1
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Silva-Dos-Santos NM, Oliveira-Abreu K, Moreira-Junior L, Santos-Nascimento TD, Silva-Alves KSD, Coelho-de-Souza AN, Ferreira-da-Silva FW, Leal-Cardoso JH. Diabetes mellitus alters electrophysiological properties in neurons of superior cervical ganglion of rats. Brain Res 2020; 1729:146599. [PMID: 31843626 DOI: 10.1016/j.brainres.2019.146599] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 11/22/2019] [Accepted: 12/11/2019] [Indexed: 01/08/2023]
Abstract
Diabetic neuropathy is the most prevalent complication associated with diabetes mellitus (DM). The superior cervical ganglion (SCG) is an important sympathetic component of the autonomic nervous system. We investigated the changes in cellular electrophysiological properties and on Na+K+-ATPase activity of SCG neurons of rats with DM induced by streptozotocin (STZ). Three types of action potentials (AP) firing pattern were observed in response to a long (1 s) depolarizing pulse. Whilst some neurons fired a single AP (single firing phasic, SFP), others fired few APs (multiple firing phasic, MFP). A third type fired APs during more than 80% of the stimulus duration (tonic-like, TL). The occurrence of SFP, MFP and TL was 84.5, 13.8, and 1.7%, respectively. SFP and MFP differed significantly in their membrane input resistance (Rin). At the end of the 4th week of its time course, DM differently affected most types of neurons: DM induced depolarization of resting membrane potential (RMP), decreased AP amplitude in SFP, and decreased Rin in MFP. DM decreased spike after-hyperpolarization amplitude in MFP and the duration in SFP. Based on the RMP depolarization, we investigated the Na+K+-ATPase action and observed that DM caused a significant decrease in Na+K+-ATPase activity of SCG. In conclusion, we have demonstrated that DM affects several parameters of SCG physiology in a manner likely to have pathophysiological relevance.
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Affiliation(s)
- Nathalia Maria Silva-Dos-Santos
- Laboratório de Eletrofisiologia, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza 60714-903, CE, Brazil
| | - Klausen Oliveira-Abreu
- Laboratório de Eletrofisiologia, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza 60714-903, CE, Brazil
| | | | | | - Kerly Shamyra da Silva-Alves
- Laboratório de Eletrofisiologia, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza 60714-903, CE, Brazil
| | - Andrelina Noronha Coelho-de-Souza
- Laboratório de Eletrofisiologia, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza 60714-903, CE, Brazil
| | - Francisco Walber Ferreira-da-Silva
- Laboratório de Eletrofisiologia, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza 60714-903, CE, Brazil
| | - José Henrique Leal-Cardoso
- Laboratório de Eletrofisiologia, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza 60714-903, CE, Brazil.
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2
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Monoterpenoid terpinen-4-ol inhibits voltage-dependent Na+ channels of small dorsal root ganglia rat neurons. Chem Biol Interact 2020; 315:108890. [DOI: 10.1016/j.cbi.2019.108890] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 09/20/2019] [Accepted: 10/28/2019] [Indexed: 02/03/2023]
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3
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1,8-Cineole blocks voltage-gated L-type calcium channels in tracheal smooth muscle. Pflugers Arch 2018; 470:1803-1813. [DOI: 10.1007/s00424-018-2201-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 08/06/2018] [Accepted: 08/27/2018] [Indexed: 12/18/2022]
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4
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Wang ZJ, Heinbockel T. Essential Oils and Their Constituents Targeting the GABAergic System and Sodium Channels as Treatment of Neurological Diseases. Molecules 2018; 23:molecules23051061. [PMID: 29724056 PMCID: PMC6099651 DOI: 10.3390/molecules23051061] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 03/28/2018] [Accepted: 04/27/2018] [Indexed: 12/27/2022] Open
Abstract
Essential oils and the constituents in them exhibit different pharmacological activities, such as antinociceptive, anxiolytic-like, and anticonvulsant effects. They are widely applied as a complementary therapy for people with anxiety, insomnia, convulsion, pain, and cognitive deficit symptoms through inhalation, oral administration, and aromatherapy. Recent studies show that essential oils are emerging as a promising source for modulation of the GABAergic system and sodium ion channels. This review summarizes the recent findings regarding the pharmacological properties of essential oils and compounds from the oils and the mechanisms underlying their effects. Specifically, the review focuses on the essential oils and their constituents targeting the GABAergic system and sodium channels, and their antinociceptive, anxiolytic, and anticonvulsant properties. Some constituents target transient receptor potential (TRP) channels to exert analgesic effects. Some components could interact with multiple therapeutic target proteins, for example, inhibit the function of sodium channels and, at the same time, activate GABAA receptors. The review concentrates on perspective compounds that could be better candidates for new drug development in the control of pain and anxiety syndromes.
