pinocarveol

ChEBI · EMBL-EBI ↗ · Källdatum saknas · Källans villkor

A pinane monoterpenoid that is a bicyclo[3.1.1]heptane substituted by two methyl groups at position 6, a methylidene group at position 2 and a hydroxy group at position 3.

KesslerArtur; Sahin-NadeemHilal; LummisSarah C R; WeigelIngrid; PischetsriederMonika; BuettnerAndrea; VillmannCarmen · GABAA receptor modulation by terpenoids from Sideritis extracts ↗ · 24 nov. 2013 · Källans villkor

GABA ≥ 99%, DMSO ≥ 99.9%, 1-Octen-3-ol ≥ 98%, Carvacrol ≥ 98%, l-Carveol (mixture of cis and trans) ≥ 95%, Isopulegol ≥ 99%, Linalool ≥ 97%, Myrtenol ≥ 95%, trans-Pinocarveol ≥ 96%, (S)-cis-Verbenol ≥ 95%, α-Pinene ≥ 98%, β-Pinene ≥ 99%, β-Caryophyllene ≥ 80%, β-Myrcene ≥ 95%, Caryophyllene oxide ≥ 95%, α-Terpineol ≥ 96%, and all other chemicals were purchased from Sigma-Aldrich (Taufkirchen, Germany). Dichloromethane (DCM) was obtained from Acros (Geel, Belgium) and freshly distilled before use. Reference compounds for GC-analyses were diluted with DCM to an appropriate concentration. Stock solutions of compounds at a concentration of 1 M were prepared using DMSO and dissolved in the appropriate buffer, prior to use. All reservoirs for control and compound application in electrophysiological recordings contained equivalent amounts of DMSO. The solvent showed no effect on GABA-mediated responses up to 0.1% concentration (data not shown).

KesslerArtur; Sahin-NadeemHilal; LummisSarah C R; WeigelIngrid; PischetsriederMonika; BuettnerAndrea; VillmannCarmen · GABAA receptor modulation by terpenoids from Sideritis extracts ↗ · 24 nov. 2013 · Källans villkor

Potent substances were tested in a high-throughput assay using a Flexstation device. Here, transfected HEK293 cells expressing the α1β2γ2 configuration of the human GABAARs were used. GABA EC50s were 1.4 μM for α1β2 and 20.8 ± 7.0 μM for α1β2γ2 GABAARs, comparable to previously published data (e.g. Boileau et al.) (Fig.5A) 24. A coapplication of diazepam (10 μM) led to a 8.3-fold decrease in GABA EC50 (Fig.5B, Table3). Coapplication of terpenes (300 μM) myrtenol, verbenol, pinocarveol, and isopulegol together with increasing GABA concentrations caused a decrease in GABA EC50 (Fig.5). Myrtenol was identified as the volatile compound with the most pronounced effect on the GABA-dose–response curve (7.4 fold decrease in GABA EC50), not dissimilar to the effect of diazepam (Table3), while the decrease was ∼ fourfold for carveol and linalool (Fig.5D, E, and H).

KesslerArtur; Sahin-NadeemHilal; LummisSarah C R; WeigelIngrid; PischetsriederMonika; BuettnerAndrea; VillmannCarmen · GABAA receptor modulation by terpenoids from Sideritis extracts ↗ · 24 nov. 2013 · Källans villkor

We also demonstrated that the effects of the terpenes and terpene-derived substances are similar in rat and human GABAAR subunits. Human α1β2γ2 GABAARs were expressed in oocytes and successful incorporation of the γ2 subunit demonstrated using Zn2+: no block was obtained, in contrast to Zn2+ inhibition for the α1β2 configuration (Fig.6A–D) 22. Linalool and 1-octen-3-ol (1000 μM) enhanced GABA-evoked currents of α1β2 GABAARs (Fig.2B). The coexpression of the γ2 subunit did not lead to significant changes in the effectiveness of GABA-current modulation by either linalool or 1-octen-3-ol (300 μM) (Fig.6E). These data indicate that the action of the volatile substances was independent of the γ2 subunit. The effectiveness of other substances and pinene metabolites on human GABAARs in an α1β2γ2 configuration was similar to the effects observed on rat α1β2 GABAARs in oocytes and Flexstation data using human α1β2γ2 in HEK293 cells. Modulation by pinocarveol, myrtenol, and verbenol achieved significance when used at concentrations >10 μM whereas for carvacrol, isopulegol, and carveol concentrations of at least 30 μM were required (Fig.6F and G). To determine the modulatory potency of these substances, however, concentration–response curves are required. The potentiating effect of structurally similar volatile substances is, therefore, independent from the origin of the GABAAR subunits. Thus, these substances most probably interact with conserved sequence motifs of the α1 and/or β2 GABAAR subunits.

