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Brosnan RJ, Cenani A, Costa LR, Condy P, Snell C. Analgesic effect of the mint terpenoid L-carvone in sheep. Vet Anaesth Analg 2023; 50:459-465. [PMID: 37500407 DOI: 10.1016/j.vaa.2023.06.004] [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: 05/15/2023] [Revised: 06/23/2023] [Accepted: 06/26/2023] [Indexed: 07/29/2023]
Abstract
OBJECTIVE To determine whether L-carvone increases the voltage threshold response to a noxious electrical stimulus in sheep. STUDY DESIGN Prospective, blinded, randomized, crossover experimental study. ANIMALS A group of six healthy adult sheep. METHODS Sheep were instrumented with cranial dorsothoracic subcutaneous copper electrodes. A stimulator delivered a 10 ms square-wave stimulus at 50 pps starting at 0.1 V with a 0.2 V second-1 ramp. The stimulus stopped once two observers who were blinded to treatment noted a behavioral pain response or when a 15 V cut-off was reached. Next, 0.15 mL kg-1 of either a 50% L-carvone solution or a saline-vehicle control was administered intramuscularly, and electrical threshold responses were measured every 5-15 minutes over a 6 hour period using methods identical to the baseline. One week following the first treatment (L-carvone or control), sheep were studied using identical methods with the second treatment (control or L-carvone). Drug and time effects were evaluated using a two-way repeated measures analysis of variance, and pairwise comparisons were evaluated with Holm-Sidák tests with values of p < 0.05 considered significant. RESULTS L-carvone significantly increased voltage threshold responses for most time points up to 75 minutes compared with baseline and with saline control. The last time point with a significantly different response between L-carvone and saline treatments was 5 hours after drug administration. The saline-vehicle control decreased voltage threshold responses at several time points after 3 hours. CONCLUSIONS AND CLINICAL RELEVANCE Intramuscular L-carvone is analgesic in sheep, although the ethanol-propylene glycol vehicle may cause mild hyperalgesia. This study demonstrates that a food-derived compound can be used to relieve pain in a food-producing animal.
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Affiliation(s)
- Robert J Brosnan
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
| | - Alessia Cenani
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Lais R Costa
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Paige Condy
- Department of Animal Science, University of California, Davis, CA 95616, USA
| | - Courtney Snell
- Department of Animal Science, University of California, Davis, CA 95616, USA
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Burgess IF. Physically Acting Treatments for Head Lice—Can We Still Claim They Are ‘Resistance Proof’? Pharmaceutics 2022; 14:pharmaceutics14112430. [PMID: 36365251 PMCID: PMC9695066 DOI: 10.3390/pharmaceutics14112430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 10/27/2022] [Accepted: 11/08/2022] [Indexed: 11/12/2022] Open
Abstract
Head lice worldwide have developed resistance to insecticides, prompting the introduction of a range of alternative treatments including plant extracts and natural and synthetic oils. Clinical studies of physically acting treatments showed them to be highly effective when first introduced, and a widely held, but unsubstantiated, belief is that lice are unlikely to develop resistance to them. However, this ignores possibilities for natural selection of traits enabling lice to survive exposure. More recent investigations of some physically acting products have shown reduced efficacy, suggesting either changes of behavior, physical structure, or physiology of some louse populations. In addition, the activity of surfactants and similar compounds, acting as solubilizing agents of insect cuticular lipids, can be compromised by the widespread use of toiletry products containing similar substances. Hitherto, most clinical investigations have provided “best case” data resulting from investigator application of treatments. In the few studies involving participant application, the effectiveness was reduced, suggesting that consumer use allows some insects to survive, which could then be selected for tolerance. Unlike neurotoxic insecticides, there is no straightforward method to test for the activity of physically acting chemicals other than by clinical investigations, which need to be rigorous to eliminate poorly effective products as a way of ensuring the continued effectiveness of those treatments that are successful in eliminating infestation.
