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Berta T, Strong JA, Zhang JM, Ji RR. Targeting dorsal root ganglia and primary sensory neurons for the treatment of chronic pain: an update. Expert Opin Ther Targets 2023; 27:665-678. [PMID: 37574713 PMCID: PMC10530032 DOI: 10.1080/14728222.2023.2247563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 06/30/2023] [Accepted: 08/09/2023] [Indexed: 08/15/2023]
Abstract
INTRODUCTION Current treatments for chronic pain are inadequate. Here, we provide an update on the new therapeutic strategies that target dorsal root ganglia (DRGs) in the peripheral nervous system for a better and safer treatment of chronic pain. AREAS COVERED Despite the complex nature of chronic pain and its underlying mechanisms, we do know that changes in the plasticity and modality of neurons in DRGs play a pivotal role. DRG neurons are heterogenous and offer potential pain targets for different therapeutic interventions. We discuss the last advancements of these interventions, which include the use of systemic and local administrations, selective nerve drug delivery, and gene therapy. In particular, we provide updates and further details on the molecular characterization of primary sensory neurons, new analgesics entering the market, and future gene therapy approaches. EXPERT OPINION DRGs and primary sensory neurons are promising targets for chronic pain treatment due to their key role in pain signaling, unique anatomical location, and the potential for different targeted therapeutic interventions.
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Affiliation(s)
- Temugin Berta
- Pain Research Center, Department of Anesthesiology, University of Cincinnati Medical Center, Cincinnati, OH 45267, USA
| | - Judith A. Strong
- Pain Research Center, Department of Anesthesiology, University of Cincinnati Medical Center, Cincinnati, OH 45267, USA
| | - Jun-Ming Zhang
- Pain Research Center, Department of Anesthesiology, University of Cincinnati Medical Center, Cincinnati, OH 45267, USA
| | - Ru-Rong Ji
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
- Departments of Cell Biology and Neurobiology, Duke University Medical Center, Durham, North Carolina 27710
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2
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Alhadyan SK, Sivaraman V, Onyenwoke RU. E-cigarette Flavors, Sensory Perception, and Evoked Responses. Chem Res Toxicol 2022; 35:2194-2209. [PMID: 36480683 DOI: 10.1021/acs.chemrestox.2c00268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The chemosensory experiences evoked by flavors encompass a number of unique sensations that include olfactory stimuli (smell), gustatory stimuli (taste, i.e., salty, sweet, sour, bitter, and umami (also known as "savoriness")), and chemesthesis (touch). As such, the responses evoked by flavors are complex and, as briefly stated above, involve multiple perceptive mechanisms. The practice of adding flavorings to tobacco products dates back to the 17th century but is likely much older. More recently, the electronic cigarette or "e-cigarette" and its accompanying flavored e-liquids emerged on to the global market. These new products contain no combustible tobacco but often contain large concentrations (reported from 0 to more than 50 mg/mL) of nicotine as well as numerous flavorings and/or flavor chemicals. At present, there are more than 400 e-cigarette brands available along with potentially >15,000 different/unique flavored products. However, surprisingly little is known about the flavors/flavor chemicals added to these products, which can account for >1% by weight of some e-liquids, and their resultant chemosensory experiences, and the US FDA has done relatively little, until recently, to regulate these products. This article will discuss e-cigarette flavors and flavor chemicals, their elicited responses, and their sensory effects in some detail.
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Affiliation(s)
- Shatha K Alhadyan
- Department of Pharmaceutical Sciences, North Carolina Central University, Durham, North Carolina 27707, United States
| | - Vijay Sivaraman
- Department of Biological and Biomedical Sciences, North Carolina Central University, Durham, North Carolina 27707, United States
| | - Rob U Onyenwoke
- Department of Pharmaceutical Sciences, North Carolina Central University, Durham, North Carolina 27707, United States.,Biomanufacturing Research Institute and Technology Enterprise (BRITE), North Carolina Central University, Durham, North Carolina 27707, United States
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Li Z, Zhang H, Wang Y, Li Y, Li Q, Zhang L. The distinctive role of menthol in pain and analgesia: Mechanisms, practices, and advances. Front Mol Neurosci 2022; 15:1006908. [PMID: 36277488 PMCID: PMC9580369 DOI: 10.3389/fnmol.2022.1006908] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 09/13/2022] [Indexed: 11/13/2022] Open
Abstract
Menthol is an important flavoring additive that triggers a cooling sensation. Under physiological condition, low to moderate concentrations of menthol activate transient receptor potential cation channel subfamily M member 8 (TRPM8) in the primary nociceptors, such as dorsal root ganglion (DRG) and trigeminal ganglion, generating a cooling sensation, whereas menthol at higher concentration could induce cold allodynia, and cold hyperalgesia mediated by TRPM8 sensitization. In addition, the paradoxical irritating properties of high concentrations of menthol is associated with its activation of transient receptor potential cation channel subfamily A member 1 (TRPA1). Under pathological situation, menthol activates TRPM8 to attenuate mechanical allodynia and thermal hyperalgesia following nerve injury or chemical stimuli. Recent reports have recapitulated the requirement of central group II/III metabotropic glutamate receptors (mGluR) with endogenous κ-opioid signaling pathways for menthol analgesia. Additionally, blockage of sodium channels and calcium influx is a determinant step after menthol exposure, suggesting the possibility of menthol for pain management. In this review, we will also discuss and summarize the advances in menthol-related drugs for pathological pain treatment in clinical trials, especially in neuropathic pain, musculoskeletal pain, cancer pain and postoperative pain, with the aim to find the promising therapeutic candidates for the resolution of pain to better manage patients with pain in clinics.
