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Jiménez-Martínez P, Sánchez-Valdepeñas J, Cornejo-Daza PJ, Cano-Castillo C, Asín-Izquierdo I, Alix-Fages C, Pareja-Blanco F, Colado JC. Effects of different phenylcapsaicin doses on neuromuscular activity and mechanical performance in trained male subjects: a randomized, triple-blinded, crossover, placebo-controlled trial. Front Physiol 2023; 14:1215644. [PMID: 37601635 PMCID: PMC10433207 DOI: 10.3389/fphys.2023.1215644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 07/17/2023] [Indexed: 08/22/2023] Open
Abstract
Objective: This study aimed to examine the effects of phenylcapsaicin (PC) supplementation on strength performance and neuromuscular activity in young trained male subjects. Materials and methods: A total of 25 trained subjects [full-squat (SQ) one repetition maximum (1RM) = 125.6 ± 21.0 kg] were enrolled in this randomized, triple-blinded, crossover, placebo-controlled trial. The subjects performed a first session and a post-24 h session for each condition. In the first session, the subjects ingested a high dose of PC (HD, 2.5 mg), a low dose (LD, 0.625 mg), or a placebo (PLA). Their performance in SQ was assessed under a 3% × 8 × 70% 1RM protocol in the first session. Their performances in countermovement jump (CMJ), SQ with 60% 1RM, and isometric squat were measured before and after the SQ protocol in both sessions. The neural activity of the vastus lateralis (VL) and vastus medialis (VM) was recorded via surface electromyography (EMG) and averaged in both sessions. Results: Significant differences between the conditions were reported for lifting velocity, velocity loss, and the 60% load in dynamic SQ (p range = 0.02-0.04). Electrical changes were not identified for any outcome, although neural activity changed across time (p range ≤0.001-0.006). A significant condition × time effect was observed in CMJ compared to PLA (p ≤0.001) and LD (p ≤0.001). Intra-set analyses revealed higher velocities in HD compared to those in LD (p = 0.01) and PLA (p range = 0.004-0.008). Conclusion: Therefore, PC may improve the strength performance and attenuate the mechanical fatigue induced by resistance training in SQ and CMJ exercises.
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Affiliation(s)
- Pablo Jiménez-Martínez
- Research Group in Prevention and Health in Exercise and Sport (PHES), University of Valencia, Valencia, Spain
- Life Pro Nutrition Research Center, INDIEX, Madrid, Spain
- ICEN Institute, Madrid, Spain
| | - Juan Sánchez-Valdepeñas
- Physical Performance and Sports Research Center, Universidad Pablo de Olavide, Sevilla, Spain
| | - Pedro J. Cornejo-Daza
- Physical Performance and Sports Research Center, Universidad Pablo de Olavide, Sevilla, Spain
| | - Clara Cano-Castillo
- Physical Performance and Sports Research Center, Universidad Pablo de Olavide, Sevilla, Spain
| | - Iván Asín-Izquierdo
- Physical Performance and Sports Research Center, Universidad Pablo de Olavide, Sevilla, Spain
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Alcalá, Madrid, Spain
| | - Carlos Alix-Fages
- Research Group in Prevention and Health in Exercise and Sport (PHES), University of Valencia, Valencia, Spain
- Life Pro Nutrition Research Center, INDIEX, Madrid, Spain
- ICEN Institute, Madrid, Spain
- Applied Biomechanics and Sport Technology Research Group, Autonomous University of Madrid, Madrid, Spain
| | - Fernando Pareja-Blanco
- Physical Performance and Sports Research Center, Universidad Pablo de Olavide, Sevilla, Spain
| | - Juan C. Colado
- Research Group in Prevention and Health in Exercise and Sport (PHES), University of Valencia, Valencia, Spain
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2
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Baamonde A, Menéndez L. Experiences and reflections about behavioral pain assays in laboratory animals. J Neurosci Methods 2023; 386:109783. [PMID: 36610617 DOI: 10.1016/j.jneumeth.2023.109783] [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: 07/29/2022] [Revised: 11/30/2022] [Accepted: 01/02/2023] [Indexed: 01/05/2023]
Abstract
Pharmacological assays based on the measurement of nociceptive responses in laboratory animals are a fundamental tool to assess analgesic strategies. During our experience with this type of experiments, we have been repeatedly challenged by different concerns related to their interpretation or relevance. Although these subjects are frequently discussed in our lab, they do not usually find a place in research articles with original data, in which the focus on results seems mandatory. In the present manuscript we try to discuss as central issues some of these aspects that often cross transversally our research. We have gathered them in five topics inspired by the results obtained in our laboratory. The two initial sections are devoted to the influence of the behavioral method used to assess nociception on the results achieved, as well as to the possibility that data may be more easily accepted when obtained with standard methods than with alternative ones. The third topic is related to the difficulties encountered when working with a molecule that may evoke dual effects, acting as pronociceptive or antinociceptive depending on the dose. The fourth point deals with the situation in which a particular hyperalgesic reaction is related to several molecules but the single inhibition of only one of them can completely prevent it. Finally, the last issue is addressed to comment the impact in the progress of pain research of experiments performed in animal models of pathological settings.
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Affiliation(s)
- Ana Baamonde
- Laboratorio de Farmacología, Facultad de Medicina, Instituto Universitario de Oncología del Principado de Asturias (IUOPA), Universidad de Oviedo, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA) Oviedo, Asturias, Spain
| | - Luis Menéndez
- Laboratorio de Farmacología, Facultad de Medicina, Instituto Universitario de Oncología del Principado de Asturias (IUOPA), Universidad de Oviedo, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA) Oviedo, Asturias, Spain.