KesslerArtur; Sahin-NadeemHilal; LummisSarah C R; WeigelIngrid; PischetsriederMonika; BuettnerAndrea; VillmannCarmen · GABAA receptor modulation by terpenoids from Sideritis extracts ↗ · 24 nov. 2013 · Källans villkor

GABA ≥ 99%, DMSO ≥ 99.9%, 1-Octen-3-ol ≥ 98%, Carvacrol ≥ 98%, l-Carveol (mixture of cis and trans) ≥ 95%, Isopulegol ≥ 99%, Linalool ≥ 97%, Myrtenol ≥ 95%, trans-Pinocarveol ≥ 96%, (S)-cis-Verbenol ≥ 95%, α-Pinene ≥ 98%, β-Pinene ≥ 99%, β-Caryophyllene ≥ 80%, β-Myrcene ≥ 95%, Caryophyllene oxide ≥ 95%, α-Terpineol ≥ 96%, and all other chemicals were purchased from Sigma-Aldrich (Taufkirchen, Germany). Dichloromethane (DCM) was obtained from Acros (Geel, Belgium) and freshly distilled before use. Reference compounds for GC-analyses were diluted with DCM to an appropriate concentration. Stock solutions of compounds at a concentration of 1 M were prepared using DMSO and dissolved in the appropriate buffer, prior to use. All reservoirs for control and compound application in electrophysiological recordings contained equivalent amounts of DMSO. The solvent showed no effect on GABA-mediated responses up to 0.1% concentration (data not shown).

KesslerArtur; Sahin-NadeemHilal; LummisSarah C R; WeigelIngrid; PischetsriederMonika; BuettnerAndrea; VillmannCarmen · GABAA receptor modulation by terpenoids from Sideritis extracts ↗ · 24 nov. 2013 · Källans villkor

HEK293 cells were grown on 90 mm tissue culture plates containing DMEM/Glutamax medium (Invitrogen, Paisley, UK), supplemented with 10% fetal calf serum, at 37°C and 5% CO2 in a humidified atmosphere. Cells were transiently transfected using polyethyleneimine (PEI, 25 kDa, linear, Polysciences, Eppelheim, Germany). For this purpose, 5 μg of human α1 and β2 were diluted together with 10 μg of γ2 subunit DNA in 1 mL of serum-free medium followed by the addition of 90 μL PEI (1 mg/mL). After 10 min incubation at room temperature, the mixture was added dropwise to a 80–90% confluent plate, and incubated for 24 h. Cells were transferred to black 96-well plates (Greiner Bio-One, Stonehouse, UK), which were pretreated with 0.01% Cultrex poly-l-Lysine (Trevigen, Gaithersburg, MD, USA). After an additional 24 h, incubation cells were used for experiments.

KesslerArtur; Sahin-NadeemHilal; LummisSarah C R; WeigelIngrid; PischetsriederMonika; BuettnerAndrea; VillmannCarmen · GABAA receptor modulation by terpenoids from Sideritis extracts ↗ · 24 nov. 2013 · Källans villkor

Potent substances were tested in a high-throughput assay using a Flexstation device. Here, transfected HEK293 cells expressing the α1β2γ2 configuration of the human GABAARs were used. GABA EC50s were 1.4 μM for α1β2 and 20.8 ± 7.0 μM for α1β2γ2 GABAARs, comparable to previously published data (e.g. Boileau et al.) (Fig.5A) 24. A coapplication of diazepam (10 μM) led to a 8.3-fold decrease in GABA EC50 (Fig.5B, Table3). Coapplication of terpenes (300 μM) myrtenol, verbenol, pinocarveol, and isopulegol together with increasing GABA concentrations caused a decrease in GABA EC50 (Fig.5). Myrtenol was identified as the volatile compound with the most pronounced effect on the GABA-dose–response curve (7.4 fold decrease in GABA EC50), not dissimilar to the effect of diazepam (Table3), while the decrease was ∼ fourfold for carveol and linalool (Fig.5D, E, and H).