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Affiliation(s)
- Ian F Burgess
- Medical Entomology Centre, Insect Research & Development Limited, 6 Quy Court, Colliers Lane, Stow-cum-Quy, Cambridge CB25 9AU, UK
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Brosnan RJ, Ramos K, Aguiar AJDA, Cenani A, Knych HK. Anesthetic Pharmacology of the Mint Extracts L-Carvone and Methyl Salicylate. Pharmacology 2022; 107:167-178. [PMID: 35100605 DOI: 10.1159/000520762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 11/04/2021] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Hydrocarbons with sufficient water solubility allosterically modulate anesthetic-sensitive ion channels. Mint extracts L-carvone and methyl salicylate water solubility exceeds modulation cutoff values for γ-amino butyric acid type A (GABAA) receptors, N-methyl-D-aspartate (NMDA) receptors, and type-2 voltage-gated sodium (Nav1.2) channels. We hypothesized that mint extracts modulate these channels at concentrations that anesthetize rats. METHODS Channels were expressed separately in frog oocytes and studied using 2-electrode voltage clamp techniques at drug concentrations up to 10 mM. Normalized current effects were fit to Hill equations. Mint compounds were formulated in a lipid emulsion and administered IV to rats. When unresponsive to the tail clamp, rats were exsanguinated, and plasma drug concentrations were measured. RESULTS Both mint compounds caused concentration-dependent inhibition of all channels except for methyl salicylate which inhibited GABAA receptors at low concentrations and potentiated at high concentrations. Plasma drug concentrations in anesthetized rats were 7.9 mM for L-carvone and 2.7 mM for methyl salicylate. This corresponded to ≥53% NMDA receptor inhibition and ≥78% Nav1.2 channel inhibition by both compounds and 30% potentiation of GABAA receptors by methyl salicylate. CONCLUSION L-Carvone and methyl salicylate allosterically modulate cell receptor targets important to molecular actions of conventional anesthetics at concentrations that also induce general anesthesia in rats.
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Affiliation(s)
- Robert J Brosnan
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Kimberly Ramos
- Department of Animal Biology, University of California, Davis, California, USA
| | | | - Alessia Cenani
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Heather K Knych
- California Animal Health and Food Safety Lab, Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California, USA
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Brosnan RJ, Pypendop BH, Stanley SD. Phenylpiperidine opioid effects on isoflurane minimum alveolar concentration in cats. J Vet Pharmacol Ther 2020; 43:533-537. [PMID: 32557697 DOI: 10.1111/jvp.12886] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/12/2020] [Accepted: 05/27/2020] [Indexed: 12/01/2022]
Abstract
Different structurally related phenylpiperidine opioids exhibit different isoflurane-sparing effects in cats. Because minimum alveolar concentration (MAC) in cats is affected only by very high plasma concentrations of some phenylpiperidine opioids, we hypothesized these effects are caused by actions on nonopioid receptors. Using a prospective, randomized, crossover design, six cats were anesthetized with isoflurane, intubated, ventilated, and instrumented. Isoflurane MAC was measured in triplicate using a tail-clamp and bracketing technique. A computer-controlled intravenous infusion using prior pharmacokinetic models targeted plasma concentrations of 60 ng/ml fentanyl, 10 ng/ml sufentanil, or 500 ng/ml alfentanil, and isoflurane MAC was measured in duplicate. Next, naltrexone 0.6 mg/kg was administered to cats hourly during the opioid infusion, and isoflurane MAC was measured in duplicate. Blood was collected during MAC determinations to measure opioid concentrations. Responses were analyzed using repeated measures ANOVA with significance at p < .05. Alfentanil and sufentanil decreased isoflurane MAC by 16.4% and 6.4%, respectively, and these effects were completely reversed by naltrexone. Fentanyl had no significant effect on isoflurane MAC. Alfentanil and sufentanil modestly reduce isoflurane MAC via agonist effects on opioid receptors. However, these effects are too small to justify clinical use of phenylpiperidine opioids as single agents to reduce MAC in cats.
