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Ni W, Yu Y, Gao X, Han Y, Zhang W, Zhang Z, Xiao W, Hu Q, Zhang Y, Huang H, Li F, Chen M, Han J. Multilocus Distance-Regulated Sensor Array for Recognition of Polyphenols via Machine Learning and Indicator Displacement Assay. Anal Chem 2024; 96:301-308. [PMID: 38102984 DOI: 10.1021/acs.analchem.3c04107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2023]
Abstract
Developing new strategies to construct sensor arrays that can effectively distinguish multiple natural components with similar structures in mixtures is an exceptionally challenging task. Here, we propose a new multilocus distance-modulated indicator displacement assay (IDA) strategy for constructing a sensor array, incorporating machine learning optimization to identify polyphenols. An 8-element array, comprising two fluorophores and their six dynamic covalent complexes (C1-C6) formed by pairing two fluorophores with three distinct distance-regulated quenchers, has been constructed. Polyphenols with diverse spatial arrangements and combinatorial forms compete with the fluorophores by forming pseudocycles with quenchers within the complexes, leading to varying degrees of fluorescence recovery. The array accurately and effectively distinguished four tea polyphenols and 16 tea varieties, thereby demonstrating the broad applicability of the multilocus distance-modulated IDA array in detecting polyhydroxy foods and natural medicines.
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Affiliation(s)
- Weiwei Ni
- State Key Laboratory of Natural Medicines, College of Engineering, China Pharmaceutical University, Nanjing 211109, China
| | - Yang Yu
- School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211109, China
| | - Xu Gao
- State Key Laboratory of Natural Medicines, College of Engineering, China Pharmaceutical University, Nanjing 211109, China
| | - Yang Han
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing 211109, China
| | - Wenhui Zhang
- State Key Laboratory of Natural Medicines, College of Engineering, China Pharmaceutical University, Nanjing 211109, China
| | - Zerui Zhang
- State Key Laboratory of Natural Medicines, College of Engineering, China Pharmaceutical University, Nanjing 211109, China
| | - Wenqi Xiao
- State Key Laboratory of Natural Medicines, College of Engineering, China Pharmaceutical University, Nanjing 211109, China
| | - Qin Hu
- Department of Laboratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Yanliang Zhang
- Nanjing Research Center for Infectious Diseases of Integrated Traditional Chinese and Western Medicine, Nanjing Hospital of Chinese Medicine Affiliated to Nanjing University of Chinese Medicine, Nanjing 211109, China
| | - Hui Huang
- State Key Laboratory of Natural Medicines, College of Engineering, China Pharmaceutical University, Nanjing 211109, China
| | - Fei Li
- State Key Laboratory of Natural Medicines, College of Engineering, China Pharmaceutical University, Nanjing 211109, China
| | - Mingqi Chen
- State Key Laboratory of Natural Medicines, College of Engineering, China Pharmaceutical University, Nanjing 211109, China
| | - Jinsong Han
- State Key Laboratory of Natural Medicines, College of Engineering, China Pharmaceutical University, Nanjing 211109, China
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Song X, Kirtipal N, Lee S, Malý P, Bharadwaj S. Current therapeutic targets and multifaceted physiological impacts of caffeine. Phytother Res 2023; 37:5558-5598. [PMID: 37679309 DOI: 10.1002/ptr.8000] [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: 04/13/2023] [Revised: 08/04/2023] [Accepted: 08/17/2023] [Indexed: 09/09/2023]
Abstract
Caffeine, which shares consubstantial structural similarity with purine adenosine, has been demonstrated as a nonselective adenosine receptor antagonist for eliciting most of the biological functions at physiologically relevant dosages. Accumulating evidence supports caffeine's beneficial effects against different disorders, such as total cardiovascular diseases and type 2 diabetes. Conversely, paradoxical effects are also linked to caffeine ingestion in humans including hypertension-hypotension and tachycardia-bradycardia. These observations suggest the association of caffeine action with its ingested concentration and/or concurrent interaction with preferential molecular targets to direct explicit events in the human body. Thus, a coherent analysis of the functional targets of caffeine, relevant to normal physiology, and disease pathophysiology, is required to understand the pharmacology of caffeine. This review provides a broad overview of the experimentally validated targets of caffeine, particularly those of therapeutic interest, and the impacts of caffeine on organ-specific physiology and pathophysiology. Overall, the available empirical and epidemiological evidence supports the dose-dependent functional activities of caffeine and advocates for further studies to get insights into the caffeine-induced changes under specific conditions, such as asthma, DNA repair, and cancer, in view of its therapeutic applications.
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Affiliation(s)
- Xinjie Song
- Zhejiang Provincial Key Lab for Chemical and Biological Processing Technology of Farm Product, School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, China
| | - Nikhil Kirtipal
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
| | - Sunjae Lee
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
| | - Petr Malý
- Laboratory of Ligand Engineering, Institute of Biotechnology of the Czech Academy of Sciences v.v.i, BIOCEV Research Center, Vestec, Czech Republic
| | - Shiv Bharadwaj
- Laboratory of Ligand Engineering, Institute of Biotechnology of the Czech Academy of Sciences v.v.i, BIOCEV Research Center, Vestec, Czech Republic
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Liwinski T, Lang UE, Brühl AB, Schneider E. Exploring the Therapeutic Potential of Gamma-Aminobutyric Acid in Stress and Depressive Disorders through the Gut-Brain Axis. Biomedicines 2023; 11:3128. [PMID: 38137351 PMCID: PMC10741010 DOI: 10.3390/biomedicines11123128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 11/16/2023] [Accepted: 11/21/2023] [Indexed: 12/24/2023] Open
Abstract
Research conducted on individuals with depression reveals that major depressive disorders (MDDs) coincide with diminished levels of the inhibitory neurotransmitter γ-aminobutyric acid (GABA) in the brain, as well as modifications in the subunit composition of the primary receptors (GABAA receptors) responsible for mediating GABAergic inhibition. Furthermore, there is substantial evidence supporting the significant role of GABA in regulating stress within the brain, which is a pivotal vulnerability factor in mood disorders. GABA is readily available and approved as a food supplement in many countries. Although there is substantial evidence indicating that orally ingested GABA may affect GABA receptors in peripheral tissues, there is comparatively less evidence supporting its direct action within the brain. Emerging evidence highlights that oral GABA intake may exert beneficial effects on the brain and psyche through the gut-brain axis. While GABA enjoys wide consumer acceptance in Eastern Asian markets, with many consumers reporting favorable effects on stress regulation, mood, and sleep, rigorous independent research is still largely lacking. Basic research, coupled with initial clinical findings, makes GABA an intriguing neuro-nutritional compound deserving of clinical studies in individuals with depression and other psychological problems.
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Affiliation(s)
| | | | | | - Else Schneider
- University Psychiatric Clinics Basel, Clinic for Adults, University of Basel, CH-4002 Basel, Switzerland; (T.L.); (U.E.L.); (A.B.B.)