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Affiliation(s)
- Ziping Li
- The Graduate School, Tianjin Medical University, Tianjin, China
| | - Haoyue Zhang
- The Graduate School, Tianjin Medical University, Tianjin, China
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
| | - Yigang Wang
- The Graduate School, Tianjin Medical University, Tianjin, China
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
| | - Yize Li
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
| | - Qing Li
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
- Qing Li,
| | - Linlin Zhang
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
- *Correspondence: Linlin Zhang,
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Hilfiger L, Triaux Z, Marcic C, Héberlé E, Emhemmed F, Darbon P, Marchioni E, Petitjean H, Charlet A. Anti-Hyperalgesic Properties of Menthol and Pulegone. Front Pharmacol 2021; 12:753873. [PMID: 34916937 PMCID: PMC8670501 DOI: 10.3389/fphar.2021.753873] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 10/29/2021] [Indexed: 12/30/2022] Open
Abstract
Context: Menthol, the main monoterpene found in Mentha piperita L. (M. piperita) is known to modulate nociceptive threshold and is present in different curative preparations that reduce sensory hypersensitivities in pain conditions. While for pulegone, a menthol-like monoterpene, only a limited number of studies focus on its putative analgesic effects, pulegone is the most abundant monoterpene present in Calamintha nepeta (L.) Savi (C. nepeta), a plant of the Lamiaceae family used in traditional medicine to alleviate rheumatic disorders, which counts amongst chronic inflammatory diseases. Objectives: Here, we analyzed the monoterpenes composition of C. nepeta and M. piperita. We then compared the putative anti-hyperalgesic effects of the main monoterpenes found, menthol and pulegone, in acute inflammatory pain conditions. Methods:C. nepeta and M. piperita extracts were obtained through pressurized liquid extraction and analyzed by gas chromatography-mass spectrometry. The in vitro anti-inflammatory activity of menthol or pulegone was evaluated by measuring the secretion of the tumour necrosis factor alpha (TNF α) from LPS-stimulated THP-1 cells. The in vivo anti-hyperalgesic effects of menthol and pulegone were tested on a rat inflammatory pain model. Results: Pulegone and menthol are the most abundant monoterpene found in C. nepeta (49.41%) and M. piperita (42.85%) extracts, respectively. In vitro, both pulegone and menthol act as strong anti-inflammatory molecules, with EC50 values of 1.2 ± 0.2 and 1.5 ± 0.1 mM, respectively, and exert cytotoxicity with EC50 values of 6.6 ± 0.3 and 3.5 ± 0.2 mM, respectively. In vivo, 100 mg/kg pulegone exerts a transient anti-hyperalgesic effect on both mechanical (pulegone: 274.25 ± 68.89 g, n = 8; vehicle: 160.88 ± 35.17 g, n = 8, p < 0.0001), thermal heat (pulegone: 4.09 ± 0.62 s, n = 8; vehicle: 2.25 ± 0.34 s, n = 8, p < 0.0001), and cold (pulegone: 2.25 ± 1.28 score, n = 8; vehicle: 4.75 ± 1.04 score, n = 8, p = 0.0003). In a similar way, 100 mg/kg menthol exerts a transient anti-hyperalgesic effect on both mechanical (mechanical: menthol: 281.63 ± 45.52 g, n = 8; vehicle: 166.25 ± 35.4 g, n = 8, p < 0.0001) and thermal heat (menthol: 3.65 ± 0.88 s, n = 8; vehicle: 2.19 ± 0.26 s, n = 8, <0.0001). Conclusion: Here, we show that both pulegone and menthol are anti-inflammatory and anti-hyperalgesic monoterpenes. These results might open the path towards new compound mixes to alleviate the pain sensation.
