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Xu X, Wang X, Xie P. Screening and unveiling antibacterial mechanism of dandelion phenolic extracts against Staphylococcus aureus by inhibiting intracellular Na +-K + ATPase based on molecular docking and molecular dynamics simulation. J Biomol Struct Dyn 2024:1-12. [PMID: 38174403 DOI: 10.1080/07391102.2023.2300123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 12/22/2023] [Indexed: 01/05/2024]
Abstract
Staphylococcus aureus is one of the most frequently food-contaminated incidence of healthcare-associated Gram-positive bacteria. The antibacterial function and mechanism of phenolic compounds from dandelion are still unclear. Herein, this work aims to screen one of dandelion phenolic extracts with the strongest antibacterial function from its organ such as flower, stem, leaf and root, and to reveal its antibacterial mechanism. The results indicated dandelion flower phenolic extract (DFPE) containing the highest content of caffeic acid, followed by luteolin and luteolin-7-O-glucoside. They, especially caffeic acid and luteolin-7-O-glucoside, played a key role in making the bacterial cellular-membrane ruptured against the bacteria. The leakage of the intracellular substances (adenosine triphosphate and Na+-K+ ATPase) was further confirmed. Conventional hydrogen bond, pi-anion, pi-alkyl were involved in the interaction between caffeic acid or luteolin-7-O-glucoside and Na+-K+ ATPase. Additionally, the dynamic equilibrium of the liganded ATPase complex were achieved after 105 ns, and the lower values from the radius of gyration and solvent accessible surface area in the complex demonstrated the highly tight and compact structure of the liganded protein. The highest free binding energy (ΔGbind = -47.80 kJ/mol) between Na+-K+ ATPase and luteolin-7-O-glycloside was observed. Overall, DFPE can be used as an effective anti-bacterial agent due to the contribution of its bioactive ingredients such as caffeic acid and luteolin-7-O-glucoside for membrane-breaking.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Xuefeng Xu
- School of Chemistry and Materials Engineering, Hainan Vocational University of Science and Technology, Haikou, Hainan, China
| | - Xiang Wang
- Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, National Engineering Laboratory for Biomass Chemical Utilization, Key and Open Laboratory on Forest Chemical Engineering, National Forestry and Grassland Administration, Key Laboratory of Biomass Energy and Material, Nanjing, China
| | - Pujun Xie
- Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, National Engineering Laboratory for Biomass Chemical Utilization, Key and Open Laboratory on Forest Chemical Engineering, National Forestry and Grassland Administration, Key Laboratory of Biomass Energy and Material, Nanjing, China
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2
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Faraj SE, Valsecchi WM, Ferreira-Gomes M, Centeno M, Saint Martin EM, Fedosova NU, Rossi JPFC, Montes MR, Rossi RC. Measurements of Na +-occluded intermediates during the catalytic cycle of the Na +/K +-ATPase provide novel insights into the mechanism of Na + transport. J Biol Chem 2022; 299:102811. [PMID: 36539036 PMCID: PMC9860123 DOI: 10.1016/j.jbc.2022.102811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 12/11/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
The Na+/K+-ATPase is an integral plasma membrane glycoprotein of all animal cells that couples the exchange of intracellular Na+ for extracellular K+ to the hydrolysis of ATP. The asymmetric distribution of Na+ and K+ is essential for cellular life and constitutes the physical basis of a series of fundamental biological phenomena. The pumping mechanism is explained by the Albers-Post model. It involves the presence of gates alternatively exposing Na+/K+-ATPase transport sites to the intracellular and extracellular sides and includes occluded states in which both gates are simultaneously closed. Unlike for K+, information is lacking about Na+-occluded intermediates, as occluded Na+ was only detected in states incapable of performing a catalytic cycle, including two Na+-containing crystallographic structures. The current knowledge is that intracellular Na+ must bind to the transport sites and become occluded upon phosphorylation by ATP to be transported to the extracellular medium. Here, taking advantage of epigallocatechin-3-gallate to instantaneously stabilize native Na+-occluded intermediates, we isolated species with tightly bound Na+ in an enzyme able to perform a catalytic cycle, consistent with a genuine occluded state. We found that Na+ becomes spontaneously occluded in the E1 dephosphorylated form of the Na+/K+-ATPase, exhibiting positive interactions between binding sites. In fact, the addition of ATP does not produce an increase in Na+ occlusion as it would have been expected; on the contrary, occluded Na+ transiently decreases, whereas ATP lasts. These results reveal new properties of E1 intermediates of the Albers-Post model for explaining the Na+ transport pathway.