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3
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Wang ZH, Feng Y, Hu Q, Wang XL, Zhang L, Liu TT, Zhang JT, Yang X, Fu QY, Fu DN, Hu J, Liu T. Keratinocyte TLR2 and TLR7 contribute to chronic itch through pruritic cytokines and chemokines in mice. J Cell Physiol 2023; 238:257-273. [PMID: 36436135 DOI: 10.1002/jcp.30923] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 11/03/2022] [Accepted: 11/10/2022] [Indexed: 11/28/2022]
Abstract
Although neuronal Toll-like receptors (TLRs) (e.g., TLR2, TLR3, and TLR7) have been implicated in itch sensation, the roles of keratinocyte TLRs in chronic itch are elusive. Herein, we evaluated the roles of keratinocyte TLR2 and TLR7 in chronic itch under dry skin and psoriasis conditions, which was induced by either acetone-ether-water treatment or 5% imiquimod cream in mice, respectively. We found that TLR2 and TLR7 signaling were significantly upregulated in dry skin and psoriatic skin in mice. Chronic itch and epidermal hyperplasia induced by dry skin or psoriasis were comparably reduced in TLR2 and TLR7 knockout mice. In the dry skin model, the enhanced messenger RNA (mRNA) expression levels of pruritic CXCL1/2, IL-31, IL-33, ST2, IL-6, IL-17A, TNF-α, and IFN-γ were inhibited in TLR2-/- mice, while CXCL2, IL-31, and IL-6 were inhibited in TLR7-/- mice. In psoriasis model, the enhanced mRNA expression levels of pruritic CXCL1/2, IL-31, IL-33, ST2, IL-6, and TNF-α were inhibited in TLR2-/- mice, while CXCL1/2, IL-31, IL-33, ST2, IL-6, IL-17A, and TNF-α were inhibited in TLR7-/- mice. Incubation with Staphylococcus aureus (S. aureus) peptidoglycan (PGN-SA) (a TLR2 agonist), imiquimod (a TLR7 agonist), and miR142-3p (a putative TLR7 agonist) were sufficient to upregulate the expression of pruritic cytokines or chemokines in cultured keratinocyte HaCaT cells. Finally, pharmacological blockade of C-X-C Motif Chemokine Receptor 1/2 and high mobility group box protein 1 dose-dependently attenuated acute and chronic itch in mice. Together, these results indicate that keratinocyte TLR2 and TLR7 signaling pathways are distinctly involved in the pathogenesis of chronic itch.
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Affiliation(s)
- Zhi-Hong Wang
- Department of Endocrinology, The Second Affiliated Hospital of Soochow University, Suzhou, China.,Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Yu Feng
- Department of Endocrinology, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Qingfang Hu
- Department of Endocrinology, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Xue-Long Wang
- Department of Thoracic Surgery, Capital Medical University Electric Power Teaching Hospital Beijing, Beijing, China
| | - Li Zhang
- Department of Anesthesiology, The First People's Hospital of Kunshan Affiliated with Jiangsu University, Kunshan, China
| | - Teng-Teng Liu
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Jiang-Tao Zhang
- Institute of Pain Medicine and Special Environmental Medicine, Nantong University, Nantong, China
| | - Xiaohua Yang
- The Affiliated Haian Hospital of Nantong University, Haian, China
| | - Qing-Yue Fu
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Dan-Ni Fu
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Ji Hu
- Department of Endocrinology, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Tong Liu
- Institute of Pain Medicine and Special Environmental Medicine, Nantong University, Nantong, China.,College of Life Sciences, Yanan University, Yanan, China.,Suzhou Key Laboratory of Intelligent Medicine and Equipment, Soochow University, Suzhou, China
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4
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Argôlo IDPR, Parisi JR, Silva JRTD, Silva MLD. Participation of Potential Transient Receptors in the Antinociceptive Effect of Pharmacopuncture. J Acupunct Meridian Stud 2022; 15:105-113. [DOI: 10.51507/j.jams.2022.15.2.105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 10/29/2021] [Accepted: 12/04/2021] [Indexed: 11/03/2022] Open
Affiliation(s)
| | - Julia Risso Parisi
- Department of Physiotherapy, Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil
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5
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Abdelnabi H, Alshaer W, Azzam H, Alqudah D, Al-Samydai A, Aburjai T. Loading of capsaicin-in-cyclodextrin inclusion complexes into PEGylated liposomes and the inhibitory effect on IL-8 production by MDA-MB-231 and A549 cancer cell lines. ACTA ACUST UNITED AC 2021; 76:503-514. [PMID: 34036759 DOI: 10.1515/znc-2021-0018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 05/08/2021] [Indexed: 01/26/2023]
Abstract
Capsaicin (CAP) is an active component in Capsicum annuum L. known to have anti inflammatory and anticancer activity. CAP is highly lipophilic and suffers low bioavailability. Therefore, developing delivery systems that enhance solubility and bioavailability can provide more promising therapeutic applications for CAP. In the current work, CAP was complexed with β-cyclodextrin (βCD) to form capsaicin-in-β-cyclodextrin (CAP-in-βCD) inclusion complexes. Then, the CAP-in-βCD inclusion complexes were characterized and loaded into PEGylated liposomes using the thin-film hydration extrusion method. The size, charge, and polydispersity index (PDI) of the PEGylated liposomes were characterized. The levels of IL-8 production were quantified after treatment using array beads. The results of this work showed that the successful formation of inclusion complexes at 1:5 M ratio of CAP to βCD respectively. PEGylated liposomes loaded with βCD/CAP inclusion complexes (CAP-in-βCD-in-liposomes) have a hydrodynamic diameter of (181 ± 36) nm, zeta potential of (-2.63 ± 4.00) mV, encapsulation efficiency (EE) of (38.65 ± 3.70)%, drug loading (DL) of (1.65 ± 0.16)%, and a stable release profile. Both free CAP and liposomal CAP showed a significant reduction in the IL-8 production by the MDA-MB-231 and A549 cancer cell lines after treatment. In conclusion, a liposomal-based drug delivery system for CAP was achieved.