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Hashimoto M, Takahashi K, Ohta T. Inhibitory effects of linalool, an essential oil component of lavender, on nociceptive TRPA1 and voltage-gated Ca 2+ channels in mouse sensory neurons. Biochem Biophys Rep 2023; 34:101468. [PMID: 37102121 PMCID: PMC10123348 DOI: 10.1016/j.bbrep.2023.101468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Revised: 03/14/2023] [Accepted: 04/05/2023] [Indexed: 04/28/2023] Open
Abstract
Linalool, an essential oil component of lavender is commonly used in fragrances. It is known that linalool has anxiolytic, sedative, and analgesic actions. However, the mechanism of its analgesic action has not yet been fully clarified. Pain signals elicited by the activation of nociceptors on peripheral neurons are transmitted to the central nervous system. In the present study, we investigated the effects of linalool on transient receptor potential (TRP) channels and voltage-gated channels, both of which are important for pain signaling via nociceptors in somatosensory neurons. For detection of channel activity, the intracellular Ca2+ concentration ([Ca2+]i) was measured using a Ca2+-imaging system, and membrane currents were recorded using the whole-cell patch-clamp technique. Analgesic actions were also examined in vivo. In mouse sensory neurons linalool at concentrations that did not induce [Ca2+]i increases did not affect [Ca2+]i responses to capsaicin and acids, TRPV1 agonists, but suppressed those induced by allyl isothiocyanate (AITC) and carvacrol, TRPA1 agonists. Similar inhibitory effects of linalool were observed in cells that heterologously expressed TRPA1. Linalool attenuated the [Ca2+]i increases induced by KCl and voltage-gated Ca2+ currents but only slightly suppressed voltage-gated Na+currents in mouse sensory neurons. Linalool diminished TRPA1-mediated nociceptive behaviors. The present data suggest that linalool exerts an analgesic action via the suppression of nociceptive TRPA1 and voltage-gated Ca2+ channels.
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Affiliation(s)
- Miho Hashimoto
- Department of Veterinary Pharmacology, Faculty of Agriculture, Tottori University, Tottori, Japan
- Joint Graduate School of Veterinary Sciences, Gifu University, Tottori University, Tottori, Japan
| | - Kenji Takahashi
- Department of Veterinary Pharmacology, Faculty of Agriculture, Tottori University, Tottori, Japan
- Joint Graduate School of Veterinary Sciences, Gifu University, Tottori University, Tottori, Japan
| | - Toshio Ohta
- Department of Veterinary Pharmacology, Faculty of Agriculture, Tottori University, Tottori, Japan
- Joint Graduate School of Veterinary Sciences, Gifu University, Tottori University, Tottori, Japan
- Corresponding author. Department of Veterinary Pharmacology, Faculty of Agriculture, Tottori University, Tottori, 680-8553, Japan.
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Chakrovorty A, Bhattacharjee B, Saxena A, Samadder A, Nandi S. Current Naturopathy to Combat Alzheimer's Disease. Curr Neuropharmacol 2023; 21:808-841. [PMID: 36173068 PMCID: PMC10227918 DOI: 10.2174/1570159x20666220927121022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 06/13/2022] [Accepted: 07/18/2022] [Indexed: 11/22/2022] Open
Abstract
Neurodegeneration is the progressive loss of structure or function of neurons, which may ultimately involve cell death. The most common neurodegenerative disorder in the brain happens with Alzheimer's disease (AD), the most common cause of dementia. It ultimately leads to neuronal death, thereby impairing the normal functionality of the central or peripheral nervous system. The onset and prevalence of AD involve heterogeneous etiology, either in terms of genetic predisposition, neurometabolomic malfunctioning, or lifestyle. The worldwide relevancies are estimated to be over 45 million people. The rapid increase in AD has led to a concomitant increase in the research work directed towards discovering a lucrative cure for AD. The neuropathology of AD comprises the deficiency in the availability of neurotransmitters and important neurotrophic factors in the brain, extracellular betaamyloid plaque depositions, and intracellular neurofibrillary tangles of hyperphosphorylated tau protein. Current pharmaceutical interventions utilizing synthetic drugs have manifested resistance and toxicity problems. This has led to the quest for new pharmacotherapeutic candidates naturally prevalent in phytochemicals. This review aims to provide an elaborative description of promising Phyto component entities having activities against various potential AD targets. Therefore, naturopathy may combine with synthetic chemotherapeutics to longer the survival of the patients.
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Affiliation(s)
- Arnob Chakrovorty
- Department of Zoology, Cytogenetics and Molecular Biology Lab., University of Kalyani, Kalyani, 741235, India
| | - Banani Bhattacharjee
- Department of Zoology, Cytogenetics and Molecular Biology Lab., University of Kalyani, Kalyani, 741235, India
| | - Aaruni Saxena
- Department of Cardiovascular Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Asmita Samadder
- Department of Zoology, Cytogenetics and Molecular Biology Lab., University of Kalyani, Kalyani, 741235, India
| | - Sisir Nandi
- Department of Pharmaceutical Chemistry, Global Institute of Pharmaceutical Education and Research, Affiliated to Uttarakhand Technical University, Kashipur, 244713, India
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Malloggi E, Menicucci D, Cesari V, Frumento S, Gemignani A, Bertoli A. Lavender aromatherapy: A systematic review from essential oil quality and administration methods to cognitive enhancing effects. Appl Psychol Health Well Being 2021; 14:663-690. [PMID: 34611999 PMCID: PMC9291879 DOI: 10.1111/aphw.12310] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/24/2021] [Accepted: 09/14/2021] [Indexed: 12/29/2022]
Abstract
Modern society is reviving the practice of aromatherapy, and lavender is reported being the most worldwide purchased plant for essential oil (EO) extraction. Since recent studies reported cognitive enhancing effects of lavender besides the hypno-inducing effects, a literature review is needed. Considering EO quality and diffusion devices, we conducted a systematic review on the effects of lavender EO inhalation on arousal, attention and memory in healthy subjects. Starting from this new multidisciplinary perspective, cognitive effects were reviewed to link outcomes to effective and reproducible protocols. A systematic search on MEDLINE, ERIC, PsycInfo, Google Scholar, and Scopus databases using Cognitive Atlas and plant-related keywords was conducted. Among the 1,203 articles yielded, 11 met eligibility criteria. Subjects administered with lavender EO displayed arousal decrease and sustained attention increase. Controversial results emerged regarding memory. Lack of EO quality assessment and protocols heterogeneity did not allow assessing whether different EO composition differentially modulates cognition and whether placebo effect can be discerned from EO effect itself. However, GABAergic pathway modulation exerted by linalool, a major lavender EO constituent, might explain cognitive functions empowerment. We speculate aromatherapy could be a burgeoning cognition enhancing tool, although further investigation is required to reach robust conclusions.
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Affiliation(s)
- Eleonora Malloggi
- Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, University of Pisa, Pisa, Italy
| | - Danilo Menicucci
- Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, University of Pisa, Pisa, Italy
| | - Valentina Cesari
- Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, University of Pisa, Pisa, Italy
| | - Sergio Frumento
- Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, University of Pisa, Pisa, Italy
| | - Angelo Gemignani
- Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, University of Pisa, Pisa, Italy
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Oshima T, Ito M. Sedative effects of l-menthol, d-camphor, phenylethyl alcohol, and geraniol. J Nat Med 2021; 75:319-325. [PMID: 33389551 DOI: 10.1007/s11418-020-01470-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 11/18/2020] [Indexed: 11/29/2022]
Abstract
Various essential oils from plants and fragrance components such as monoterpenes have been discovered to reduce spontaneous movements in mice; thus, it has been made clear that the odor itself has the sedative activity. In the present study, we examined the sedative activity of the odors of fragrance components added to eye drops; l-menthol, d-camphor, phenylethyl alcohol, and geraniol, which are often used as refreshers or preservatives. Each fragrance component was administered by the inhalation route to mice, and the sedative effects were evaluated using an open field test. The results showed that four components administered via inhalation to mice significantly decreased the amount of spontaneous motor activity in a dose-dependent manner, indicating that all four components have a sedative effect. The optimal concentrations at which l-menthol, d-camphor, phenylethyl alcohol, and geraniol showed the highest sedative activity were 4 × 10-2 mg per cage, 4 × 10-4 mg per cage, 4 × 10-2 mg per cage, and both 4 × 10-4 and 4 × 10-2 mg per cage, respectively. The AUC graph of geraniol was represented as a W-shaped curve, suggesting that the sedative action of geraniol was biphasic. The present finding demonstrates a new perspective on a possible pharmacological property of eye drop additives used with no expected pharmacological functions.