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Affiliation(s)
- Louis Hilfiger
- Benephyt, Strasbourg, France.,Centre National de la Recherche Scientifique, University of Strasbourg, Institute of Cellular and Integrative Neurosciences, INCI UPR3212, Strasbourg, France
| | - Zélie Triaux
- Benephyt, Strasbourg, France.,Centre National de la Recherche Scientifique, University of Strasbourg, Institut Pluridisciplinaire Hubert Curien, IPHC UMR, Strasbourg, France
| | - Christophe Marcic
- Centre National de la Recherche Scientifique, University of Strasbourg, Institut Pluridisciplinaire Hubert Curien, IPHC UMR, Strasbourg, France
| | | | - Fathi Emhemmed
- Centre National de la Recherche Scientifique, University of Strasbourg, Institut Pluridisciplinaire Hubert Curien, IPHC UMR, Strasbourg, France
| | - Pascal Darbon
- Centre National de la Recherche Scientifique, University of Strasbourg, Institute of Cellular and Integrative Neurosciences, INCI UPR3212, Strasbourg, France
| | - Eric Marchioni
- Centre National de la Recherche Scientifique, University of Strasbourg, Institut Pluridisciplinaire Hubert Curien, IPHC UMR, Strasbourg, France
| | | | - Alexandre Charlet
- Centre National de la Recherche Scientifique, University of Strasbourg, Institute of Cellular and Integrative Neurosciences, INCI UPR3212, Strasbourg, France
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Wang G. Ligand-stereoselective allosteric activation of cold-sensing TRPM8 channels by an H-bonded homochiral menthol dimer with head-to-head or head-to-tail. Chirality 2021; 33:783-796. [PMID: 34596287 DOI: 10.1002/chir.23364] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 09/01/2021] [Accepted: 09/02/2021] [Indexed: 11/07/2022]
Abstract
Both menthol and its analog WS-12 share the same hydrophobic intra-subunit binding pocket between a voltage-sensor-like domain and a TRP domain in a cold-sensing TRPM8 channel. However, unlike WS-12, menthol upregulates TRPM8 with a low efficacy but a high coefficient of a dose response at membrane hyperpolarization and with ligand stereoselectivity at membrane depolarization. The underlying mechanisms are unknown. Here, this in silico research suggested that the ligand-stereoselective sequential cooperativity between two menthol molecules in the WS-12 pocket is required for allosteric activation of TRPM8. Furthermore, two H-bonded homochiral menthol dimers with both head-to-head and head-to-tail can compete for the WS-12 site via non-covalent interactions. Although both dimers can form an H-bonding network with a voltage sensor S4 to disrupt a S3-S4 salt bridge in the voltage-sensor-like domain to release a "parking brake," only one dimer may drive channel opening by pushing a "gas pedal" in the TRP domain away from the S6 gate against S4. In this way, the efficacy is decreased, but the cooperativity is increased for the menthol effect at membrane hyperpolarization. Therefore, this review may extend a new pathway for ligand-stereoselective allosteric regulation of other voltage- and ligand-gated ion channels by menthol.
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Affiliation(s)
- Guangyu Wang
- Department of Drug Research and Development, Institute of Biophysical Medico-chemistry, Reno, NV, USA
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6
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Cooper SY, Akers AT, Journigan VB, Henderson BJ. Novel Putative Positive Modulators of α4β2 nAChRs Potentiate Nicotine Reward-Related Behavior. Molecules 2021; 26:4793. [PMID: 34443380 PMCID: PMC8398432 DOI: 10.3390/molecules26164793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 08/03/2021] [Accepted: 08/05/2021] [Indexed: 11/18/2022] Open
Abstract
The popular tobacco and e-cigarette chemical flavorant (-)-menthol acts as a nonselective, noncompetitive antagonist of nicotinic acetylcholine receptors (nAChRs), and contributes to multiple physiological effects that exacerbates nicotine addiction-related behavior. Menthol is classically known as a TRPM8 agonist; therefore, some have postulated that TRPM8 antagonists may be potential candidates for novel nicotine cessation pharmacotherapies. Here, we examine a novel class of TRPM8 antagonists for their ability to alter nicotine reward-related behavior in a mouse model of conditioned place preference. We found that these novel ligands enhanced nicotine reward-related behavior in a mouse model of conditioned place preference. To gain an understanding of the potential mechanism, we examined these ligands on mouse α4β2 nAChRs transiently transfected into neuroblastoma-2a cells. Using calcium flux assays, we determined that these ligands act as positive modulators (PMs) on α4β2 nAChRs. Due to α4β2 nAChRs' important role in nicotine dependence, as well as various neurological disorders including Parkinson's disease, the identification of these ligands as α4β2 nAChR PMs is an important finding, and they may serve as novel molecular tools for future nAChR-related investigations.
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Affiliation(s)
- Skylar Y. Cooper
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25703, USA; (S.Y.C.); (A.T.A.); (V.B.J.)
| | - Austin T. Akers
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25703, USA; (S.Y.C.); (A.T.A.); (V.B.J.)
| | - Velvet Blair Journigan
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25703, USA; (S.Y.C.); (A.T.A.); (V.B.J.)
- Department of Pharmaceutical Sciences, School of Pharmacy, Marshall University, Huntington, WV 25701, USA
| | - Brandon J. Henderson
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25703, USA; (S.Y.C.); (A.T.A.); (V.B.J.)
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Henderson BJ, Cooper SY. Nicotine formulations impact reinforcement-related behaviors in a mouse model of vapor self-administration. Drug Alcohol Depend 2021; 224:108732. [PMID: 33930641 PMCID: PMC8180495 DOI: 10.1016/j.drugalcdep.2021.108732] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 03/15/2021] [Accepted: 03/16/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND Electronic nicotine delivery systems (ENDS) differ from combustible cigarettes given that nicotine-salt or nicotine-freebase may be used depending on the product. We have investigated how nicotine-salt and freebase formulations alter e-Vape® self-administration (EVSA) behavior and plasma cotinine levels in male and female mice. METHODS Adult C57/BL6 J mice were used in EVSA and assigned vaping e-liquids (50:50 PGVG, 6 mg/mL nicotine-freebase, or 6 mg/mL nicotine-salt). Mice were escalated on a fixed ratio 1 (FR1) schedule in daily 2 h sessions and then transitioned to a FR3 to examine reinforcement-related behaviors. RESULTS Here we observed that mice assigned nicotine-salt exhibited increased EVSA on a FR3 schedule compared to nicotine-freebase. Additionally, mice assigned nicotine-salt exhibited higher plasma cotinine concentrations following delivery-controlled passive-inhalation sessions. CONCLUSIONS These data provide evidence nicotine-salt formulations may contribute to greater reinforcement-related behavior and highlight the need for further investigations regarding nicotine formulation in ENDS.
