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Torquati L, Gajanand T, Cox ER, Willis C, Zaugg J, Keating SE, Coombes JS. Effects of exercise intensity on gut microbiome composition and function in people with type 2 diabetes. Eur J Sport Sci 2022; 23:530-541. [PMID: 35107058 DOI: 10.1080/17461391.2022.2035436] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Exercise is positively associated with higher microbial diversity, but there is limited information on exercise intensity's effect on gut microbiome composition and function in clinical populations. This study examines whether different intensities of exercise exert differential effects on gut microbiome composition and function in low active people with type 2 diabetes.This is a sub-study of the Exercise for Type 2 Diabetes Study, a single centre, prospective, randomised controlled trial. Participants (n=12) completed 8-weeks of combined aerobic and resistance moderate intensity continuous training (C-MICT) or combined aerobic and resistance high-intensity interval training (C-HIIT). Faecal samples were collected before and after intervention to measure gut microbiome composition and metabolic pathways (metagenome shotgun sequencing) and short-chain fatty acids.Post-exercise α-diversity was different between groups as was the relative abundance of specific taxa was (p<0.05). Post-exercise relative abundance of Bifidobacterium, A. municiphila, and butyrate-producers Lachnospira eligens, Enterococcus spp., and Clostridium Cluster IV were higher at lower exercise intensity. Other butyrate-producers (from Eryspelothrichales and Oscillospirales), and methane producer Methanobrevibacter smithii were higher at higher exercise intensity. Pyruvate metabolism (ko00620),COG 'Cell wall membrane envelope biogenesis' and 'Unknown function' pathways were significantly different between groups and higher in C-MICT post-exercise. Differential abundance analysis on KO showed higher expression of Two-component system in C-HIIT. Transcription factors and 'unknown metabolism' related pathways decreased in both groups. There were no significant between group changes in faecal short chain fatty acids.Exercise intensity had a distinct effect on gut microbiome abundance and metabolic function, without impacting short-chain fatty acid outputTrial registration: Australian New Zealand Clinical Trials Registry identifier: ACTRN12615000475549..
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Affiliation(s)
- L Torquati
- Department of Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX1 2LU, United Kingdom
| | - T Gajanand
- Centre for Research on Exercise, Physical Activity and Health, The University of Queensland, Brisbane, St Lucia campus 4072, Australia
| | - E R Cox
- Centre for Research on Exercise, Physical Activity and Health, The University of Queensland, Brisbane, St Lucia campus 4072, Australia
| | - Crg Willis
- Department of Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX1 2LU, United Kingdom
| | - J Zaugg
- Australian Centre for Ecogenomics, The University of Queensland, Brisbane, St Lucia campus 4072, Australia
| | - S E Keating
- Centre for Research on Exercise, Physical Activity and Health, The University of Queensland, Brisbane, St Lucia campus 4072, Australia
| | - J S Coombes
- Centre for Research on Exercise, Physical Activity and Health, The University of Queensland, Brisbane, St Lucia campus 4072, Australia
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Schramm A, Ebrahimi SN, Raith M, Zaugg J, Rueda DC, Hering S, Hamburger M. Phytochemical profiling of Curcuma kwangsiensis rhizome extract, and identification of labdane diterpenoids as positive GABAA receptor modulators. Phytochemistry 2013; 96:318-329. [PMID: 24011802 DOI: 10.1016/j.phytochem.2013.08.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 07/29/2013] [Accepted: 08/09/2013] [Indexed: 06/02/2023]
Abstract
An ethyl acetate extract of Curcuma kwangsiensis S.G. Lee & C.F. Liang (Zingiberaceae) rhizomes (100 μg/ml) enhanced the GABA-induced chloride current (IGABA) through GABAA receptors of the α1β2γ2S subtype by 79.0±7.0%. Potentiation of IGABA was measured using the two-microelectrode voltage-clamp technique and Xenopus laevis oocytes. HPLC-based activity profiling of the crude extract led to the identification of 11 structurally related labdane diterpenoids, including four new compounds. Structure elucidation was achieved by comprehensive analysis of on-line (LC-PDA-ESI-TOF-MS) and off-line (microprobe 1D and 2D NMR) spectroscopic data. The absolute configuration of the compounds was established by comparison of experimental and calculated ECD spectra. Labdane diterpenes represent a new class of plant secondary metabolites eliciting positive GABAA receptor modulation. The highest efficiency was observed for zerumin A (maximum potentiation of IGABA by 309.4±35.6%, and EC50 of 24.9±8.8 μM).