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Affiliation(s)
- Ze-Jun Wang
- Department of Anatomy, Howard University College of Medicine, 520 W Str., NW, Washington, DC 20059, USA.
| | - Thomas Heinbockel
- Department of Anatomy, Howard University College of Medicine, 520 W Str., NW, Washington, DC 20059, USA.
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5
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Oliveira-Abreu K, Ferreira-da-Silva FW, Silva-Alves KSD, Silva-Dos-Santos NM, Cardoso-Teixeira AC, Amaral FGD, Cipolla-Neto J, Leal-Cardoso JH. Melatonin decreases neuronal excitability in a sub-population of dorsal root ganglion neurons. Brain Res 2018; 1692:1-8. [PMID: 29702086 DOI: 10.1016/j.brainres.2018.04.027] [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: 09/21/2017] [Revised: 04/10/2018] [Accepted: 04/23/2018] [Indexed: 12/29/2022]
Abstract
Melatonin, a powerful antioxidant, participates in the regulation of important physiological and pathological processes. We investigated the actions of melatonin on neuronal excitability of intact dorsal root ganglions (DRG) from rats using intracellular recording techniques in current clamps. Melatonin blocked the generation of action potentials in a concentration-dependent manner. Bath applied melatonin (1.0-1000.0 nM) hyperpolarized the resting membrane potential, and increased the input resistance and rheobase. Melatonin also altered the active electrophysiological properties of the action potential, amplitude and maximum descendant inclination, in a statistically significant way. In order to provide evidence on the mechanism of action of melatonin in the DRG, quantitative PCR (qPCR) was performed. Analyses were performed for melatonin membrane receptors, MT1 and MT2, and it was observed that the DRG expresses MT1 receptors. In addition, we noted that the melatonin-induced effects were blocked in the presence of luzindole, a melatonin receptor antagonist. The minimal effective concentrations of melatonin (10.0 nM) and the blockade of effects caused by luzindole suggest that the effects of melatonin are hormonal, and are induced when it binds to MT1 receptors.
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Affiliation(s)
- Klausen Oliveira-Abreu
- Laboratório de Eletrofisiologia, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE, Brazil
| | | | - Kerly Shamyra da Silva-Alves
- Laboratório de Eletrofisiologia, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE, Brazil
| | - Nathalia Maria Silva-Dos-Santos
- Laboratório de Eletrofisiologia, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE, Brazil
| | - Ana Carolina Cardoso-Teixeira
- Laboratório de Eletrofisiologia, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE, Brazil
| | - Fernanda Gaspar do Amaral
- Laboratório de Neurobiologia, Instituto de Ciências Biomédicas 1, Universidade de São Paulo, São Paulo, SP, Brazil
| | - José Cipolla-Neto
- Laboratório de Neurobiologia, Instituto de Ciências Biomédicas 1, Universidade de São Paulo, São Paulo, SP, Brazil
| | - José Henrique Leal-Cardoso
- Laboratório de Eletrofisiologia, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE, Brazil.