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Affiliation(s)
- Brandon J. Henderson
- Department of Biomedical Sciences, Joan C Edwards School of Medicine at Marshall University, 1700 3rd ave, Huntington, WV 25703, USA,Corresponding Author: Brandon J. Henderson, PhD, Department of Biomedical Sciences Joan C Edwards School of Medicine at Marshall University 1700 3rd Ave, 410 BBSC, Huntington, WV 25703 Phone: 304-696-7316
| | - Skylar Y. Cooper
- Department of Biomedical Sciences, Joan C Edwards School of Medicine at Marshall University, 1700 3rd ave, Huntington, WV 25703, USA
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Arazi E, Blecher G, Zilberberg N. Monoterpenes Differently Regulate Acid-Sensitive and Mechano-Gated K 2P Channels. Front Pharmacol 2020; 11:704. [PMID: 32508645 PMCID: PMC7251055 DOI: 10.3389/fphar.2020.00704] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 04/29/2020] [Indexed: 11/13/2022] Open
Abstract
Potassium K2P (“leak”) channels conduct current across the entire physiological voltage range and carry leak or “background” currents that are, in part, time- and voltage-independent. The activity of K2P channels affects numerous physiological processes, such as cardiac function, pain perception, depression, neuroprotection, and cancer development. We have recently established that, when expressed in Xenopus laevis oocytes, K2P2.1 (TREK-1) channels are activated by several monoterpenes (MTs). Here, we show that, within a few minutes of exposure, other mechano-gated K2P channels, K2P4.1 (TRAAK) and K2P10.1 (TREK-2), are opened by monoterpenes as well (up to an eightfold increase in current). Furthermor\e, carvacrol and cinnamaldehyde robustly enhance currents of the alkaline-sensitive K2P5.1 (up to a 17-fold increase in current). Other members of the K2P potassium channels, K2P17.1, K2P18.1, but not K2P16.1, were also activated by various MTs. Conversely, the activity of members of the acid-sensitive (TASK) K2P channels (K2P3.1 and K2P9.1) was rapidly decreased by monoterpenes. We found that MT selectively decreased the voltage-dependent portion of the current and that current inhibition was reduced with the elevation of external K+ concentration. These findings suggest that penetration of MTs into the outer leaflet of the membrane results in immediate changes at the selectivity filter of members of the TASK channel family. Thus, we suggest MTs as promising new tools for the study of K2P channels’ activity in vitro as well as in vivo.
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Affiliation(s)
- Eden Arazi
- Department of Life Sciences Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Galit Blecher
- Department of Life Sciences Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Noam Zilberberg
- Department of Life Sciences Ben-Gurion University of the Negev, Beer-Sheva, Israel.,The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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Solomon VR, Tallapragada VJ, Chebib M, Johnston G, Hanrahan JR. GABA allosteric modulators: An overview of recent developments in non-benzodiazepine modulators. Eur J Med Chem 2019; 171:434-461. [DOI: 10.1016/j.ejmech.2019.03.043] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Revised: 02/17/2019] [Accepted: 03/17/2019] [Indexed: 01/13/2023]
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Henderson BJ, Grant S, Chu BW, Shahoei R, Huard SM, Saladi SSM, Tajkhorshid E, Dougherty DA, Lester HA. Menthol Stereoisomers Exhibit Different Effects on α4β2 nAChR Upregulation and Dopamine Neuron Spontaneous Firing. eNeuro 2018; 5:ENEURO.0465-18.2018. [PMID: 30627659 PMCID: PMC6325563 DOI: 10.1523/eneuro.0465-18.2018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 12/08/2018] [Indexed: 11/21/2022] Open
Abstract
Menthol contributes to poor cessation rates among smokers, in part because menthol enhances nicotine reward and reinforcement. Mentholated tobacco products contain (-)-menthol and (+)-menthol, in varying proportions. We examined these two menthol stereoisomers for their ability to upregulate α4β2 nAChRs and to alter dopamine neuron firing frequency using long-term, low-dose (≤500 nm) exposure that is pharmacologically relevant to smoking. We found that (-)-menthol upregulates α4β2 nAChRs while (+)-menthol does not. We also found that (-)-menthol decreases dopamine neuron baseline firing and dopamine neuron excitability, while (+)-menthol exhibits no effect. We then examined both stereoisomers for their ability to inhibit α4β2 nAChR function at higher concentrations (>10 µm) using the Xenopus oocyte expression system. To probe for the potential binding site of menthol, we conducted flooding simulations and site-directed mutagenesis. We found that menthol likely binds to the 9´ position on the TM2 (transmembrane M2) helix. We found that menthol inhibition is dependent on the end-to-end distance of the side chain at the 9´ residue. Additionally, we have found that (-)-menthol is only modestly (∼25%) more potent than (+)-menthol at inhibiting wild-type α4β2 nAChRs and a series of L9´ mutant nAChRs. These data reveal that menthol exhibits a stereoselective effect on nAChRs and that the stereochemical effect is much greater for long-term, submicromolar exposure in mice than for acute, higher-level exposure. We hypothesize that of the two menthol stereoisomers, only (-)-menthol plays a role in enhancing nicotine reward through nAChRs on dopamine neurons.
