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Wang J, Liao N, Liu G, Li Y, Xu F, Shi J. Diversity and regioselectivity of O-methyltransferases catalyzing the formation of O-methylated flavonoids. Crit Rev Biotechnol 2023:1-23. [PMID: 38035668 DOI: 10.1080/07388551.2023.2280755] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Accepted: 10/17/2023] [Indexed: 12/02/2023]
Abstract
Flavonoids and their methylated derivatives have immense market potential in the food and biomedical industries due to their multiple beneficial effects, such as antimicrobial, anti-inflammatory, and anticancer activities. The biological synthesis of flavonoids and their derivatives is often accomplished via the use of genetically modified microorganisms to ensure large-scale production. Therefore, it is pivotal to understand the properties of O-methyltransferases (OMTs) that mediate the methylation of flavonoids. However, the properties of these OMTs are governed by their: sources, substrate specificity, amino acid residues in the active sites, and the intricate mechanism. In order to obtain a clue for the selection of suitable OMTs for the biosynthesis of a target methylated flavonoid, we made a comprehensive review of the currently reported results, with a particular focus on their comparative regioselectivity for different flavonoid substrates. Additionally, the possible mechanisms for the diversity of this class of enzymes were explored using molecular simulation technology. Finally, major gaps in our understanding and areas for future studies were discussed. The findings of this study may be useful in selecting genes that encode OMTs and designing enzyme-based processes for synthesizing O-methylated flavonoids.
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Affiliation(s)
- Juan Wang
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, People's Republic of China
| | - Ning Liao
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, People's Republic of China
| | - Guanwen Liu
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, People's Republic of China
| | - Yinghui Li
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, People's Republic of China
| | - Fengqin Xu
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, People's Republic of China
| | - Junling Shi
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, People's Republic of China
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2
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Richter-Laskowska M, Trybek P, Delfino DV, Wawrzkiewicz-Jałowiecka A. Flavonoids as Modulators of Potassium Channels. Int J Mol Sci 2023; 24:1311. [PMID: 36674825 PMCID: PMC9861088 DOI: 10.3390/ijms24021311] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 01/02/2023] [Accepted: 01/04/2023] [Indexed: 01/12/2023] Open
Abstract
Potassium channels are widely distributed integral proteins responsible for the effective and selective transport of K+ ions through the biological membranes. According to the existing structural and mechanistic differences, they are divided into several groups. All of them are considered important molecular drug targets due to their physiological roles, including the regulation of membrane potential or cell signaling. One of the recent trends in molecular pharmacology is the evaluation of the therapeutic potential of natural compounds and their derivatives, which can exhibit high specificity and effectiveness. Among the pharmaceuticals of plant origin, which are potassium channel modulators, flavonoids appear as a powerful group of biologically active substances. It is caused by their well-documented anti-oxidative, anti-inflammatory, anti-mutagenic, anti-carcinogenic, and antidiabetic effects on human health. Here, we focus on presenting the current state of knowledge about the possibilities of modulation of particular types of potassium channels by different flavonoids. Additionally, the biological meaning of the flavonoid-mediated changes in the activity of K+ channels will be outlined. Finally, novel promising directions for further research in this area will be proposed.
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Affiliation(s)
- Monika Richter-Laskowska
- The Centre for Biomedical Engineering, Łukasiewicz Research Network—Krakow Institute of Technology, 30-418 Krakow, Poland
| | - Paulina Trybek
- Faculty of Science and Technology, University of Silesia in Katowice, 41-500 Chorzów, Poland
| | | | - Agata Wawrzkiewicz-Jałowiecka
- Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, 44-100 Gliwice, Poland
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3
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Saponara S, Fusi F, Iovinelli D, Ahmed A, Trezza A, Spiga O, Sgaragli G, Valoti M. Flavonoids and hERG channels: Friends or foes? Eur J Pharmacol 2021; 899:174030. [PMID: 33727059 DOI: 10.1016/j.ejphar.2021.174030] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 02/28/2021] [Accepted: 03/11/2021] [Indexed: 01/24/2023]
Abstract
The cardiac action potential is regulated by several ion channels. Drugs capable to block these channels, in particular the human ether-à-go-go-related gene (hERG) channel, also known as KV11.1 channel, may lead to a potentially lethal ventricular tachyarrhythmia called "Torsades de Pointes". Thus, evaluation of the hERG channel off-target activity of novel chemical entities is nowadays required to safeguard patients as well as to avoid attrition in drug development. Flavonoids, a large class of natural compounds abundantly present in food, beverages, herbal medicines, and dietary food supplements, generally escape this assessment, though consumed in consistent amounts. Continuously growing evidence indicates that these compounds may interact with the hERG channel and block it. The present review, by examining numerous studies, summarizes the state-of-the-art in this field, describing the most significant examples of direct and indirect inhibition of the hERG channel current operated by flavonoids. A description of the molecular interactions between a few of these natural molecules and the Rattus norvegicus channel protein, achieved by an in silico approach, is also presented.