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Affiliation(s)
- Anja Schramm
- Division of Pharmaceutical Biology, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
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3
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Khom S, Strommer B, Schöffmann A, Hintersteiner J, Baburin I, Erker T, Schwarz T, Schwarzer C, Zaugg J, Hamburger M, Hering S. GABAA receptor modulation by piperine and a non-TRPV1 activating derivative. Biochem Pharmacol 2013; 85:1827-36. [PMID: 23623790 PMCID: PMC3776227 DOI: 10.1016/j.bcp.2013.04.017] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 04/15/2013] [Accepted: 04/17/2013] [Indexed: 01/11/2023]
Abstract
The action of piperine (the pungent component of pepper) and its derivative SCT-66 ((2E,4E)-5-(1,3-benzodioxol-5-yl))-N,N-diisobutyl-2,4-pentadienamide) on different gamma-aminobutyric acid (GABA) type A (GABAA) receptors, transient-receptor-potential-vanilloid-1 (TRPV1) receptors and behavioural effects were investigated. GABAA receptor subtypes and TRPV1 receptors were expressed in Xenopus laevis oocytes. Modulation of GABA-induced chloride currents (IGABA) by piperine and SCT-66 and activation of TRPV1 was studied using the two-microelectrode-voltage-clamp technique and fast perfusion. Their effects on explorative behaviour, thermoregulation and seizure threshold were analysed in mice. Piperine acted with similar potency on all GABAA receptor subtypes (EC50 range: 42.8 ± 7.6 μM (α2β2)–59.6 ± 12.3 μM (α3β2)). IGABA modulation by piperine did not require the presence of a γ2S-subunit, suggesting a binding site involving only α and β subunits. IGABA activation was slightly more efficacious on receptors formed from β2/3 subunits (maximal IGABA stimulation through α1β3 receptors: 332 ± 64% and α1β2: 271 ± 36% vs. α1β1: 171 ± 22%, p < 0.05) and α3-subunits (α3β2: 375 ± 51% vs. α5β2:136 ± 22%, p < 0.05). Replacing the piperidine ring by a N,N-diisobutyl residue (SCT-66) prevents interactions with TRPV1 and simultaneously increases the potency and efficiency of GABAA receptor modulation. SCT-66 displayed greater efficacy on GABAA receptors than piperine, with different subunit-dependence. Both compounds induced anxiolytic, anticonvulsant effects and reduced locomotor activity; however, SCT-66 induced stronger anxiolysis without decreasing body temperature and without the proconvulsive effects of TRPV1 activation and thus may serve as a scaffold for the development of novel GABAA receptor modulators.
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Affiliation(s)
- Sophia Khom
- Department of Pharmacology and Toxicology, University of Vienna, Althanstraße 14, A-1090 Wien, Austria
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Ebrahimi SN, Zimmermann S, Zaugg J, Smiesko M, Brun R, Hamburger M. Abietane diterpenoids from Salvia sahendica--antiprotozoal activity and determination of their absolute configurations. Planta Med 2013; 79:150-156. [PMID: 23299758 DOI: 10.1055/s-0032-1328063] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In a screening of Iranian plants for antiprotozoal activity, an n-hexane extract of the roots of Salvia sahendica potently inhibited the growth of Plasmodium falciparum K1 strain. Subsequent HPLC-based activity profiling led to the identification of seven known and one new abietane-type diterpenoid. Structure elucidation was achieved by analysis of spectroscopic data including 1D and 2D NMR. The absolute configuration of sahandol (7) and sahandone (8) were assigned by comparison of experimental ECD spectra with calculated ECD data, using time-dependent density functional theory and methanol as the solvent. In vitro biological activity against P. falciparum and Trypanosoma brucei rhodesiense STIB 900 strain and cytotoxicity in rat myoblast (L6) cells were determined. The IC50 values of the compounds ranged from 0.8 µM to over 8.8 µM against P. falciparum, and from 1.8 µM to over 32.3 µM against T. brucei rhodesiense. The cytotoxic IC50 values ranged from 0.5-15.5 µM. Selectivity indices for P. falciparum were 0.1 to 18.2, and 0.1 to 1.2 for T. brucei rhodesiense.