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Affiliation(s)
- Hiba Abdelnabi
- School of Pharmacy, The University of Jordan, Amman 11942, Jordan
| | - Walhan Alshaer
- Cell Therapy Center, The University of Jordan, Amman 11942, Jordan
| | - Hanan Azzam
- Hamdi Mango Center for Scientific Research, The University of Jordan, Amman 11942, Jordan
| | - Dana Alqudah
- Cell Therapy Center, The University of Jordan, Amman 11942, Jordan
| | - Ali Al-Samydai
- Pharmacological and Diagnostic Research Center, Faculty of Pharmacy, Al-Ahliyya Amman University, Amman 19328, Jordan
| | - Talal Aburjai
- School of Pharmacy, The University of Jordan, Amman 11942, Jordan
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6
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Small A, Fisher AD, Lee C, Colditz I. Analgesia for Sheep in Commercial Production: Where to Next? Animals (Basel) 2021; 11:ani11041127. [PMID: 33920025 PMCID: PMC8070992 DOI: 10.3390/ani11041127] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/08/2021] [Accepted: 04/12/2021] [Indexed: 12/11/2022] Open
Abstract
Simple Summary Increasing societal and customer pressure to provide animals with ‘a life worth living’ continues to apply pressure on industry to alleviate pain associated with husbandry practices, injury and illness. Although a number of analgesic solutions are now available for sheep, providing some amelioration of the acute pain responses, this review has highlighted a number of potential areas for further research. Abstract Increasing societal and customer pressure to provide animals with ‘a life worth living’ continues to apply pressure on livestock production industries to alleviate pain associated with husbandry practices, injury and illness. Over the past 15–20 years, there has been considerable research effort to understand and develop mitigation strategies for painful husbandry procedures in sheep, leading to the successful launch of analgesic approaches specific to sheep in a number of countries. However, even with multi-modal approaches to analgesia, using both local anaesthetic and non-steroidal anti-inflammatory drugs (NSAID), pain is not obliterated, and the challenge of pain mitigation and phasing out of painful husbandry practices remains. It is timely to review and reflect on progress to date in order to strategically focus on the most important challenges, and the avenues which offer the greatest potential to be incorporated into industry practice in a process of continuous improvement. A structured, systematic literature search was carried out, incorporating peer-reviewed scientific literature in the period 2000–2019. An enormous volume of research is underway, testament to the fact that we have not solved the pain and analgesia challenge for any species, including our own. This review has highlighted a number of potential areas for further research.
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Affiliation(s)
- Alison Small
- CSIRO Agriculture & Food, Locked Bag 1, Armidale, NSW 2350, Australia; (C.L.); (I.C.)
- Correspondence: ; Tel.: +61-2-6776-1435
| | - Andrew David Fisher
- Animal Welfare Science Centre, University of Melbourne, Parkville, VIC 3052, Australia;
| | - Caroline Lee
- CSIRO Agriculture & Food, Locked Bag 1, Armidale, NSW 2350, Australia; (C.L.); (I.C.)
| | - Ian Colditz
- CSIRO Agriculture & Food, Locked Bag 1, Armidale, NSW 2350, Australia; (C.L.); (I.C.)
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7
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Zhang D, Sun X, Battino M, Wei X, Shi J, Zhao L, Liu S, Xiao J, Shi B, Zou X. A comparative overview on chili pepper (capsicum genus) and sichuan pepper (zanthoxylum genus): From pungent spices to pharma-foods. Trends Food Sci Technol 2021. [DOI: 10.1016/j.tifs.2021.03.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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8
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Duarte Y, Cáceres J, Sepúlveda RV, Arriagada D, Olivares P, Díaz-Franulic I, Stehberg J, González-Nilo F. Novel TRPV1 Channel Agonists With Faster and More Potent Analgesic Properties Than Capsaicin. Front Pharmacol 2020; 11:1040. [PMID: 32760273 PMCID: PMC7372189 DOI: 10.3389/fphar.2020.01040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 06/26/2020] [Indexed: 01/12/2023] Open
Abstract
The transient receptor potential vanilloid 1 (TRPV1) ion channel is a member of the family of Transient Receptor Potential (TRP) channels that acts as a molecular detector of noxious signals in primary sensory neurons. Activated by capsaicin, heat, voltage and protons, it is also well known for its desensitization, which led to the medical use of topically applied TRPV1 agonist capsaicin for its long-lasting analgesic effects. Here we report three novel small molecules, which were identified using a Structure-Based Virtual Screening for TRPV1 from the ZINC database. The three compounds were tested using electrophysiological assays, which confirmed their capsaicin-like agonist activity. von Frey filaments were used to measure the analgesic effects of the compounds applied topically on tactile allodynia induced by intra-plantar carrageenan. All compounds had anti-nociceptive activity, but two of them showed faster and longer lasting analgesic effects than capsaicin. The present results suggest that TRPV1 agonists different from capsaicin could be used to develop topical analgesics with faster onset and more potent effects.
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Affiliation(s)
- Yorley Duarte
- Center for Bioinformatics and Integrative Biology, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Javier Cáceres
- Center for Bioinformatics and Integrative Biology, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Romina V Sepúlveda
- Center for Bioinformatics and Integrative Biology, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Diego Arriagada
- Laboratorio de Neurobiologia, Instituto de Ciencias Biomédicas, Facultad de Medicina y Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Pedro Olivares
- Laboratorio de Neurobiologia, Instituto de Ciencias Biomédicas, Facultad de Medicina y Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Ignacio Díaz-Franulic
- Center for Bioinformatics and Integrative Biology, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile.,Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Jimmy Stehberg
- Laboratorio de Neurobiologia, Instituto de Ciencias Biomédicas, Facultad de Medicina y Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Fernando González-Nilo
- Center for Bioinformatics and Integrative Biology, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile.,Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
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9
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Changes in TRPV1-Mediated Physiological Function in Rats Systemically Treated With Capsaicin on the Neonate. Int J Mol Sci 2020; 21:ijms21093143. [PMID: 32365623 PMCID: PMC7247669 DOI: 10.3390/ijms21093143] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 04/24/2020] [Accepted: 04/27/2020] [Indexed: 12/15/2022] Open
Abstract
Capsaicin is the active component of chili peppers and is a hydrophobic, colorless, odorless, and crystalline to waxy compound. The transient receptor potential vanilloid 1 (TRPV1) is the capsaicin receptor channels that are involved in a variety of functions like transduction and transmission of the physiological stimulus. Subcutaneous injection of capsaicin to a newborn rat leads to involuntary lifelong TRPV1 desensitization. Various physiological changes including sensory and homeostatic actions in the body associated with neonatal capsaicin treatment are induced by direct TRPV1 channel targeting. Interesting changes include unique phenomena such as the reduction in pain perception, abnormal body temperature, increase in infection, infectious or neuropathological itching, and irregular circadian core body temperature rhythm. These symptoms are associated with relatively higher fever or loss of sensory c-fiber related to TRPV1 desensitization. The aforementioned outcomes not only provide a warning about the risk of capsaicin exposure in newborns but also indicate the possible occurrence of relatively rare diseases that are difficult to diagnose. Therefore, Therefore, the present review aims to summarize the unique phenomena caused by systemic capsaicin administration in neonatal rats.