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Affiliation(s)
- Simona Saponara
- Dipartimento di Scienze della Vita, Università degli Studi di Siena, via A. Moro 2, 53100, Siena, Italy
| | - Fabio Fusi
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, via A. Moro 2, 53100, Siena, Italy.
| | - Daniele Iovinelli
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, via A. Moro 2, 53100, Siena, Italy
| | - Amer Ahmed
- Dipartimento di Scienze della Vita, Università degli Studi di Siena, via A. Moro 2, 53100, Siena, Italy
| | - Alfonso Trezza
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, via A. Moro 2, 53100, Siena, Italy
| | - Ottavia Spiga
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, via A. Moro 2, 53100, Siena, Italy
| | - Giampietro Sgaragli
- Dipartimento di Scienze della Vita, Università degli Studi di Siena, via A. Moro 2, 53100, Siena, Italy; Accademia Italiana della Vite e del Vino, via Logge degli Uffizi Corti 1, 50122, Florence, Italy
| | - Massimo Valoti
- Dipartimento di Scienze della Vita, Università degli Studi di Siena, via A. Moro 2, 53100, Siena, Italy
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4
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Fusi F, Trezza A, Tramaglino M, Sgaragli G, Saponara S, Spiga O. The beneficial health effects of flavonoids on the cardiovascular system: Focus on K+ channels. Pharmacol Res 2020; 152:104625. [DOI: 10.1016/j.phrs.2019.104625] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 12/14/2019] [Accepted: 12/31/2019] [Indexed: 01/17/2023]
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5
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Zhao Z, Ruan S, Ma X, Feng Q, Xie Z, Nie Z, Fan P, Qian M, He X, Wu S, Zhang Y, Zheng X. Challenges Faced with Small Molecular Modulators of Potassium Current Channel Isoform Kv1.5. Biomolecules 2019; 10:E10. [PMID: 31861703 PMCID: PMC7022446 DOI: 10.3390/biom10010010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 12/08/2019] [Accepted: 12/10/2019] [Indexed: 12/30/2022] Open
Abstract
The voltage-gated potassium channel Kv1.5, which mediates the cardiac ultra-rapid delayed-rectifier (IKur) current in human cells, has a crucial role in atrial fibrillation. Therefore, the design of selective Kv1.5 modulators is essential for the treatment of pathophysiological conditions involving Kv1.5 activity. This review summarizes the progress of molecular structures and the functionality of different types of Kv1.5 modulators, with a focus on clinical cardiovascular drugs and a number of active natural products, through a summarization of 96 compounds currently widely used. Furthermore, we also discuss the contributions of Kv1.5 and the regulation of the structure-activity relationship (SAR) of synthetic Kv1.5 inhibitors in human pathophysiology. SAR analysis is regarded as a useful strategy in structural elucidation, as it relates to the characteristics that improve compounds targeting Kv1.5. Herein, we present previous studies regarding the structural, pharmacological, and SAR information of the Kv1.5 modulator, through which we can assist in identifying and designing potent and specific Kv1.5 inhibitors in the treatment of diseases involving Kv1.5 activity.
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Affiliation(s)
- Zefeng Zhao
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, 229 Taibai Road, Xi’an 710069, China; (Z.Z.); (S.R.); (X.M.); (Q.F.); (Z.X.); (Z.N.); (P.F.); (Y.Z.); (X.Z.)