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Affiliation(s)
- Brandon J. Henderson
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine at Marshall University, Huntington, West Virginia 25703
| | - Stephen Grant
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Betty W. Chu
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125
| | - Rezvan Shahoei
- Department of Physics, National Institutes of Health Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Stephanie M. Huard
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125
| | - Shyam S. M. Saladi
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Emad Tajkhorshid
- Department of Biochemistry, National Institutes of Health Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Dennis A. Dougherty
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Henry A. Lester
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125
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Discrimination of Stereoisomers by Their Enantioselective Interactions with Chiral Cholesterol-Containing Membranes. Molecules 2017; 23:molecules23010049. [PMID: 29295605 PMCID: PMC5943951 DOI: 10.3390/molecules23010049] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 12/22/2017] [Accepted: 12/22/2017] [Indexed: 12/02/2022] Open
Abstract
Discrimination between enantiomers is an important subject in medicinal and biological chemistry because they exhibit markedly different bioactivity and toxicity. Although stereoisomers should vary in the mechanistic interactions with chiral targets, their discrimination associated with the mode of action on membrane lipids is scarce. The aim of this study is to reveal whether enantiomers selectively act on chiral lipid membranes. Different classes of stereoisomers were subjected at 5–200 μM to reactions with biomimetic phospholipid membranes containing ~40 mol % cholesterol to endow the lipid bilayers with chirality and their membrane interactions were comparatively evaluated by measuring fluorescence polarization. All of the tested compounds interacted with cholesterol-containing membranes to modify their physicochemical property with different potencies between enantiomers, correlating to those of their experimental and clinical effects. The rank order of membrane interactivity was reversed by changing cholesterol to C3-epimeric α-cholesterol. The same selectivity was also obtained from membranes prepared with 5α-cholestan-3β-ol and 5β-cholestan-3α-ol diastereomers. The opposite configuration allows molecules to interact with chiral sterol-containing membranes enantioselectively, and the specific β configuration of cholesterol’s 3-hydroxyl group is responsible for such selectivity. The enantioselective membrane interaction has medicinal implications for the characterization of the stereostructures with higher bioactivity and lower toxicity.
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12
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Oz M, El Nebrisi EG, Yang KHS, Howarth FC, Al Kury LT. Cellular and Molecular Targets of Menthol Actions. Front Pharmacol 2017; 8:472. [PMID: 28769802 PMCID: PMC5513973 DOI: 10.3389/fphar.2017.00472] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 07/03/2017] [Indexed: 02/04/2023] Open
Abstract
Menthol belongs to monoterpene class of a structurally diverse group of phytochemicals found in plant-derived essential oils. Menthol is widely used in pharmaceuticals, confectionary, oral hygiene products, pesticides, cosmetics, and as a flavoring agent. In addition, menthol is known to have antioxidant, anti-inflammatory, and analgesic effects. Recently, there has been renewed awareness in comprehending the biological and pharmacological effects of menthol. TRP channels have been demonstrated to mediate the cooling actions of menthol. There has been new evidence demonstrating that menthol can significantly influence the functional characteristics of a number of different kinds of ligand and voltage-gated ion channels, indicating that at least some of the biological and pharmacological effects of menthol can be mediated by alterations in cellular excitability. In this article, we examine the results of earlier studies on the actions of menthol with voltage and ligand-gated ion channels.
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Affiliation(s)
- Murat Oz
- Department of Pharmacology, College of Medicine and Health Sciences, United Arab Emirates UniversityAl Ain, United Arab Emirates.,Department of Basic Medical Sciences, College of Medicine, Qatar UniversityDoha, Qatar
| | - Eslam G El Nebrisi
- Department of Pharmacology, College of Medicine and Health Sciences, United Arab Emirates UniversityAl Ain, United Arab Emirates
| | - Keun-Hang S Yang
- Department of Biological Sciences, Schmid College of Science and Technology, Chapman UniversityOrange, CA, United States
| | - Frank C Howarth
- Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates UniversityAl Ain, United Arab Emirates
| | - Lina T Al Kury
- Department of Health Sciences, College of Natural and Health Sciences, Zayed UniversityAbu Dhabi, United Arab Emirates
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Sánchez-Borzone ME, Mariani ME, Miguel V, Gleiser RM, Odhav B, Venugopala KN, García DA. Membrane effects of dihydropyrimidine analogues with larvicidal activity. Colloids Surf B Biointerfaces 2017; 150:106-113. [DOI: 10.1016/j.colsurfb.2016.11.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 11/18/2016] [Accepted: 11/22/2016] [Indexed: 10/20/2022]
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Manayi A, Nabavi SM, Daglia M, Jafari S. Natural terpenoids as a promising source for modulation of GABAergic system and treatment of neurological diseases. Pharmacol Rep 2016; 68:671-9. [PMID: 27110875 DOI: 10.1016/j.pharep.2016.03.014] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 02/28/2016] [Accepted: 03/24/2016] [Indexed: 02/06/2023]
Abstract
γ-Aminobutyric acid (GABA) is the main inhibitory neurotransmitter reducing neural excitability in the mammalian central nervous system (CNS) with three subclasses of receptors. Several conventional drugs and compounds modulate the GABAergic system, demonstrating different pharmacological effects. In this review, interactions of natural terpenoids with the GABAergic system are highlighted with relation to disorders like anxiety, insomnia, convulsion, pain, and cognitive deficits. Terpenoids with various structures affect the function of the GABAergic system via dissimilar mechanisms. Most of the discussed compounds interact with GABA receptors, but especially with the GABAA subtype. This may be due to the fact that researchers tend to assess the interaction of compounds using GABAA receptors. However, bilobalide, a sesquiterpene, showed anticonvulsant properties through the activation of glutamic acid decarboxylase (GAD) enzyme, which is a key enzyme in biosynthesis of GABA. Therefore, further studies evaluating and comparing terpenoids of different classes and their interaction with the GABA system, along with their pharmacokinetic properties, could be worthwhile in future studies.
