1
|
Nwokocha C, Palacios J, Ojukwu VE, Nna VU, Owu DU, Nwokocha M, McGrowder D, Orie NN. Oxidant-induced disruption of vascular K + channel function: implications for diabetic vasculopathy. Arch Physiol Biochem 2024; 130:361-372. [PMID: 35757993 DOI: 10.1080/13813455.2022.2090578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 06/07/2022] [Indexed: 11/02/2022]
Abstract
Diabetes in humans a chronic metabolic disorder characterised by hyperglycaemia, it is associated with an increased risk of cardiovascular disease, disruptions to metabolism and vascular functions. It is also linked to oxidative stress and its complications. Its role in vascular dysfunctions is generally reported without detailed impact on the molecular mechanisms. Potassium ion channel (K+ channels) are key regulators of vascular tone, and as membrane proteins, are modifiable by oxidant stress associated with diabetes. This review manuscript examined the impact of oxidant stress on vascular K+ channel functions in diabetes, its implication in vascular complications and metabolic and cardiovascular diseases.
Collapse
Affiliation(s)
| | - Javier Palacios
- Department of Pharmacy, Faculty of Health Sciences, Arturo Prat University, Iquique, Chile
| | - Victoria E Ojukwu
- Basic Medical Sciences, University of the West Indies, Mona, Kingston, Jamaica
| | - Victor Udo Nna
- Department of Physiology, College of Medical Sciences, University of Calabar, Calabar, Nigeria
| | - Daniel Udofia Owu
- Department of Physiology, College of Medical Sciences, University of Calabar, Calabar, Nigeria
| | - Magdalene Nwokocha
- Department of Pathology, Faculty of Medical Sciences, University of the West Indies, Mona, Kingston, Jamaica
| | - Donovan McGrowder
- Department of Pathology, Faculty of Medical Sciences, University of the West Indies, Mona, Kingston, Jamaica
| | - Nelson N Orie
- Centre of Metabolism and Inflammation, University College London, London, UK
| |
Collapse
|
2
|
Palacios J, Asunción-Alvarez D, Aravena D, Chiong M, Catalán MA, Parra C, Cifuentes F, Paredes A. A new oxime synthesized from Senecio nutans SCh. Bip (chachacoma) reduces calcium influx in the vascular contractile response in rat aorta. RSC Adv 2024; 14:9933-9942. [PMID: 38528924 PMCID: PMC10962255 DOI: 10.1039/d4ra01058b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2024] [Accepted: 03/13/2024] [Indexed: 03/27/2024] Open
Abstract
Senecio nutans Sch. Bip is an endemic plant commonly employed in the Andes culture to counteract the effects of mountain sickness, and its bioactive molecules could provide new drugs for treating hypertension. The purpose was to determine whether the vascular response of the plant bioactive molecules, such as (5-acetyl-6-hydroxy-2-isopropenyl-2,3-dihydrobenzofurane; Sn-I), could be improved by a simple structural modification to synthesize oximes (Ox-Sn-I). We characterized both compounds using IR and NMR spectroscopy and Heteronuclear Multiple Quantum Coherence (HMQC). We investigated vascular relaxation mechanisms in response to Sn-I and Ox-Sn-I using rat aorta and vascular smooth muscle cells (A7r5) as experimental models. Preincubation of aortic rings with Sn-I (10-5 M) significantly (p < 0.001) decreased the contractile effect in response to phenylephrine (PE) and potassium chloride (KCl). The sensitivity (EC50) to PE significantly (p < 0.01) decreased in the presence of Sn-I (10-5 M), but not with Ox-Sn-I. Sn-I significantly (p < 0.001) reduced the PE-induced contraction under calcium-free conditions. When A7r5 cells were preincubated with Sn-I and Ox-Sn-I (10-5 M), both compounds blunted the increase in intracellular Ca2+ induced by KCl. 2,3-Dihydrobenzofurane derived from S. nutans (Sn-I) reduces the contractile response probably by blocking Ca2+ entry through voltage-gated Ca2+ channels (VGCC) in vascular smooth cells. This effect also causes relaxation in rat aorta mediated by reduction of intracellular Ca2+ concentration, rather than an increase of NO generation in endothelial vascular cells.