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Affiliation(s)
- Tomoko Oshima
- Department of Pharmacognosy, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-Shimoadachi-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Michiho Ito
- Department of Pharmacognosy, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-Shimoadachi-cho, Sakyo-ku, Kyoto, 606-8501, Japan.
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8
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GABA-enriched teas as neuro-nutraceuticals. Neurochem Int 2020; 141:104895. [PMID: 33144101 DOI: 10.1016/j.neuint.2020.104895] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 10/22/2020] [Accepted: 10/28/2020] [Indexed: 01/02/2023]
Abstract
Teas enriched in GABA are consumed for their beneficial effects on blood pressure, stress and anxiety. These effects may involve actions of GABA on the central and peripheral nervous systems. The anaerobic procedures for the production of GABA-enriched teas increase GABA levels by 10-20 times. They also significantly alter the levels of other constituents that may interact with the actions of GABA. These include epigallocatechin gallate, caffeine and theanine. The possible interactions of these active constituents make the understanding of the effects of GABA-enriched teas complex. More data is needed to establish where and how GABA is acting following consumption of GABA-enriched teas. While there is considerable evidence that such GABA is acting on GABA receptors in the periphery, there is rather less evidence that is acting directly in the brain. Certainly, there is more to the action of GABA-enriched teas than GABA itself.
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10
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Benkherouf AY, Logrén N, Somborac T, Kortesniemi M, Soini SL, Yang B, Salo-Ahen OMH, Laaksonen O, Uusi-Oukari M. Hops compounds modulatory effects and 6-prenylnaringenin dual mode of action on GABA A receptors. Eur J Pharmacol 2020; 873:172962. [PMID: 32001220 DOI: 10.1016/j.ejphar.2020.172962] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 12/17/2019] [Accepted: 01/24/2020] [Indexed: 02/05/2023]
Abstract
Hops (Humulus lupulus L.), a major component of beer, contain potentially neuroactive compounds that made it useful in traditional medicine as a sleeping aid. The present study aims to investigate the individual components in hops acting as allosteric modulators in GABAA receptors and bring further insight into the mode of action behind the sedative properties of hops. GABA-potentiating effects were measured using [3H]ethynylbicycloorthobenzoate (EBOB) radioligand binding assay in native GABAA receptors. Flumazenil sensitivity of GABA-potentiating effects, [3H]Ro 15-4513, and [3H]flunitrazepam binding assays were used to examine the binding to the classical benzodiazepines site. Humulone (alpha acid) and 6-prenylnaringenin (prenylflavonoid) were the most potent compounds displaying a modulatory activity at low micromolar concentrations. Humulone and 6-prenylnaringenin potentiated GABA-induced displacement of [3H]EBOB binding in a concentration-dependent manner where the IC50 values for this potentiation in native GABAA receptors were 3.2 μM and 3.7 μM, respectively. Flumazenil had no significant effects on humulone- or 6-prenylnaringenin-induced displacement of [3H]EBOB binding. [3H]Ro 15-4513 and [3H]flunitrazepam displacements were only minor with humulone but surprisingly prominent with 6-prenylnaringenin despite its flumazenil-insensitive modulatory activity. Thus, we applied molecular docking methods to investigate putative binding sites and poses of 6-prenylnaringenin at the GABAA receptor α1β2γ2 isoform. Radioligand binding and docking results suggest a dual mode of action by 6-prenylnaringenin on GABAA receptors where it may act as a positive allosteric modulator at α+β- binding interface as well as a null modulator at the flumazenil-sensitive α+γ2- binding interface.
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Affiliation(s)
- Ali Y Benkherouf
- Integrative Physiology and Pharmacology, Institute of Biomedicine, University of Turku, Finland
| | - Nora Logrén
- Food Chemistry and Food Development, Department of Biochemistry, University of Turku, Finland
| | - Tamara Somborac
- Pharmaceutical Sciences Laboratory and Structural Bioinformatics Laboratory, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
| | - Maaria Kortesniemi
- Food Chemistry and Food Development, Department of Biochemistry, University of Turku, Finland
| | - Sanna L Soini
- Integrative Physiology and Pharmacology, Institute of Biomedicine, University of Turku, Finland
| | - Baoru Yang
- Food Chemistry and Food Development, Department of Biochemistry, University of Turku, Finland
| | - Outi M H Salo-Ahen
- Pharmaceutical Sciences Laboratory and Structural Bioinformatics Laboratory, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
| | - Oskar Laaksonen
- Food Chemistry and Food Development, Department of Biochemistry, University of Turku, Finland
| | - Mikko Uusi-Oukari
- Integrative Physiology and Pharmacology, Institute of Biomedicine, University of Turku, Finland.
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Hinton T, Jelinek HF, Viengkhou V, Johnston GA, Matthews S. Effect of GABA-Fortified Oolong Tea on Reducing Stress in a University Student Cohort. Front Nutr 2019; 6:27. [PMID: 30972340 PMCID: PMC6443991 DOI: 10.3389/fnut.2019.00027] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 02/22/2019] [Indexed: 02/06/2023] Open
Abstract
GABA-containing tea has gained popularity as an accessible intervention to reduce the impact of chronic stress-induced autonomic imbalance and increased risk for cardiovascular disease despite a lack of evidence concerning the γ-aminobutyric acid (GABA) content in a cup of the tea and its effects on physiological and psychological stress as measures of cognitive function. We aimed to measure the effects of GABA-fortified tea consumption on heart rate variability (HRV) and stress in 30 participants using a pre-post cohort study design. Ten minute lead II ECG recordings were analyzed with Kubios software. Frequency domain parameters including total power, high and low frequency power, along with heart rate, were determined. A control group that consumed a non-fortified tea was included in the research. Statistical analysis was by two-way ANOVA for two-group comparison with time as an interaction and a significance level of p < 0.05. Oolong tea consumption led to a significant decrease in the immediate stress score and a significant improvement in HRV. We conclude that autonomic imbalance and HRV in people with acute stress is significantly reduced following a cup of GABA fortified oolong tea and highlights the complex interaction between autonomic nervous system function and mood.
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Affiliation(s)
- Tina Hinton
- Pharmacology, School of Medical Sciences, University of Sydney, Sydney, NSW, Australia
| | - Herbert F Jelinek
- Clinical Medicine, Macquarie University, Sydney, NSW, Australia.,School of Community Health, Charles Sturt University, Bathurst, NSW, Australia
| | - Vincent Viengkhou
- Pharmacology, School of Medical Sciences, University of Sydney, Sydney, NSW, Australia
| | - Graham A Johnston
- Pharmacology, School of Medical Sciences, University of Sydney, Sydney, NSW, Australia
| | - Slade Matthews
- Pharmacology, School of Medical Sciences, University of Sydney, Sydney, NSW, Australia
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Milanos S, Kuenzel K, Gilbert DF, Janzen D, Sasi M, Buettner A, Frimurer TM, Villmann C. Structural changes at the myrtenol backbone reverse its positive allosteric potential into inhibitory GABAA receptor modulation. Biol Chem 2018; 399:549-563. [DOI: 10.1515/hsz-2017-0262] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 01/24/2018] [Indexed: 02/07/2023]
Abstract
Abstract
GABAA receptors are ligand-gated anion channels that form pentameric arrangements of various subunits. Positive allosteric modulators of GABAA receptors have been reported as being isolated either from plants or synthesized analogs of known GABAA receptor targeting drugs. Recently, we identified monoterpenes, e.g. myrtenol as a positive allosteric modulator at α1β2 GABAA receptors. Here, along with pharmacophore-based virtual screening studies, we demonstrate that scaffold modifications of myrtenol resulted in the loss of modulatory activity. Two independent approaches, fluorescence-based compound analysis and electrophysiological recordings in whole-cell configurations were used for analysis of transfected cells. C-atoms 1 and 2 of the myrtenol backbone were identified as crucial to preserve positive allosteric potential. A modification at C-atom 2 and lack of the hydroxyl group at C-atom 1 exhibited significantly reduced GABAergic currents at α1β2, α1β2γ, α2β3, α2β3γ and α4β3δ receptors. This effect was independent of the γ2 subunit. A sub-screen with side chain length and volume differences at the C-atom 1 identified two compounds that inhibited GABAergic responses but without receptor subtype specificity. Our combined approach of pharmacophore-based virtual screening and functional readouts reveals that side chain modifications of the bridged six-membered ring structure of myrtenol are crucial for its modulatory potential at GABAA receptors.