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Affiliation(s)
- Azadeh Manayi
- Medicinal Plants Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Seyed Mohammad Nabavi
- Applied Biotechnology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Maria Daglia
- Department of Drug Sciences, Medicinal Chemistry and Pharmaceutical Technology Section, University of Pavia, Pavia, Italy
| | - Samineh Jafari
- Department of Pharmacognosy, Faculty of Pharmacy, Zanjan University of Medical Sciences, Zanjan, Iran.
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Chowdhury L, Croft CJ, Goel S, Zaman N, Tai ACS, Walch EM, Smith K, Page A, Shea KM, Hall CD, Jishkariani D, Pillai GG, Hall AC. Differential Potency of 2,6-Dimethylcyclohexanol Isomers for Positive Modulation of GABAA Receptor Currents. J Pharmacol Exp Ther 2016; 357:570-9. [PMID: 27029583 DOI: 10.1124/jpet.115.228890] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 03/22/2016] [Indexed: 11/22/2022] Open
Abstract
GABAA receptors meet all of the pharmacological requirements necessary to be considered important targets for the action of general anesthetic agents in the mammalian brain. In the following patch-clamp study, the relative modulatory effects of 2,6-dimethylcyclohexanol diastereomers were investigated on human GABAA (α1β3γ2s) receptor currents stably expressed in human embryonic kidney cells. Cis,cis-, trans,trans-, and cis,trans-isomers were isolated from commercially available 2,6-dimethylcyclohexanol and were tested for positive modulation of submaximal GABA responses. For example, the addition of 30 μM cis,cis-isomer resulted in an approximately 2- to 3-fold enhancement of the EC20 GABA current. Coapplications of 30 μM 2,6-dimethylcyclohexanol isomers produced a range of positive enhancements of control GABA responses with a rank order for positive modulation: cis,cis > trans,trans ≥ mixture of isomers > > cis,trans-isomer. In molecular modeling studies, the three cyclohexanol isomers bound with the highest binding energies to a pocket within transmembrane helices M1 and M2 of the β3 subunit through hydrogen-bonding interactions with a glutamine at the 224 position and a tyrosine at the 220 position. The energies for binding to and hydrogen-bond lengths within this pocket corresponded with the relative potencies of the agents for positive modulation of GABAA receptor currents (cis,cis > trans,trans > cis,trans-2,6-dimethylcyclohexanol). In conclusion, the stereochemical configuration within the dimethylcyclohexanols is an important molecular feature in conferring positive modulation of GABAA receptor activity and for binding to the receptor, a consideration that needs to be taken into account when designing novel anesthetics with enhanced therapeutic indices.
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Affiliation(s)
- Luvana Chowdhury
- Neuroscience Program, Departments of Biological Sciences (L.C., C.J.C., S.G., N.Z., A.C.-S.T., E.M.W., A.C.H.) and Chemistry (K.S., A.P., K.M.S.), Smith College, Northampton, Massachusetts; Department of Chemistry, University of Florida, Gainesville, Florida (C.D.H., D.J., G.G.P.); and Department of Chemistry, University of Tartu, Ravila, Estonia (G.G.P.)
| | - Celine J Croft
- Neuroscience Program, Departments of Biological Sciences (L.C., C.J.C., S.G., N.Z., A.C.-S.T., E.M.W., A.C.H.) and Chemistry (K.S., A.P., K.M.S.), Smith College, Northampton, Massachusetts; Department of Chemistry, University of Florida, Gainesville, Florida (C.D.H., D.J., G.G.P.); and Department of Chemistry, University of Tartu, Ravila, Estonia (G.G.P.)
| | - Shikha Goel
- Neuroscience Program, Departments of Biological Sciences (L.C., C.J.C., S.G., N.Z., A.C.-S.T., E.M.W., A.C.H.) and Chemistry (K.S., A.P., K.M.S.), Smith College, Northampton, Massachusetts; Department of Chemistry, University of Florida, Gainesville, Florida (C.D.H., D.J., G.G.P.); and Department of Chemistry, University of Tartu, Ravila, Estonia (G.G.P.)
| | - Naina Zaman
- Neuroscience Program, Departments of Biological Sciences (L.C., C.J.C., S.G., N.Z., A.C.-S.T., E.M.W., A.C.H.) and Chemistry (K.S., A.P., K.M.S.), Smith College, Northampton, Massachusetts; Department of Chemistry, University of Florida, Gainesville, Florida (C.D.H., D.J., G.G.P.); and Department of Chemistry, University of Tartu, Ravila, Estonia (G.G.P.)
| | - Angela C-S Tai
- Neuroscience Program, Departments of Biological Sciences (L.C., C.J.C., S.G., N.Z., A.C.-S.T., E.M.W., A.C.H.) and Chemistry (K.S., A.P., K.M.S.), Smith College, Northampton, Massachusetts; Department of Chemistry, University of Florida, Gainesville, Florida (C.D.H., D.J., G.G.P.); and Department of Chemistry, University of Tartu, Ravila, Estonia (G.G.P.)