Collapse
Affiliation(s)
- Javier Palacios
- Laboratorio de Bioquímica Aplicada, Facultad de Ciencias de la Salud, Universidad Arturo Prat Iquique 1110939 Chile
| | - Daniel Asunción-Alvarez
- Laboratorio de Bioquímica Aplicada, Facultad de Ciencias de la Salud, Universidad Arturo Prat Iquique 1110939 Chile
| | - Diego Aravena
- Laboratorio de Bioquímica Aplicada, Facultad de Ciencias de la Salud, Universidad Arturo Prat Iquique 1110939 Chile
| | - Mario Chiong
- Universidad de Chile, Advanced Center for Chronic Diseases (ACCDiS), Facultad de Ciencias Químicas y Farmacéuticas Santiago Chile
| | - Marcelo A Catalán
- Instituto de Fisiología, Facultad de Medicina, Universidad Austral de Chile Valdivia 5090000 Chile
| | - Claudio Parra
- Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad de Concepción Edmundo Larenas 129 Concepción 4070371 Chile
| | - Fredi Cifuentes
- Laboratorio de Fisiología Experimental (EPhyL), Instituto Antofagasta (IA), Universidad de Antofagasta Antofagasta 1271155 Chile
| | - Adrián Paredes
- Departamento de Química, Facultad de Ciencias Básicas, Universidad de Antofagasta Antofagasta 1271155 Chile
| |
Collapse
|
3
|
Li L, Lin L, Wen B, Zhao PC, Liu DS, Pang GM, Wang ZR, Tan Y, Lu C. Promising Natural Medicines for the Treatment of High-Altitude Illness. High Alt Med Biol 2023; 24:175-185. [PMID: 37504973 PMCID: PMC10516238 DOI: 10.1089/ham.2022.0139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 06/27/2023] [Indexed: 07/29/2023] Open
Abstract
Li Li, Lin Lin, Bo Wen, Peng-cheng Zhao, Da-sheng Liu, Guo-ming Pang, Zi-rong Wang, Yong Tan, and Cheng Lu. Promising natural medicines for the treatment of high-altitude illness. High Alt Med Biol. 24:175-185, 2023.-High-altitude illness (HAI) is a dangerous disease characterized by oxidative stress, inflammatory damage and hemodynamic changes in the body that can lead to severe damage to the lungs, heart, and brain. Natural medicines are widely known for their multiple active ingredients and pharmacological effects, which may be important in the treatment of HAI. In this review, we outline the specific types of HAI and the underlying pathological mechanisms and summarize the currently documented natural medicines applied in the treatment of acute mountain sickness and high-altitude cerebral edema, high-altitude pulmonary edema, chronic mountain sickness, and high-altitude pulmonary hypertension. Their sources, types, and medicinal sites are summarized, and their active ingredients, pharmacological effects, related mechanisms, and potential toxicity are discussed. In conclusion, natural medicines, as an acceptable complementary and alternative strategy with fewer side effects and more long-term application, can provide a reference for developing more natural antialtitude sickness medicines in the future and have good application prospects in HAI treatment.