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6
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Tsuchiya H. Anesthetic Agents of Plant Origin: A Review of Phytochemicals with Anesthetic Activity. Molecules 2017; 22:E1369. [PMID: 28820497 PMCID: PMC6152143 DOI: 10.3390/molecules22081369] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 08/17/2017] [Accepted: 08/17/2017] [Indexed: 12/15/2022] Open
Abstract
The majority of currently used anesthetic agents are derived from or associated with natural products, especially plants, as evidenced by cocaine that was isolated from coca (Erythroxylum coca, Erythroxylaceae) and became a prototype of modern local anesthetics and by thymol and eugenol contained in thyme (Thymus vulgaris, Lamiaceae) and clove (Syzygium aromaticum, Myrtaceae), respectively, both of which are structurally and mechanistically similar to intravenous phenolic anesthetics. This paper reviews different classes of phytochemicals with the anesthetic activity and their characteristic molecular structures that could be lead compounds for anesthetics and anesthesia-related drugs. Phytochemicals in research papers published between 1996 and 2016 were retrieved from the point of view of well-known modes of anesthetic action, that is, the mechanistic interactions with Na⁺ channels, γ-aminobutyric acid type A receptors, N-methyl-d-aspartate receptors and lipid membranes. The searched phytochemicals include terpenoids, alkaloids and flavonoids because they have been frequently reported to possess local anesthetic, general anesthetic, antinociceptive, analgesic or sedative property. Clinical applicability of phytochemicals to local and general anesthesia is discussed by referring to animal in vivo experiments and human pre-clinical trials. This review will give structural suggestions for novel anesthetic agents of plant origin.
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Affiliation(s)
- Hironori Tsuchiya
- Department of Dental Basic Education, Asahi University School of Dentistry, 1851 Hozumi, Mizuho, Gifu 501-0296, Japan.
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7
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Essential Oil of Ocimum basilicum L. and (-)-Linalool Blocks the Excitability of Rat Sciatic Nerve. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2016; 2016:9012605. [PMID: 27446227 PMCID: PMC4944029 DOI: 10.1155/2016/9012605] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 05/31/2016] [Indexed: 01/18/2023]
Abstract
The racemate linalool and its levogyrus enantiomer [(−)-LIN] are present in many essential oils and possess several pharmacological activities, such as antinociceptive and anti-inflammatory. In this work, the effects of essential oil obtained from the cultivation of the Ocimum basilicum L. (EOOb) derived from Germplasm Bank rich in (−)-LIN content in the excitability of peripheral nervous system were studied. We used rat sciatic nerve to investigate the EOOb and (−)-LIN effects on neuron excitability and the extracellular recording technique was used to register the compound action potential (CAP). EOOb and (−)-LIN blocked the CAP in a concentration-dependent way and these effects were reversible after washout. EOOb blocked positive amplitude of 1st and 2nd CAP components with IC50 of 0.38 ± 0.2 and 0.17 ± 0.0 mg/mL, respectively. For (−)-LIN, these values were 0.23 ± 0.0 and 0.13 ± 0.0 mg/mL. Both components reduced the conduction velocity of CAP and the 2nd component seems to be more affected than the 1st component. In conclusion EOOb and (−)-LIN inhibited the excitability of peripheral nervous system in a similar way and potency, revealing that the effects of EOOb on excitability are due to the presence of (−)-LIN in the essential oil.
