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Antinociceptive and Antiallodynic Activity of Some 3-(3-Methylthiophen-2-yl)pyrrolidine-2,5-dione Derivatives in Mouse Models of Tonic and Neuropathic Pain. Int J Mol Sci 2022; 23:ijms23074057. [PMID: 35409413 PMCID: PMC8999233 DOI: 10.3390/ijms23074057] [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: 03/03/2022] [Revised: 04/01/2022] [Accepted: 04/04/2022] [Indexed: 11/16/2022] Open
Abstract
Antiseizure drugs (ASDs) are commonly used to treat a wide range of nonepileptic conditions, including pain. In this context, the analgesic effect of four pyrrolidine-2,5-dione derivatives (compounds 3, 4, 6, and 9), with previously confirmed anticonvulsant and preliminary antinociceptive activity, was assessed in established pain models. Consequently, antinociceptive activity was examined in a mouse model of tonic pain (the formalin test). In turn, antiallodynic and antihyperalgesic activity were examined in the oxaliplatin-induced model of peripheral neuropathy as well as in the streptozotocin-induced model of painful diabetic neuropathy in mice. In order to assess potential sedative properties (drug safety evaluation), the influence on locomotor activity was also investigated. As a result, three compounds, namely 3, 6, and 9, demonstrated a significant antinociceptive effect in the formalin-induced model of tonic pain. Furthermore, these substances also revealed antiallodynic properties in the model of oxaliplatin-induced peripheral neuropathy, while compound 3 attenuated tactile allodynia in the model of diabetic streptozotocin-induced peripheral neuropathy. Apart from favorable analgesic properties, the most active compound 3 did not induce any sedative effects at the active dose of 30 mg/kg after intraperitoneal (i.p.) injection.
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Kubacka M, Rapacz A, Sałat K, Filipek B, Cios A, Pociecha K, Wyska E, Hubicka U, Żuromska-Witek B, Kwiecień A, Marona H, Waszkielewicz AM. KM-416, a novel phenoxyalkylaminoalkanol derivative with anticonvulsant properties exerts analgesic, local anesthetic, and antidepressant-like activities. Pharmacodynamic, pharmacokinetic, and forced degradation studies. Eur J Pharmacol 2020; 886:173540. [PMID: 32896552 DOI: 10.1016/j.ejphar.2020.173540] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 09/01/2020] [Accepted: 09/03/2020] [Indexed: 10/23/2022]
Abstract
Anticonvulsant drugs are used to treat a wide range of non-epileptic conditions, including chronic, neuropathic pain. We obtained a phenoxyalkylaminoalkanol derivative, KM-416 which had previously demonstrated a significant anticonvulsant activity and had also been shown to bind to 5-HT1A, α2-receptors and SERT and not to exhibit mutagenic properties. As KM-416 is a promising compound in our search for drug candidates, in the present study we further assessed its pharmacological profile (analgesic, local anesthetic, and antidepressant-like activities) accompanied with patch-clamp studies. Considering the importance of drug safety, its influence on the cardiovascular system was also evaluated. Moreover, KM-416 was subjected to forced degradation and pharmacokinetic studies to examine its stability and pharmacokinetic parameters. KM-416 revealed a significant antinociceptive activity in the tonic - the formalin test, neurogenic - the capsaicin test, and neuropathic pain model - streptozotocin-induced peripheral neuropathy. Moreover, it exerted a local anesthetic effect. In addition, KM-416 exhibited anti-depressant like activity. The results from the patch-clamp studies indicated that KM-416 can inhibit currents elicited by activation of NMDA receptors, while it also exhibited a voltage-dependent inhibition of Na+ currents. KM-416 did not influence ventricular depolarization and repolarization. Following oral administration, pharmacokinetics of KM-416 was characterized by a rapid absorption in the rat. The brain-to-plasma AUC ratio was 6.7, indicating that KM-416 was well distributed to brain. The forced degradation studies showed that KM-416 was very stable under stress conditions. All these features made KM-416 a promising drug candidate for further development against neuropathic pain and epilepsy.