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Affiliation(s)
- Samad N Ebrahimi
- Division of Pharmaceutical Biology, University of Basel, Basel, Switzerland
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Kim HJ, Baburin I, Zaugg J, Ebrahimi SN, Hering S, Hamburger M. HPLC-based activity profiling--discovery of sanggenons as GABAA receptor modulators in the traditional Chinese drug Sang bai pi (Morus alba root bark). Planta Med 2012; 78:440-447. [PMID: 22294264 DOI: 10.1055/s-0031-1298229] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
EtOAc extracts from two batches of Morus alba root bark (Sang bai pi) potentiated γ-aminobutyric acid (GABA)-induced chloride influx in Xenopus oocytes, which transiently expressed GABA (A) receptors of the subunit composition α₁β₂γ(2S). With the aid of HPLC-based activity profiling of the extract from the first batch, activity was traced to a peak subsequently identified as sanggenon G (3). The second batch had a different phytochemical profile, and HPLC-based activity profiling led to the identification of sanggenon C (4) and a stereoisomer of sanggenon D (2) as positive GABA (A) receptor modulators. The structurally related compound kuwanon L (1) was inactive. The sanggenons represent a new scaffold of positive GABA (A) receptor modulators.
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Affiliation(s)
- Hyun Jung Kim
- Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland
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Rueda DC, Zaugg J, Quitschau M, Reich E, Hering S, Hamburger M. Discovery of GABA(A) receptor modulator aristolactone in a commercial sample of the Chinese herbal drug "Chaihu" (Bupleurum chinense roots) unravels adulteration by nephrotoxic Aristolochia manshuriensis roots. Planta Med 2012; 78:207-210. [PMID: 22271081 DOI: 10.1055/s-0031-1298171] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In a two-microelectrode voltage clamp assay using Xenopus laevis oocytes, a petroleum ether extract prepared from a commercial sample of the traditional Chinese herbal drug labelled as " Chaihu" (Bupleurum chinense DC. roots) enhanced the I(GABA) by 156 % ± 22 % when tested at 100 µg/mL. By means of HPLC-based activity profiling combined with high-resolution LC-MS and microprobe NMR, the germacranolide aristolactone was identified as one of the main active compounds (EC₅₀ 56.02 µM ± 5.09 µM). However, aristolactone has been previously reported only from the genus Aristolochia (Aristolochiaceae), suggesting a possible adulteration. With the aid of a validated HPTLC protocol for detection of aristolochic acids and with reference samples, the commercial sample was confirmed to be a mixture of Aristolochia manshuriensis root and Bupleurum chinense root. This finding was corroborated by macroscopic inspection of the drug. This case of adulteration with a highly nephrotoxic drug raises concerns about adequate quality control of TCM drugs commercialized in Europe.