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Affiliation(s)
- Santiago E. Faraj
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) – Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina
| | - Wanda M. Valsecchi
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) – Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina
| | - Mariela Ferreira-Gomes
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) – Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina
| | - Mercedes Centeno
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) – Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina
| | - Elina Malén Saint Martin
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina
| | | | - Juan Pablo FC. Rossi
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) – Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina
| | - Mónica R. Montes
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) – Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina
| | - Rolando C. Rossi
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) – Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina,For correspondence: Rolando C. Rossi
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3
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Rinaldi DE, Ontiveros MQ, Saffioti NA, Vigil MA, Mangialavori IC, Rossi RC, Rossi JP, Espelt MV, Ferreira-Gomes MS. Epigallocatechin 3-gallate inhibits the plasma membrane Ca 2+-ATPase: effects on calcium homeostasis. Heliyon 2021; 7:e06337. [PMID: 33681501 PMCID: PMC7930289 DOI: 10.1016/j.heliyon.2021.e06337] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 01/16/2021] [Accepted: 02/17/2021] [Indexed: 12/27/2022] Open
Abstract
Flavonoids are natural compounds responsible for the health benefits of green tea. Some of the flavonoids present in green tea are catechins, among which are: epigallocatechin, epicatechin-3-gallate, epicatechin, catechin and epigallocatechin-3-gallate (EGCG). The latter was found to induce apoptosis, reduce reactive oxygen species, in some conditions though in others it acts as an oxidizing agent, induce cell cycle arrest, and inhibit carcinogenesis. EGCG also was found to be involved in calcium (Ca2+) homeostasis in excitable and in non-excitable cells. In this study, we investigate the effect of catechins on plasma membrane Ca2+-ATPase (PMCA), which is one of the main mechanisms that extrude Ca2+ out of the cell. Our studies comprised experiments on the isolated PMCA and on cells overexpressing the pump. Among catechins that inhibited PMCA activity, the most potent inhibitor was EGCG. EGCG inhibited PMCA activity in a reversible way favoring E1P conformation. EGCG inhibition also occurred in the presence of calmodulin, the main pump activator. Finally, the effect of EGCG on PMCA activity was studied in human embryonic kidney cells (HEK293T) that transiently overexpress hPMCA4. Results show that EGCG inhibited PMCA activity in HEK293T cells, suggesting that the effects observed on isolated PMCA occur in living cells.