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Affiliation(s)
- Monika Kubacka
- Department of Pharmacodynamics, Jagiellonian University Medical College, Faculty of Pharmacy, 9 Medyczna Street, 30-688, Kraków, Poland.
| | - Anna Rapacz
- Department of Pharmacodynamics, Jagiellonian University Medical College, Faculty of Pharmacy, 9 Medyczna Street, 30-688, Kraków, Poland
| | - Kinga Sałat
- Department of Pharmacodynamics, Jagiellonian University Medical College, Faculty of Pharmacy, 9 Medyczna Street, 30-688, Kraków, Poland
| | - Barbara Filipek
- Department of Pharmacodynamics, Jagiellonian University Medical College, Faculty of Pharmacy, 9 Medyczna Street, 30-688, Kraków, Poland
| | - Agnieszka Cios
- Department of Pharmacokinetics and Physical Pharmacy, Jagiellonian University Medical College, Faculty of Pharmacy, 9 Medyczna Street, 30-688, Kraków, Poland
| | - Krzysztof Pociecha
- Department of Pharmacokinetics and Physical Pharmacy, Jagiellonian University Medical College, Faculty of Pharmacy, 9 Medyczna Street, 30-688, Kraków, Poland
| | - Elżbieta Wyska
- Department of Pharmacokinetics and Physical Pharmacy, Jagiellonian University Medical College, Faculty of Pharmacy, 9 Medyczna Street, 30-688, Kraków, Poland
| | - Urszula Hubicka
- Department of Inorganic and Analytical Chemistry, Jagiellonian University Medical College, Faculty of Pharmacy, 9 Medyczna Street, 30-688, Kraków, Poland
| | - Barbara Żuromska-Witek
- Department of Inorganic and Analytical Chemistry, Jagiellonian University Medical College, Faculty of Pharmacy, 9 Medyczna Street, 30-688, Kraków, Poland
| | - Anna Kwiecień
- Department of Inorganic and Analytical Chemistry, Jagiellonian University Medical College, Faculty of Pharmacy, 9 Medyczna Street, 30-688, Kraków, Poland
| | - Henryk Marona
- Department of Bioorganic Chemistry, Jagiellonian University Medical College, Faculty of Pharmacy, 9 Medyczna Street, 30-688, Kraków, Poland
| | - Anna M Waszkielewicz
- Department of Bioorganic Chemistry, Jagiellonian University Medical College, Faculty of Pharmacy, 9 Medyczna Street, 30-688, Kraków, Poland
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Inhibition of Fast Nerve Conduction Produced by Analgesics and Analgesic Adjuvants-Possible Involvement in Pain Alleviation. Pharmaceuticals (Basel) 2020; 13:ph13040062. [PMID: 32260535 PMCID: PMC7243109 DOI: 10.3390/ph13040062] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 03/29/2020] [Accepted: 04/01/2020] [Indexed: 02/07/2023] Open
Abstract
Nociceptive information is transmitted from the periphery to the cerebral cortex mainly by action potential (AP) conduction in nerve fibers and chemical transmission at synapses. Although this nociceptive transmission is largely inhibited at synapses by analgesics and their adjuvants, it is possible that the antinociceptive drugs inhibit nerve AP conduction, contributing to their antinociceptive effects. Many of the drugs are reported to inhibit the nerve conduction of AP and voltage-gated Na+ and K+ channels involved in its production. Compound action potential (CAP) is a useful measure to know whether drugs act on nerve AP conduction. Clinically-used analgesics and analgesic adjuvants (opioids, non-steroidal anti-inflammatory drugs, 2-adrenoceptor agonists, antiepileptics, antidepressants and local anesthetics) were found to inhibit fast-conducting CAPs recorded from the frog sciatic nerve by using the air-gap method. Similar actions were produced by antinociceptive plant-derived chemicals. Their inhibitory actions depended on the concentrations and chemical structures of the drugs. This review article will mention the inhibitory actions of the antinociceptive compounds on CAPs in frog and mammalian peripheral (particularly, sciatic) nerves and on voltage-gated Na+ and K+ channels involved in AP production. Nerve AP conduction inhibition produced by analgesics and analgesic adjuvants is suggested to contribute to at least a part of their antinociceptive effects.