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Affiliation(s)
- Robert J Brosnan
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, USA
| | - Bruno H Pypendop
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, USA
| | - Scott D Stanley
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, USA
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Brosnan RJ, Pham TL. Anesthetic-sensitive ion channel modulation is associated with a molar water solubility cut-off. BMC Pharmacol Toxicol 2018; 19:57. [PMID: 30217234 PMCID: PMC6137927 DOI: 10.1186/s40360-018-0244-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 08/22/2018] [Indexed: 12/31/2022] Open
Abstract
Background NMDA receptor modulation by hydrocarbons is associated with a molar water solubility cut-off. Low-affinity phenolic modulation of GABAA receptors is also associated with a cut-off, but at much lower molar solubility values. We hypothesized that other anesthetic-sensitive ion channels exhibit distinct cut-off effects associated with hydrocarbon molar water solubility, and that cut-off values are comparatively similar between related receptors than phylogenetically distant ones. Methods Glycine or GABAA receptors or TREK-1, TRESK, Nav1.2, or Nav1.4 channels were expressed separately in frog oocytes. Two electrode voltage clamp techniques were used to study current responses in the presence and absence of hydrocarbon series from eight functional groups with progressively increasing size at saturated aqueous concentrations. Null response (cut-off) was defined by current measurements that were statistically indistinguishable between baseline and hydrocarbon exposure. Results Ion channels exhibited cut-off effects associated with hydrocarbon molar water solubility in the following order of decreasing solubility: Nav1.2 ≈ Nav1.4 ≳ TRESK ≈ TREK-1 > GABAA >> glycine. Previously measured solubility cut-off values for NMDA receptors were intermediate between those for Nav1.4 and TRESK. Conclusions Water solubility cut-off responses were present for all anesthetic-sensitive ion channels; distinct cut-off effects may exist for all cell surface receptors that are sensitive to volatile anesthetics. Suggested is the presence of amphipathic receptor sites normally occupied by water molecules that have dissociation constants inversely related to the cut-off solubility value. Poorly soluble hydrocarbons unable to reach concentrations sufficient to out-compete water for binding site access fail to modulate the receptor.
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Affiliation(s)
- Robert J Brosnan
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, One Shields Avenue, Davis, CA, 95616, USA.
| | - Trung L Pham
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, One Shields Avenue, Davis, CA, 95616, USA
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Viswanathan A, Zhurina A, Assoah B, Paakkunainen A, Musa A, Kute D, Saravanan KM, Yli-Harja O, Candeias NR, Kandhavelu M. Decane-1,2-diol derivatives as potential antitumor agents for the treatment of glioblastoma. Eur J Pharmacol 2018; 837:105-116. [PMID: 30179612 DOI: 10.1016/j.ejphar.2018.08.041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 08/29/2018] [Accepted: 08/30/2018] [Indexed: 12/20/2022]
Abstract
Glioblastoma remains the most common and aggressive type of malignant brain tumor among adults thus, considerable attention has been given to discovery of novel anti-tumor drugs for its treatment. This study reports the synthesis of a series of twelve novel decane-1,2-diol derivatives and evaluation of its anti-tumor activity in mammalian glioblastoma cell lines, U87 and LN229. Starting from decane-1,2-diol, several derivatives were prepared using a diversity oriented synthesis approach through which a small library composed of esters, silyl ethers, sulfonates, sulfites, sulfates, ketals, and phosphonates was built. The decane-1,2-diol ditosylated derivative, DBT, found to have higher cytotoxicity than the standard drug cisplatin, has IC50 value of 52 µM in U87 and 270 µM in LN229. Migration analysis of U87 cell line treated with the DBT indicated its ability to effectively suppress proliferation during initial hours of treatment and decrease anti-proliferative property over time. Additionally, DBT was assessed for its role in apoptosis, oxidative stress and caspase 3/7 activation in U87. Interestingly, our experiments indicated that its cytotoxicity is independent of Reactive oxygen species induced caspase 3/7 activity. The compound also exhibited caspase independent apoptosis activity in U87. DBT treatment led to G1/S cell cycle arrest and apoptosis induction of glioma cell lines. In addition, we identified 1533 genes with significant changes at the transcriptional level, in response to DBT. A molecular docking study accounting for the interaction of DBT with NMDA receptor disclosed several hydrogen bonds and charged residue interactions with 17 amino acids, which might be the basis of the DBT cytotoxicity observed. We conclude that this molecule exerts its cytotoxicity via caspase 3/7 independent pathways in glioblastoma cells. Concisely, simple decane-1,2-diol derivatives might serve as scaffolds for the development of effective anti-glioblastoma agents.
