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Saleh DO, Sedik AA. Novel drugs affecting diabetic peripheral neuropathy. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2024; 27:657-670. [PMID: 38645500 PMCID: PMC11024403 DOI: 10.22038/ijbms.2024.75367.16334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 12/27/2023] [Indexed: 04/23/2024]
Abstract
Diabetic peripheral neuropathy (DPN) poses a significant threat, affecting half of the global diabetic population and leading to severe complications, including pain, impaired mobility, and potential amputation. The delayed manifestation of diabetic neuropathy (DN) makes early diagnosis challenging, contributing to its debilitating impact on individuals with diabetes mellitus (DM). This review examines the multifaceted nature of DPN, focusing on the intricate interplay between oxidative stress, metabolic pathways, and the resulting neuronal damage. It delves into the challenges of diagnosing DN, emphasizing the critical role played by hyperglycemia in triggering these cascading effects. Furthermore, the study explores the limitations of current neuropathic pain drugs, prompting an investigation into a myriad of pharmaceutical agents tested in both human and animal trials over the past decade. The methodology scrutinizes these agents for their potential to provide symptomatic relief for DPN. The investigation reveals promising results from various pharmaceutical agents tested for DPN relief, showcasing their efficacy in ameliorating symptoms. However, a notable gap persists in addressing the underlying problem of DPN. The results underscore the complexity of DPN and the challenges in developing therapies that go beyond symptomatic relief. Despite advancements in treating DPN symptoms, there remains a scarcity of options addressing the underlying problem. This review consolidates the state-of-the-art drugs designed to combat DPN, highlighting their efficacy in alleviating symptoms. Additionally, it emphasizes the need for a deeper understanding of the diverse processes and pathways involved in DPN pathogenesis.
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Affiliation(s)
- Dalia O. Saleh
- Pharmacology Department, Medical Research and Clinical Studies Institute, National Research Centre, 12622, Egypt
| | - Ahmed A. Sedik
- Pharmacology Department, Medical Research and Clinical Studies Institute, National Research Centre, 12622, Egypt
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Marchesi N, Fahmideh F, Pascale A, Allegri M, Govoni S. Neuropathic Pain in Aged People: An Unresolved Issue Open to Novel Drug Approaches, Focusing on Painful Diabetic Neuropathy. Curr Neuropharmacol 2024; 22:53-64. [PMID: 37550909 DOI: 10.2174/1570159x21666230807103642] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 02/17/2023] [Accepted: 03/15/2023] [Indexed: 08/09/2023] Open
Abstract
A majority of older patients suffer from neuropathic pain (NP) that significantly alters their daily activities and imposes a significant burden on health care. Multiple comorbidities and the risk of polypharmacy in the elderly make it challenging to determine the appropriate drug, dosage, and maintenance of therapy. Age-dependent processes play a contributing role in neuropathy given that diabetic neuropathy (DN) is the most common form of neuropathy. This narrative review is mainly focused on the drug treatment approach for neuropathy-associated pain in aged people including both drugs and dietary supplements, considering the latter as add-on mechanism-based treatments to increase the effectiveness of usual treatments by implementing their activity or activating other analgesic pathways. On one hand, the limited clinical studies assessing the effectiveness and the adverse effects of existing pain management options in this age segment of the population (> 65), on the other hand, the expanding global demographics of the elderly contribute to building up an unresolved pain management problem that needs the attention of healthcare providers, researchers, and health authorities as well as the expansion of the current therapeutic options.