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Inhibition by general anesthetic propofol of compound action potentials in the frog sciatic nerve and its chemical structure. Naunyn Schmiedebergs Arch Pharmacol 2018; 392:359-369. [PMID: 30519707 DOI: 10.1007/s00210-018-01596-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 11/27/2018] [Indexed: 02/07/2023]
Abstract
Although the intravenous general anesthetic propofol (2,6-diisopropylphenol) has an ability to inhibit nerve conduction, this has not been fully examined. Various agents inhibit compound action potentials (CAPs) in a manner dependent on their chemical structures. To determine propofol's chemical structure that is important in nerve conduction inhibition, we examined the effects of propofol and its related compounds on fast-conducting CAPs recorded from the frog sciatic nerve by using the air-gap method. Propofol concentration-dependently reduced the peak amplitude of the CAP with a half-maximal inhibitory concentration (IC50) value of 0.14 mM. A similar inhibition was produced by other phenols, 4-sec-butylphenol and 4-amylphenol (IC50 values: 0.33 and 0.20 mM, respectively). IC50 values for these and more phenols (4-isopropylphenol, 4-tert-butylphenol, and 4-ter-amylphenol; data published previously) were correlated with the logarithm of their octanol-water partition coefficients. A phenol having ketone group (raspberry ketone) and alcohols (3-phenyl-1-propanol and 2-phenylethylalcohol) inhibited CAPs less effectively than the above-mentioned phenols. The local anesthetic (LA) benzocaine reduced CAP peak amplitudes with an IC50 of 0.80 mM, a value larger than that of propofol. When compared with other LAs, propofol activity was close to those of ropivacaine, levobupivacaine, and pramoxine, while benzocaine activity was similar to those of cocaine and lidocaine. It is concluded that propofol inhibits nerve conduction, possibly owing to isopropyl and hydroxyl groups bound to the benzene ring of propofol and to its lipophilicity; propofol's efficacy is comparable to those of some LAs. These results could serve to develop propofol-related agents exhibiting analgesia when applied topically.
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Suzuki R, Fujita T, Mizuta K, Kumamoto E. Inhibition by non-steroidal anti-inflammatory drugs of compound action potentials in frog sciatic nerve fibers. Biomed Pharmacother 2018; 103:326-335. [PMID: 29665554 DOI: 10.1016/j.biopha.2018.04.041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 04/06/2018] [Accepted: 04/06/2018] [Indexed: 02/01/2023] Open
Abstract
AIMS Although antinociception produced by non-steroidal anti-inflammatory drugs (NSAIDs) is partly attributed to nerve conduction inhibition, this has not been thoroughly examined yet. The aim of the present study was to reveal quantitatively how various types of NSAIDs affect compound action potentials (CAPs), a measure of nerve conduction. MAIN METHODS CAPs were recorded from the frog sciatic nerve by using the air-gap method. KEY FINDINGS Soaking the sciatic nerve with acetic acid-based NSAIDs (diclofenac and aceclofenac) reduced the peak amplitude of CAP in a concentration-dependent manner; their IC50 values were 0.94 and 0.47 mM, respectively. Other acetic acid-based NSAIDs (indomethacin, acemetacin and etodolac) also inhibited CAPs [the extent of inhibition: some 40% (1 mM), 40% (0.5 mM) and 15% (1 mM), respectively], except for sulindac and felbinac at 1 mM that had no effects on CAP peak amplitudes. A similar inhibition was produced by fenamic acid-based NSAIDs [tolfenamic acid (IC50 = 0.29 mM), meclofenamic acid (0.19 mM), flufenamic acid (0.22 mM) and mefenamic acid] which are similar in chemical structure to diclofenac and aceclofenac; their derivatives (2,6-dichlorodiphenylamine and N-phenylanthranilic acid) also inhibited. On the other hand, salicylic acid-based (aspirin), propionic acid-based (ketoprofen, naproxen, ibuprofen, loxoprofen and flurbiprofen) and enolic acid-based (meloxicam and piroxicam) NSAIDs had no effects on CAP peak amplitudes. SIGNIFICANCE At least a part of antinociception produced by NSAIDs used as a dermatological drug to alleviate pain may be attributed to their inhibitory effects on nerve conduction, which depend on the chemical structures of NSAIDs.
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Affiliation(s)
- Rika Suzuki
- Department of Physiology, Saga Medical School, Nabeshima 5-1-1, Saga 849-8501, Japan
| | - Tsugumi Fujita
- Department of Physiology, Saga Medical School, Nabeshima 5-1-1, Saga 849-8501, Japan
| | - Kotaro Mizuta
- Department of Physiology, Saga Medical School, Nabeshima 5-1-1, Saga 849-8501, Japan
| | - Eiichi Kumamoto
- Department of Physiology, Saga Medical School, Nabeshima 5-1-1, Saga 849-8501, Japan.