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10
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Changes in TRPV1-Mediated Physiological Function in Rats Systemically Treated With Capsaicin on the Neonate. Int J Mol Sci 2020. [PMID: 32365623 DOI: 10.3390/ijms21093143.] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Capsaicin is the active component of chili peppers and is a hydrophobic, colorless, odorless, and crystalline to waxy compound. The transient receptor potential vanilloid 1 (TRPV1) is the capsaicin receptor channels that are involved in a variety of functions like transduction and transmission of the physiological stimulus. Subcutaneous injection of capsaicin to a newborn rat leads to involuntary lifelong TRPV1 desensitization. Various physiological changes including sensory and homeostatic actions in the body associated with neonatal capsaicin treatment are induced by direct TRPV1 channel targeting. Interesting changes include unique phenomena such as the reduction in pain perception, abnormal body temperature, increase in infection, infectious or neuropathological itching, and irregular circadian core body temperature rhythm. These symptoms are associated with relatively higher fever or loss of sensory c-fiber related to TRPV1 desensitization. The aforementioned outcomes not only provide a warning about the risk of capsaicin exposure in newborns but also indicate the possible occurrence of relatively rare diseases that are difficult to diagnose. Therefore, Therefore, the present review aims to summarize the unique phenomena caused by systemic capsaicin administration in neonatal rats.
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11
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Conaghan PG, Cook AD, Hamilton JA, Tak PP. Therapeutic options for targeting inflammatory osteoarthritis pain. Nat Rev Rheumatol 2020; 15:355-363. [PMID: 31068673 DOI: 10.1038/s41584-019-0221-y] [Citation(s) in RCA: 207] [Impact Index Per Article: 51.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Pain is the major symptom of osteoarthritis (OA) and is an important factor in strategies to manage this disease. However, the current standard of care does not provide satisfactory pain relief for many patients. The pathophysiology of OA is complex, and its presentation as a clinical syndrome is associated with pathologies of multiple joint tissues. Inflammation is associated with both OA pain and disease outcome and is therefore a major treatment target for OA and OA pain. Unlike TNF inhibitors and IL-1 inhibitors, established drugs such as glucocorticoids and methotrexate can reduce OA pain. Although central nociceptive pathways contribute to OA pain, crosstalk between the immune system and nociceptive neurons is central to inflammatory pain; therefore, new therapies might target this crosstalk. Newly identified drug targets, including neurotrophins and the granulocyte-macrophage colony-stimulating factor (GM-CSF)-CC-chemokine ligand 17 (CCL17) chemokine axis, offer the hope of better results but require clinical validation.
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Affiliation(s)
- Philip G Conaghan
- Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, and National Institute of Health Research Leeds Biomedical Research Centre, Leeds, UK
| | - Andrew D Cook
- The University of Melbourne, Department of Medicine, Royal Melbourne Hospital, Parkville, Victoria, Australia
| | - John A Hamilton
- The University of Melbourne, Department of Medicine, Royal Melbourne Hospital, Parkville, Victoria, Australia.,Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St Albans, Victoria, Australia
| | - Paul P Tak
- Department of Clinical Immunology & Rheumatology, Academic Medical Centre, Amsterdam University Medical Centre, Amsterdam, Netherlands. .,Department of Rheumatology, Ghent University, Ghent, Belgium. .,Department of Medicine, Cambridge University, Cambridge, UK. .,Flagship Pioneering, Cambridge, MA, USA.
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12
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Lu M, Ho CT, Huang Q. Extraction, bioavailability, and bioefficacy of capsaicinoids. J Food Drug Anal 2017; 25:27-36. [PMID: 28911540 PMCID: PMC9333420 DOI: 10.1016/j.jfda.2016.10.023] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 10/27/2016] [Accepted: 10/28/2016] [Indexed: 12/18/2022] Open
Abstract
Capsaicinoids are active constituents responsible for the pungent and spicy flavor in chili peppers. During the past few decades, various extraction methods of capsaicinoids from peppers have been developed with high yields. Through biological studies, pharmacological benefits have been reported such as pain relief, antiinflammation, anticancer, cardioprotection, as well as weight loss. In this paper, the extraction methods and bioavailability of capsaicinoids are reviewed and discussed. In addition, the pharmacological effects and their underlying mechanisms are also studied.
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Affiliation(s)
| | - Chi-Tang Ho
- Corresponding authors: Department of Food Science, Rutgers University, 65 Dudley Road, New Brunswick, NJ 08901-8520, USA. E-mail addresses: (C.-T. Ho), (Q. Huang)
| | - Qingrong Huang
- Corresponding authors: Department of Food Science, Rutgers University, 65 Dudley Road, New Brunswick, NJ 08901-8520, USA. E-mail addresses: (C.-T. Ho), (Q. Huang)
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13
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Abstract
Pain is a complex disease which can progress into a debilitating condition. The effective treatment of pain remains a challenge as current therapies often lack the desired level of efficacy or tolerability. One therapeutic avenue, the modulation of ion channel signaling by small molecules, has shown the ability to treat pain. However, of the 215 ion channels that exist in the human genome, with 85 ion channels having a strong literature link to pain, only a small number of these channels have been successfully drugged for pain. The focus of future research will be to fully explore the possibilities surrounding these unexplored ion channels. Toward this end, a greater understanding of ion channel modulation will be the greatest tool we have in developing the next generation of drugs for the treatment of pain.