- Biomedicine Key Laboratory of Shaanxi Province, School of Pharmacy, Northwest University, 229 Taibai Road, Xi’an 710069, China
| | - Songsong Ruan
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, 229 Taibai Road, Xi’an 710069, China; (Z.Z.); (S.R.); (X.M.); (Q.F.); (Z.X.); (Z.N.); (P.F.); (Y.Z.); (X.Z.)
- Biomedicine Key Laboratory of Shaanxi Province, School of Pharmacy, Northwest University, 229 Taibai Road, Xi’an 710069, China
| | - Xiaoming Ma
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, 229 Taibai Road, Xi’an 710069, China; (Z.Z.); (S.R.); (X.M.); (Q.F.); (Z.X.); (Z.N.); (P.F.); (Y.Z.); (X.Z.)
- Biomedicine Key Laboratory of Shaanxi Province, School of Pharmacy, Northwest University, 229 Taibai Road, Xi’an 710069, China
| | - Qian Feng
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, 229 Taibai Road, Xi’an 710069, China; (Z.Z.); (S.R.); (X.M.); (Q.F.); (Z.X.); (Z.N.); (P.F.); (Y.Z.); (X.Z.)
- Biomedicine Key Laboratory of Shaanxi Province, School of Pharmacy, Northwest University, 229 Taibai Road, Xi’an 710069, China
| | - Zhuosong Xie
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, 229 Taibai Road, Xi’an 710069, China; (Z.Z.); (S.R.); (X.M.); (Q.F.); (Z.X.); (Z.N.); (P.F.); (Y.Z.); (X.Z.)
- Biomedicine Key Laboratory of Shaanxi Province, School of Pharmacy, Northwest University, 229 Taibai Road, Xi’an 710069, China
| | - Zhuang Nie
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, 229 Taibai Road, Xi’an 710069, China; (Z.Z.); (S.R.); (X.M.); (Q.F.); (Z.X.); (Z.N.); (P.F.); (Y.Z.); (X.Z.)
- Biomedicine Key Laboratory of Shaanxi Province, School of Pharmacy, Northwest University, 229 Taibai Road, Xi’an 710069, China
| | - Peinan Fan
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, 229 Taibai Road, Xi’an 710069, China; (Z.Z.); (S.R.); (X.M.); (Q.F.); (Z.X.); (Z.N.); (P.F.); (Y.Z.); (X.Z.)
- Biomedicine Key Laboratory of Shaanxi Province, School of Pharmacy, Northwest University, 229 Taibai Road, Xi’an 710069, China
| | - Mingcheng Qian
- Department of Medicinal Chemistry, School of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou 213164, China;
- Laboratory for Medicinal Chemistry, Ghent University, Ottergemsesteenweg 460, B-9000 Ghent, Belgium
| | - Xirui He
- Department of Bioengineering, Zhuhai Campus of Zunyi Medical University, Zhuhai 519041, China;
| | - Shaoping Wu
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, 229 Taibai Road, Xi’an 710069, China; (Z.Z.); (S.R.); (X.M.); (Q.F.); (Z.X.); (Z.N.); (P.F.); (Y.Z.); (X.Z.)
- Biomedicine Key Laboratory of Shaanxi Province, School of Pharmacy, Northwest University, 229 Taibai Road, Xi’an 710069, China
| | - Yongmin Zhang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, 229 Taibai Road, Xi’an 710069, China; (Z.Z.); (S.R.); (X.M.); (Q.F.); (Z.X.); (Z.N.); (P.F.); (Y.Z.); (X.Z.)
- Biomedicine Key Laboratory of Shaanxi Province, School of Pharmacy, Northwest University, 229 Taibai Road, Xi’an 710069, China
- Sorbonne Université, Institut Parisien de Chimie Moléculaire, CNRS UMR 8232, 4 place Jussieu, 75005 Paris, France
| | - Xiaohui Zheng
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, 229 Taibai Road, Xi’an 710069, China; (Z.Z.); (S.R.); (X.M.); (Q.F.); (Z.X.); (Z.N.); (P.F.); (Y.Z.); (X.Z.)