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Hirao R, Fujita T, Sakai A, Kumamoto E. Compound action potential inhibition produced by various antidepressants in the frog sciatic nerve. Eur J Pharmacol 2018; 819:122-128. [DOI: 10.1016/j.ejphar.2017.11.047] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 10/31/2017] [Accepted: 11/30/2017] [Indexed: 11/25/2022]
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Hinokitiol inhibits compound action potentials in the frog sciatic nerve. Eur J Pharmacol 2018; 819:254-260. [DOI: 10.1016/j.ejphar.2017.12.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 11/29/2017] [Accepted: 12/06/2017] [Indexed: 11/19/2022]
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Hamasaki T, Yano S, Nakamura K, Yamada K. Pregabalin as a salvage preoperative treatment for refractory trigeminal neuralgia. J Clin Neurosci 2018; 47:240-244. [DOI: 10.1016/j.jocn.2017.10.039] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Accepted: 10/10/2017] [Indexed: 01/27/2023]
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Tuncer S, Tuncer Peker T, Burat İ, Kiziltan E, İlhan B, Dalkiliç N. Axonal excitability and conduction alterations caused by levobupivacaine in rat. ACTA PHARMACEUTICA (ZAGREB, CROATIA) 2017; 67:293-307. [PMID: 28858839 DOI: 10.1515/acph-2017-0025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/10/2017] [Indexed: 11/15/2022]
Abstract
In this study, effects of the long-acting amide-type local anesthetic levobupivacaine on axonal conduction and excitability parameters of the rat sciatic nerve were thoroughly examined both in vitro and in vivo. In order to deduce its effects on isolated nerve conduction, compound nerve action potential (CNAP) recordings were performed using the suction method over sciatic nerves of Wistar rats before and after administration of 0.05 % (1.7 mmol L-1) levobupivacaine. Levobupivacaine caused complete CNAP area and amplitude depression by blocking conduction in a time-dependent manner. To assess the influence of levobupivacaine on in vivo excitability properties, threshold-tracking (TT) protocols were performed at sciatic nerves of rats injected with perineural 0.05 % (1.7 mmol L-1) levobupivacaine or vehicle alone. Charge-duration TT results revealed that levobupivacaine increases the rheobase and decreases the strength-duration time constant, suggesting interference of the anesthetic with the opening of Na+ channels. Twenty and 40 % threshold electrotonus curves were found for both groups to follow the same paths, suggesting no significant effect of levobupivacaine on K+ channels for either the fastest or relatively slow conducting fibers. Current-threshold relationship results revealed no significant effect on axonal rectifying channels. However, according to the results of the recovery cycle protocol yielding the pattern of excitability changes following the impulse, potential deviation was found in the recovery characteristics of Na+ channels from the absolute refractory period. Consequently, conduction blockage caused by levobupivacaine may not be due to the passive (capacitive) properties of axon or the conductance of potassium channels but to the decrease in sodium channel conductance.
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Affiliation(s)
- Seçkin Tuncer
- N.E. University , Meram Faculty of Medicine, Biophysics Department , Konya , Turkey
| | - Tülay Tuncer Peker
- Ankara University , Faculty of Medicine, Anesthesiology Department , Ankara , Turkey
| | - İlksen Burat
- N.E. University , Meram Faculty of Medicine, Biophysics Department , Konya , Turkey
| | - Erhan Kiziltan
- Başkent University , Faculty of Medicine, Physiology Department , Ankara , Turkey
| | - Barkin İlhan
- N.E. University , Meram Faculty of Medicine, Biophysics Department , Konya , Turkey
| | - Nizamettin Dalkiliç
- N.E. University , Meram Faculty of Medicine, Biophysics Department , Konya , Turkey
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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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Bisphenol A inhibits compound action potentials in the frog sciatic nerve in a manner independent of estrogen receptors. Biochem Biophys Rep 2017; 10:145-151. [PMID: 28955742 PMCID: PMC5614631 DOI: 10.1016/j.bbrep.2017.03.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 03/18/2017] [Accepted: 03/22/2017] [Indexed: 01/18/2023] Open
Abstract
Although the endocrine disruptor bisphenol A (BPA) is reported to inhibit nerve conduction, the underlying mechanisms are unclear. Therefore, in the present study, we examined the effect of BPA on compound action potentials (CAPs) recorded from the frog sciatic nerve using the air-gap method. Treatment of the sciatic nerve with BPA (0.5 mM) for 20 min reduced the peak amplitude of the CAP by approximately 60% in a partially reversible manner. The reduction in the CAP peak amplitude was concentration-dependent, with a half-maximal inhibitory concentration (IC50) value of 0.31 mM. This effect of BPA was unaffected by an estrogen-receptor antagonist, 4-hydroxytamoxifen, which by itself reduced CAP peak amplitude, with an IC50 value of 0.26 mM (comparable to that of BPA). The natural estrogen 17β-estradiol, at the highest dissolvable concentration (0.05 mM), had an effect similar to that of BPA. The IC50 value of BPA was comparable to those of some local anesthetics in inhibiting frog CAPs. Our findings suggest that BPA inhibits nerve conduction in a manner independent of estrogen receptors. This action of BPA may underlie, at least in part, the neurotoxicity of the compound. Bisphenol A acutely inhibits compound action potentials in nerve fibers. The effect of bisphenol A is not mediated by estrogen receptors. The effect of bisphenol A is comparable to those of local anesthetics.