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Affiliation(s)
| | | | - Nicolas A. Saffioti
- IQUIFIB – Instituto de Química y Fisicoquímica Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, CONICET, Junín 956, 1113 Buenos Aires, Argentina
| | - Maximiliano A. Vigil
- IQUIFIB – Instituto de Química y Fisicoquímica Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, CONICET, Junín 956, 1113 Buenos Aires, Argentina
| | - Irene C. Mangialavori
- IQUIFIB – Instituto de Química y Fisicoquímica Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, CONICET, Junín 956, 1113 Buenos Aires, Argentina
| | - Rolando C. Rossi
- IQUIFIB – Instituto de Química y Fisicoquímica Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, CONICET, Junín 956, 1113 Buenos Aires, Argentina
| | - Juan P. Rossi
- IQUIFIB – Instituto de Química y Fisicoquímica Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, CONICET, Junín 956, 1113 Buenos Aires, Argentina
| | - María V. Espelt
- IQUIFIB – Instituto de Química y Fisicoquímica Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, CONICET, Junín 956, 1113 Buenos Aires, Argentina
| | - Mariela S. Ferreira-Gomes
- IQUIFIB – Instituto de Química y Fisicoquímica Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, CONICET, Junín 956, 1113 Buenos Aires, Argentina
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4
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Faraj SE, Valsecchi WM, Cerf NT, Fedosova NU, Rossi RC, Montes MR. The interaction of Na +, K +, and phosphate with the gastric H,K-ATPase. Kinetics of E1-E2 conformational changes assessed by eosin fluorescence measurements. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1863:183477. [PMID: 32949561 DOI: 10.1016/j.bbamem.2020.183477] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 09/10/2020] [Accepted: 09/11/2020] [Indexed: 12/12/2022]
Abstract
H,K-ATPase and Na,K-ATPase show the highest degree of sequence similarity among all other members of the P-type ATPases family. To explore their common features in terms of ligand binding, we evaluated conformational transitions due to the binding of Na+, K+ and Pi in the H,K-ATPase, and compared the results with those obtained for the Na,K-ATPase. This work shows that eosin fluorescence time courses provide a reasonably precise method to study the kinetics of the E1-E2 conformational changes in the H,K-ATPase. We found that, although Na+ shifts the equilibrium toward the E1 conformation and seems to compete with H+ in ATPase activity assays, it was neither possible to isolate a Na+-occluded state, nor to reveal an influx of Na+ related to H,K-ATPase activity. The high rate of the E2K → E1 transition found for the H,K-ATPase, which is not compatible with the presence of a K+-occluded form, agrees with the negligible level of occluded Rb+ (used as a K+ congener) found in the absence of added ligands. The use of vanadate and fluorinated metals to induce E2P-like states increased the level of occluded Rb+ and suggests that-during dephosphorylation-the probability of K+ to remain occluded increases from the E2P-ground to the E2P-product state. From kinetic experiments we found an unexpected increase in the values of kobs for E2P formation with [Pi]; consequently, to obey the Albers-Post model, the binding of Pi to the E2 state cannot be a rapid-equilibrium reaction.
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Affiliation(s)
- S E Faraj
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina
| | - W M Valsecchi
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina
| | - N T Cerf
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina
| | - N U Fedosova
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - R C Rossi
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina
| | - M R Montes
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina.
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5
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Ni D, Ai Z, Munoz-Sandoval D, Suresh R, Ellis PR, Yuqiong C, Sharp PA, Butterworth PJ, Yu Z, Corpe CP. Inhibition of the facilitative sugar transporters (GLUTs) by tea extracts and catechins. FASEB J 2020; 34:9995-10010. [PMID: 32564472 DOI: 10.1096/fj.202000057rr] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 04/17/2020] [Accepted: 05/05/2020] [Indexed: 01/21/2023]
Abstract
Tea polyphenolics have been suggested to possess blood glucose lowering properties by inhibiting sugar transporters in the small intestine and improving insulin sensitivity. In this report, we studied the effects of teas and tea catechins on the small intestinal sugar transporters, SGLT1 and GLUTs (GLUT1, 2 and 5). Green tea extract (GT), oolong tea extract (OT), and black tea extract (BT) inhibited glucose uptake into the intestinal Caco-2 cells with GT being the most potent inhibitor (IC50 : 0.077 mg/mL), followed by OT (IC50 : 0.136 mg/mL) and BT (IC50 : 0.56 mg/mL). GT and OT inhibition of glucose uptake was partial non-competitive, with an inhibitor constant (Ki ) = 0.0317 and 0.0571 mg/mL, respectively, whereas BT was pure non-competitive, Ki = 0.36 mg/mL. Oocytes injected to express small intestinal GLUTs were inhibited by teas, but SGLT1 was not. Furthermore, catechins present in teas were the predominant inhibitor of glucose uptake into Caco-2 cells, and gallated catechins the most potent: CG > ECG > EGCG ≥ GCG when compared to the non-gallated catechins (C, EC, GC, and EGC). In Caco-2 cells, individual tea catechins reduced the SGLT1 gene, but not protein expression levels. In contrast, GLUT2 gene and protein expression levels were reduced after 2 hours exposure to catechins but increased after 24 hours. These in vitro studies suggest teas containing catechins may be useful dietary supplements capable of blunting postprandial glycaemia in humans, including those with or at risk to Type 2 diabetes mellitus.