Collapse
Affiliation(s)
- Li Li
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
| | - Lin Lin
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
| | - Bo Wen
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
| | - Peng-cheng Zhao
- School of Life Science, Northwestern Polytechnical University, Xi'an, China
| | - Da-sheng Liu
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
| | - Guo-ming Pang
- Kaifeng Traditional Chinese Medicine Hospital, Kaifeng, China
| | - Zi-rong Wang
- Logistics Support Division, National Immigration Administration, Beijing, China
| | - Yong Tan
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
| | - Cheng Lu
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
| |
Collapse
|
4
|
Tomou EM, Papakyriakopoulou P, Skaltsa H, Valsami G, Kadoglou NPE. Bio-Actives from Natural Products with Potential Cardioprotective Properties: Isolation, Identification, and Pharmacological Actions of Apigenin, Quercetin, and Silibinin. Molecules 2023; 28:molecules28052387. [PMID: 36903630 PMCID: PMC10005323 DOI: 10.3390/molecules28052387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 02/23/2023] [Accepted: 03/01/2023] [Indexed: 03/08/2023] Open
Abstract
Cardiovascular diseases (CVDs) are the leading cause of morbidity and mortality worldwide. As a result, pharmaceutical and non-pharmaceutical interventions modifying risk factors for CVDs are a top priority of scientific research. Non-pharmaceutical therapeutical approaches, including herbal supplements, have gained growing interest from researchers as part of the therapeutic strategies for primary or secondary prevention of CVDs. Several experimental studies have supported the potential effects of apigenin, quercetin, and silibinin as beneficial supplements in cohorts at risk of CVDs. Accordingly, this comprehensive review focused critically on the cardioprotective effects/mechanisms of the abovementioned three bio-active compounds from natural products. For this purpose, we have included in vitro, preclinical, and clinical studies associated with atherosclerosis and a wide variety of cardiovascular risk factors (hypertension, diabetes, dyslipidemia, obesity, cardiac injury, and metabolic syndrome). In addition, we attempted to summarize and categorize the laboratory methods for their isolation and identification from plant extracts. This review unveiled many uncertainties which are still unexplored, such as the extrapolation of experimental results to clinical practice, mainly due to the small clinical studies, heterogeneous doses, divergent constituents, and the absence of pharmacodynamic/pharmacokinetic analyses.
Collapse
Affiliation(s)
- Ekaterina-Michaela Tomou
- Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Panepistimiopolis, 15784 Athens, Greece
| | - Paraskevi Papakyriakopoulou
- Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Panepistimiopolis, 15784 Athens, Greece
| | - Helen Skaltsa
- Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Panepistimiopolis, 15784 Athens, Greece
| | - Georgia Valsami
- Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Panepistimiopolis, 15784 Athens, Greece
| | | |
Collapse
|
5
|
Palacios J, Paredes A, Cifuentes F, Catalán MA, García-Villalón AL, Borquez J, Simirgiotis MJ, Jones M, Foster A, Greensmith DJ. A hydroalcoholic extract of Senecio nutans SCh. Bip (Asteraceae); its effects on cardiac function and chemical characterization. JOURNAL OF ETHNOPHARMACOLOGY 2023; 300:115747. [PMID: 36152785 DOI: 10.1016/j.jep.2022.115747] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 09/07/2022] [Accepted: 09/18/2022] [Indexed: 06/16/2023]
Abstract
ETHNOPHARMACOLOGY RELEVANCE The plant Senecio nutans SCh. Bip. is used by Andean communities to treat altitude sickness. Recent evidence suggests it may produce vasodilation and negative cardiac inotropy, though the cellular mechanisms have not been elucidated. PURPOSE To determinate the mechanisms action of S. nutans on cardiovascular function in normotensive animals. METHODS The effect of the extract on rat blood pressure was measured with a transducer in the carotid artery and intraventricular pressure by a Langendorff system. The effects on sheep ventricular intracellular calcium handling and contractility were evaluated using photometry. Ultra-high-performance liquid-chromatography with diode array detection coupled with heated electrospray-ionization quadrupole-orbitrap mass spectrometric detection (UHPLC-DAD-ESI-Q-OT-MSn) was used for extract chemical characterization. RESULTS In normotensive rats, S. nutans (10 mg/kg) reduced mean arterial pressure (MAP) by 40% (p < 0.05), causing a dose-dependent coronary artery dilation and decreased left ventricular pressure. In isolated cells, S. nutans extract (1 μg/ml) rapidly reduced the [Ca2+]i transient amplitude and sarcomere shorting by 40 and 49% (p < 0.001), respectively. The amplitude of the caffeine evoked [Ca2+]i transient was reduced by 24% (p < 0.001), indicating reduced sarcoplasmic reticulum (SR) Ca2+ content. Sodium-calcium exchanger (NCX) activity increased by 17% (p < 0.05), while sarcoendoplasmic reticulum Ca2+-ATPase (SERCA) activity was decreased by 21% (p < 0.05). LC-MS results showed the presence of vitamin C, malic acid, and several antioxidant phenolic acids reported for the first time. Dihydroeuparin and 4-hydroxy-3-(3-methylbut-2-enyl) acetophenone were abundant in the extract. CONCLUSION In normotensive animals, S. nutans partially reduces MAP by decreasing heart rate and cardiac contractility. This negative inotropy is accounted for by decreased SERCA activity and increased NCX activity which reduces SR Ca2+ content. These results highlight the plant's potential as a source of novel cardio-active phytopharmaceuticals or nutraceuticals.