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Affiliation(s)
- Nicoletta Marchesi
- Department of Drug Sciences, Section of Pharmacology, University of Pavia, Pavia, Italy
| | - Foroogh Fahmideh
- Department of Drug Sciences, Section of Pharmacology, University of Pavia, Pavia, Italy
| | - Alessia Pascale
- Department of Drug Sciences, Section of Pharmacology, University of Pavia, Pavia, Italy
| | - Massimo Allegri
- Ensemble Hospitalier de la Cote - Centre Lemanique d'antalgie et Neuromodulation, Morges, Switzerland
| | - Stefano Govoni
- Department of Drug Sciences, Section of Pharmacology, University of Pavia, Pavia, Italy
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Basem JI, Bah FN, Mehta ND. A Brief Review on the Novel Therapies for Painful Diabetic Neuropathy. Curr Pain Headache Rep 2023; 27:299-305. [PMID: 37392335 DOI: 10.1007/s11916-023-01126-1] [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] [Accepted: 05/01/2023] [Indexed: 07/03/2023]
Abstract
PURPOSE OF REVIEW Almost half of people diagnosed with diabetes mellitus will develop painful diabetic neuropathy (PDN), a condition greatly impacting quality of life with complicated pathology. While there are different FDA approved forms of treatment, many of the existing options are difficult to manage with comorbities and are associated with unwanted side effects. Here, we summarize the current and novel treatments for PDN. RECENT FINDINGS Current research is exploring alternative pain management treatments from the first line options of pregabalin, gabapentin, duloxetine, and amitriptyline which often have side effects. The use of FDA approved capsaicin and spinal cord stimulators (SCS) has been incredibly beneficial in addressing this. In addition, new treatments looking at different targets, such as NMDA receptor and the endocannabinoid system, show promising results. There are several treatment options that have been shown to be successful in helping treat PDN, but often require adjunct treatment or alterations due to side effects. While there is ample research for standard medications, treatments such as palmitoylethanolamide and endocannabinoid targets have extremely limited clinical trials. We also found that many studies did not evaluate additional variables other than pain relief, such as functional changes nor were there consistent measurement methods. Future research should continue trials comparing treatment efficacies along with more quality of life measures.
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Affiliation(s)
- Jade I Basem
- Pain Medicine, Department of Anesthesiology, Weill Cornell Medicine, New York, NY, USA.
| | - Fatoumata N Bah
- Pain Medicine, Department of Anesthesiology, Weill Cornell Medicine, New York, NY, USA
| | - Neel D Mehta
- Pain Medicine, Department of Anesthesiology, Weill Cornell Medicine, New York, NY, USA
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Pickering E, Steels EL, Steadman KJ, Rao A, Vitetta L. A randomized controlled trial assessing the safety and efficacy of palmitoylethanolamide for treating diabetic-related peripheral neuropathic pain. Inflammopharmacology 2022; 30:2063-2077. [PMID: 36057884 PMCID: PMC9700575 DOI: 10.1007/s10787-022-01033-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 06/30/2022] [Indexed: 12/04/2022]
Abstract
Background Peripheral neuropathy is a common complication of diabetes. The management of the associated neuropathic pain remains difficult to treat. Objective This study explored the safety, tolerability and efficacy of a palmitoylethanolamide (PEA) formulation in treating diabetic-related peripheral neuropathic pain (PNP). Secondary outcomes included systemic inflammation, sleep and mood changes in patients diagnosed with type 1 and type 2 diabetes and PNP. Design This study was a single-centre, quadruple-blinded, placebo-controlled trial with 70 participants receiving 600 mg of PEA or placebo daily, for 8 weeks, with a 94% rate of study participation completion. Primary outcomes were neuropathic pain and specific pain types (the BPI-DPN and NPSI). The secondary outcomes were sleep quality (MOS sleep scale), mood (DASS-21), glucose metabolism and inflammation. Results There was a significant reduction (P ≤ 0.001) in BPI-DPN total pain and pain interference, NPSI total score and sub-scores, except for evoked pain (P = 0.09) in the PEA group compared with the placebo group. The MOS sleep problem index and sub-scores significantly improved (P ≤ 0.001). DASS-21 depression scores significantly reduced (P = 0.03), but not anxiety or stress scores. Interleukin-6 and elevated C-reactive protein levels significantly reduced in the PEA group (P = 0.05), with no differences in fibrinogen between groups (P = 0.78) at treatment completion. There were no changes in safety pathology parameters, and the treatment was well tolerated. Conclusions The study demonstrated that the PEA formulation reduced diabetic peripheral neuropathic pain and inflammation along with improving mood and sleep. Further studies on the mechanistic effectiveness of PEA as an adjunct medicine and as a monotherapy pain analgesic are warranted. Clinical Trial Registration Registry name: Australian New Zealand Clinical Trials Registry (ANZCTR), Registration number: ACTRN12620001302943, Registration link: https://anzctr.org.au/Trial/Registration/TrialReview.aspx?id=380826, Actual study start date: 20 November 2020.