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Affiliation(s)
- Diana C Rueda
- Division of Pharmaceutical Biology, University of Basel, Basel, Switzerland
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Zaugg J, Ebrahimi SN, Smiesko M, Baburin I, Hering S, Hamburger M. Identification of GABA A receptor modulators in Kadsura longipedunculata and assignment of absolute configurations by quantum-chemical ECD calculations. Phytochemistry 2011; 72:2385-2395. [PMID: 21889177 PMCID: PMC3201904 DOI: 10.1016/j.phytochem.2011.08.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 07/14/2011] [Accepted: 08/04/2011] [Indexed: 05/31/2023]
Abstract
A petroleum ether extract of Kadsura longipedunculata enhanced the GABA-induced chloride current (I(GABA)) by 122.5±0.3% (n=2) when tested at 100 μg/ml in Xenopuslaevis oocytes expressing GABA A receptors (α(1)β(2)γ(2S) subtype) in two-microelectrode voltage clamp measurements. Thirteen compounds were subsequently identified by HPLC-based activity profiling as responsible for GABA A receptor activity and purified in preparative scale. 6-Cinnamoyl-6,7-dihydro-7-myrceneol and 5,6-dihydrocuparenic acid were thereby isolated for the first time. The determination of the absolute stereochemistry of these compounds was achieved by comparison of experimental and calculated ECD spectra. All but one of the 13 isolated compounds from K. longipedunculata potentiated I(GABA) through GABA A receptors composed of α(1)β(2)γ(2S) subunits in a concentration-dependent manner. Potencies ranged from 12.8±3.1 to 135.6±85.7 μM, and efficiencies ranged from 129.7±36.8% to 885.8±291.2%. The phytochemical profiles of petroleum ether extracts of Kadsura japonica fruits (114.1±2.6% potentiation of I(GABA) at 100 μg/ml, n=2), and Schisandra chinensis fruits (inactive at 100 μg/ml) were compared by HPLC-PDA-ESIMS with that of K. longipedunculata.
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Affiliation(s)
- Janine Zaugg
- Division of Pharmaceutical Biology, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
| | - Samad Nejad Ebrahimi
- Division of Pharmaceutical Biology, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
- Departement of Phytochemistry, Medicinal Plant and Drugs Research Institute, Shahid Beheshti University, G.C., Tehran, Iran
| | - Martin Smiesko
- Division of Molecular Modeling, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
| | - Igor Baburin
- Institute of Pharmacology and Toxicology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Steffen Hering
- Institute of Pharmacology and Toxicology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Matthias Hamburger
- Division of Pharmaceutical Biology, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
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8
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Zaugg J, Khom S, Eigenmann D, Baburin I, Hamburger M, Hering S. Identification and characterization of GABA(A) receptor modulatory diterpenes from Biota orientalis that decrease locomotor activity in mice. J Nat Prod 2011; 74:1764-1772. [PMID: 21793559 DOI: 10.1021/np200317p] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
An ethyl acetate extract of Biota orientalis leaves potentiated GABA-induced control current by 92.6% ± 22.5% when tested at 100 μg/mL in Xenopus laevis oocytes expressing GABA(A) receptors (α₁β₂γ(2S) subtype) in two-microelectrode voltage clamp measurements. HPLC-based activity profiling was used to identify isopimaric acid (4) and sandaracopimaric acid (5) as the compounds largely responsible for the activity. Sandaracopimaradienolal (3) was characterized as a new natural product. Compounds 4 and 5 were investigated for GABA(A) receptor subtype selectivity at the subtypes α₁β₁γ(2S), α₁β₂γ(2S), α₁β₃γ(2S), α₂β₂γ(2S), α₃β₂γ(2S), and α₅β₂γ(2S). Sandaracopimaric acid (5) was significantly more potent than isopimaric acid (4) at the GABA(A) receptor subtypes α₁β₁γ(2S), α₂β₂γ(2S), and α₅β₂γ(2S) (EC₅₀4: 289.5 ± 82.0, 364.8 ± 85.0, and 317.0 ± 83.7 μM vs EC₅₀5: 48.1 ± 13.4, 31.2 ± 4.8, and 40.7 ± 14.7 μM). The highest efficiency was reached by 4 and 5 on α₂- and α₃-containing receptor subtypes. In the open field test, ip administration of 5 induced a dose-dependent decrease of locomotor activity in a range of 3 to 30 mg/kg body weight in mice. No significant anxiolytic-like activity was observed in doses between 1 and 30 mg/kg body weight in mice.