Collapse
Affiliation(s)
- Javier Palacios
- Laboratorio de Bioquímica Aplicada, Química y Farmacia, Facultad de Ciencias de la Salud, Universidad Arturo Prat, Iquique, 1110939, Chile.
| | - Adrián Paredes
- Departamento de Química, Facultad de Ciencias Básicas, Universidad de Antofagasta, Antofagasta, 1271155, Chile; Instituto Antofagasta (IA), Universidad de Antofagasta, Antofagasta, 1271155, Chile.
| | - Fredi Cifuentes
- Instituto Antofagasta (IA), Universidad de Antofagasta, Antofagasta, 1271155, Chile; Departamento de Biomédico, Facultad Ciencias de la Salud, Universidad de Antofagasta, Antofagasta, 1271155, Chile.
| | - Marcelo A Catalán
- Instituto de Fisiología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, 5090000, Chile.
| | | | - Jorge Borquez
- Departamento de Química, Facultad de Ciencias Básicas, Universidad de Antofagasta, Antofagasta, 1271155, Chile.
| | - Mario J Simirgiotis
- Center for Interdisciplinary Studies on the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, 5090000, Chile.
| | - Matthew Jones
- Biomedical Research Centre, School of Science, Engineering and Environment, The University of Salford, Salford, United Kingdom.
| | - Amy Foster
- Biomedical Research Centre, School of Science, Engineering and Environment, The University of Salford, Salford, United Kingdom.
| | - David J Greensmith
- Biomedical Research Centre, School of Science, Engineering and Environment, The University of Salford, Salford, United Kingdom.
| |
Collapse
|
6
|
Novel Oxime Synthesized from a Natural Product of Senecio nutans SCh. Bip. (Asteraceae) Enhances Vascular Relaxation in Rats by an Endothelium-Independent Mechanism. Molecules 2022; 27:molecules27103333. [PMID: 35630811 PMCID: PMC9146311 DOI: 10.3390/molecules27103333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 05/17/2022] [Accepted: 05/20/2022] [Indexed: 02/01/2023] Open
Abstract
Senecio nutans Sch. Bip. and its constituents are reported to have antihypertensive effects. We isolated metabolite−1, a natural compound from S. nutans (4-hydroxy-3-(isopenten-2-yl)-acetophenone), and synthesized novel oxime − 1 (4-hydroxy-3-(isopenten-2-yl)-acetophenoxime) to evaluate their effect on vascular reactivity. Compounds were purified (metabolite−1) or synthetized (oxime−1) and characterized using IR and NMR spectroscopy and Heteronuclear Multiple Quantum Coherence (HMQC). Using pharmacological agents such as phenylephrine (PE) and KCl (enhancing contraction), acetylcholine (ACh), L-NAME (nitric oxide (NO) and endothelial function), Bay K8644-induced CaV1.2 channel (calcium channel modulator), and isolated aortic rings in an organ bath setup, the possible mechanisms of vascular action were determined. Pre-incubation of aortic rings with 10−5 M oxime−1 significantly (p < 0.001) decreased the contractile response to 30 mM KCl. EC50 to KCl significantly (p < 0.01) increased in the presence of oxime−1 (37.72 ± 2.10 mM) compared to that obtained under control conditions (22.37 ± 1.40 mM). Oxime−1 significantly reduced (p < 0.001) the contractile response to different concentrations of PE (10−7 to 10−5 M) by a mechanism that decreases Cav1.2-mediated Ca2+ influx from the extracellular space and reduces Ca2+ release from intracellular stores. At a submaximal concentration (10−5 M), oxime−1 caused a significant relaxation in rat aorta even without vascular endothelium or after pre-incubate the tissue with L-NAME. Oxime−1 decreases the contractile response to PE by blunting the release of Ca2+ from intracellular stores and blocking of Ca2+ influx by channels. Metabolite−1 reduces the contractile response to KCl, apparently by reducing the plasma membrane depolarization and Ca2+ influx from the extracellular space. These acetophenone derivates from S. nutans (metabolite−1 and oxime−1) cause vasorelaxation through pathways involving an increase of the endothelial NO generation or a higher bioavailability, further highlighting that structural modification of naturally occurring metabolites can enhance their intended pharmacological functions.