- Biomedicine Key Laboratory of Shaanxi Province, School of Pharmacy, Northwest University, 229 Taibai Road, Xi’an 710069, China
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Hamburger M. HPLC-based activity profiling for pharmacologically and toxicologically relevant natural products - principles and recent examples. PHARMACEUTICAL BIOLOGY 2019; 57:328-334. [PMID: 31057026 PMCID: PMC6507960 DOI: 10.1080/13880209.2019.1606261] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 04/02/2019] [Indexed: 05/30/2023]
Abstract
CONTEXT Discovery of pharmacologically active natural products as starting points for drug development remains important and, for reasons of consumer safety, the identification of toxicologically relevant compounds in herbal drugs. OBJECTIVE To explain, with the aid of relevant examples from our own research, how these goals can be achieved. METHODS An in-house technology platform comprising pre-formatted extract libraries in 96-well format, miniaturized tracking of activity in extracts via HPLC-activity profiling, structure elucidation with microprobe NMR, and in vitro and in vivo pharmacological methods were used. RESULTS Piperine was identified as a new scaffold for allosteric GABAA receptor modulators with in vivo activity that interacts at a benzodiazepine-independent binding site. Selectivity and potency were improved by iterative optimization towards synthetic piperine analogues. Dehydroevodiamine and hortiamine from the traditional Chinese herbal drug Evodiae fructus were identified as potent hERG channel blockers in vitro. The compounds induced torsades de pointes arrhythmia in animal models. CONCLUSIONS The allosteric binding site for piperine analogues remains to be characterized and cardiac risks of herbal drugs need to be further evaluated to ensure consumer safety.
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Affiliation(s)
- Matthias Hamburger
- Pharmaceutical Biology, Pharmacenter, University of Basel, Basel, Switzerland
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7
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Tatsuzaki J, Ohwada T, Otani Y, Inagi R, Ishikawa T. A simple and effective preparation of quercetin pentamethyl ether from quercetin. Beilstein J Org Chem 2018; 14:3112-3121. [PMID: 30643589 PMCID: PMC6317434 DOI: 10.3762/bjoc.14.291] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 12/12/2018] [Indexed: 11/23/2022] Open
Abstract
Among the five hydroxy (OH) groups of quercetin (3,5,7,3',4'-pentahydroxyflavone), the OH group at 5 position is the most resistant to methylation due to its strong intramolecular hydrogen bonding with the carbonyl group at 4 position. Thus, it is generally difficult to synthesize the pentamethyl ether efficiently by conventional methylation. Here, we describe a simple and effective per-O-methylation of quercetin with dimethyl sulfate in potassium (or sodium) hydroxide/dimethyl sulfoxide at room temperature for about 2 hours, affording quercetin pentamethyl ether (QPE) quantitatively as a single product. When methyl iodide was used in place of dimethyl sulfate, the C-methylation product 6-methylquercetin pentamethyl ether was also formed. A computational study provided a rationale for the experimental results.
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Affiliation(s)
- Jin Tatsuzaki
- Tokiwa Phytochemical Co. Ltd., 158 Kinoko, Sakura, Chiba 285-0801, Japan
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0013, Japan
| | - Tomohiko Ohwada
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0013, Japan
| | - Yuko Otani
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0013, Japan
| | - Reiko Inagi
- Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0013, Japan
| | - Tsutomu Ishikawa
- Tokiwa Phytochemical Co. Ltd., 158 Kinoko, Sakura, Chiba 285-0801, Japan
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8
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Elhennawy MG, Lin HS. Dose- and time-dependent pharmacokinetics of apigenin trimethyl ether. Eur J Pharm Sci 2018; 118:96-102. [PMID: 29574080 DOI: 10.1016/j.ejps.2018.03.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 03/05/2018] [Accepted: 03/20/2018] [Indexed: 12/20/2022]
Abstract
Apigenin trimethyl ether (5,7,4'-trimethoxyflavone, ATE), one of the key polymethoxyflavones present in black ginger (rhizome of Kaempferia parviflora) possesses various health-promoting activities. To optimize its medicinal application, the pharmacokinetics of ATE was assessed in Sprague-Dawley rats with emphases to identify the impacts from dose and repeated dosing on its major pharmacokinetic parameters. Plasma ATE levels were monitored by liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Upon single intravenous administration (2 mg/kg), plasma levels of ATE declined through an apparent first-order process while dose-escalation to 4 and 8 mg/kg led to its non-linear disposition, which could be described by the Michaelis-Menten model. Similarly, dose-dependent oral pharmacokinetics was confirmed and when the dose was escalated from 5 to 15 and 45 mg/kg, much longer mean residence time (MRT0→last), higher dose-normalized maximal plasma concentration (Cmax/Dose) and exposure (AUC/Dose) were observed at 15 and/or 45 mg/kg. One-week daily oral administration of ATE at 15 mg/kg caused its accelerated elimination and the plasma exposure (AUC) after intravenous (2 mg/kg) and oral administration (15 mg/kg) dropped ~40 and 60%, respectively. As ATE displayed both dose- and time-dependent pharmacokinetics, caution is needed in the medicinal applications of ATE and/or black ginger.