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Affiliation(s)
- Emily Pickering
- School of Pharmacy, University of Queensland, PACE Precinct, 20 Cornwall Street, Wooloongabba, Brisbane, QLD, 4102, Australia.,Evidence Sciences Pty. Ltd., Brisbane, QLD, Australia
| | - Elizabeth L Steels
- School of Pharmacy, University of Queensland, PACE Precinct, 20 Cornwall Street, Wooloongabba, Brisbane, QLD, 4102, Australia. .,Evidence Sciences Pty. Ltd., Brisbane, QLD, Australia.
| | - Kathryn J Steadman
- School of Pharmacy, University of Queensland, PACE Precinct, 20 Cornwall Street, Wooloongabba, Brisbane, QLD, 4102, Australia
| | - Amanda Rao
- School of Human Movement and Nutrition Sciences, University of Queensland, Brisbane, QLD, 4102, Australia
| | - Luis Vitetta
- Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
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Cristiano C, Avagliano C, Cuozzo M, Liguori FM, Calignano A, Russo R. The Beneficial Effects of Ultramicronized Palmitoylethanolamide in the Management of Neuropathic Pain and Associated Mood Disorders Induced by Paclitaxel in Mice. Biomolecules 2022; 12:biom12081155. [PMID: 36009049 PMCID: PMC9406031 DOI: 10.3390/biom12081155] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 08/17/2022] [Accepted: 08/18/2022] [Indexed: 12/02/2022] Open
Abstract
Chemotherapy-induced peripheral neuropathy (CIPN) is a common complication of antineoplastic drugs, particularly paclitaxel (PTX). It can affect the quality of patients’ lives and increase the risk of developing mood disorders. Although several drugs are recommended, they yielded inconclusive results in clinical trials. The aim of the present work is to investigate whether the palmitoylethanolamide (PEA) would reduce PTX-induced CIPN and associated mood disorders. Moreover, the role PPAR-α and the endocannabinoid system will also be investigated. CIPN was induced by intraperitoneally injection of PTX (8 mg/kg) every other day for a week. PEA, 30 mg/kg, was orally administrated in a bioavailable form (i.e., ultramicronized PEA, um-PEA) one hour after the last PTX injection, for 7 days. In the antagonism experiments, AM281 (1 mg/kg) and GW6471 (2 mg/kg) were administrated 30 min before um-PEA. Our results demonstrated that um-PEA reduced the development of hypersensitivity with the effect being associated with the reduction in spinal and hippocampal pro-inflammatory cytokines, as well as antidepressive and anxiolytic effects. Moreover, the PPAR-α and CB1 receptor antagonists blocked the behavioral and antinociceptive effects of um-PEA. Our findings suggest that um-PEA is a promising adjunct in CIPN and associated mood disorders through the activation of PPAR-α, which influences the endocannabinoid system.
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Scuteri D, Guida F, Boccella S, Palazzo E, Maione S, Rodríguez-Landa JF, Martínez-Mota L, Tonin P, Bagetta G, Corasaniti MT. Effects of Palmitoylethanolamide (PEA) on Nociceptive, Musculoskeletal and Neuropathic Pain: Systematic Review and Meta-Analysis of Clinical Evidence. Pharmaceutics 2022; 14:pharmaceutics14081672. [PMID: 36015298 PMCID: PMC9414729 DOI: 10.3390/pharmaceutics14081672] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 08/03/2022] [Accepted: 08/08/2022] [Indexed: 11/16/2022] Open
Abstract
Some 30−50% of the global population and almost 20% of the European population actually suffer from chronic pain, which presents a tremendous burden to society when this pain turns into a disability and hospitalization. Palmitoylethanolamide (PEA) has been demonstrated to improve pain in preclinical contexts, but an appraisal of clinical evidence is still lacking. The present study aimed at addressing the working hypothesis for the efficacy of PEA for nociceptive musculoskeletal and neuropathic pain in the clinical setting. The systematic search, selection and analysis were performed in agreement with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 recommendations. The primary outcome was pain reduction, as measured by a pain assessment scale. The secondary outcome was improvement in quality of life and/or of parameters of function. The results obtained for a total of 933 patients demonstrate the efficacy of PEA over the control (p < 0.00001), in particular in six studies apart from the two randomized, double-blind clinical trials included. However, the results are downgraded due to the high heterogeneity of the studies (I2 = 99%), and the funnel plot suggests publication bias. Efficacy in achieving a reduction in the need for rescue medications and improvement in functioning, neuropathic symptoms and quality of life are reported. Therefore, adequately powered randomized, double-blind clinical trials are needed to deepen the domains of efficacy of add-on therapy with PEA for chronic pain. PROSPERO registration: CRD42022314395.