Collapse
|
7
|
Nwokocha CR, Gordon A, Palacios J, Paredes A, Cifuentes F, Francis S, Watson J, Delgoda R, Nwokocha M, Alexander-Lindo R, Thompson R, Minott-Kates D, Yakubu MA. Hypotensive and antihypertensive effects of an aqueous extract from Guinep fruit (Melicoccus bijugatus Jacq) in rats. Sci Rep 2020; 10:18623. [PMID: 33122667 PMCID: PMC7596469 DOI: 10.1038/s41598-020-75607-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 10/06/2020] [Indexed: 11/09/2022] Open
Abstract
Melicoccus bijugatus Jacq (Mb) has been reported to have cardiovascular modulatory effects. In this study, we evaluated the antihypertensive effects and mechanism of action of Mb on NG-Nitro-l-arginine Methyl Ester (l-NAME) and Deoxycorticosterone Acetate (DOCA) rat models. Aqueous extract of Mb fruit (100 mg/kg) was administered for 6 weeks to rats by gavage and blood pressure was recorded. Effects of the extract on vascular reactivity was evaluated using isolated organ baths, and tissues were collected for biochemical and histological analysis. The systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) were significantly (P < 0.05) reduced with extract (100 mg/kg) administration and treatment compared to the hypertensive models. Mb (100 µg/mL) reduced the vascular contractility induced by phenylephrine (PE), and caused a dose-dependent relaxation of PE-induced contraction of aortic vascular rings. The vasorelaxation properties seemed to be endothelium dependent, as well as nitric oxide (NO) and guanylyl cyclase, but not prostaglandin dependent. Histomicrograph of transverse sections of the ventricles from the Mb group did not show abnormalities. The extract significantly (P < 0.05) reduced an l-NAME induced elevation of cardiac output and Creatine Kinase Muscle-Brain (CKMB), but had no significant impact on the activities of arylamine N-acetyltransferase. In conclusion, Mb significantly decreased blood pressure in hypertensive models. The extract possesses the ability to induce endothelium dependent vasodilation, which is dependent on guanylyl cyclase but not prostaglandins.
Collapse
Affiliation(s)
- Chukwuemeka R Nwokocha
- Department of Basic Medical Sciences, Faculty of Medical Sciences, The University of the West Indies, Mona Campus, Kingston 7, Jamaica.
| | - Alexia Gordon
- Department of Basic Medical Sciences, Faculty of Medical Sciences, The University of the West Indies, Mona Campus, Kingston 7, Jamaica
| | - Javier Palacios
- Laboratorio de Bioquímica Aplicada, Departamento Química y Farmacia, Facultad de Ciencias de la Salud, Universidad Arturo Prat, 1110939, Iquique, Chile.