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Affiliation(s)
- Sinem Milanos
- Institute for Clinical Neurobiology , Julius-Maximilians-Universität Würzburg , Versbacherstr. 5 , D-97078 Würzburg , Germany
- Department of Chemistry and Pharmacy, Food Chemistry, Emil-Fischer-Center , Friedrich-Alexander-Universität Erlangen-Nürnberg , D-90154 Erlangen , Germany
| | - Katharina Kuenzel
- Institute of Medical Biotechnology , Friedrich-Alexander-Universität Erlangen-Nürnberg , D-91052 Erlangen , Germany
| | - Daniel F. Gilbert
- Institute of Medical Biotechnology , Friedrich-Alexander-Universität Erlangen-Nürnberg , D-91052 Erlangen , Germany
| | - Dieter Janzen
- Institute for Clinical Neurobiology , Julius-Maximilians-Universität Würzburg , Versbacherstr. 5 , D-97078 Würzburg , Germany
| | - Manju Sasi
- Institute for Clinical Neurobiology , Julius-Maximilians-Universität Würzburg , Versbacherstr. 5 , D-97078 Würzburg , Germany
| | - Andrea Buettner
- Department of Chemistry and Pharmacy, Food Chemistry, Emil-Fischer-Center , Friedrich-Alexander-Universität Erlangen-Nürnberg , D-90154 Erlangen , Germany
- Department of Sensory Analytics , Fraunhofer-Institute for Process Engineering and Packaging , D-85354 Freising , Germany
| | - Thomas M. Frimurer
- Section for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research , University of Copenhagen , Copenhagen , Denmark
| | - Carmen Villmann
- Institute for Clinical Neurobiology , Julius-Maximilians-Universität Würzburg , Versbacherstr. 5 , D-97078 Würzburg , Germany
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Jankowska M, Rogalska J, Wyszkowska J, Stankiewicz M. Molecular Targets for Components of Essential Oils in the Insect Nervous System-A Review. Molecules 2017; 23:E34. [PMID: 29295521 PMCID: PMC5943938 DOI: 10.3390/molecules23010034] [Citation(s) in RCA: 141] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 12/18/2017] [Accepted: 12/21/2017] [Indexed: 12/29/2022] Open
Abstract
Essential oils (EOs) are lipophilic secondary metabolites obtained from plants; terpenoids represent the main components of them. A lot of studies showed neurotoxic actions of EOs. In insects, they cause paralysis followed by death. This feature let us consider components of EOs as potential bioinsecticides. The inhibition of acetylcholinesterase (AChE) is the one of the most investigated mechanisms of action in EOs. However, EOs are rather weak inhibitors of AChE. Another proposed mechanism of EO action is a positive allosteric modulation of GABA receptors (GABArs). There are several papers that prove the potentiation of GABA effect on mammalian receptors induced by EOs. In contrast, there is lack of any data concerning the binding of EO components in insects GABArs. In insects, EOs act also via the octopaminergic system. Available data show that EOs can increase the level of both cAMP and calcium in nervous cells. Moreover, some EO components compete with octopamine in binding to its receptor. Electrophysiological experiments performed on Periplaneta americana have shown similarity in the action of EO components and octopamine. This suggests that EOs can modify neuron activity by octopamine receptors. A multitude of potential targets in the insect nervous system makes EO components interesting candidates for bio-insecticides.
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Affiliation(s)
- Milena Jankowska
- Department of Biophysics, Faculty of Biology and Environmental Protection, Nicolaus Copernicus University, Toruń, Poland; Lwowska 1, 87-100 Toruń, Poland.
| | - Justyna Rogalska
- Department of Animal Physiology, Faculty of Biology and Environmental Protection, Nicolaus Copernicus University, Toruń, Poland; Lwowska 1, 87-100 Toruń, Poland.
| | - Joanna Wyszkowska
- Department of Biophysics, Faculty of Biology and Environmental Protection, Nicolaus Copernicus University, Toruń, Poland; Lwowska 1, 87-100 Toruń, Poland.
| | - Maria Stankiewicz
- Department of Biophysics, Faculty of Biology and Environmental Protection, Nicolaus Copernicus University, Toruń, Poland; Lwowska 1, 87-100 Toruń, Poland.
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Sahin S, Eulenburg V, Heinlein A, Villmann C, Pischetsrieder M. Identification of eugenol as the major determinant of GABAA-receptor activation by aqueous Syzygium aromaticum L. (clove buds) extract. J Funct Foods 2017. [DOI: 10.1016/j.jff.2017.08.033] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Milanos S, Elsharif SA, Janzen D, Buettner A, Villmann C. Metabolic Products of Linalool and Modulation of GABA A Receptors. Front Chem 2017; 5:46. [PMID: 28680877 PMCID: PMC5478857 DOI: 10.3389/fchem.2017.00046] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 06/12/2017] [Indexed: 12/15/2022] Open
Abstract
Terpenoids are major subcomponents in aroma substances which harbor sedative physiological potential. We have demonstrated that various monoterpenoids such as the acyclic linalool enhance GABAergic currents in an allosteric manner in vitro upon overexpression of inhibitory α1β2 GABAA receptors in various expression systems. However, in plants or humans, i.e., following intake via inhalation or ingestion, linalool undergoes metabolic modifications including oxygenation and acetylation, which may affect the modulatory efficacy of the generated linalool derivatives. Here, we analyzed the modulatory potential of linalool derivatives at α1β2γ2 GABAA receptors upon transient overexpression. Following receptor expression control, electrophysiological recordings in a whole cell configuration were used to determine the chloride influx upon co-application of GABA EC10−30 together with the modulatory substance. Our results show that only oxygenated linalool metabolites at carbon 8 positively affect GABAergic currents whereas derivatives hydroxylated or carboxylated at carbon 8 were rather ineffective. Acetylated linalool derivatives resulted in non-significant changes of GABAergic currents. We can conclude that metabolism of linalool reduces its positive allosteric potential at GABAA receptors compared to the significant potentiation effects of the parent molecule linalool itself.