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Affiliation(s)
- Sarah E Skerratt
- a Worldwide Medicinal Chemistry; Pfizer Global R&D ; Cambridge , UK
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14
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Malek N, Starowicz K. Dual-Acting Compounds Targeting Endocannabinoid and Endovanilloid Systems-A Novel Treatment Option for Chronic Pain Management. Front Pharmacol 2016; 7:257. [PMID: 27582708 PMCID: PMC4987369 DOI: 10.3389/fphar.2016.00257] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 08/02/2016] [Indexed: 12/17/2022] Open
Abstract
Compared with acute pain that arises suddenly in response to a specific injury and is usually treatable, chronic pain persists over time, and is often resistant to medical treatment. Because of the heterogeneity of chronic pain origins, satisfactory therapies for its treatment are lacking, leading to an urgent need for the development of new treatments. The leading approach in drug design is selective compounds, though they are often less effective and require chronic dosing with many side effects. Herein, we review novel approaches to drug design for the treatment of chronic pain represented by dual-acting compounds, which operate at more than one biological target. A number of studies suggest the involvement of the cannabinoid and vanilloid receptors in pain. Interestingly cannabinoid system is in interrelation with other systems that comprise lipid mediators: prostaglandins, produced by COX enzyme. Therefore, in the present review, we summarize the role of dual-acting molecules (FAAH/TRPV1 and FAAH/COX-2 inhibitors) that interact with endocannabinoid and endovanillinoid systems and act as analgesics by elevating the endogenously produced endocannabinoids and dampening the production of pro-inflammatory prostaglandins. The plasticity of the endocannabinoid system (ECS) and the ability of a single chemical entity to exert an activity on two receptor systems has been developed and extensively investigated. Here, we review up-to-date pharmacological studies on compounds interacting with FAAH enzyme together with TRPV1 receptor or COX-2 enzyme respectively. Multi-target pharmacological intervention for treating pain may lead to the development of original and efficient treatments.
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Affiliation(s)
- Natalia Malek
- Laboratory of Pain Pathophysiology, Department of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences Krakow, Poland
| | - Katarzyna Starowicz
- Laboratory of Pain Pathophysiology, Department of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences Krakow, Poland
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Fattori V, Hohmann MSN, Rossaneis AC, Pinho-Ribeiro FA, Verri WA. Capsaicin: Current Understanding of Its Mechanisms and Therapy of Pain and Other Pre-Clinical and Clinical Uses. Molecules 2016; 21:E844. [PMID: 27367653 PMCID: PMC6273101 DOI: 10.3390/molecules21070844] [Citation(s) in RCA: 218] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 04/27/2016] [Indexed: 02/06/2023] Open
Abstract
In this review, we discuss the importance of capsaicin to the current understanding of neuronal modulation of pain and explore the mechanisms of capsaicin-induced pain. We will focus on the analgesic effects of capsaicin and its clinical applicability in treating pain. Furthermore, we will draw attention to the rationale for other clinical therapeutic uses and implications of capsaicin in diseases such as obesity, diabetes, cardiovascular conditions, cancer, airway diseases, itch, gastric, and urological disorders.
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Affiliation(s)
- Victor Fattori
- Departamento de Ciências Patológicas, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Rodovia Celso Garcia Cid KM480 PR445, Caixa Postal 10.011, 86057-970 Londrina, Paraná, Brazil.
| | - Miriam S N Hohmann
- Departamento de Ciências Patológicas, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Rodovia Celso Garcia Cid KM480 PR445, Caixa Postal 10.011, 86057-970 Londrina, Paraná, Brazil.
| | - Ana C Rossaneis
- Departamento de Ciências Patológicas, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Rodovia Celso Garcia Cid KM480 PR445, Caixa Postal 10.011, 86057-970 Londrina, Paraná, Brazil.
| | - Felipe A Pinho-Ribeiro
- Departamento de Ciências Patológicas, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Rodovia Celso Garcia Cid KM480 PR445, Caixa Postal 10.011, 86057-970 Londrina, Paraná, Brazil.
| | - Waldiceu A Verri
- Departamento de Ciências Patológicas, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Rodovia Celso Garcia Cid KM480 PR445, Caixa Postal 10.011, 86057-970 Londrina, Paraná, Brazil.
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Malek N, Kostrzewa M, Makuch W, Pajak A, Kucharczyk M, Piscitelli F, Przewlocka B, Di Marzo V, Starowicz K. The multiplicity of spinal AA-5-HT anti-nociceptive action in a rat model of neuropathic pain. Pharmacol Res 2016; 111:251-263. [PMID: 27326920 DOI: 10.1016/j.phrs.2016.06.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 05/25/2016] [Accepted: 06/11/2016] [Indexed: 11/27/2022]
Abstract
There is considerable evidence to support the role of anandamide (AEA), an endogenous ligand of cannabinoid receptors, in neuropathic pain modulation. AEA also produces effects mediated by other biological targets, of which the transient receptor potential vanilloid type 1 (TRPV1) has been the most investigated. Both, inhibition of AEA breakdown by fatty acid amide hydrolase (FAAH) and blockage of TRPV1 have been shown to produce anti-nociceptive effects. Recent research suggests the usefulness of dual-action compounds, which may afford greater anti-allodynic efficacy. Therefore, in the present study, we examined the effect of N-arachidonoyl-serotonin (AA-5-HT), a blocker of FAAH and TRPV1, in a rat model of neuropathic pain after intrathecal administration. We found that treatment with AA-5-HT increased the pain threshold to mechanical and thermal stimuli, with highest effect at the dose of 500nM, which was most strongly attenuated by AM-630, CB2 antagonist, administration. The single action blockers PF-3845 (1000nM, for FAAH) and I-RTX (1nM, for TRPV1) showed lower efficacy than AA-5-HT. Moreover AA-5-HT (500nM) elevated AEA and palmitoylethanolamide (PEA) levels. Among the possible targets of these mediators, only the mRNA levels of CB2, GPR18 and GPR55, which are believed to be novel cannabinoid receptors, were upregulated in the spinal cord and/or DRG of CCI rats. It was previously reported that AA-5-HT acts in CB1 and TRPV1-dependent manner after systemic administration, but here for the first time we show that AA-5-HT action at the spinal level involves CB2, with potential contributions from GRP18 and/or GPR55 receptors.