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8
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Eucalyptol induces hyperexcitability and epileptiform activity in snail neurons by inhibiting potassium channels. Eur J Pharmacol 2015; 764:70-78. [DOI: 10.1016/j.ejphar.2015.06.050] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 05/31/2015] [Accepted: 06/25/2015] [Indexed: 11/18/2022]
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9
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Sousa DG, Sousa SDG, Silva RER, Silva-Alves KS, Ferreira-da-Silva FW, Kerntopf MR, Menezes IRA, Leal-Cardoso JH, Barbosa R. Essential oil of Lippia alba and its main constituent citral block the excitability of rat sciatic nerves. ACTA ACUST UNITED AC 2015; 48:697-702. [PMID: 26132093 PMCID: PMC4541688 DOI: 10.1590/1414-431x20154710] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 04/06/2015] [Indexed: 11/29/2022]
Abstract
Lippia alba is empirically used for infusions, teas, macerates, and
hydroalcoholic extracts because of its antispasmodic, analgesic, sedative, and
anxiolytic effects. Citral is a mixture of trans-geranial and cis-neral and is the
main constituent of L. alba essential oil and possesses analgesic,
anxiolytic, anticonvulsant, and sedative effects. The present study evaluated the
effects of the essential oil of L. alba (EOLa) and citral on
compound action potentials (CAPs) in Wistar rat sciatic nerves. Both drugs inhibited
CAP in a concentration-dependent manner. The calculated half-maximal inhibitory
concentrations (IC50) of peak-to-peak amplitude were 53.2 µg/mL and 35.00
µg/mL (or 230 µM) for EOLa and citral, respectively. Peak-to-peak amplitude of the
CAP was significantly reduced by 30 µg/mL EOLa and 10 µg/mL citral. EOLa and citral
(at 60 and 30 µg/mL, values close to their respective IC50 for CAP
blockade) significantly increased chronaxy and rheobase. The conduction velocity of
the first and second CAP components was statistically reduced to ∼86% of control with
10 µg/mL EOLa and ∼90% of control with 3 µg/mL citral. This study showed that EOLa
inhibited nerve excitability and this effect can be explained by the presence of
citral in its composition. Both EOLa and citral showed inhibitory actions at lower
concentrations compared with other essential oils and constituents with local
anesthetic activity. In conclusion, these data demonstrate that EOLa and citral are
promising agents in the development of new drugs with local anesthetic activity.
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Affiliation(s)
- D G Sousa
- Laboratório de Fisiofarmacologia das Células Excitáveis, Universidade Regional do Cariri, Crato, CE, Brasil
| | - S D G Sousa
- Laboratório de Fisiofarmacologia das Células Excitáveis, Universidade Regional do Cariri, Crato, CE, Brasil
| | - R E R Silva
- Laboratório de Fisiofarmacologia das Células Excitáveis, Universidade Regional do Cariri, Crato, CE, Brasil
| | - K S Silva-Alves
- Laboratório de Eletrofisiologia, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE, Brasil
| | - F W Ferreira-da-Silva
- Laboratório de Eletrofisiologia, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE, Brasil
| | - M R Kerntopf
- Laboratório de Farmacologia e Química Medicinal, Universidade Regional do Cariri, Crato, CE, Brasil
| | - I R A Menezes
- Laboratório de Farmacologia e Química Medicinal, Universidade Regional do Cariri, Crato, CE, Brasil
| | - J H Leal-Cardoso
- Laboratório de Eletrofisiologia, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE, Brasil
| | - R Barbosa
- Laboratório de Fisiofarmacologia das Células Excitáveis, Universidade Regional do Cariri, Crato, CE, Brasil
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10
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Effects of monoterpenes on ion channels of excitable cells. Pharmacol Ther 2015; 152:83-97. [PMID: 25956464 DOI: 10.1016/j.pharmthera.2015.05.006] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 04/23/2015] [Indexed: 11/20/2022]
Abstract
Monoterpenes are a structurally diverse group of phytochemicals and a major constituent of plant-derived 'essential oils'. Monoterpenes such as menthol, carvacrol, and eugenol have been utilized for therapeutical purposes and food additives for centuries and have been reported to have anti-inflammatory, antioxidant and analgesic actions. In recent years there has been increasing interest in understanding the pharmacological actions of these molecules. There is evidence indicating that monoterpenes can modulate the functional properties of several types of voltage and ligand-gated ion channels, suggesting that some of their pharmacological actions may be mediated by modulations of ion channel function. In this report, we review the literature concerning the interaction of monoterpenes with various ion channels.