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Affiliation(s)
- Sinem Milanos
- Institute of Clinical Neurobiology, Julius-Maximilians-University of WürzburgWürzburg, Germany.,Department of Chemistry and Pharmacy, Food Chemistry, Emil-Fischer-Center, Friedrich-Alexander-University Erlangen-NürnbergErlangen, Germany
| | - Shaimaa A Elsharif
- Department of Chemistry and Pharmacy, Food Chemistry, Emil-Fischer-Center, Friedrich-Alexander-University Erlangen-NürnbergErlangen, Germany
| | - Dieter Janzen
- Institute of Clinical Neurobiology, Julius-Maximilians-University of WürzburgWürzburg, Germany
| | - Andrea Buettner
- Department of Chemistry and Pharmacy, Food Chemistry, Emil-Fischer-Center, Friedrich-Alexander-University Erlangen-NürnbergErlangen, Germany.,Department of Sensory Analytics, Fraunhofer Institute for Process Engineering and PackagingFreising, Germany
| | - Carmen Villmann
- Institute of Clinical Neurobiology, Julius-Maximilians-University of WürzburgWürzburg, Germany
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Sahin S, Eulenburg V, Kreis W, Villmann C, Pischetsrieder M. Three-Step Test System for the Identification of Novel GABA A Receptor Modulating Food Plants. PLANT FOODS FOR HUMAN NUTRITION (DORDRECHT, NETHERLANDS) 2016; 71:355-360. [PMID: 27392961 DOI: 10.1007/s11130-016-0566-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Potentiation of γ-amino butyric acid (GABA)-induced GABAA receptor (GABAAR) activation is a common pathway to achieve sedative, sleep-enhancing, anxiolytic, and antidepressant effects. Presently, a three-component test system was established for the identification of novel GABAAR modulating food plants. In the first step, potentiation of GABA-induced response of the GABAAR was analysed by two-electrode voltage clamp (TEVC) for activity on human α1β2-GABAAR expressed in Xenopus laevis oocytes. Positively tested food plants were then subjected to quantification of GABA content by high-performance liquid chromatography with fluorescence detection (HPLC-FLD) to exclude test foods, which evoke a TEVC-response by endogenous GABA. In the third step, specificity of GABAA-modulating activity was assessed by TEVC analysis of Xenopus laevis oocytes expressing the homologous glycine receptor (GlyR). The three-component test was then applied to screen 10 aqueous extracts of food plants for their GABAAR activity. Thus, hop cones (Humulus lupulus) and Sideritis sipylea were identified as the most potent specific GABAAR modulators eliciting significant potentiation of the current by 182 ± 27 and 172 ± 19 %, respectively, at the lowest concentration of 0.5 μg/mL. The extracts can now be further evaluated by in vivo studies and by structural evaluation of the active components.
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Affiliation(s)
- Sümeyye Sahin
- Food Chemistry Unit, Department of Chemistry and Pharmacy, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Schuhstr. 19, 91052, Erlangen, Germany
| | - Volker Eulenburg
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Fahrstr. 17, 91054, Erlangen, Germany
| | - Wolfgang Kreis
- Department of Biology, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Staudtstr. 5, 91058, Erlangen, Germany
| | - Carmen Villmann
- Institute for Clinical Neurobiology, Universitätsklinikum Würzburg, Versbacherstr. 5, 97078, Würzburg, Germany
| | - Monika Pischetsrieder
- Food Chemistry Unit, Department of Chemistry and Pharmacy, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Schuhstr. 19, 91052, Erlangen, Germany.
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van Brederode J, Atak S, Kessler A, Pischetsrieder M, Villmann C, Alzheimer C. The terpenoids Myrtenol and Verbenol act on δ subunit-containing GABAA receptors and enhance tonic inhibition in dentate gyrus granule cells. Neurosci Lett 2016; 628:91-7. [DOI: 10.1016/j.neulet.2016.06.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Revised: 06/09/2016] [Accepted: 06/12/2016] [Indexed: 10/21/2022]
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A Systematic Review of the Anxiolytic-Like Effects of Essential Oils in Animal Models. Molecules 2015; 20:18620-60. [PMID: 26473822 PMCID: PMC6332383 DOI: 10.3390/molecules201018620] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 09/24/2015] [Accepted: 10/02/2015] [Indexed: 01/22/2023] Open
Abstract
The clinical efficacy of standardized essential oils (such as Lavender officinalis), in treating anxiety disorders strongly suggests that these natural products are an important candidate source for new anxiolytic drugs. A systematic review of essential oils, their bioactive constituents, and anxiolytic-like activity is conducted. The essential oil with the best profile is Lavendula angustifolia, which has already been tested in controlled clinical trials with positive results. Citrus aurantium using different routes of administration also showed significant effects in several animal models, and was corroborated by different research groups. Other promising essential oils are Citrus sinensis and bergamot oil, which showed certain clinical anxiolytic actions; along with Achillea wilhemsii, Alpinia zerumbet, Citrus aurantium, and Spiranthera odoratissima, which, like Lavendula angustifolia, appear to exert anxiolytic-like effects without GABA/benzodiazepine activity, thus differing in their mechanisms of action from the benzodiazepines. The anxiolytic activity of 25 compounds commonly found in essential oils is also discussed.
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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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Gostner JM, Ganzera M, Becker K, Geisler S, Schroecksnadel S, Überall F, Schennach H, Fuchs D. Lavender oil suppresses indoleamine 2,3-dioxygenase activity in human PBMC. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2014; 14:503. [PMID: 25515049 PMCID: PMC4301885 DOI: 10.1186/1472-6882-14-503] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 12/09/2014] [Indexed: 12/30/2022]
Abstract
BACKGROUND Lavender remedies have been used in traditional medicine because of antimicrobial, anti-inflammatory and mood alleviating effects, but underlying molecular mechanisms are not yet fully elucidated. Recently, studies investigating the effects of lavender oil in the context of psychiatric disorders have indicated potent pharmacological properties. Metabolism of tryptophan by indoleamine 2,3-dioxygenase (IDO) was found to provide a biochemical link between immunology and neuroendocrinology and to be a frequent target of natural products. METHODS In this in vitro study, interferences of lavender oil and constituents (-)-linalool, (+)-α-pinene and (+)-limonene with tryptophan catabolism by IDO and formation of neopterin via guanosine triphosphate (GTP)-cyclohydrolase-I and of interferon-γ have been investigated using unstimulated and phytohemagglutinin (PHA)-stimulated human peripheral blood mononuclear cells (PBMC). RESULTS Treatment with lavender oil dose-dependently suppressed PHA-induced tryptophan breakdown and kynurenine formation. Similar effects were observed for the three constituents. In parallel, formation of neopterin and interferon-γ was diminished upon lavender oil treatment. In unstimulated PBMC, effect of lavender oil treatment was similar, but less pronounced. CONCLUSION Data from this in vitro study suggest that lavender oil treatment might contribute to the modulation of the immune and neuroendocrine system by interfering with activation-induced tryptophan breakdown and IDO activity.
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Positive allosteric modulation of the GHB high-affinity binding site by the GABAA receptor modulator monastrol and the flavonoid catechin. Eur J Pharmacol 2014; 740:570-7. [PMID: 24973695 DOI: 10.1016/j.ejphar.2014.06.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 06/16/2014] [Accepted: 06/18/2014] [Indexed: 11/21/2022]
Abstract
γ-Hydroxybutyric acid (GHB) is a metabolite of γ-aminobutyric acid (GABA) and a proposed neurotransmitter in the mammalian brain. We recently identified α4βδ GABAA receptors as possible high-affinity GHB targets. GABAA receptors are highly sensitive to allosteric modulation. Thus to investigate whether GHB high-affinity binding sites are also sensitive to allosteric modulation, we screened both known GABAA receptor ligands and a library of natural compounds in the rat cortical membrane GHB specific high-affinity [3H]NCS-382 binding assay. Two hits were identified: Monastrol, a positive allosteric modulator of GABA function at δ-containing GABAA receptors, and the naturally occurring flavonoid catechin. These compounds increased [3H]NCS-382 binding to 185-272% in high micromolar concentrations. Monastrol and (+)-catechin significantly reduced [3H]NCS-382 dissociation rates and induced conformational changes in the binding site, demonstrating a positive allosteric modulation of radioligand binding. Surprisingly, binding of [3H]GHB and the GHB high-affinity site-specific radioligands [125I]BnOPh-GHB and [3H]HOCPCA was either decreased or only weakly increased, indicating that the observed modulation was critically probe-dependent. Both monastrol and (+)-catechin were agonists at recombinant α4β3δ receptors expressed in Xenopus laevis oocytes. When monastrol and GHB were co-applied no changes were seen compared to the individual responses. In summary, we have identified the compounds monastrol and catechin as the first allosteric modulators of GHB high-affinity binding sites. Despite their relatively weak affinity, these compounds may aid in further characterization of the GHB high-affinity sites that are likely to represent certain GABAA receptors.