| | - Erin M Walch
- Neuroscience Program, Departments of Biological Sciences (L.C., C.J.C., S.G., N.Z., A.C.-S.T., E.M.W., A.C.H.) and Chemistry (K.S., A.P., K.M.S.), Smith College, Northampton, Massachusetts; Department of Chemistry, University of Florida, Gainesville, Florida (C.D.H., D.J., G.G.P.); and Department of Chemistry, University of Tartu, Ravila, Estonia (G.G.P.)
| | - Kelly Smith
- Neuroscience Program, Departments of Biological Sciences (L.C., C.J.C., S.G., N.Z., A.C.-S.T., E.M.W., A.C.H.) and Chemistry (K.S., A.P., K.M.S.), Smith College, Northampton, Massachusetts; Department of Chemistry, University of Florida, Gainesville, Florida (C.D.H., D.J., G.G.P.); and Department of Chemistry, University of Tartu, Ravila, Estonia (G.G.P.)
| | - Alexandra Page
- Neuroscience Program, Departments of Biological Sciences (L.C., C.J.C., S.G., N.Z., A.C.-S.T., E.M.W., A.C.H.) and Chemistry (K.S., A.P., K.M.S.), Smith College, Northampton, Massachusetts; Department of Chemistry, University of Florida, Gainesville, Florida (C.D.H., D.J., G.G.P.); and Department of Chemistry, University of Tartu, Ravila, Estonia (G.G.P.)
| | - Kevin M Shea
- Neuroscience Program, Departments of Biological Sciences (L.C., C.J.C., S.G., N.Z., A.C.-S.T., E.M.W., A.C.H.) and Chemistry (K.S., A.P., K.M.S.), Smith College, Northampton, Massachusetts; Department of Chemistry, University of Florida, Gainesville, Florida (C.D.H., D.J., G.G.P.); and Department of Chemistry, University of Tartu, Ravila, Estonia (G.G.P.)
| | - C Dennis Hall
- Neuroscience Program, Departments of Biological Sciences (L.C., C.J.C., S.G., N.Z., A.C.-S.T., E.M.W., A.C.H.) and Chemistry (K.S., A.P., K.M.S.), Smith College, Northampton, Massachusetts; Department of Chemistry, University of Florida, Gainesville, Florida (C.D.H., D.J., G.G.P.); and Department of Chemistry, University of Tartu, Ravila, Estonia (G.G.P.)
| | - D Jishkariani
- Neuroscience Program, Departments of Biological Sciences (L.C., C.J.C., S.G., N.Z., A.C.-S.T., E.M.W., A.C.H.) and Chemistry (K.S., A.P., K.M.S.), Smith College, Northampton, Massachusetts; Department of Chemistry, University of Florida, Gainesville, Florida (C.D.H., D.J., G.G.P.); and Department of Chemistry, University of Tartu, Ravila, Estonia (G.G.P.)
| | - Girinath G Pillai
- Neuroscience Program, Departments of Biological Sciences (L.C., C.J.C., S.G., N.Z., A.C.-S.T., E.M.W., A.C.H.) and Chemistry (K.S., A.P., K.M.S.), Smith College, Northampton, Massachusetts; Department of Chemistry, University of Florida, Gainesville, Florida (C.D.H., D.J., G.G.P.); and Department of Chemistry, University of Tartu, Ravila, Estonia (G.G.P.)
| | - Adam C Hall
- Neuroscience Program, Departments of Biological Sciences (L.C., C.J.C., S.G., N.Z., A.C.-S.T., E.M.W., A.C.H.) and Chemistry (K.S., A.P., K.M.S.), Smith College, Northampton, Massachusetts; Department of Chemistry, University of Florida, Gainesville, Florida (C.D.H., D.J., G.G.P.); and Department of Chemistry, University of Tartu, Ravila, Estonia (G.G.P.)
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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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Kamatou GPP, Vermaak I, Viljoen AM, Lawrence BM. Menthol: a simple monoterpene with remarkable biological properties. PHYTOCHEMISTRY 2013; 96:15-25. [PMID: 24054028 DOI: 10.1016/j.phytochem.2013.08.005] [Citation(s) in RCA: 228] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2013] [Accepted: 08/09/2013] [Indexed: 05/04/2023]
Abstract
Menthol is a cyclic monoterpene alcohol which possesses well-known cooling characteristics and a residual minty smell of the oil remnants from which it was obtained. Because of these attributes it is one of the most important flavouring additives besides vanilla and citrus. Due to this reason it is used in a variety of consumer products ranging from confections such as chocolate and chewing gum to oral-care products such as toothpaste as well as in over-the-counter medicinal products for its cooling and biological effects. Its cooling effects are not exclusive to medicinal use. Approximately one quarter of the cigarettes on the market contain menthol and small amounts of menthol are even included in non-mentholated cigarettes. Natural menthol is isolated exclusively from Mentha canadensis, but can also be synthesised on industrial scale through various processes. Although menthol exists in eight stereoisomeric forms, (-)-menthol from the natural source and synthesised menthol with the same structure is the most preferred isomer. The demand for menthol is high and it was previously estimated that the worldwide use of menthol was 30-32,000 metric tonnes per annum. Menthol is not a predominant compound of the essential oils as it can only be found as a constituent of a limited number of aromatic plants. These plants are known to exhibit biological activity in vitro and in vivo such as antibacterial, antifungal, antipruritic, anticancer and analgesic effects, and are also an effective fumigant. In addition, menthol is one of the most effective terpenes used to enhance the dermal penetration of pharmaceuticals. This review summarises the chemical and biological properties of menthol and highlights its cooling effects and toxicity.