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11
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Ferreira-da-Silva FW, da Silva-Alves KS, Alves-Fernandes TA, Coelho-de-Souza AN, Leal-Cardoso JH. Effects of 1,8-cineole on Na(+) currents of dissociated superior cervical ganglia neurons. Neurosci Lett 2015; 595:45-9. [PMID: 25849529 DOI: 10.1016/j.neulet.2015.04.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 03/26/2015] [Accepted: 04/02/2015] [Indexed: 12/19/2022]
Abstract
1,8-Cineole is a terpenoid present in many essential oil of plants with several pharmacological and biological effects, including antinociceptive, smooth muscle relaxant and ion channel activation. Also, 1,8-cineole blocked action potentials, reducing excitability of peripheral neurons. The objective of this work was to investigate effects of 1,8-cineole on Na(+) currents (INa(+)) in dissociated superior cervical ganglion neurons (SCG). Wistar rats of both sexes were used (10-12 weeks old, 200-300g). SCG's were dissected and neurons were enzymatically treated. To study 1,8-cineole effect on INa(+), the patch-clamp technique in whole-cell mode was employed. 1,8-Cineole (6.0mM) partially blocked INa(+) in SCG neurons. The effect stabilized within ∼150s and there was a partial recovery of INa(+) after washout. Current density was reduced from -105.8 to -83.7pA/pF, corresponding to a decrease to ∼20% of control. 1,8-Cineole also reduced the time-to-peak of INa(+) activation and the amplitude and decay time constants of INa(+) inactivation. Current-voltage plots revealed that 1,8-cineole left-shifted the V1/2 of both activation and inactivation curves by ∼10 and ∼20mV, respectively. In conclusion, we demonstrate that 1,8-cineole directly affects Na(+) channels of the SCG by modifying several gating parameters that are likely to be the major cause of excitability blockade.
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Affiliation(s)
| | - Kerly Shamyra da Silva-Alves
- Laboratory of Electrophysiology, Superior Institute of Biomedical Sciences, State University of Ceará, Fortaleza, Ceará, Brazil
| | - Thaís Antônia Alves-Fernandes
- Laboratory of Electrophysiology, Superior Institute of Biomedical Sciences, State University of Ceará, Fortaleza, Ceará, Brazil
| | | | - José Henrique Leal-Cardoso
- Laboratory of Electrophysiology, Superior Institute of Biomedical Sciences, State University of Ceará, Fortaleza, Ceará, Brazil.
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12
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dos Santos-Nascimento T, Veras KM, Cruz JS, Leal-Cardoso JH. Inhibitory effect of terpinen-4-ol on voltage-dependent potassium currents in rat small sensory neurons. JOURNAL OF NATURAL PRODUCTS 2015; 78:173-180. [PMID: 25607610 DOI: 10.1021/np4009249] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The biological and pharmacological activities of the terpenoid terpinen-4-ol (1), which include depressant effects in the central nervous system, are of potential therapeutic interest. In the present study, the effects of 1 on neuronal excitability and voltage-dependent K(+) currents in the somatic sensory system were investigated. Intact and dissociated neurons of rat dorsal root ganglia (DRG) were used for intracellular and patch-clamp recordings, respectively. In neurons of intact DRG, 1 caused concentration-dependent depolarization of the resting membrane potential and increased input resistance. 1 also inhibited action potentials (AP) and decreased AP parameters, with the exception of AP duration, which was increased. In dissociated DRG neurons, 1 partially blocked the total K(+) current in a concentration-dependent manner. 1 inhibited I(A), I(D), and I(K) with IC50 values of 3.2 ± 03, 0.7 ± 0.1, and 1.6 ± 0.7 mM, respectively. 1 did not shift either the steady-state activation or inactivation curves of I(A), I(D), and I(K) but reduced the decay time course of I(A). The alterations in DRG reported here are consistent with the inhibition of K(+) currents and might partially explain the effect of 1 on excitable tissues.