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Heinlein A, Metzger M, Walles H, Buettner A. Transport of hop aroma compounds across Caco-2 monolayers. Food Funct 2014; 5:2719-30. [DOI: 10.1039/c3fo60675a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Hop aroma compounds and digestive transformation products thereof were investigated in view of their human intestinal absorption and biotransformation processes.
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Affiliation(s)
- A. Heinlein
- Department of Chemistry and Pharmacy
- Food Chemistry
- University Erlangen-Nuremberg
- 91052 Erlangen, Germany
| | - M. Metzger
- Tissue Engineering and Regenerative Medicine
- University Wuerzburg
- 97070 Wuerzburg, Germany
| | - H. Walles
- Tissue Engineering and Regenerative Medicine
- University Wuerzburg
- 97070 Wuerzburg, Germany
| | - A. Buettner
- Department of Chemistry and Pharmacy
- Food Chemistry
- University Erlangen-Nuremberg
- 91052 Erlangen, Germany
- Fraunhofer Institute for Process Engineering and Packaging (IVV)
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Kessler A, Sahin-Nadeem H, Lummis SCR, Weigel I, Pischetsrieder M, Buettner A, Villmann C. GABA(A) receptor modulation by terpenoids from Sideritis extracts. Mol Nutr Food Res 2013; 58:851-62. [PMID: 24273211 PMCID: PMC4384808 DOI: 10.1002/mnfr.201300420] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 09/12/2013] [Accepted: 09/15/2013] [Indexed: 11/10/2022]
Abstract
SCOPE GABAA receptors are modulated by Sideritis extracts. The aim of this study was to identify single substances from Sideritis extracts responsible for GABAA receptor modulation. METHODS AND RESULTS Single volatile substances identified by GC have been tested in two expression systems, Xenopus oocytes and human embryonic kidney cells. Some of these substances, especially carvacrol, were highly potent on GABAA receptors composed of α1β2 and α1β2γ2 subunits. All effects measured were independent from the presence of the γ2 subunit. As Sideritis extracts contain a high amount of terpenes, 13 terpenes with similar structure elements were tested in the same way. Following a prescreening on α1β2 GABAA receptors, a high-throughput method was used for identification of the most effective terpenoid substances on GABA-affinity of α1β2γ2 receptors expressed in transfected cell lines. Isopulegol, pinocarveol, verbenol, and myrtenol were the most potent modifiers of GABAA receptor function. CONCLUSION Comparing the chemical structures, the action of terpenes on GABAA receptors is most probably due to the presence of hydroxyl groups and a bicyclic character of the substances tested. We propose an allosteric modulation independent from the γ2 subunit and similar to the action of alcohols and anesthetics.
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Affiliation(s)
- Artur Kessler
- Department of Chemistry and Pharmacy, Food Chemistry Division, University of Erlangen-Nuernberg, Erlangen, Germany
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Okuyama S, Sawasaki E, Yokogoshi H. Conductor Compounds of Phenylpentane inMycoleptodonoides aitchisoniiMycelium Enhance the Release of Dopamine from Rat Brain Striatum Slices. Nutr Neurosci 2013; 7:107-11. [PMID: 15279496 DOI: 10.1080/10284150410001710429] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Monoterpene compound is a major component of essential oils in various aromatic species. Previous reports about the monoterpene compound linalool and its effect on the brain neurotransmitters glutamic acid, GABA and acetylcholine, but not catecholamines, have been reported. In this study, we investigated the effect of linalool or conductor compounds of phenylpentane, including 1-phenyl-3-pentanol and 1-phenyl-3-pentanone, on dopamine release using rat striatal slices. The edible mushroom Mycoleptodonoides aitchisonii belongs to the Climacodontaceae family, and its cultivate medium or mycelium contains derivatives of the fragrant conductor compound, phenylpentane. Compared to basal levels, 2.5 microg linalool increased dopamine from striatal slices 3-fold. A 4-fold increase in dopamine release resulted from 2.5 microg 1-phenyl-3-pentanol administration, while a half dose of this compound induced a 2.5-fold increase. A greater than 2-fold increase resulted with 2.5 microg 1-phenyl-3-pentanone. These data indicate that striatum has sensitivity for these fragrant compounds and different releasing effects result with differ structures. These actions may affect other neurotransmitters and influence brain function.
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Affiliation(s)
- Satoshi Okuyama
- Laboratory of Nutritional Biochemistry, COE Program in the 21st Century and Cooperation of Innovative Technology and Advanced Research in Evolutional Area (CITY AREA), University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan.
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Nasrin S, Osano A, Ito Y, Yamada S. Beneficial effects of Gosha-jinki-gan and green tea extract in rats with chemical cystitis. J Pharmacol Sci 2013; 122:270-7. [PMID: 23842285 DOI: 10.1254/jphs.13075fp] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
The aim of this study was to characterize pharmacological effects of gosha-jinki-gan (GJG) and green tea extract (GTE), on urodynamic parameters, bladder receptors, and urinary cytokines in rats with cyclophosphamide (CYP)-induced cystitis. Urodynamic parameters in CYP-treated rats were measured using the cystometric method. Muscarinic and purinergic receptors in rat tissues were measured by radioreceptor assays. Urinary cytokine levels were measured with ELISA kits. GJG and GTE were orally administered to rats once a day for 7 days. The GJG treatment significantly ameliorated changes in urodynamic parameters in CYP-treated rats. Similar treatment with GTE slightly attenuated changes in urodynamic parameters. The maximal number of binding sites for [³H]NMS and [³H]αβ-MeATP in the bladder was significantly lower in CYP-treated rats than in sham rats. Such a reduction in receptor density was significantly attenuated by the GJG treatment. GTE treatment also significantly attenuated the down-regulation of muscarinic receptors, but not P2X receptors in bladders of rats with CYP-induced cystitis. The elevation in urinary cytokine levels in CYP-treated rats was effectively attenuated by GJG treatment. The elevation in cytokine levels in CYP-treated rats was alleviated by GTE treatment. In conclusion, GJG may be a pharmacologically useful plant extract for cystitis.