| | - Adrian Paredes
- Departamento Química y Farmacia, Facultad de Ciencias Básicas, Universidad de Antofagasta, 1271155, Antofagasta, Chile
| | - Fredi Cifuentes
- Laboratorio de Fisiología Experimental, Instituto Antofagasta (IA), Universidad de Antofagasta, 1270300, Antofagasta, Chile
| | - Sheena Francis
- Natural Products Institute, Faculty of Science and Technology, The University of the West Indies, Mona, Kingston 7, Jamaica
| | - JeAnn Watson
- Natural Products Institute, Faculty of Science and Technology, The University of the West Indies, Mona, Kingston 7, Jamaica
| | - Rupika Delgoda
- Natural Products Institute, Faculty of Science and Technology, The University of the West Indies, Mona, Kingston 7, Jamaica
| | - Magdalene Nwokocha
- Department of Pathology, Faculty of Medical Sciences, University of the West Indies, Mona Campus, Kingston 7, Jamaica
| | - Ruby Alexander-Lindo
- Department of Basic Medical Sciences, Faculty of Medical Sciences, The University of the West Indies, Mona Campus, Kingston 7, Jamaica
| | - Rory Thompson
- Department of Pathology, Faculty of Medical Sciences, University of the West Indies, Mona Campus, Kingston 7, Jamaica
| | - Donna Minott-Kates
- Department of Chemistry, University of the West Indies, Mona, Kingston 7, Jamaica
| | - Momoh A Yakubu
- Department of Environmental and Interdisciplinary Sciences, College of Science, Engineering and Technology, Texas Southern University, Houston, TX, 77004, USA
| |
Collapse
|
8
|
Cifuentes F, Palacios J, R. Nwokocha C, Bórquez J, Simirgiotis MJ, Norambuena I, Chiong M, Paredes A. Polyphenolic Composition and Hypotensive Effects of Parastrephia quadrangularis (Meyen) Cabrera in Rat. Antioxidants (Basel) 2019; 8:antiox8120591. [PMID: 31783548 PMCID: PMC6943605 DOI: 10.3390/antiox8120591] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 11/23/2019] [Accepted: 11/23/2019] [Indexed: 12/20/2022] Open
Abstract
Parastrephia quadrangularis (Pq), commonly called "Tola", is widely used in folk medicine in the Andes, including for altitude sickness. In this study, polyphenolic composition was determined, and hypotensive effects were measured; the ethnopharmacological use as hypotensive was related to the presence of phenolic compounds. For this purpose, male Sprague-Dawley rats (6 to 8 weeks of age, 160 to 190 g) were fed Pq extract (10 to 40 mg/kg) for 10 days through gavage. Blood pressures and heart rate were significantly (p < 0.01) reduced in normotensive rats receiving Pq extract (40 mg/kg body weight). Pq extract induced a negative inotropic effect, and endothelium-dependent vasodilation mediated by nitric oxide (NO). Furthermore, preincubation with Pq extract significantly decreased the cytosolic calcium on vascular smooth muscle cells A7r5 in response to L-phenylephrine (PE). Seven metabolites were isolated from the Pq extract, but three flavonoids (10-4 M) showed similar vasodilation to the extract in intact rat aorta as follows: 5,3',4'-trihydroxy-7-methoxyflavanone (2); 3,5,4'-trihydroxy-7,8,3'-trimethoxyflavone (6); and 5,4'-dihydroxy-3,7,8,3'-tetramethoxyflavone (7). The Pq extract and compounds 2 and 7 significantly (p < 0.05) reduced the contraction to Bay K8644 (10 nM, an agonist of CaV1.2 channels). Administration of Pq decreased cardiac contractility and increased endothelium-dependent and -independent vasodilation.
Collapse
Affiliation(s)
- Fredi Cifuentes
- Laboratorio de Fisiología Experimental (EPhyL), Instituto Antofagasta (IA), Universidad de Antofagasta, 1270300 Antofagasta, Chile;
| | - Javier Palacios
- Laboratorio de Bioquímica Aplicada, Facultad de Ciencias de la Salud, Universidad Arturo Prat, 1110939 Iquique, Chile
- Correspondence: (J.P.); (A.P.); Tel.: +56-57-2526910 (J.P.); +56-55-2513507 (A.P.)
| | - Chukwuemeka R. Nwokocha
- Department of Basic Medical Sciences (Physiology Section), Faculty of Medical Sciences, The University of the West Indies, Mona, Kingston 7, Jamaica;
| | - Jorge Bórquez
- Laboratorio de Productos Naturales, Departamento de Química, Universidad de Antofagasta, 1270300 Antofagasta, Chile;
| | - Mario J. Simirgiotis
- Instituto de Farmacia, Facultad de Ciencias, Universidad Austral de Chile, Valdivia 5090000, Chile;
| | - Ignacio Norambuena
- Advanced Center for Chronic Diseases (ACCDiS), CEMC, Department of Biochemistry and Molecular Biology, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, Santiago 8380492, Chile; (I.N.); (M.C.)