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Affiliation(s)
- Tiago dos Santos-Nascimento
- Laboratory of Electrophysiology, Superior Institute of Biomedical Sciences, State University of Ceará , Campus of Itaperi, Fortaleza, CE, Brazil
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13
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Silva-Alves KS, Ferreira-da-Silva FW, Peixoto-Neves D, Viana-Cardoso KV, Moreira-Júnior L, Oquendo MB, Oliveira-Abreu K, Albuquerque AAC, Coelho-de-Souza AN, Leal-Cardoso JH. Estragole blocks neuronal excitability by direct inhibition of Na+ channels. Braz J Med Biol Res 2013; 46:1056-1063. [PMID: 24345915 PMCID: PMC3935278 DOI: 10.1590/1414-431x20133191] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Accepted: 08/27/2013] [Indexed: 12/16/2022] Open
Abstract
Estragole is a volatile terpenoid, which occurs naturally as a constituent of the essential oils of many plants. It has several pharmacological and biological activities. The objective of the present study was to investigate the mechanism of action of estragole on neuronal excitability. Intact and dissociated dorsal root ganglion neurons of rats were used to record action potential and Na+ currents with intracellular and patch-clamp techniques, respectively. Estragole blocked the generation of action potentials in cells with or without inflexions on their descendant (repolarization) phase (Ninf and N0 neurons, respectively) in a concentration-dependent manner. The resting potentials and input resistances of Ninf and N0 cells were not altered by estragole (2, 4, and 6 mM). Estragole also inhibited total Na+ current and tetrodotoxin-resistant Na+ current in a concentration-dependent manner (IC50 of 3.2 and 3.6 mM, respectively). Kinetic analysis of Na+ current in the presence of 4 mM estragole showed a statistically significant reduction of fast and slow inactivation time constants, indicating an acceleration of the inactivation process. These data demonstrate that estragole blocks neuronal excitability by direct inhibition of Na+ channel conductance activation. This action of estragole is likely to be relevant to the understanding of the mechanisms of several pharmacological effects of this substance.
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Affiliation(s)
- K S Silva-Alves
- Universidade Estadual do Ceará, Instituto Superior de Ciências Biomédicas, Laboratório de Eletrofisiologia, FortalezaCE, Brasil
| | - F W Ferreira-da-Silva
- Universidade Estadual do Ceará, Instituto Superior de Ciências Biomédicas, Laboratório de Eletrofisiologia, FortalezaCE, Brasil
| | - D Peixoto-Neves
- Universidade Estadual do Ceará, Instituto Superior de Ciências Biomédicas, Laboratório de Eletrofisiologia, FortalezaCE, Brasil
| | - K V Viana-Cardoso
- Universidade Federal do Ceará, Faculdade de Medicina, Curso de Fisioterapia, FortalezaCE, Brasil
| | - L Moreira-Júnior
- Universidade Estadual do Ceará, Instituto Superior de Ciências Biomédicas, Laboratório de Eletrofisiologia, FortalezaCE, Brasil
| | - M B Oquendo
- Universidade Estadual do Ceará, Instituto Superior de Ciências Biomédicas, Laboratório de Eletrofisiologia, FortalezaCE, Brasil
| | - K Oliveira-Abreu
- Universidade Estadual do Ceará, Instituto Superior de Ciências Biomédicas, Laboratório de Eletrofisiologia, FortalezaCE, Brasil
| | - A A C Albuquerque
- Universidade Estadual do Ceará, Instituto Superior de Ciências Biomédicas, Laboratório de Eletrofisiologia, FortalezaCE, Brasil
| | - A N Coelho-de-Souza
- Universidade Estadual do Ceará, Instituto Superior de Ciências Biomédicas, Laboratório de Eletrofisiologia, FortalezaCE, Brasil
| | - J H Leal-Cardoso
- Universidade Estadual do Ceará, Instituto Superior de Ciências Biomédicas, Laboratório de Eletrofisiologia, FortalezaCE, Brasil
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14
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n5-STZ Diabetic Model Develops Alterations in Sciatic Nerve and Dorsal Root Ganglia Neurons of Wistar Rats. ISRN ENDOCRINOLOGY 2013; 2013:638028. [PMID: 23476801 PMCID: PMC3588209 DOI: 10.1155/2013/638028] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 12/18/2012] [Indexed: 12/20/2022]
Abstract
One experimental model of diabetes mellitus (DM) similar to type
II DM, called n5-STZ, is obtained by a single injection (via i.p.)
of streptozotocin (STZ) in the 5th day of life of newborn rats.