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Affiliation(s)
- Dejiang Ni
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan City, China.,Faculty of Life Sciences and Medicine, Departments of Biochemistry and Nutrition, King's College London, London, UK
| | - Zeyi Ai
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan City, China.,Institute of Leisure Agriculture, Jiangsu Academy of Agricultural Sciences, Nanjing City, China
| | - Diana Munoz-Sandoval
- Faculty of Life Sciences and Medicine, Department of Nutritional Sciences, King's College London, London, UK
| | - Reshma Suresh
- Faculty of Life Sciences and Medicine, Department of Nutritional Sciences, King's College London, London, UK
| | - Peter R Ellis
- Faculty of Life Sciences and Medicine, Departments of Biochemistry and Nutrition, King's College London, London, UK
| | - Chen Yuqiong
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan City, China
| | - Paul A Sharp
- Faculty of Life Sciences and Medicine, Department of Nutritional Sciences, King's College London, London, UK
| | - Peter J Butterworth
- Faculty of Life Sciences and Medicine, Departments of Biochemistry and Nutrition, King's College London, London, UK
| | - Zhi Yu
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan City, China
| | - Christopher P Corpe
- Faculty of Life Sciences and Medicine, Department of Nutritional Sciences, King's College London, London, UK
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Qi Y, Yang C, Jiang Z, Wang Y, Zhu F, Li T, Wan X, Xu Y, Xie Z, Li D, Pierre SV. Epicatechin-3-Gallate Signaling and Protection against Cardiac Ischemia/Reperfusion Injury. J Pharmacol Exp Ther 2019; 371:663-674. [DOI: 10.1124/jpet.119.260117] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 09/09/2019] [Indexed: 12/17/2022] Open
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Sasaki T, Kamata R, Ueno S, Kaneda T, Temma K. Green tea catechins increase the force of contraction in isolated guinea pig atrial muscle preparations by increasing the amplitude of intracellular Ca2+ concentration. J Vet Med Sci 2012; 74:1603-8. [PMID: 22864409 DOI: 10.1292/jvms.12-0254] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
It has been reported that green tea catechins enhance the force of contraction of isolated heart muscle preparations. However, it remains controversial whether or not the increase in force of contraction is related to an increase in the intracellular Ca(2+) concentration ([Ca(2+)]i). In this study, the relationship was investigated using a left atrial muscle preparation isolated from guinea pig heart. In the left atrial muscle preparations without fura-2/AM loading, neither EGC (epigallocatechin) nor EC (epicatechin) influenced the force of contraction, but EGCG (epigallocatechin gallate) and ECG (epicatechin gallate) increased the force of contraction in a dose-dependent manner. The ED(50) value of EGCG was significantly higher than that of ECG. In the atrial muscle preparations loaded with fura-2/AM, EGCG and ECG increased the amplitude of [Ca(2+)]i(peak [Ca(2+)]i minus diastolic [Ca(2+)]i) which is associated with the increase in force of contraction. Simple regression analysis between the degree of increase in the force of contraction and the increase in the amplitude of [Ca(2+)]i revealed a positive correlation in EGCG, ECG and CaCl(2). In addition, the slopes of the regression lines of EGCG and ECG were comparable with those of CaCl(2). It was suggested that atrial muscle preparations had a higher affinity for ECG than EGCG, and that the increase in the force of contraction by EGCG and ECG was closely related to the increase in the amplitude of [Ca(2+)]i.