KesslerArtur; Sahin-NadeemHilal; LummisSarah C R; WeigelIngrid; PischetsriederMonika; BuettnerAndrea; VillmannCarmen · GABAA receptor modulation by terpenoids from Sideritis extracts ↗ · 24 nov. 2013 · Källans villkor

GABA ≥ 99%, DMSO ≥ 99.9%, 1-Octen-3-ol ≥ 98%, Carvacrol ≥ 98%, l-Carveol (mixture of cis and trans) ≥ 95%, Isopulegol ≥ 99%, Linalool ≥ 97%, Myrtenol ≥ 95%, trans-Pinocarveol ≥ 96%, (S)-cis-Verbenol ≥ 95%, α-Pinene ≥ 98%, β-Pinene ≥ 99%, β-Caryophyllene ≥ 80%, β-Myrcene ≥ 95%, Caryophyllene oxide ≥ 95%, α-Terpineol ≥ 96%, and all other chemicals were purchased from Sigma-Aldrich (Taufkirchen, Germany). Dichloromethane (DCM) was obtained from Acros (Geel, Belgium) and freshly distilled before use. Reference compounds for GC-analyses were diluted with DCM to an appropriate concentration. Stock solutions of compounds at a concentration of 1 M were prepared using DMSO and dissolved in the appropriate buffer, prior to use. All reservoirs for control and compound application in electrophysiological recordings contained equivalent amounts of DMSO. The solvent showed no effect on GABA-mediated responses up to 0.1% concentration (data not shown).

KesslerArtur; Sahin-NadeemHilal; LummisSarah C R; WeigelIngrid; PischetsriederMonika; BuettnerAndrea; VillmannCarmen · GABAA receptor modulation by terpenoids from Sideritis extracts ↗ · 24 nov. 2013 · Källans villkor

We also demonstrated that the effects of the terpenes and terpene-derived substances are similar in rat and human GABAAR subunits. Human α1β2γ2 GABAARs were expressed in oocytes and successful incorporation of the γ2 subunit demonstrated using Zn2+: no block was obtained, in contrast to Zn2+ inhibition for the α1β2 configuration (Fig.6A–D) 22. Linalool and 1-octen-3-ol (1000 μM) enhanced GABA-evoked currents of α1β2 GABAARs (Fig.2B). The coexpression of the γ2 subunit did not lead to significant changes in the effectiveness of GABA-current modulation by either linalool or 1-octen-3-ol (300 μM) (Fig.6E). These data indicate that the action of the volatile substances was independent of the γ2 subunit. The effectiveness of other substances and pinene metabolites on human GABAARs in an α1β2γ2 configuration was similar to the effects observed on rat α1β2 GABAARs in oocytes and Flexstation data using human α1β2γ2 in HEK293 cells. Modulation by pinocarveol, myrtenol, and verbenol achieved significance when used at concentrations >10 μM whereas for carvacrol, isopulegol, and carveol concentrations of at least 30 μM were required (Fig.6F and G). To determine the modulatory potency of these substances, however, concentration–response curves are required. The potentiating effect of structurally similar volatile substances is, therefore, independent from the origin of the GABAAR subunits. Thus, these substances most probably interact with conserved sequence motifs of the α1 and/or β2 GABAAR subunits.

KesslerArtur; Sahin-NadeemHilal; LummisSarah C R; WeigelIngrid; PischetsriederMonika; BuettnerAndrea; VillmannCarmen · GABAA receptor modulation by terpenoids from Sideritis extracts ↗ · 24 nov. 2013 · Källans villkor

In summary, we have identified some distinct volatiles, specifically terpenes, as modulators of the GABAARs providing an explanation of sedative effects. It was demonstrated by Löw et al. that in contrast to α1-containing receptors α2- and α3-containing receptors mediate anxiolytic effects 6. If terpenes act in a subunit-specific manner or act nonspecifically, it still needs further investigation. Recordings from GABAARs expressing neurons or brain slices might also prove useful to investigate the role of these substances in the target neuronal tissue. Thus, terpenes with distinct structural properties may mediate sedative or anxiolytic mechanisms involving GABAARs.

KesslerArtur; Sahin-NadeemHilal; LummisSarah C R; WeigelIngrid; PischetsriederMonika; BuettnerAndrea; VillmannCarmen · GABAA receptor modulation by terpenoids from Sideritis extracts ↗ · 24 nov. 2013 · Källans villkor

Nevertheless, the concentrations of volatile odorants that indeed are present at CNS neurons are still unknown and need further studies for clarification of this issue.