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Affiliation(s)
| | - Hai-Shu Lin
- Department of Pharmacy, National University of Singapore, Singapore.
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9
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Hong J, Fristiohady A, Nguyen CH, Milovanovic D, Huttary N, Krieger S, Hong J, Geleff S, Birner P, Jäger W, Özmen A, Krenn L, Krupitza G. Apigenin and Luteolin Attenuate the Breaching of MDA-MB231 Breast Cancer Spheroids Through the Lymph Endothelial Barrier in Vitro. Front Pharmacol 2018; 9:220. [PMID: 29593542 PMCID: PMC5861143 DOI: 10.3389/fphar.2018.00220] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 02/27/2018] [Indexed: 11/13/2022] Open
Abstract
Flavonoids, present in fruits, vegetables and traditional medicinal plants, show anticancer effects in experimental systems and are reportedly non-toxic. This is a favorable property for long term strategies for the attenuation of lymph node metastasis, which may effectively improve the prognostic states in breast cancer. Hence, we studied two flavonoids, apigenin and luteolin exhibiting strong bio-activity in various test systems in cancer research and are readily available on the market. This study has further advanced the mechanistic understanding of breast cancer intravasation through the lymphatic barrier. Apigenin and luteolin were tested in a three-dimensional (3-D) assay consisting of MDA-MB231 breast cancer spheroids and immortalized lymph endothelial cell (LEC) monolayers. The 3-D model faithfully resembles the intravasation of breast cancer emboli through the lymphatic vasculature. Western blot analysis, intracellular Ca2+ determination, EROD assay and siRNA transfection revealed insights into mechanisms of intravasation as well as the anti-intravasative outcome of flavonoid action. Both flavonoids suppressed pro-intravasative trigger factors in MDA-MB231 breast cancer cells, specifically MMP1 expression and CYP1A1 activity. A pro-intravasative contribution of FAK expression in LECs was established as FAK supported the retraction of the LEC monolayer upon contact with cancer cells thereby enabling them to cross the endothelial barrier. As mechanistic basis, MMP1 caused the phosphorylation (activation) of FAK at Tyr397 in LECs. Apigenin and luteolin prevented MMP1-induced FAK activation, but not constitutive FAK phosphorylation. Luteolin, unlike apigenin, inhibited MMP1-induced Ca2+ release. Free intracellular Ca2+ is a central signal amplifier triggering LEC retraction through activation of the mobility protein MLC2, thereby enhancing intravasation. FAK activity and Ca2+ levels did not correlate. This implicates that the pro-intravasative contribution of FAK and of Ca2+ release in LECs was independent of each other and explains the better anti-intravasative effects of luteolin in vitro. In specific formulations, flavonoid concentrations causing significant anti-intravasative effects, can certainly be achieved in vivo. As the therapeutic strategy has to be based on permanent flavonoid treatment both the beneficial and adverse effects have to be investigated in future studies.