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Affiliation(s)
- Sweety Nasrin
- Department of Pharmacokinetics and Pharmacodynamics, School of Pharmaceutical Sciences, University of Shizuoka, Japan
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26
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Kessler A, Villmann C, Sahin-Nadeem H, Pischetsrieder M, Buettner A. GABAA receptor modulation by the volatile fractions of Sideritis species used as ‘Greek’ or ‘Turkish’ mountain tea. FLAVOUR FRAG J 2012. [DOI: 10.1002/ffj.3099] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Artur Kessler
- Department of Chemistry and Pharmacy; University of Erlangen-Nuremberg; 91052; Erlangen; Germany
| | - Carmen Villmann
- Institute of Biochemistry; University Erlangen-Nuremberg; 91054; Erlangen; Germany
| | - Hilal Sahin-Nadeem
- Akdeniz University; Faculty of Engineering, Department of Food Engineering; 07059; Antalya; Turkey
| | - Monika Pischetsrieder
- Department of Chemistry and Pharmacy; University of Erlangen-Nuremberg; 91052; Erlangen; Germany
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Guimarães AG, Quintans JSS, Quintans-Júnior LJ. Monoterpenes with Analgesic Activity-A Systematic Review. Phytother Res 2012; 27:1-15. [DOI: 10.1002/ptr.4686] [Citation(s) in RCA: 192] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Revised: 03/03/2012] [Accepted: 03/07/2012] [Indexed: 11/06/2022]
Affiliation(s)
- Adriana G. Guimarães
- Departamento de Fisiologia; Universidade Federal de Sergipe (DFS/UFS); São Cristóvão SE Brazil
| | - Jullyana S. S. Quintans
- Departamento de Fisiologia; Universidade Federal de Sergipe (DFS/UFS); São Cristóvão SE Brazil
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Heldwein CG, Silva LL, Reckziegel P, Barros FMC, Bürger ME, Baldisserotto B, Mallmann CA, Schmidt D, Caron BO, Heinzmann BM. Participation of the GABAergic system in the anesthetic effect of Lippia alba (Mill.) N.E. Brown essential oil. Braz J Med Biol Res 2012; 45:436-43. [PMID: 22473320 PMCID: PMC3854290 DOI: 10.1590/s0100-879x2012007500052] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Accepted: 03/20/2012] [Indexed: 02/03/2023] Open
Abstract
The objective of this study was to identify the possible involvement of the GABAergic system in the anesthetic effect of Lippia alba essential oil (EO). We propose a new animal model using silver catfish (Rhamdia quelen) exposed to an anesthetic bath to study the mechanism of action of EO. To observe the induction and potentiation of the anesthetic effect of EO, juvenile silver catfish (9.30 ± 1.85 g; 10.15 ± 0.95 cm; N = 6) were exposed to various concentrations of L. alba EO in the presence or absence of diazepam [an agonist of high-affinity binding sites for benzodiazepinic (BDZ) sites coupled to the GABA A receptor complex]. In another experiment, fish (N = 6) were initially anesthetized with the EO and then transferred to an anesthetic-free aquarium containing flumazenil (a selective antagonist of binding sites for BDZ coupled to the GABA A receptor complex) or water to assess recovery time from the anesthesia. In this case, flumazenil was used to observe the involvement of the GABA-BDZ receptor in the EO mechanism of action. The results showed that diazepam potentiates the anesthetic effect of EO at all concentrations tested. Fish exposed to diazepam and EO showed faster recovery from anesthesia when flumazenil was added to the recovery bath (12.0 ± 0.3 and 7.2 ± 0.7, respectively) than those exposed to water (9.2 ± 0.2 and 3.5 ± 0.3, respectively). In conclusion, the results demonstrated the involvement of the GABAergic system in the anesthetic effect of L. alba EO on silver catfish.
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Affiliation(s)
- C G Heldwein
- Departamento de Farmácia Industrial, Universidade Federal de Santa Maria, RS, Brasil
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Heinlein A, Buettner A. Monitoring of biotransformation of hop aroma compounds in an in vitro digestion model. Food Funct 2012; 3:1059-67. [DOI: 10.1039/c2fo30061c] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Analysis of Indonesian Spice Essential Oil Compounds That Inhibit Locomotor Activity in Mice. Pharmaceuticals (Basel) 2011. [PMCID: PMC4055880 DOI: 10.3390/ph4040590] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Some fragrance components of spices used for cooking are known to have an effect on human behavior. The aim of this investigation was to examine the effect of the essential oils of basil (Ocimum formacitratum L.) leaves, lemongrass (Cymbopogon citrates L.) herbs, ki lemo (Litsea cubeba L.) bark, and laja gowah (Alpinia malaccencis Roxb.) rhizomes on locomotor activity in mice and identify the active component(s) that might be responsible for the activity. The effect of the essential oils was studied by a wheel cage method and the active compounds of the essential oils were identified by GC/MS analysis. The essential oils were administered by inhalation at doses of 0.1, 0.3, and 0.5 mL/cage. The results showed that the four essential oils had inhibitory effects on locomotor activity in mice. Inhalation of the essential oils of basil leaves, lemongrass herbs, ki lemo bark, and laja gowah rhizomes showed the highest inhibitory activity at doses of 0.5 (57.64%), 0.1 (55.72%), 0.5 (60.75%), and 0.1 mL/cage (47.09%), respectively. The major volatile compounds 1,8-cineole, α-terpineol, 4-terpineol, citronelol, citronelal, and methyl cinnamate were identified in blood plasma of mice after inhalation of the four oils. These compounds had a significant inhibitory effect on locomotion after inhalation. The volatile compounds of essential oils identified in the blood plasma may correlate with the locomotor-inhibiting properties of the oil when administered by inhalation.
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Identification of compounds in the essential oil of nutmeg seeds (Myristica fragrans Houtt.) that inhibit locomotor activity in mice. Int J Mol Sci 2010; 11:4771-81. [PMID: 21151471 PMCID: PMC3000115 DOI: 10.3390/ijms11114771] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Revised: 11/08/2010] [Accepted: 11/15/2010] [Indexed: 11/25/2022] Open
Abstract
The present study was designed to evaluate the inhibitory effect of nutmeg (Myristica fragrans Houtt.) seed essential oil on the locomotor activity of mice in a wheel cage. Active compounds in the essential oil were identified by off-line solid phase extraction (SPE-C18) and GC/MS analysis. The essential oil was administered by inhalation at doses of 0.1, 0.3, and 0.5 mL/cage. The results showed that inhalation of nutmeg seed essential oil at a dose of 0.5 mL/cage decreased locomotion by 68.62%; and inhalation of 0.1 and 0.3 mL/cage inhibited locomotion by 62.81% and 65.33%, respectively. Generally, larger doses and longer administrations of nutmeg seed essential oil exhibited greater locomotor inhibition. Subsequently, the plasma concentrations of essential oil compounds were measured. The most concentrated compound in the plasma was myristicin. Half an hour after the addition of 1 mL/cage of nutmeg seed oil, the plasma concentration of myristicin was 3.7 μg/mL; one and two hours after the addition, the blood levels of myristicin were 5.2 μg/mL and 7.1 μg/mL, respectively. Other essential oil compounds identified in plasma were safrole (two-hour inhalation: 1.28 μg/mL), 4-terpineol (half-hour inhalation: 1.49 μg/mL, one-hour inhalation: 2.95 μg/mL, two-hour inhalation: 6.28 μg/mL) and fatty esters. The concentrations of the essential oil compounds in the blood plasma were relatively low (μg/mL or ppm). In conclusion, the volatile compounds of nutmeg seed essential oil identified in the blood plasma may correlate with the locomotor-inhibiting properties of the oil when administered by inhalation.
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Affiliation(s)
- Hector W H Tsang
- Neuropsychiatric Rehabilitation Laboratory, Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Honk Kong.
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Mewett KN, Fernandez SP, Pasricha AK, Pong A, Devenish SO, Hibbs DE, Chebib M, Johnston GAR, Hanrahan JR. Synthesis and biological evaluation of flavan-3-ol derivatives as positive modulators of GABAA receptors. Bioorg Med Chem 2009; 17:7156-73. [PMID: 19783443 DOI: 10.1016/j.bmc.2009.08.062] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Revised: 08/21/2009] [Accepted: 08/29/2009] [Indexed: 10/20/2022]
Abstract
We herein describe the synthesis and positive modulatory activities of a small library of flavan-3-ol derivatives on alpha(1)beta(2)gamma(2L) GABA(A) receptors. Structure-activity relationships of various substituents on the A, B and C rings were evaluated in a functional electrophysiological assay. A trans configuration and a 3-acetoxy moiety are essential for activity. Substitution of the B ring appears to be well tolerated, with substituents on the A ring playing a major role in determining activity.