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Affiliation(s)
- Janine Zaugg
- Division of Pharmaceutical Biology, University of Basel , Klingelbergstrasse 50, 4056 Basel, Switzerland
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Zaugg J, Eickmeier E, Ebrahimi SN, Baburin I, Hering S, Hamburger M. Positive GABA(A) receptor modulators from Acorus calamus and structural analysis of (+)-dioxosarcoguaiacol by 1D and 2D NMR and molecular modeling. J Nat Prod 2011; 74:1437-43. [PMID: 21563811 PMCID: PMC3199944 DOI: 10.1021/np200181d] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
In a two-microelectrode voltage clamp with Xenopus laevis oocytes, a petroleum ether extract of Acorus calamus rhizomes enhanced the GABA-induced chloride current through GABA(A) receptors of the α₁β₂γ(2S) subtype by 277% ± 9.7% (100 μg/mL). β-Asarone (1), (+)-dioxosarcoguaiacol (2), (+)-shyobunone (3), and (+)-preisocalamenediol (4) were subsequently identified as main active principles through HPLC-based activity profiling and targeted isolation. The compounds induced maximum potentiation of the chloride current ranging from 588% ± 126% (EC₅₀: 65.3 ± 21.6 μM) (2) to 1200% ± 163% (EC(50): 171.5 ± 34.6 μM) (1), whereas (-)-isoshyobunone (5) and (-)-acorenone (6) exhibited weak GABA(A) modulating properties (5: 164% ± 42.9%; EC₅₀: 109.4 ± 46.6 μM and 6: 241% ± 23.1%; EC₅₀: 34.0 ± 6.7 μM). The relative configuration of 2 was established as 4R*8S*10R* by NOESY experiments and conformational analysis.
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Affiliation(s)
- Janine Zaugg
- Division of Pharmaceutical Biology, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
| | - Eva Eickmeier
- Division of Pharmaceutical Biology, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
| | - Samad Nejad Ebrahimi
- Division of Pharmaceutical Biology, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
- Departement of Phytochemistry, Medicinal Plant and Drugs Research Institute, Shahid Beheshti University, G. C., Tehran, Iran
| | - Igor Baburin
- Departement of Pharmacology and Toxicology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Steffen Hering
- Departement of Pharmacology and Toxicology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Matthias Hamburger
- Division of Pharmaceutical Biology, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
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Zaugg J, Eickmeier E, Rueda DC, Hering S, Hamburger M. HPLC-based activity profiling of Angelica pubescens roots for new positive GABAA receptor modulators in Xenopus oocytes. Fitoterapia 2010; 82:434-40. [PMID: 21147202 DOI: 10.1016/j.fitote.2010.12.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Revised: 11/30/2010] [Accepted: 12/02/2010] [Indexed: 10/18/2022]
Abstract
A petroleum ether extract of the traditional Chinese herbal drug Duhuo (roots of Angelica pubescens Maxim. f. biserrata Shan et Yuan), showed significant activity in a functional two-microelectrode voltage clamp assay with Xenopus oocytes which expressed recombinant γ-aminobutyric acid type A (GABA(A)) receptors of the subtype α(1)β(2)γ(2S). HPLC-based activity profiling of the active extract revealed six compounds responsible for the GABA(A) receptor modulating activity. They were identified by microprobe NMR and high resolution mass spectrometry as columbianetin acetate (1), imperatorin (3), cnidilin (4), osthol (5), and columbianedin (6). In concentration-dependent experiments, osthol and cnidilin showed the highest potentiation of the GABA induced chloride current (273.6%±39.4% and 204.5%±33.2%, respectively at 300 μM). Bisabolangelone (2) only showed minor activity at the GABA(A) receptor. The example demonstrates that HPLC-based activity profiling is a simple and efficient method to rapidly identify GABA(A) receptor modulators in a bioactive plant extract.
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Affiliation(s)
- Janine Zaugg
- Institute of Pharmaceutical Biology, University of Basel, Basel, Switzerland
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Li Y, Plitzko I, Zaugg J, Hering S, Hamburger M. HPLC-based activity profiling for GABA(A) receptor modulators: a new dihydroisocoumarin from Haloxylon scoparium. J Nat Prod 2010; 73:768-770. [PMID: 20210326 DOI: 10.1021/np900803w] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A new dihydroisocoumarin was isolated from a dichloromethane extract of Haloxylon scoparium with the aid of a functional assay with Xenopus oocytes transiently expressing GABA(A) receptors of defined subunit composition (alpha(1)beta(2)gamma(2S)). Compound 1 induced a maximum potentiation of the chloride currents by 144.6 +/- 35.3% with an EC(50) of 140.2 +/- 51.2 muM.