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Affiliation(s)
- Anisha Viswanathan
- Molecular Signaling Lab, Computational Systems Biology Research Group, BioMediTech and Faculty of Biomedical Sciences and Engineering, Tampere University of Technology, P.O. Box 553, 33101 Tampere, Finland
| | - Anastasia Zhurina
- Molecular Signaling Lab, Computational Systems Biology Research Group, BioMediTech and Faculty of Biomedical Sciences and Engineering, Tampere University of Technology, P.O. Box 553, 33101 Tampere, Finland
| | - Benedicta Assoah
- Laboratory of Chemistry and Bioengineering, Tampere University of Technology, Korkeakoulunkatu 8, 33101 Tampere, Finland
| | - Aleksi Paakkunainen
- Laboratory of Chemistry and Bioengineering, Tampere University of Technology, Korkeakoulunkatu 8, 33101 Tampere, Finland
| | - Aliyu Musa
- Predictive Medicine and Data Analytics Lab, Faculty of Biomedical Sciences and Engineering, Tampere University of Technology, P.O. Box 553, 33101 Tampere, Finland
| | - Dinesh Kute
- Molecular Signaling Lab, Computational Systems Biology Research Group, BioMediTech and Faculty of Biomedical Sciences and Engineering, Tampere University of Technology, P.O. Box 553, 33101 Tampere, Finland
| | - Konda Mani Saravanan
- Centre of Advanced Study in Crystallography & Biophysics, University of Madras, Chennai 600025, India
| | - Olli Yli-Harja
- Molecular Signaling Lab, Computational Systems Biology Research Group, BioMediTech and Faculty of Biomedical Sciences and Engineering, Tampere University of Technology, P.O. Box 553, 33101 Tampere, Finland; Institute for Systems Biology, 1441N 34th Street, Seattle, WA 98103-8904, USA
| | - Nuno R Candeias
- Laboratory of Chemistry and Bioengineering, Tampere University of Technology, Korkeakoulunkatu 8, 33101 Tampere, Finland.
| | - Meenakshisundaram Kandhavelu
- Molecular Signaling Lab, Computational Systems Biology Research Group, BioMediTech and Faculty of Biomedical Sciences and Engineering, Tampere University of Technology, P.O. Box 553, 33101 Tampere, Finland.
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Sneyd J. Thiopental to desflurane - an anaesthetic journey. Where are we going next? Br J Anaesth 2017; 119:i44-i52. [DOI: 10.1093/bja/aex328] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/21/2017] [Indexed: 01/06/2023] Open
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Brosnan RJ, Fukushima FB, Pham TL. Anesthetic synergy between two n-alkanes. Vet Anaesth Analg 2017; 44:577-588. [PMID: 28583773 DOI: 10.1016/j.vaa.2016.07.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Revised: 06/28/2016] [Accepted: 07/03/2016] [Indexed: 11/17/2022]
Abstract
OBJECTIVE N-butane and n-pentane can both produce general anesthesia. Both compounds potentiate γ-aminobutyric acid type A (GABAA) receptor function, but only butane inhibits N-methyl-d-aspartate (NMDA) receptors. It was hypothesized that butane and pentane would exhibit anesthetic synergy due to their different actions on ligand-gated ion channels. STUDY DESIGN Prospective experimental study. ANIMALS A total of four Xenopus laevis frogs and 43 Sprague-Dawley rats. METHODS Alkane concentrations for all studies were determined via gas chromatography. Using a Xenopus oocyte expression model, standard two-electrode voltage clamp techniques were used to measure NMDA and GABAA receptor responses in vitro as a function of butane and pentane concentrations relevant to anesthesia. The minimum alveolar concentrations (MAC) of butane and pentane were measured separately in rats, and then pentane MAC was measured during coadministration of 0.25, 0.50 or 0.75 times MAC of butane. An isobole with 95% confidence intervals was constructed using regression analysis. A sum of butane and pentane that was statistically less than the lower-end confidence bound isobole indicated a synergistic interaction. RESULTS Both butane and pentane dose-dependently potentiated GABAA receptor currents over the study concentration range. Butane dose-dependently inhibited NMDA receptor currents, but pentane did not modulate NMDA receptors. Butane and pentane MAC in rats was 39.4±0.7 and 13.7±0.4 %, respectively. A small but significant (p<0.03) synergistic anesthetic effect with pentane was observed during administration of either 0.50 or 0.75×MAC butane. CONCLUSIONS Butane and pentane show synergistic anesthetic effects in vivo consistent with their different in vitro receptor effects. CLINICAL RELEVANCE Findings support the relevance of NMDA receptors in mediating anesthetic actions for some, but not all, inhaled agents.
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Affiliation(s)
- Robert J Brosnan
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA.
| | - Fabíola B Fukushima
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Trung L Pham
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA
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