement of glucose tolerance [13] are reported. Until the expression of these bioactivities, orally administered polyphenols having catechol groups have to overcome some important steps for pharmacokinetics (absorption, metabolism and distribution). However, there are limited studies that focus on absorption and bioactivities the methylation of polyphenols with catechol group. It is still unclear how much polyphenols with catechol group are absorbed and which polyphenols, intact polyphenol or its methylated metabolite, contributes to the bioactivities in vivo. Here, I focused on my interest on the absorption and bioactivities of polyphenols with catechol groups. In this study, I will clarify the absorption and bioactivities of (-)-Epigallocatechin-3-O-gallate (EGCG), which is found in green tea, and piceatannol, which is found in passion fruit seed, in rats.     6  Chapter 1  Comparison of (-)-Epigallocatechin-3-O-gallate (EGCG) and O-Methyl EGCG Bioavailability in Rat 30  Chapter 2  Absorption and Metabolism of Piceatannol in Rats   57  Chapter 3  Enhanced glucose tolerance by intravascularly administered piceatannol in freely moving healthy rats    81  General discussion In this study, I elucidated how much polyphenols with catechol groups are absorbed using with EGCG, piceatannol and their analogs as representatives. My results demonstrated that modification of catechol groups in polyphenols affected the pharmacokinetics. In the case of EGCG (Chapter 1), the change of pharmacokinetics is dependent on methylated position at the catechol group and may affect the strength of bioactivities. Especially, methylation on the 3’’position in EGCG molecule drastically elevated the blood concentration of intact form in comparison with methylation on the 4’’position or no methylation, because the methylation on the 3’’position enhanced absorption and decreased volume of distribution. On the other hand, in the case of piceatannol (Chapter 2), the absorption of it was superior to that of resveratrol, which has no catechol group. These results for EGCG3′′Me and piceatannol suggested that one ‘simple’ catechol group is enough for effective absorption, because both EGCG3′′Me and piceatannol demonstrate the best absorption among the same skeletal structure in this study, and they have one catechol group at D ring at EGCG3′′Me and at B ring of piceatannol, respectively. Both resveratrol and EGCG4′′Me, respectively, have no catechol group in the equivalent ring, and EGCG have catechol group composed of 3 hydroxyl group in D ring. Further detailed investigations are required to elucidate the  82  hypothesis about the effective absorption in polyphenols with catechol group. Next, I have also clarified which polyphenols, intact polyphenol or its methylated metabolite contributes to the bioactivities in vivo. As a representative polyphenol with catechol group, piceatannol and its methylated metabolite, isorhapontigenin, were used in the glucose tolerance test (Chapter 3). On the glucose tolerance test, it was revealed that only piceatannol have the potential to enhance glucose tolerance, and isorhapontigenin did not. These results has indicated that methylation on catechol group in polyphenols change its bioactivity drastically.  In conclusion, I elucidated the absorption of EGCG, piceatannol and their analog as representatives of polyphenols with catechol groups, and my results suggested that the catechol group in polyphenols may be important for effective absorption in rats. Furthermore, in comparison of piceatannol and isorhapontigenin, it was clearly shown that the bioactivities are affected by the metabolism. These results indicated that the modifications of catechol groups in polyphenols affects the strength of their bioactivities thorough the various steps after oral administration such as absorption, distribution and activities itself. Results in this study may help to predict the absorption and bioactivities on the basis of polyphenolic structure.   