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Key Words
- 17β-Estradiol
- 4-OHT, 4-hydroxytamoxifen
- BPA, bisphenol A
- Bisphenol A
- CAP, compound action potential
- DMSO, dimethyl sulfoxide
- DRG, dorsal root ganglion
- ERRγ, estrogen-related receptor γ
- ERα, estrogen receptor α
- ERβ, estrogen receptor β
- Frog
- IC50, half-maximal inhibitory concentration
- LA, local anesthetic
- Local anesthetic
- Nerve conduction inhibition
- Sciatic nerve
- TTX, tetrodotoxin
- nH, Hill coefficient
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Piao LH, Fujita T, Yu T, Kumamoto E. Presynaptic facilitation by tetracaine of glutamatergic spontaneous excitatory transmission in the rat spinal substantia gelatinosa – Involvement of TRPA1 channels. Brain Res 2017; 1657:245-252. [DOI: 10.1016/j.brainres.2016.12.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 11/07/2016] [Accepted: 12/21/2016] [Indexed: 11/29/2022]
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Matsushita A, Fujita T, Ohtsubo S, Kumamoto E. Traditional Japanese medicines inhibit compound action potentials in the frog sciatic nerve. JOURNAL OF ETHNOPHARMACOLOGY 2016; 178:272-80. [PMID: 26707752 DOI: 10.1016/j.jep.2015.12.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 12/08/2015] [Accepted: 12/14/2015] [Indexed: 06/05/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Traditional Japanese (Kampo) medicines have a variety of clinical effects including pain alleviation, but evidence for a mechanism for their pain relief has not yet been elucidated fully. Considering that Kampo medicine contains many plant-derived chemicals having an ability to inhibit nerve action potential conduction, it is possible that this medicine inhibits nerve conduction. The purpose of the present study was to know how various Kampo medicines affect nerve conduction. MATERIALS AND METHODS We examined the effects of Kampo and crude medicines on compound action potentials (CAPs) recorded from the frog sciatic nerve by using the air-gap method. RESULTS Daikenchuto, rikkosan, kikyoto, rikkunshito, shakuyakukanzoto and kakkonto concentration-dependently reduced the peak amplitude of the CAP. Among the Kampo medicines, daikenchuto was the most effective in inhibiting CAPs. Daikenchuto is composed of three kinds of crude medicine, Japanese pepper, processed ginger and ginseng radix. When the crude medicines were tested, Japanese pepper and processed ginger reduced CAP peak amplitudes, while ginseng radix hardly affected CAPs. Moreover, there was an interaction between the Japanese pepper and processed ginger activities in such that one medicine at low but not high concentrations increased the extent of the inhibition by the other one that was co-applied. CONCLUSIONS Kampo medicines have an ability to inhibit nerve conduction. This action of daikenchuto is due to Japanese pepper and processed ginger but not ginseng radix, probably through an interaction between Japanese pepper and processed ginger in a manner dependent on their concentrations. Nerve conduction inhibition could contribute to at least a part of Kampo medicine's clinical effects such as pain alleviation.
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Affiliation(s)
| | - Tsugumi Fujita
- Department of Physiology, Saga Medical School, Saga, Japan.
| | - Sena Ohtsubo
- Department of Physiology, Saga Medical School, Saga, Japan.