The present investigation aimed to characterize alterations in
excitability of rat peripheral neurons in n5-STZ model. n5-STZ DM
was induced, and electrophysiological evaluation was done at 12th
week of rat life. Rats developed glucose intolerance, sensory
alteration, and hyperglycemia or near-normoglycemia (21.2 ± 1.6 and 7.4 ± 0.4 mmol/L). In near-normoglycemia group the significant
electrophysiological alteration observed was decreased in
amplitude of 2nd wave (2nd component, conduction velocity:
48.8 m/s) of compound action potential (CAP) of sciatic nerve. For
hyperglycemic rats, decreased excitability, amplitude, and
conduction velocity of 2nd CAP component of sciatic nerve were
found; a depolarization of resting potential (4-5 mV) and reduction
in maximum ascendant and descendant inclinations of action
potential were found in DRG neurons but no alteration on
Na+ current (INa+).
Thus, n5-STZ rats develop alterations in
excitability which were related to glycemic levels but were not
likely attributable to changes on INa+. Our data confirm that
n5-STZ model is a useful model to study type II DM.
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Joca HC, Cruz-Mendes Y, Oliveira-Abreu K, Maia-Joca RPM, Barbosa R, Lemos TL, Lacerda Beirão PS, Leal-Cardoso JH. Carvacrol decreases neuronal excitability by inhibition of voltage-gated sodium channels. JOURNAL OF NATURAL PRODUCTS 2012; 75:1511-1517. [PMID: 22967040 DOI: 10.1021/np300050g] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The monoterpenoid carvacrol (1) is present in many essential oils of plants and has attracted attention because of its beneficial biological activities, especially analgesic activity. However, the mechanism of action of 1 remains unknown. The present study aimed to explore the mechanisms whereby 1 produces its effects on the peripheral nervous system. Carvacrol reversibly blocked the excitability of the rat sciatic nerve in a concentration-dependent manner with an IC(50) value of 0.50 ± 0.04 mM. At 0.6 mM, 1 increased the rheobase from 3.30 ± 0.06 V to 4.16 ± 0.14 V and the chronaxy from 59.6 ± 1.22 μs to 75.0 ± 1.82 μs. Also, 1 blocked the generation of action potentials (IC(50) 0.36 ± 0.14 mM) of the intact dorsal root ganglion (DRG) neurons without altering the resting potential and input resistance. Carvacrol reduced the voltage-gated sodium current of dissociated DRG neurons (IC(50) 0.37 ± 0.05 mM). In this study it has been demonstrated that 1 blocks neuronal excitability by a direct inhibition of the voltage-gated sodium current, which suggests that this compound acts as a local anesthetic. The present findings add valuable information to help understand the mechanisms implicated in the analgesic activity of carvacrol.