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Affiliation(s)
- Takushi Sasaki
- Laboratory of Toxicology, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan
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Flavonoids in prevention of diseases with respect to modulation of Ca-pump function. Interdiscip Toxicol 2011; 4:114-24. [PMID: 22058652 PMCID: PMC3203913 DOI: 10.2478/v10102-011-0019-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 08/10/2011] [Accepted: 08/13/2011] [Indexed: 11/20/2022] Open
Abstract
Flavonoids, natural phenolic compounds, are known as agents with strong antioxidant properties. In many diseases associated with oxidative/nitrosative stress and aging they provide multiple biological health benefits. Ca2+-ATPases belong to the main calcium regulating proteins involved in the balance of calcium homeostasis, which is impaired in oxidative/nitrosative stress and related diseases or aging. The mechanisms of Ca2+-ATPases dysfunction are discussed, focusing on cystein oxidation and tyrosine nitration. Flavonoids act not only as antioxidants but are also able to bind directly to Ca2+-ATPases, thus changing their conformation, which results in modulation of enzyme activity. Dysfunction of Ca2+-ATPases is summarized with respect to their posttranslational and conformational changes in diseases related to oxidative/nitrosative stress and aging. Ca2+-ATPases are discussed as a therapeutic tool and the possible role of flavonoids in this process is suggested.
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Yamamoto E, Nishimura N, Okada K, Sekido C, Yamamichi S, Hasumi K. Inhibitors of Autoactivation of Plasma Hyaluronan-Binding Protein (Factor VII Activating Protease). Biol Pharm Bull 2011; 34:462-70. [DOI: 10.1248/bpb.34.462] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Eisaku Yamamoto
- Department of Applied Biological Science, Tokyo Noko University
| | - Naoko Nishimura
- Department of Applied Biological Science, Tokyo Noko University
| | - Ken Okada
- Department of Applied Biological Science, Tokyo Noko University
| | - Chikako Sekido
- Department of Applied Biological Science, Tokyo Noko University
| | | | - Keiji Hasumi
- Department of Applied Biological Science, Tokyo Noko University
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Kiran S, Ratho RK, Sharma P, Harjai K, Capalash N, Tiwari RP. Effect of black tea (Camellia sinensis) on virulence traits of clinical isolates of Shigella dysenteriae and Escherichia coli EPEC P2 1265 strain. Eur Food Res Technol 2010. [DOI: 10.1007/s00217-010-1328-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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11
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Ivermectin is a nonselective inhibitor of mammalian P-type ATPases. Naunyn Schmiedebergs Arch Pharmacol 2009; 381:147-52. [PMID: 20041321 DOI: 10.1007/s00210-009-0483-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Accepted: 12/01/2009] [Indexed: 10/20/2022]
Abstract
Ivermectin is a large spectrum antiparasitic drug that is very safe at the doses actually used. However, as it is being studied for new applications that would require higher doses, we should pay attention to its effects at high concentrations. As micromolar concentrations of ivermectin have been reported to inhibit the sarco-endoplasmic reticulum Ca(2+)-ATPase (SERCA), we decided to investigate its putative inhibitory effect on other two important P-type ATPases, namely the Na(+) , K(+)-ATPase and H(+)/K(+)-ATPase. We first extended the data on SERCA, using preparations from rat enriched in SERCA1a (extensor digitorum longus) and 1b (heart) isoforms. Secondly, we tested the effect of ivermectin in two preparations of rat Na(+), K(+)-ATPase in order to appreciate its putative selectivity towards the alpha(1) isoform (kidney) and the alpha(2)/alpha(3) isoforms (brain), and in an H(+)/K(+)-ATPase preparation from rat stomach. Ivermectin inhibited all these ATPases with similar IC(50) values (6-17 microM). With respect to the inhibition of the Na(+), K(+)-ATPase, ivermectin acts by a mechanism different from the classical cardiac glycosides, based on selectivity towards the isoforms, sensibility to the antagonistic effect of K(+) and to ionic conditions favoring different conformations of the enzyme. We conclude that ivermectin is a nonselective inhibitor of three important mammalian P-type ATPases, which is indicative of putative important adverse effects if this drug were used at high doses. As a consequence, we propose that novel analogs of ivermectin should be developed and tested both for their parasitic activity and in vitro effects on P-type ATPases.
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