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Affiliation(s)
- Guy P P Kamatou
- Department of Pharmaceutical Sciences, Faculty of Science, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa
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18
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TRPM8 is the principal mediator of menthol-induced analgesia of acute and inflammatory pain. Pain 2013; 154:2169-2177. [PMID: 23820004 DOI: 10.1016/j.pain.2013.06.043] [Citation(s) in RCA: 182] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 05/17/2013] [Accepted: 06/26/2013] [Indexed: 11/20/2022]
Abstract
Menthol, the cooling natural product of peppermint, is widely used in medicinal preparations for the relief of acute and inflammatory pain in sports injuries, arthritis, and other painful conditions. Menthol induces the sensation of cooling by activating TRPM8, an ion channel in cold-sensitive peripheral sensory neurons. Recent studies identified additional targets of menthol, including the irritant receptor, TRPA1, voltage-gated ion channels and neurotransmitter receptors. It remains unclear which of these targets contribute to menthol-induced analgesia, or to the irritating side effects associated with menthol therapy. Here, we use genetic and pharmacological approaches in mice to probe the role of TRPM8 in analgesia induced by L-menthol, the predominant analgesic menthol isomer in medicinal preparations. L-menthol effectively diminished pain behavior elicited by chemical stimuli (capsaicin, acrolein, acetic acid), noxious heat, and inflammation (complete Freund's adjuvant). Genetic deletion of TRPM8 completely abolished analgesia by L-menthol in all these models, although other analgesics (acetaminophen) remained effective. Loss of L-menthol-induced analgesia was recapitulated in mice treated with a selective TRPM8 inhibitor, AMG2850. Selective activation of TRPM8 with WS-12, a menthol derivative that we characterized as a specific TRPM8 agonist in cultured sensory neurons and in vivo, also induced TRPM8-dependent analgesia of acute and inflammatory pain. L-menthol- and WS-12-induced analgesia was blocked by naloxone, suggesting activation of endogenous opioid-dependent analgesic pathways. Our data show that TRPM8 is the principal mediator of menthol-induced analgesia of acute and inflammatory pain. In contrast to menthol, selective TRPM8 agonists may produce analgesia more effectively, with diminished side effects.
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20
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Zunino MP, Turina AV, Zygadlo JA, Perillo MA. Stereoselective effects of monoterpenes on the microviscosity and curvature of model membranes assessed by DPH steady-state fluorescence anisotropy and light scattering analysis. Chirality 2011; 23:867-77. [DOI: 10.1002/chir.20998] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Accepted: 05/19/2011] [Indexed: 11/09/2022]
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Hall AC, Griffith TN, Tsikolia M, Kotey FO, Gill N, Humbert DJ, Watt EE, Yermolina YA, Goel S, El-Ghendy B, Hall CD. Cyclohexanol analogues are positive modulators of GABA(A) receptor currents and act as general anaesthetics in vivo. Eur J Pharmacol 2011; 667:175-81. [PMID: 21658385 DOI: 10.1016/j.ejphar.2011.05.058] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 05/18/2011] [Accepted: 05/22/2011] [Indexed: 11/16/2022]
Abstract
GABA(A) receptors meet all the pharmacological criteria required to be considered important general anaesthetic targets. In the following study, the modulatory effects of various commercially available and novel cyclohexanols were investigated on recombinant human γ-aminobutyric acid (GABA(A), α(1)β(2)γ(2s)) receptors expressed in Xenopus oocytes, and compared to the modulatory effects on GABA currents observed with exposures to the intravenous anaesthetic agent, propofol. Submaximal EC(20) GABA currents were typically enhanced by co-applications of 3-300 μM cyclohexanols. For instance, at 30 μM 2,6-diisopropylcyclohexanol (a novel compound) GABA responses were increased ~3-fold (although similar enhancements were achieved at 3 μM propofol). As regards rank order for modulation by the cyclohexanol analogues at 30 μM, the % enhancements for 2,6-dimethylcyclohexanol~2,6-diethylcyclohexanol~2,6-diisopropylcyclohexanol~2,6-di-sec-butylcyclohexanol ≫2,6-di-tert-butylcyclohexanol~4-tert-butylcyclohexanol>cyclohexanol~cyclopentanol~2-methylcyclohexanol. We further tested the potencies of the cyclohexanol analogues as general anaesthetics using a tadpole in vivo assay. Both 2,6-diisopropylcyclohexanol and 2,6-dimethylcyclohexanol were effective as anaesthetics with EC(50)s of 14.0 μM and 13.1 μM respectively, while other cyclohexanols with bulkier side chains were less potent. In conclusion, our data indicate that cyclohexanols are both positive modulators of GABA(A) receptors currents and anaesthetics. The positioning and size of the alkyl groups at the 2 and 6 positions on the cyclohexanol ring were critical determinants of activity.
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Affiliation(s)
- Adam C Hall
- Neuroscience Program, Department of Biological Sciences, Smith College, Northampton, MA 01063, USA.
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Effects of menthol stereoisomers on the growth, sporulation and fumonisin B1 production of Fusarium verticillioides. Food Chem 2010. [DOI: 10.1016/j.foodchem.2010.04.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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