| | - Mario Chiong
- Advanced Center for Chronic Diseases (ACCDiS), CEMC, Department of Biochemistry and Molecular Biology, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, Santiago 8380492, Chile; (I.N.); (M.C.)
| | - Adrián Paredes
- Laboratorio de Química Biológica, Instituto Antofagasta (IA), Universidad de Antofagasta, 1270300 Antofagasta, Chile
- Correspondence: (J.P.); (A.P.); Tel.: +56-57-2526910 (J.P.); +56-55-2513507 (A.P.)
| |
Collapse
|
9
|
Romero F, Palacios J, Jofré I, Paz C, Nwokocha CR, Paredes A, Cifuentes F. Aristoteline, an Indole-Alkaloid, Induces Relaxation by Activating Potassium Channels and Blocking Calcium Channels in Isolated Rat Aorta. Molecules 2019; 24:molecules24152748. [PMID: 31362388 PMCID: PMC6695676 DOI: 10.3390/molecules24152748] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 05/08/2019] [Accepted: 05/11/2019] [Indexed: 11/16/2022] Open
Abstract
Alkaloids derived from plants have shown great medicinal benefits, and are often reported for their use in cardiovascular disease management. Aristotelia chilensis (Molina) Stuntz (Maqui) has shown important medicinal properties in traditional useage. In this study, we evaluated the effect of the indole-alkaloid aristoteline (ARI), isolated from leaves of Maqui, on vascular reactivity of isolated aortic rings from normotensive rats. ARI induced relaxation (100%) in a concentration-dependent manner in intact or denuded-endothelium aortic rings pre-contracted with phenylephrine (PE; 1 μM). However, a specific soluble guanylyl cyclase inhibitor (ODQ; 1 μM) significantly reduced the relaxation to ARI in aortic rings pre-contracted with PE. In the presence of ARI, the contraction induced by KCl or PE was significantly (p < 0.05) decreased. Interestingly, the potassium channel blockade with 10 μM BaCl2 (Kir), 10 μM glibenclamide (KATP), 1 mM tetraethylammonium (TEA; KCa1.1), or 1 mM 4-aminopyridine (4-AP; Kv) significantly (p < 0.05) reduced the ARI-induced relaxation. ARI significantly (p < 0.05) reduced the contractile response to agonist of CaV1.2 channels (Bay K8644; 10 nM), likely reducing the influx of extracellular calcium through plasma membrane. The mechanisms associated with this process suggest an activation of the potassium channels, a calcium-induced antagonism and endothelium independent vasodilation that possibly involves the nitric oxide-independent soluble guanylate cyclase pathway.
Collapse
Affiliation(s)
- Fernando Romero
- Vicerrectoría de Investigación y Postgrado, Programa de Doctorado en Ciencias Médicas, Universidad de la Frontera, Temuco 4780000, Chile.
| | - Javier Palacios
- Laboratorio de Bioquímica Aplicada, Departamento de Química y Farmacia, Facultad Ciencias de la Salud, Universidad Arturo Prat, Iquique 1110939, Chile.
| | - Ignacio Jofré
- Laboratorio de Neurociencias y Biología de Péptidos, Centro de Excelencia en Biotecnología de La Reproducción, Facultad de Medicina, Universidad de La Frontera, Temuco 4811230, Chile
| | - Cristian Paz
- Laboratorio de Productos Naturales y Descubrimiento de Fármacos, Departamento de Ciencias básicas, Universidad de La Frontera, Temuco 4811230, Chile
| | - Chukwuemeka R Nwokocha
- Department of Basic Medical Sciences Physiology Section, Faculty of Medical Sciences, The University of the West Indies, Mona, Kingston 7, KGN, Jamaica (W.I.)
| | - Adrián Paredes
- Laboratorio de Química Biológica, Instituto Antofagasta, Universidad de Antofagasta, Antofagasta 1270300, Chile
| | - Fredi Cifuentes
- Laboratorio de Fisiología Experimental, Instituto Antofagasta, Universidad de Antofagasta, Antofagasta 1270300, Chile
| |
Collapse
|