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Affiliation(s)
- Kenneth N Mewett
- Adrien Albert Laboratory of Medicinal Chemistry, Department of Pharmacology, Faculty of Medicine, The University of Sydney, NSW 2006, Australia
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MUBASSARA S, HOSSAIN SJ, AHMED F, YAMAMOTO M, TAN N, AOSHIMA H. Potentiation of the Response of GABAA Receptors by Bangladeshi Medicinal Plants. FOOD SCIENCE AND TECHNOLOGY RESEARCH 2009. [DOI: 10.3136/fstr.15.315] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Kim TH, Lim JM, Kim SS, Kim J, Park M, Song JH. Effects of (-) epigallocatechin-3-gallate on Na(+) currents in rat dorsal root ganglion neurons. Eur J Pharmacol 2008; 604:20-6. [PMID: 19111536 DOI: 10.1016/j.ejphar.2008.12.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2008] [Revised: 11/20/2008] [Accepted: 12/09/2008] [Indexed: 11/24/2022]
Abstract
The natural product (-) epigallocatechin-3-gallate (EGCG) is the major polyphenolic constituent found in green tea. Dorsal root ganglion neurons are primary sensory neurons, and express tetrodotoxin-sensitive and tetrodotoxin-resistant Na(+) currents, which are both actively involved in the generation and propagation of nociceptive signals. Effects of EGCG on tetrodotoxin-sensitive and tetrodotoxin-resistant Na(+) currents in rat dorsal root ganglion neurons were investigated using the whole-cell variation of the patch-clamp techniques. EGCG inhibited both types of Na(+) currents potently and in a concentration-dependent manner. The apparent dissociation constant, K(d), was estimated to be 0.74 and 0.80 microM for tetrodotoxin-sensitive and tetrodotoxin-resistant Na(+) currents, respectively. (-) Epigallocatechin (EGC) was far less potent to inhibit Na(+) currents than EGCG, suggesting that gallate moiety of EGCG is an important functional group to modulate Na(+) currents. EGCG had little or no effect on the activation or steady-state inactivation voltage of either type of Na(+) current. EGCG simply reduced the availability of Na(+) channels for activation. Thus, EGCG appears to bind to resting Na(+) channels to inhibit them. EGCG slowed the recovery of tetrodotoxin-sensitive Na(+) current from inactivation. The property of EGCG to inhibit sensory Na(+) currents can be utilized to develop an analgesic agent.
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Affiliation(s)
- Tae Hoon Kim
- Department of Pharmacology, College of Medicine, Chung-Ang University, Seoul 156-756, Republic of Korea
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Flavan-3-ol derivatives are positive modulators of GABAA receptors with higher efficacy for the α2 subtype and anxiolytic action in mice. Neuropharmacology 2008; 55:900-7. [DOI: 10.1016/j.neuropharm.2008.06.069] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2008] [Revised: 06/30/2008] [Accepted: 06/30/2008] [Indexed: 11/19/2022]
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Mitou M, Shigemori Y, Aoshima H, Yokoyama S. Effect of dried bonito (katsuobushi) and some of its components on GABAA receptors. Food Chem 2008; 108:840-6. [DOI: 10.1016/j.foodchem.2007.11.045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2007] [Revised: 10/09/2007] [Accepted: 11/19/2007] [Indexed: 10/22/2022]
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Kako H, Fukumoto S, Kobayashi Y, Yokogoshi H. Effects of direct exposure of green odour components on dopamine release from rat brain striatal slices and PC12 cells. Brain Res Bull 2008; 75:706-12. [DOI: 10.1016/j.brainresbull.2007.11.016] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2007] [Revised: 11/27/2007] [Accepted: 11/27/2007] [Indexed: 11/27/2022]
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Hossain SJ, Aoshima H, Koda H, Kiso Y. Review of Functional Studies of Beverage Components Acting on the Recombinant GABAANeuroreceptor, and Na+/Glucose Cotransporter-Response Using theXenopusOocyte Expression System and Electrophysiological Measurements. FOOD BIOTECHNOL 2007. [DOI: 10.1080/08905430701534081] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Aoshima H, Hirata S, Ayabe S. Antioxidative and anti-hydrogen peroxide activities of various herbal teas. Food Chem 2007. [DOI: 10.1016/j.foodchem.2006.08.032] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Umezu T, Nagano K, Ito H, Kosakai K, Sakaniwa M, Morita M. Anticonflict effects of lavender oil and identification of its active constituents. Pharmacol Biochem Behav 2006; 85:713-21. [PMID: 17173962 DOI: 10.1016/j.pbb.2006.10.026] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Revised: 10/27/2006] [Accepted: 10/31/2006] [Indexed: 10/23/2022]
Abstract
The pharmacological effects of lavender oil were investigated using two conflict tests in ICR mice, and then the active constituents were identified. Lavender oil produced significant anticonflict effects at 800 and 1600 mg/kg in the Geller conflict test and at 800 mg/kg in the Vogel conflict test, suggesting that the oil has an anti-anxiety effect. Analysis using GC/MS revealed that lavender oil contains 26 constituents, among which alpha-pinene (ratio, 0.22%), camphene (0.06%), beta-myrcene (5.33%), p-cymene (0.3%), limonene (1.06%), cineol (0.51%), linalool (26.12%), borneol (1.21%), terpinene-4-ol (4.64%), linalyl acetate (26.32%), geranyl acetate (2.14%) and caryophyllene (7.55%) were identified. We examined the effects of linalool, linalyl acetate, borneol, camphene, cineol, terpinen-4-ol, alpha-pinene and beta-myrcene using the Geller and Vogel conflict tests in ICR mice. Cineol, terpinen-4-ol, alpha-pinene and beta-myrcene did not produce any significant anticonflict effects in the Geller test. Linalyl acetate did not produce any significant anticonflict effects in either test. Both borneol and camphene at 800 mg/kg produced significant anticonflict effects in the Geller, but not in the Vogel conflict test. Linalool, a major constituent of lavender oil, produced significant anticonflict effects at 600 and 400 mg/kg in the Geller and Vogel tests, respectively, findings that were similar to those of lavender oil. Thus, we concluded that linalool is the major pharmacologically active constituent involved in the anti-anxiety effect of lavender oil.
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Affiliation(s)
- Toyoshi Umezu
- Environmental Chemistry Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-0053, Japan.
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Johnston GAR, Hanrahan JR, Chebib M, Duke RK, Mewett KN. Modulation of Ionotropic GABA Receptors by Natural Products of Plant Origin. GABA 2006; 54:285-316. [PMID: 17175819 DOI: 10.1016/s1054-3589(06)54012-8] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Campbell EL, Chebib M, Johnston GAR. The dietary flavonoids apigenin and (-)-epigallocatechin gallate enhance the positive modulation by diazepam of the activation by GABA of recombinant GABA(A) receptors. Biochem Pharmacol 2005; 68:1631-8. [PMID: 15451406 DOI: 10.1016/j.bcp.2004.07.022] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2004] [Accepted: 07/08/2004] [Indexed: 11/29/2022]
Abstract
The dietary flavonoids apigenin, genistein and (-)-epigallocatechin gallate (EGCG) inhibited the activation by GABA (40 microM) of recombinant human alpha1beta2gamma2L GABA(A) receptors expressed in Xenopus laevis oocytes with IC(50) values of 8, 30 and 15 microM, respectively. Apigenin and genistein also acted as GABA antagonists at flumazenil-insensitive alpha1beta2 GABA(A) receptors, indicating that they were not acting as negative modulators through flumazenil-sensitive benzodiazepine sites on GABA(A) receptors. In addition to these GABA(A) antagonist effects, a novel second order modulatory action was found for apigenin and EGCG on the first order enhancement of GABA responses by diazepam. Apigenin (1 microM) and EGCG (0.1 microM) enhanced the modulatory action of diazepam (3 microM) on the activation by GABA (5 microM) of recombinant human alpha1beta2gamma2L GABA(A) receptors by up to 22% and 52%, respectively. This was not found with genistein, nor was it observed with enhancement by allopregnanolone or pentobarbitone.
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Affiliation(s)
- Erica L Campbell
- Department of Pharmacology, The University of Sydney, Sydney 2006, NSW, Australia
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