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Affiliation(s)
- Natalia Malek
- Laboratory of Pain Pathophysiology, Department of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12 Street, 31-343 Krakow, Poland; Department of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12 Street, 31-343 Krakow, Poland.
| | - Magdalena Kostrzewa
- Laboratory of Pain Pathophysiology, Department of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12 Street, 31-343 Krakow, Poland; Department of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12 Street, 31-343 Krakow, Poland.
| | - Wioletta Makuch
- Department of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12 Street, 31-343 Krakow, Poland.
| | - Agnieszka Pajak
- Laboratory of Pain Pathophysiology, Department of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12 Street, 31-343 Krakow, Poland; Department of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12 Street, 31-343 Krakow, Poland.
| | - Mateusz Kucharczyk
- Laboratory of Pain Pathophysiology, Department of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12 Street, 31-343 Krakow, Poland; Department of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12 Street, 31-343 Krakow, Poland.
| | - Fabiana Piscitelli
- Endocannabinoid Research Group, Institute of Biomolecular ChemistryC.N.R., Via Campi Flegrei 34, Comprensorio Olivetti, 80078 Pozzuoli (NA), Italy.
| | - Barbara Przewlocka
- Department of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12 Street, 31-343 Krakow, Poland.
| | - Vincenzo Di Marzo
- Endocannabinoid Research Group, Institute of Biomolecular ChemistryC.N.R., Via Campi Flegrei 34, Comprensorio Olivetti, 80078 Pozzuoli (NA), Italy.
| | - Katarzyna Starowicz
- Laboratory of Pain Pathophysiology, Department of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12 Street, 31-343 Krakow, Poland; Department of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12 Street, 31-343 Krakow, Poland.
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Song T, Wang L, Gu K, Yang Y, Yang L, Ma P, Ma X, Zhao J, Yan R, Guan J, Wang C, Qi Y, Ya J. Involvement of peripheral TRPV1 channels in the analgesic effects of thalidomide. Neurochem Int 2015; 85-86:40-5. [DOI: 10.1016/j.neuint.2015.04.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 04/21/2015] [Accepted: 04/22/2015] [Indexed: 10/23/2022]
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Köles L, Garção P, Zádori ZS, Ferreira SG, Pinheiro BS, da Silva-Santos CS, Ledent C, Köfalvi A. Presynaptic TRPV1 vanilloid receptor function is age- but not CB1 cannabinoid receptor-dependent in the rodent forebrain. Brain Res Bull 2013; 97:126-35. [PMID: 23831917 DOI: 10.1016/j.brainresbull.2013.06.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 06/14/2013] [Accepted: 06/27/2013] [Indexed: 02/01/2023]
Abstract
Neocortical and striatal TRPV1 (vanilloid or capsaicin) receptors (TRPV1Rs) are excitatory ligand-gated ion channels, and are implicated in psychiatric disorders. However, the purported presynaptic neuromodulator role of TRPV1Rs in glutamatergic, serotonergic or dopaminergic terminals of the rodent forebrain remains little understood. With the help of patch-clamp electrophysiology and neurochemical approaches, we mapped the age-dependence of presynaptic TRPV1R function, and furthermore, we aimed at exploring whether the presence of CB1 cannabinoid receptors (CB1Rs) influences the function of the TRPV1Rs, as both receptor types share endogenous ligands. We found that the major factor which affects presynaptic TRPV1R function is age: by post-natal day 13, the amplitude of capsaicin-induced release of dopamine and glutamate is halved in the rat striatum, and two weeks later, capsaicin already loses its effect. However, TRPV1R receptor function is not enhanced by chemical or genetic ablation of the CB1Rs in dopaminergic, glutamatergic and serotonergic terminals of the mouse brain. Altogether, our data indicate a possible neurodevelopmental role for presynaptic TRPV1Rs in the rodent brain, but we found no cross-talk between TRPV1Rs and CB1Rs in the same nerve terminal.