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Affiliation(s)
- Humberto Cavalcante Joca
- Laboratório de Eletrofisiologia, Instituto Superior de Ciências Biomédicas, Campus do Itaperi, Universidade Estadual do Ceará, Fortaleza, CE, Brazil
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Ciftci O, Ozdemir I, Tanyildizi S, Yildiz S, Oguzturk H. Antioxidative effects of curcumin, β-myrcene and 1,8-cineole against 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced oxidative stress in rats liver. Toxicol Ind Health 2011; 27:447-53. [PMID: 21245202 DOI: 10.1177/0748233710388452] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The aim of this study was to investigate the effectiveness of curcumin, β-myrcene (myrcene) and 1,8-cineole (cineole) on antioxidant defense system in rats given a persistent environmental pollutant (2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD). Rats (n = 112) were divided randomly into 8 equal groups. One group was kept as control and given corn oil as carrier. TCDD was orally administered at the dose of 2 μg/kg/week. Curcumin, myrcene and cineole were orally administered at the doses of 100 mg/kg/day, 200 mg/kg/day and 100 mg/kg/ day, respectively, by gavages dissolved in corn oil with and without TCDD. The liver samples were taken from half of all rats on day 30 and from the remaining half on day 60 for the determination of thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH), catalase (CAT), glutathione peroxidase (GSH-Px) and CuZn-SOD levels by spectrophotometric method. The results indicated that although TCDD significantly (p ≤ 0.01) increased formation of TBARS, it caused a significant decline in the levels of GSH, CAT, GSH-Px and CuZn-SOD in rats. In contrast, curcumin, myrcene and cineole significantly increased GSH, CAT, GSH-Px and CuZn-SOD levels but decreased formation of TBARS. Additionally, the antioxidative effects of curcumin, myrcene and cineole were increased at day 60 compared to day 30. In the TCDD groups given curcumin, myrcene and cineole, oxidative stress decreased by time. In conclusion, curcumin, myrcene and cineole showed antioxidant activity and eliminated TCDD-induced oxidative stress in rats in a time-dependent manner.
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Affiliation(s)
- Osman Ciftci
- Department of Pharmaceutical Toxicology, Faculty of Pharmacy, University of Inonu, Malatya, Turkey.
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Leal-Cardoso JH, Lahlou S, Weinreich D, Caldas Magalhães PJ. The essential oil of Croton nepetaefolius selectively blocks histamine-augmented neuronal excitability in guinea-pig celiac ganglion. J Pharm Pharmacol 2010; 62:1045-53. [PMID: 20663039 DOI: 10.1111/j.2042-7158.2010.01121.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES Croton nepetaefolius is a medicinal plant useful against intestinal disorders. In this study, we elucidate the effects of its essential oil (EOCN) on sympathetic neurons, with emphasis on the interaction of EOCN- and histamine-induced effects. METHODS The effects of EOCN and histamine were studied in guinea-pig celiac ganglion in vitro. KEY FINDINGS Histamine significantly altered the resting potential (E(m)) and the input resistance (R(i)) of phasic neurons (from -56.6 +/- 1.78 mV and 88.6 +/- 11.43 MOmega, to -52.9 +/- 1.96 mV and 108.6 +/- 11.00 MOmega, respectively). E(m), R(i) and the histamine-induced alterations of these parameters were not affected by 200 microg/ml EOCN. The number of action potentials produced by a 1-s (two-times threshold) depolarising current and the current threshold (I(th)) for eliciting action potentials (rheobase) were evaluated. Number of action potentials and I(th) were altered by histamine (from 2.6 +/- 0.43 action potentials and 105.4 +/- 11.15 pA to 6.2 +/- 1.16 action potentials and 67.3 +/- 8.21 pA, respectively). EOCN alone did not affect number of action potentials and I(th) but it fully blocked the histamine-induced modifications of number of action potentials and I(th). All the effects produced by histamine were abolished by pyrilamine. CONCLUSIONS EOCN selectively blocked histamine-induced modulation of active membrane properties.
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Leal-Cardoso JH, da Silva-Alves KS, Ferreira-da-Silva FW, dos Santos-Nascimento T, Joca HC, de Macedo FHP, de Albuquerque-Neto PM, Magalhães PJC, Lahlou S, Cruz JS, Barbosa R. Linalool blocks excitability in peripheral nerves and voltage-dependent Na+ current in dissociated dorsal root ganglia neurons. Eur J Pharmacol 2010; 645:86-93. [DOI: 10.1016/j.ejphar.2010.07.014] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Revised: 06/24/2010] [Accepted: 07/11/2010] [Indexed: 10/19/2022]
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