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Differential effects of lacosamide, phenytoin and topiramate on peripheral nerve excitability: An ex vivo electrophysiological study. Neurotoxicology 2015; 52:57-63. [PMID: 26542247 DOI: 10.1016/j.neuro.2015.10.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 10/10/2015] [Accepted: 10/29/2015] [Indexed: 11/23/2022]
Abstract
BACKGROUND Antiepileptic drugs (AEDs) are mainly used to control cortical hyperexcitability. Some of them (e.g. phenytoin (PHT) and topiramate (TPM)) have also effects on the peripheral nervous system (PNS). Lacosamide (LCM) is a novel AED that stabilizes hyperexcitable neuronal membranes by selectively enhancing the slow inactivation of voltage-gated sodium channels (VGSCs). Although the mechanism of action of LCM is fairly well understood, there are no in vitro data available regarding any possible PNS effects of LCM. OBJECTIVE To investigate, in vitro, the effects of LCM on peripheral nerve excitability in comparison with PHT and TPM, two AEDs that act, in part, by stabilizing the fast inactivation state of VGSCs. METHODS Experiments were conducted on the isolated sciatic nerve of the adult rat using standard electrophysiological methods. The effects of LCM on the amplitude and latency of the evoked compound action potential (CAP) during a 48h period of drug exposure were recorded and compared with the effects of PHT and TPM. RESULTS LCM produced inhibitory effects on CAP at concentrations significantly higher than the therapeutic levels (>25μg/ml). At these concentrations (62.57-125.15μg/ml), an acute and immediate increment of the latency and decrement of the amplitude of the CAP were observed. In contrast to LCM, PHT caused an acute decrement in the amplitude as well as an increment in the latency of the CAP even at subtherapeutic levels (5μg/ml). With regard to TPM, the amplitude of the CAP was not affected at the supratherapeutic concentrations but at the therapeutic concentration of 33.94μg/ml a reduced decrement of the CAP amplitude compared to the controls was observed. CONCLUSIONS LCM, PHT and TPM exert differential effects on peripheral nerve excitability. PHT inhibited the sciatic nerve CAP even at subtherapeutic levels whereas LCM was safe within the therapeutic concentration range. TPM did not affect the CAP amplitude even at high supratherapeutic concentrations whereas in the therapeutic range a neuroprotective effect was observed. Possible underlying mechanisms and the clinical implications of these findings are discussed.
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Matsumoto A, Arisaka H, Hosokawa Y, Sakuraba S, Sugita T, Umezawa N, Kaku Y, Yoshida KI, Kuwana SI. Effect of carbamazepine and gabapentin on excitability in the trigeminal subnucleus caudalis of neonatal rats using a voltage-sensitive dye imaging technique. Biol Res 2015. [PMID: 26195075 PMCID: PMC4508818 DOI: 10.1186/s40659-015-0027-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Background The antiepileptic drugs
carbamazepine and gabapentin are effective in treating neuropathic pain and trigeminal neuralgia. In the present study, to analyze the effects of carbamazepine and gabapentin on neuronal excitation in the spinal trigeminal subnucleus caudalis (Sp5c) in the medulla oblongata, we recorded temporal changes in nociceptive afferent activity in the Sp5c of trigeminal nerve-attached brainstem slices of neonatal rats using a voltage-sensitive dye imaging technique. Results Electrical stimulation of the trigeminal nerve rootlet evoked changes in the fluorescence intensity of dye in the Sp5c. The optical signals were composed of two phases, a fast component with a sharp peak followed by a long-lasting component with a period of more than 500 ms. This evoked excitation was not influenced by administration of carbamazepine (10, 100 and 1,000 μM) or gabapentin (1 and 10 μM), but was increased by administration of 100 μM gabapentin. This evoked excitation was increased further in low Mg2+ (0.8 mM) conditions, and this effect of low Mg2+ concentration was antagonized by 30 μM DL-2-amino-5-phosphonopentanoic acid (AP5), a N-methyl-d-aspartate (NMDA) receptor blocker. The increased excitation in low Mg2+ conditions was also antagonized by carbamazepine (1,000 μM) and gabapentin (100 μM). Conclusion Carbamazepine and gabapentin did not decrease electrically evoked excitation in the Sp5c in control conditions. Further excitation in low Mg2+ conditions was antagonized by the NMDA receptor blocker AP5. Carbamazepine and gabapentin had similar effects to AP5 on evoked excitation in the Sp5c in low Mg2+ conditions. Thus, we concluded that carbamazepine and gabapentin may act by blocking NMDA receptors in the Sp5c, which contributes to its anti-hypersensitivity in neuropathic pain.