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Key Words
- 3Rs
- 4-AP
- 4-aminopyridine
- 7-, 14-, 29- and 60-day-old
- 7D, 14D, 29D, 60D
- ACEA
- ARC
- ARRIVE
- AUC
- American Radiolabeled Chemicals
- Animal Research: Reporting In Vivo Experiments
- BCA
- BSA
- CB(1) cannabinoid receptor
- CB(1)R
- DMSO
- DPM
- DTT
- Dopamine
- ECF
- EDTA
- EGTA
- FR%
- Federation for Laboratory Animal Science Associations
- Felasa
- GABA
- Glutamate
- HEPES
- KHR
- KO
- Krebs-HEPES-Ringer
- LiGTP
- MAO B
- MgATP
- N-(2-hydroxyethyl)piperazine-N′-(2-ethanesulfonic acid)
- N-arachidonyl dopamine
- NADA
- NO
- PMSF
- PVDF
- RTX
- SDS
- SEM
- Serotonin
- Striatum
- TBS-T
- TRPV(1) vanilloid receptor
- TRPV(1)R and TRPV(4)R
- Tris
- Tris-buffered saline with Tween 20
- WT
- aCSF
- arachidonyl-2′-chloroethylamide
- area-under-the-curve
- artificial cerebrospinal fluid
- bicinchoninic acid
- bovine serum albumin
- cannabinoid receptor type 1
- dimethyl sulfoxide
- disintegration per minute
- dithiothreitol
- enhanced chemi-fluorescence
- ethylene glycol-bis(2-aminoethylether)-N,N,N′,N′-tetraacetic acid
- ethylenediaminetetraacetic acid
- fractional release %
- knockout
- lithium guanozine triphosphate
- magnesium adenosine triphosphate
- monoamine oxidase B
- nitric oxide
- phenylmethanesulfonyl fluoride
- polyvinylidene difluoride
- replacement, reduction, refinement
- resiniferatoxin
- sEPSCs
- sodium dodecyl sulfate
- spontaneous excitatory postsynaptic currents
- standard error of the mean
- transient release potential receptor vanilloid type 4
- tris(hydroxymethyl)aminomethane
- wild-type
- γ-aminobutyric acid
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Affiliation(s)
- László Köles
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, 1089 Budapest, Hungary
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Haddock RE, Hill CE. Sympathetic overdrive in obesity involves purinergic hyperactivity in the resistance vasculature. J Physiol 2011; 589:3289-307. [PMID: 21576274 DOI: 10.1113/jphysiol.2011.207944] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
While a close correlation exists in obese humans between sympathetic, adrenergic hyperactivity and structural and functional organ damage, a role for the co-transmitter, ATP, in vascular function remains unexplored. We therefore studied sympathetic nerve-mediated responses of pressurised small mesenteric arteries from control and obese rats. Diet-induced obesity significantly increased the amplitude of vasoconstriction to transmural nerve stimulation (1-10 Hz; P <0.05). At 1 and 5 Hz, both adrenergic and purinergic responses were significantly augmented, while only the purinergic component was increased at 10 Hz (P <0.05). Nerve stimulation at 1 Hz evoked contractions and underlying excitatory junction potentials (EJPs), which were both significantly increased in amplitude during obesity (P <0.05) and abolished by αβ-methylene ATP (1 μM; desensitises purinergic receptors). The rise time and rate of decay of these EJPs were significant decreased (P <0.05), without change in resting membrane potential. Amplitude and frequency of spontaneous EJPs and the density of perivascular sympathetic nerves were also significantly increased (P <0.05). Inhibition of sensory neurotransmitter release (capsaicin; 10 μM) significantly increased the amplitude of nerve-mediated contraction (P <0.05), with a greater effect in control than obese animals, although the density of sensory nerves was unaffected by obesity. We demonstrate that sympathetic nerve-mediated vasoconstriction is enhanced by diet-induced obesity due to upregulation of purinergic, in addition to adrenergic, neurotransmission. Changes result from increased perivascular sympathetic innervation and release of ATP. We conclude that augmented sympathetic control of vasoconstriction induced by obesity could contribute directly to hypertension and global organ damage. A decrease in sensitivity to sensory vasodilatory neurotransmitters may also affect these processes.
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Affiliation(s)
- Rebecca E Haddock
- Department of Neuroscience, John Curtin School of Medical Research, Australian National University, GPO Box 334, Canberra, ACT, 0200, Australia.
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Abstract
OBJECTIVE In this review, we explain our current understanding of the molecular basis for pain relief by capsaicin and other transient receptor potential vanilloid subfamily, member 1 (TRPV1) agonists. We summarize disease-related changes in TRPV1 expression and its implications for therapy and potential adverse effects. Last, we provide an overview of the current clinical uses of topical and injectable TRPV1 agonist preparations in both oncologic and nononcologic populations. METHOD Search of MEDLINE and other databases. RESULTS The capsaicin receptor TRPV1 is a polymodal nociceptor exhibiting a dynamic threshold of activation that could be lowered under inflammatory conditions. Consistent with this model, TRPV1 knock-out mice are devoid of post-inflammatory thermal hyperalgesia. TRPV1 desensitization of primary sensory neurons is a powerful approach to relieve symptoms of nociceptive behavior in animal models of chronic pain. However, over-the-counter capsaicin creams have shown moderate to poor analgesic efficacy. This is in part related to low dose, poor skin absorption, and compliance factors. Recently developed site-specific capsaicin therapy with high-dose patches and injectable preparations seem to be safe and reportedly provide long-lasting analgesia with rapid onset. CONCLUSIONS We argue that TRPV1 agonists and antagonists are not mutually exclusive but rather complimentary pharmacologic approaches for pain relief and we predict a "revival" for capsaicin and other TRPV1 agonists in the clinical management of pain associated with inflammation, metabolic imbalances (eg, diabetes), infections (HIV), and cancer, despite the current focus of the pharmaceutical industry on TRPV1 antagonists.
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Maione S, De Petrocellis L, de Novellis V, Moriello AS, Petrosino S, Palazzo E, Rossi FS, Woodward DF, Di Marzo V. Analgesic actions of N-arachidonoyl-serotonin, a fatty acid amide hydrolase inhibitor with antagonistic activity at vanilloid TRPV1 receptors. Br J Pharmacol 2007; 150:766-81. [PMID: 17279090 PMCID: PMC2013858 DOI: 10.1038/sj.bjp.0707145] [Citation(s) in RCA: 164] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND AND PURPOSE N-arachidonoyl-serotonin (AA-5-HT) is an inhibitor of fatty acid amide hydrolase (FAAH)-catalysed hydrolysis of the endocannabinoid/ endovanilloid compound, anandamide (AEA). We investigated if AA-5-HT antagonizes the transient receptor potential vanilloid-1 (TRPV1) channel and, as FAAH and TRPV1 are targets for analgesic compounds, if it exerts analgesia in rodent models of hyperalgesia. EXPERIMENTAL APPROACH AA-5-HT was tested in vitro, on HEK-293 cells overexpressing the human or the rat recombinant TRPV1 receptor, and in vivo, in rats and mice treated with formalin and in rats with chronic constriction injury of the sciatic nerve. The levels of the endocannabinoids, AEA and 2-arachidonoylglycerol, in supraspinal (periaqueductal grey, rostral ventromedial medulla), spinal or peripheral (skin) tissues were measured. KEY RESULTS AA-5-HT behaved as an antagonist at both rat and human TRPV1 receptors (IC(50)=37-40 nM against 100 nM capsaicin). It exerted strong analgesic activity in all pain models used here. This activity was partly due to FAAH inhibition, elevation of AEA tissue levels and indirect activation of cannabinoid CB(1) receptors, as it was reversed by AM251, a CB(1) antagonist. AA-5-HT also appeared to act either via activation/desensitization of TRPV1, following elevation of AEA, or as a direct TRPV1 antagonist, as suggested by the fact that its effects were either reversed by capsazepine and 5'-iodo-resiniferatoxin, two TRPV1 antagonists, or mimicked by these compounds administered alone. CONCLUSIONS AND IMPLICATIONS Possibly due to its dual activity as a FAAH inhibitor and TRPV1 antagonist, AA-5-HT was highly effective against both acute and chronic peripheral pain.