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Affiliation(s)
- Junli Hong
- Department of Pharmacognosy, Faculty of Life Sciences, University of Vienna, Vienna, Austria.,School of Pharmacy, Nanjing Medical University, Nanjing, China.,Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
| | - Adryan Fristiohady
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria.,Department for Clinical Pharmacy and Diagnostics, Faculty of Life Sciences, University of Vienna, Vienna, Austria.,Faculty of Pharmacy, Halu Oleo University, Kendari, Indonesia
| | - Chi H Nguyen
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria.,Department for Clinical Pharmacy and Diagnostics, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Daniela Milovanovic
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
| | - Nicole Huttary
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
| | - Sigurd Krieger
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
| | - Junqiang Hong
- Department of Medical Oncology, The 188th Hospital of People's Liberation Army of China, Chaozhou, China
| | - Silvana Geleff
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
| | - Peter Birner
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
| | - Walter Jäger
- Department for Clinical Pharmacy and Diagnostics, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Ali Özmen
- Department of Biology, Faculty of Science and Art, Adnan Menderes University, Aydin, Turkey
| | - Liselotte Krenn
- Department of Pharmacognosy, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Georg Krupitza
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
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10
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Kratz JM, Grienke U, Scheel O, Mann SA, Rollinger JM. Natural products modulating the hERG channel: heartaches and hope. Nat Prod Rep 2017; 34:957-980. [PMID: 28497823 PMCID: PMC5708533 DOI: 10.1039/c7np00014f] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
This review covers natural products modulating the hERG potassium channel. Risk assessment strategies, structural features of blockers, and the duality target/antitarget are discussed.
Covering: 1996–December 2016 The human Ether-à-go-go Related Gene (hERG) channel is a voltage-gated potassium channel playing an essential role in the normal electrical activity in the heart. It is involved in the repolarization and termination of action potentials in excitable cardiac cells. Mutations in the hERG gene and hERG channel blockage by small molecules are associated with increased risk of fatal arrhythmias. Several drugs have been withdrawn from the market due to hERG channel-related cardiotoxicity. Moreover, as a result of its notorious ligand promiscuity, this ion channel has emerged as an important antitarget in early drug discovery and development. Surprisingly, the hERG channel blocking profile of natural compounds present in frequently consumed botanicals (i.e. dietary supplements, spices, and herbal medicinal products) is not routinely assessed. This comprehensive review will address these issues and provide a critical compilation of hERG channel data for isolated natural products and extracts over the past two decades (1996–2016). In addition, the review will provide (i) a solid basis for the molecular understanding of the physiological functions of the hERG channel, (ii) the translational potential of in vitro/in vivo results to cardiotoxicity in humans, (iii) approaches for the identification of hERG channel blockers from natural sources, (iv) future perspectives for cardiac safety guidelines and their applications within phytopharmaceuticals and dietary supplements, and (v) novel applications of hERG channel modulation (e.g. as a drug target).
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Affiliation(s)
- Jadel M Kratz
- Department of Pharmacognosy, Faculty of Life Sciences, University of Vienna, Althanstraße 14, 1090 Vienna, Austria.
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11
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Elhennawy MG, Lin HS. Quantification of apigenin trimethyl ether in rat plasma by liquid chromatography-tandem mass spectrometry: Application to a pre-clinical pharmacokinetic study. J Pharm Biomed Anal 2017; 142:35-41. [PMID: 28494337 DOI: 10.1016/j.jpba.2017.03.070] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 03/22/2017] [Accepted: 03/31/2017] [Indexed: 10/19/2022]
Abstract
Apigenin trimethyl ether (5,7,4'-trimethoxyflavone, ATE) is a naturally occurring polymethoxyflavone with a wide range of health-promoting activities. In this study, a sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantification of ATE in rat plasma. Protein precipitation was applied as plasma clean-up procedure; the electrospray ionization was operated in its positive ion mode while ATE and formononetin (internal standard) were measured by multiple reactions monitoring (ATE: m/z 313.1→298.1; formononetin: 269.2→213.3). This LC-MS/MS method displayed good selectivity, sensitivity (lower limit of quantification=2.5ng/ml), accuracy (both intra- and inter-day analytical recovery within 100±10%) and precision (both intra- and inter-day RSD <10%). The matrix effect was found to be insignificant. The pharmacokinetic profiles of ATE were subsequently examined in Sprague-Dawley rats after single oral administration (10mg/kg). When given in an aqueous suspension, ATE was slowly absorbed with quite low plasma exposure (AUC). Fasting further attenuated its oral absorption and led to ∼70% drops in average maximal plasma concentration (Cmax) and AUC. When dosed in a solution formulated with 2-hydroxypropyl-β-cyclodextrin, the oral absorption of ATE was substantially improved with ∼500% increases in average Cmax and AUC. Clearly, aqueous solubility has been identified as a barrier to the oral absorption of ATE. The information obtained from this study will facilitate further medicinal exploration on ATE.