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Affiliation(s)
- Yanfang Li
- Institute of Pharmaceutical Biology, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
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Zaugg J, Baburin I, Strommer B, Kim HJ, Hering S, Hamburger M. HPLC-based activity profiling: discovery of piperine as a positive GABA(A) receptor modulator targeting a benzodiazepine-independent binding site. J Nat Prod 2010; 73:185-91. [PMID: 20085307 PMCID: PMC3196983 DOI: 10.1021/np900656g] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A plant extract library was screened for GABA(A) receptor activity making use of a two-microelectrode voltage clamp assay on Xenopus laevis oocytes. An ethyl acetate extract of black pepper fruits [Piper nigrum L. (Piperaceae) 100 microg/mL] potentiated GABA-induced chloride currents through GABA(A) receptors (composed of alpha(1), beta(2), and gamma(2S) subunits) by 169.1 +/- 2.4%. With the aid of an HPLC-based activity profiling approach, piperine (5) was identified as the main active compound, together with 12 structurally related less active or inactive piperamides (1-4, 6-13). Identification was achieved by on-line high-resolution mass spectrometry and off-line microprobe 1D and 2D NMR spectroscopy, using only milligram amounts of extract. Compound 5 induced a maximum potentiation of the chloride currents by 301.9 +/- 26.5% with an EC(50) of 52.4 +/- 9.4 microM. A comparison of the modulatory activity of 5 and other naturally occurring piperamides enabled insights into structural features critical for GABA(A) receptor modulation. The stimulation of chloride currents through GABA(A) receptors by compound 5 was not antagonized by flumazenil (10 microM). These data show that piperine (5) represents a new scaffold of positive allosteric GABA(A) receptor modulators targeting a benzodiazepine-independent binding site.
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Affiliation(s)
- Janine Zaugg
- Institute of Pharmaceutical Biology, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
| | - Igor Baburin
- Departement of Pharmacology and Toxicology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Barbara Strommer
- Departement of Pharmacology and Toxicology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Hyun-Jung Kim
- Institute of Pharmaceutical Biology, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
| | - Steffen Hering
- Departement of Pharmacology and Toxicology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Matthias Hamburger
- Institute of Pharmaceutical Biology, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
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Zaugg J, Potterat O, Plescher A, Honermeier B, Hamburger M. Quantitative analysis of anti-inflammatory and radical scavenging triterpenoid esters in evening primrose seeds. J Agric Food Chem 2006; 54:6623-8. [PMID: 16939318 DOI: 10.1021/jf0611466] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Lipophilic triterpenoidal esters with radical scavenging and cyclooxygenase inhibitory properties were recently found in cold-pressed, nonraffinated evening primrose oil (EPO). A quantitative assay for the analysis of 3-O-trans-caffeoyl derivatives of betulinic, morolic, and oleanolic acid in evening primrose seeds was developed and validated. Extraction efficiency >99% was achieved by means of pressurized liquid extraction with two extraction cycles and 80% (v/v) ethanol at 120 degrees C. Analysis of esters was by normal-phase high-performance liquid chromatography on a Diol column and hexane/ethyl acetate (containing 0.1% formic acid) (65:35) as the eluent. The analytes were determined without further prepurification. Seeds from defined cultures of Oenothera biennis, Oenothera lamarckiana, and Oenothera ammophila, grown under identical conditions, were analyzed. The cultures originated from seeds from eight collections in the wild and from selections from five cultivars. The content of total triterpenoidal esters in seeds varied between 1.34 and 2.78 mg/g. Three types of qualitative patterns were observed for the triterpenoidal esters. The influence of different harvest times and plant treatments was studied with the cultivar Anothera. Variations between 1.5 and 2.3 mg/g were found.
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Affiliation(s)
- Janine Zaugg
- Institute of Pharmaceutical Biology, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
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