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Affiliation(s)
- S Maione
- Department of Experimental Medicine – Section of Pharmacology ‘L Donatelli', Second University of Naples Naples, Italy
| | - L De Petrocellis
- Endocannabinoid Research Group, Institute of Cybernetics ‘E Caianiello' CNR, Pozzuoli (Naples), Italy
| | - V de Novellis
- Department of Experimental Medicine – Section of Pharmacology ‘L Donatelli', Second University of Naples Naples, Italy
| | - A Schiano Moriello
- Endocannabinoid Research Group, Institute of Cybernetics ‘E Caianiello' CNR, Pozzuoli (Naples), Italy
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry CNR, Pozzuoli (Naples), Italy
| | - S Petrosino
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry CNR, Pozzuoli (Naples), Italy
- Department of Pharmaceutical Sciences, University of Salerno Fisciano, Italy
| | - E Palazzo
- Department of Experimental Medicine – Section of Pharmacology ‘L Donatelli', Second University of Naples Naples, Italy
| | - F Sca Rossi
- Department of Experimental Medicine – Section of Pharmacology ‘L Donatelli', Second University of Naples Naples, Italy
| | | | - V Di Marzo
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry CNR, Pozzuoli (Naples), Italy
- Author for correspondence:
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Chen HS, He X, Wang Y, Wen WW, You HJ, Arendt-Nielsen L. Roles of capsaicin-sensitive primary afferents in differential rat models of inflammatory pain: a systematic comparative study in conscious rats. Exp Neurol 2006; 204:244-51. [PMID: 17188267 DOI: 10.1016/j.expneurol.2006.10.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2006] [Revised: 10/26/2006] [Accepted: 10/31/2006] [Indexed: 11/20/2022]
Abstract
To characterize the role of capsaicin-sensitive primary afferents in inflammatory pain, the effects of subcutaneous (s.c.) injection of 0.15% capsaicin on different chemical irritants-induced pathological nociception including persistent spontaneous nociception, primary thermal and mechanical hyperalgesia, and inflammatory response were systematically investigated in unanesthetized conscious rats. Four different animal models of inflammatory pain: the bee venom (BV) test, the formalin test, the carrageenan model, and the complete Freund's adjuvant (CFA) model, were employed and compared. Local pre-treatment with capsaicin produced a significant inhibition on the s.c. BV and formalin induced long-lasting persistent spontaneous nociception. However, this capsaicin-induced inhibitory effect on spontaneous nociception in the BV test was only found within the late phase (tonic nociception; 11-60 min), but not the early phase (acute nociception; 0-10 min). A complete preventing effect of capsaicin on the decreased thermal paw withdrawal latency was found in the BV, carrageenan, and CFA models. Nevertheless, pre-treatment with capsaicin only produced complete blocking effects on the decreased mechanical paw withdrawal threshold in the BV and carrageenan models, but not in the CFA model. For inflammatory response, a significant inhibition of the BV-elicited paw swelling was found following capsaicin treatment. In marked contrast, capsaicin did not produce any effects on the paw inflammation during exposure to carrageenan, CFA, and formalin. These data suggest that capsaicin-sensitive primary afferents may play differential roles in the induction and development of pathological nociception in differential inflammatory pain models. In contrast to other chemical irritants, BV-induced long-term spontaneous nociception, facilitated nociceptive behavior, and inflammation are modulated by peripheral capsaicin-sensitive afferents.
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Affiliation(s)
- Hui-Sheng Chen
- Department of Neurology, General Hospital of Shen-Yang Military Region, Shen Yang 110016, PR China.
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Blumberg P, Szallasi A. Complex Regulation of TRPV1 by Vanilloids. TRP ION CHANNEL FUNCTION IN SENSORY TRANSDUCTION AND CELLULAR SIGNALING CASCADES 2006. [DOI: 10.1201/9781420005844.ch6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Szallasi A. Small molecule vanilloid TRPV1 receptor antagonists approaching drug status: can they live up to the expectations? Naunyn Schmiedebergs Arch Pharmacol 2006; 373:273-86. [PMID: 16773387 DOI: 10.1007/s00210-006-0072-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2006] [Accepted: 04/10/2006] [Indexed: 01/05/2023]
Abstract
The cloning of the transient receptor potential vanilloid type-1 (TRPV1) receptor initiated the discovery of potent small molecule antagonists, many of which are in preclinical phase or already undergoing clinical trials. While animal experiments imply a therapeutic value for these compounds as novel analgesic-antiphlogistic drugs, new findings with TRPV1 deficient (trpv1 -/-) mice signal troubles for TRPV1 antagonists as clinical research gains impetus. An emerging concept with important implications for drug development is that TRPV1 may be differentially regulated under physiological and pathological conditions. If so, it is conceivable that such TRPV1 ligands can be synthesized that specifically target TRPV1 in diseased (e.g. inflamed or neoplastic) tissues but spare TRPV1 that subserves its physiological functions in healthy organs. This review explores the current status of this field and seeks an answer to the question how these new discoveries could be factored into TRPV1 drug discovery and development.
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Affiliation(s)
- Arpad Szallasi
- Department of Pathology, Monmouth Medical Center, 300 Second Avenue, Long Branch, NJ 07740, USA.
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