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Affiliation(s)
- Mai Gamal Elhennawy
- Department of Pharmacy, National University of Singapore, 10 Kent Ridge Crescent, 119260, Singapore
| | - Hai-Shu Lin
- Department of Pharmacy, National University of Singapore, 10 Kent Ridge Crescent, 119260, Singapore.
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Synthesis of a highly water-soluble acacetin prodrug for treating experimental atrial fibrillation in beagle dogs. Sci Rep 2016; 6:25743. [PMID: 27160397 PMCID: PMC4861903 DOI: 10.1038/srep25743] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 04/21/2016] [Indexed: 11/16/2022] Open
Abstract
We previously reported that duodenal administration of the natural flavone acacetin can effectively prevent the induction of experimental atrial fibrillation (AF) in canines; however, it may not be used intravenously to terminate AF due to its poor water-solubility. The present study was to design a water-soluble prodrug of acacetin and investigate its anti-AF effect in beagle dogs. Acacetin prodrug was synthesized by a three-step procedure. Aqueous solubility, bioconversion and anti-AF efficacy of acacetin prodrug were determined with different methodologies. Our results demonstrated that the synthesized phosphate sodium salt of acacetin prodrug had a remarkable increase of aqueous solubility in H2O and clinically acceptable solution (5% glucose or 0.9% NaCl). The acacetin prodrug was effectively converted into acacetin in ex vivo rat plasma and liver microsome, and in vivo beagle dogs. Intravenous infusion of acacetin prodrug (3, 6 and 12 mg/kg) terminated experimental AF without increasing ECG QTc interval in beagle dogs. The intravenous LD50 of acacetin prodrug was 721 mg/kg in mice. Our preclinical study indicates that the synthesized acacetin prodrug is highly water-soluble and safe; it effectively terminates experimental AF in beagle dogs and therefore may be a promising drug candidate for clinical trial to treat patients with acute AF.
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Protective Effect and Mechanism of Total Flavones from Rhododendron simsii Planch Flower on Cultured Rat Cardiomyocytes with Anoxia and Reoxygenation. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 2015:863531. [PMID: 25861370 PMCID: PMC4377486 DOI: 10.1155/2015/863531] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 12/25/2014] [Accepted: 12/31/2014] [Indexed: 01/08/2023]
Abstract
Many flavonoids have cardioprotection against myocardial ischemia/reperfusion (I/R) injury. Total flavones from Rhododendron simsii Planch flower (TFR) can protect myocardial ischemic injuries. However, its protective mechanism is still unknown. The present study was designed to investigate the mechanism of TFR on myocardial I/R and anoxia/reoxygenation (A/R) injuries. Rat model of myocardial I/R injury was made, and myocardial infarction was determined. A/R injury was induced in cultured rat cardiomyocytes; cellular damage was evaluated by measuring cell viability, LDH and cTnT releases, and MDA content. Expressions of ROCK1 and ROCK2 protein were examined by Western blot analysis, and K+ currents were recorded by using whole-cell patch clamp technique. TFR 20~80 mg/kg markedly reduced I/R-induced myocardial infarction. TFR 3.7~300 mg/L significantly inhibited A/R-induced reduction of cell viability, LDH and cTnT releases, and MDA production. Exposure to A/R significantly increased ROCK1 and ROCK2 expressions in rat cardiomyocytes, but TFR 33.3~300 mg/L obviously inhibited this increase. 300 mg/L TFR significantly augmented inward rectifier K+ current and other K+ currents in rat cardiomyocytes. These results indicate that TFR has a protective effect on rat cardiomyocytes A/R damage, and the protective mechanism may be engaged with the inhibition of ROCK1 and ROCK2 and activation of K+ channels.
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