83  Acknowledgements I am most grateful to Prof. Kazuichi Sakamoto (the University of Tsukuba) for his valuable discussion, guidance and encouragement.  I also deeply grateful to Prof. Shoji Takeuchi (the University of Tokyo), Prof. Teru Okitsu (the University of Tokyo), Prof. Takashi Ichiyanagi (Niigata Institute of Technology), Dr. Tatsuhiko Ito and Ms. Yuko Setoguchi for their appropriate guidance, advice and encouragement. Further, I express sincere gratitude to Mr. Masahiko Sai, Mr. Ryouichi Ito, Dr. Masahiro Umehara, Ms. Hiroko Maruki-Uchida, Dr. Takayuki Yamamoto, Dr. Eisaku Nishimura, Dr. Hiroyuki Inagaki, Mr. Yosuke Kinoshita, Mr. Masanori Sugitani and Dr. Minoru Morita and all of colleagues (Morinaga Co. & Ltd.) for their technical support and valuable advice. Finally, I also thanks to Y. Seishi, S. Mori, M. Yano, M. Kiyosawa and H. Aoyagi (the University of Tokyo) for their support.     84  References [1] C. Manach, A. Scalbert, C. Morand, C. Remesy, L. Jimenez, Polyphenols: food sources and bioavailability, The American journal of clinical nutrition, 79 (2004) 727-747. [2] A.W. Boots, G.R.M.M. Haenen, G.J.M. den Hartog, A. Bast, Oxidative damage shifts from lipid peroxidation to thiol arylation by catechol-containing antioxidants, Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids, 1583 (2002) 279-284. [3] J.K. Willcox, S.L. Ash, G.L. Catignani, Antioxidants and prevention of chronic disease, Critical reviews in food science and nutrition, 44 (2004) 275-295. [4] J. Volavka, R. Bilder, K. Nolan, Catecholamines and aggression: the role of COMT and MAO polymorphisms, Annals of the New York Academy of Sciences, 1036 (2004) 393-398. [5] C. Tilgmann, I. Ulmanen, Purification methods of mammalian catechol-O-methyltransferases, Journal of chromatography. B, Biomedical applications, 684 (1996) 147-161. [6] M.K. Piskula, J. Terao, Accumulation of (-)-epicatechin metabolites in rat plasma after oral administration and distribution of conjugation enzymes in rat tissues, The  85  Journal of nutrition, 128 (1998) 1172-1178. [7] M.J. Waring, Defining optimum lipophilicity and molecular weight ranges for drug candidates—Molecular weight dependent lower logD limits based on permeability, Bioorganic & Medicinal Chemistry Letters, 19 (2009) 2844-2851. [8] A. Scalbert, G. Williamson, Dietary intake and bioavailability of polyphenols, The Journal of nutrition, 130 (2000) 2073s-2085s. [9] H.-S. Kim, M.J. Quon, J.-a. Kim, New insights into the mechanisms of polyphenols beyond antioxidant properties; lessons from the green tea polyphenol, epigallocatechin 3-gallate, Redox biology, 2 (2014) 187-195. [10] I. Kurita, J.H. Kim, C. Auger, Y. Kinoshita, T. Miyase, T. Ito, V.B. Schini-Kerth, Hydroxylation of (-)-epigallocatechin-3-O-gallate at 3'', but not 4'', is essential for the PI3-kinase/Akt-dependent phosphorylation of endothelial NO synthase in endothelial cells and relaxation of coronary artery rings, Food & function, 4 (2013) 249-257. [11] Q. Du, Y. Xu, L. Li, Y. Zhao, G. Jerz, P. Winterhalter, Antioxidant constituents in the fruits of Luffa cylindrica (L.) Roem, J Agric Food Chem, 54 (2006) 4186-4190. [12] K. Yoshino, T. Miyase, M. Sano, Preventive effects of C-2 epimeric isomers of tea catechins on mouse type I allergy, Journal of nutritional science and vitaminology, 56 (2010) 211-215.  86  [13] M. Minakawa, Y. Miura, K. Yagasaki, Piceatannol, a resveratrol derivative, promotes glucose uptake through glucose transporter 4 translocation to plasma membrane in L6 myocytes and suppresses blood glucose levels in type 2 diabetic model db/db mice, Biochem Biophys Res Commun, 422 (2012) 469-475.  

カテコール構造を持つポリフェノールの吸収と生理活性に関する研究

https://tsukuba.repo.nii.ac.jp/?action=repository_action_common_download&item_id=46903&item_no=1&attribute_id=17&file_no=1

カテコール構造を持つポリフェノールの吸収と生理活性に関する研究

Abstract

Similar works

Full text

Available Versions

Tsukuba Repository (Tulips-R)