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Affiliation(s)
- Akiko Matsumoto
- Division of Anesthesiology, Department of Clinical Care Medicine, Kanagawa Dental College, Yokosuka, Kanagawa, 238-8580, Japan.
| | - Hirofumi Arisaka
- Division of Anesthesiology, Department of Clinical Care Medicine, Kanagawa Dental College, Yokosuka, Kanagawa, 238-8580, Japan.
| | - Yuki Hosokawa
- Department of Anesthesiology, Kitasato University School of Medicine, Sagamihara, Kanagawa, 252-0375, Japan.
| | - Shigeki Sakuraba
- Division of Anesthesiology, Department of Clinical Care Medicine, Kanagawa Dental College, Yokosuka, Kanagawa, 238-8580, Japan.
| | - Takeo Sugita
- Division of Anesthesiology, Department of Clinical Care Medicine, Kanagawa Dental College, Yokosuka, Kanagawa, 238-8580, Japan.
| | - Nobuo Umezawa
- Division of Anesthesiology, Department of Clinical Care Medicine, Kanagawa Dental College, Yokosuka, Kanagawa, 238-8580, Japan.
| | - Yuki Kaku
- Center for Medical Sciences, Ibaraki Prefectural University of Health Sciences, Ami, Inashiki-gun, Ibaraki, 300-0394, Japan.
| | - Kazu-ichi Yoshida
- Division of Anesthesiology, Department of Clinical Care Medicine, Kanagawa Dental College, Yokosuka, Kanagawa, 238-8580, Japan.
| | - Shun-ichi Kuwana
- Faculty of Health Sciences, Uekusa Gakuen University, Ogura-cho, Wakaba-ku, Chiba, 264-0007, Japan.
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17
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Ohtsubo S, Fujita T, Matsushita A, Kumamoto E. Inhibition of the compound action potentials of frog sciatic nerves by aroma oil compounds having various chemical structures. Pharmacol Res Perspect 2015; 3:e00127. [PMID: 26038703 PMCID: PMC4448976 DOI: 10.1002/prp2.127] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 01/09/2015] [Accepted: 01/21/2015] [Indexed: 12/12/2022] Open
Abstract
Plant-derived chemicals including aroma oil compounds have an ability to inhibit nerve conduction and modulate transient receptor potential (TRP) channels. Although applying aroma oils to the skin produces a local anesthetic effect, this has not been yet examined throughly. The aim of the present study was to know how nerve conduction inhibitions by aroma oil compounds are related to their chemical structures and whether these activities are mediated by TRP activation. Compound action potentials (CAPs) were recorded from the frog sciatic nerve by using the air-gap method. Citral (aldehyde), which activates various types of TRP channels, attenuated the peak amplitude of CAP with the half-maximal inhibitory concentration (IC50) value of 0.46 mmol/L. Another aldehyde (citronellal), alcohol (citronellol, geraniol, (±)-linalool, (−)-linalool, (+)-borneol, (−)-borneol, α-terpineol), ester (geranyl acetate, linalyl acetate, bornyl acetate), and oxide (rose oxide) compounds also reduced CAP peak amplitudes (IC50: 0.50, 0.35, 0.53, 1.7, 2.0, 1.5, 2.3, 2.7, 0.51, 0.71, 0.44, and 2.6 mmol/L, respectively). On the other hand, the amplitudes were reduced by a small extent by hydrocarbons (myrcene and p-cymene) and ketone (camphor) at high concentrations (2–5 mmol/L). The activities of citral and other TRP agonists ((+)-borneol and camphor) were resistant to TRP antagonist ruthenium red. An efficacy sequence for the CAP inhibitions was generally aldehydes ≥ esters ≥ alcohols > oxides >> hydrocarbons. The CAP inhibition by the aroma oil compound was not related to its octanol–water partition coefficient. It is suggested that aroma oil compounds inhibit nerve conduction in a manner specific to their chemical structures without TRP activation.
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Affiliation(s)
- Sena Ohtsubo
- Department of Physiology, Saga Medical School Saga, Japan
| | - Tsugumi Fujita
- Department of Physiology, Saga Medical School Saga, Japan
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