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Affiliation(s)
- Damiana Scuteri
- Pharmacotechnology Documentation and Transfer Unit, Preclinical and Translational Pharmacology, Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Rende, Italy
- Regional Center for Serious Brain Injuries, S. Anna Institute, 88900 Crotone, Italy
- Correspondence: (D.S.); (G.B.); Tel.: +39-0984-493462 (D.S. & G.B.)
| | - Francesca Guida
- Department of Experimental Medicine, Pharmacology Division, University of Campania “L. Vanvitelli”, 80138 Naples, Italy
| | - Serena Boccella
- Department of Experimental Medicine, Pharmacology Division, University of Campania “L. Vanvitelli”, 80138 Naples, Italy
| | - Enza Palazzo
- Department of Experimental Medicine, Pharmacology Division, University of Campania “L. Vanvitelli”, 80138 Naples, Italy
| | - Sabatino Maione
- Department of Experimental Medicine, Pharmacology Division, University of Campania “L. Vanvitelli”, 80138 Naples, Italy
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry, CNR, 80078 Pozzuoli, Italy
- IRCSS, Neuromed, 86077 Pozzilli, Italy
| | - Juan Francisco Rodríguez-Landa
- Laboratorio de Neurofarmacología, Instituto de Neuroetología, Universidad Veracruzana, Xalapa 91190, Mexico
- Facultad de Química Farmacéutica Biológica, Universidad Veracruzana, Xalapa 91001, Mexico
| | - Lucia Martínez-Mota
- Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Mexico City 03440, Mexico
| | - Paolo Tonin
- Regional Center for Serious Brain Injuries, S. Anna Institute, 88900 Crotone, Italy
| | - Giacinto Bagetta
- Pharmacotechnology Documentation and Transfer Unit, Preclinical and Translational Pharmacology, Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Rende, Italy
- Correspondence: (D.S.); (G.B.); Tel.: +39-0984-493462 (D.S. & G.B.)
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Zeraatkar D, Cooper MA, Agarwal A, Vernooij RWM, Leung G, Loniewski K, Dookie JE, Ahmed MM, Hong BY, Hong C, Hong P, Couban R, Agoritsas T, Busse JW. Long-term and serious harms of medical cannabis and cannabinoids for chronic pain: a systematic review of non-randomised studies. BMJ Open 2022; 12:e054282. [PMID: 35926992 PMCID: PMC9358949 DOI: 10.1136/bmjopen-2021-054282] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVE To establish the prevalence of long-term and serious harms of medical cannabis for chronic pain. DESIGN Systematic review and meta-analysis. DATA SOURCES MEDLINE, EMBASE, PsycINFO and CENTRAL from inception to 1 April 2020. STUDY SELECTION Non-randomised studies reporting on harms of medical cannabis or cannabinoids in adults or children living with chronic pain with ≥4 weeks of follow-up. DATA EXTRACTION AND SYNTHESIS A parallel guideline panel provided input on the design and interpretation of the systematic review, including selection of adverse events for consideration. Two reviewers, working independently and in duplicate, screened the search results, extracted data and assessed risk of bias. We used random-effects models for all meta-analyses and the Grades of Recommendations, Assessment, Development and Evaluation approach to evaluate the certainty of evidence. RESULTS We identified 39 eligible studies that enrolled 12 143 adult patients with chronic pain. Very low certainty evidence suggests that adverse events are common (prevalence: 26.0%; 95% CI 13.2% to 41.2%) among users of medical cannabis for chronic pain, particularly any psychiatric adverse events (prevalence: 13.5%; 95% CI 2.6% to 30.6%). Very low certainty evidence, however, indicates serious adverse events, adverse events leading to discontinuation, cognitive adverse events, accidents and injuries, and dependence and withdrawal syndrome are less common and each typically occur in fewer than 1 in 20 patients. We compared studies with <24 weeks and ≥24 weeks of cannabis use and found more adverse events reported among studies with longer follow-up (test for interaction p<0.01). Palmitoylethanolamide was usually associated with few to no adverse events. We found insufficient evidence addressing the harms of medical cannabis compared with other pain management options, such as opioids. CONCLUSIONS There is very low certainty evidence that adverse events are common among people living with chronic pain who use medical cannabis or cannabinoids, but that few patients experience serious adverse events.
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Affiliation(s)
- Dena Zeraatkar
- Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada
- Department of Biomedical Informatics, Harvard Medical School, Boston, Massachusetts, USA
| | - Matthew Adam Cooper
- Michael G. Degroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Arnav Agarwal
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Robin W M Vernooij
- Department of Research and Development, Netherlands Comprehensive Cancer Organisation, Utrecht, The Netherlands
| | - Gareth Leung
- Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
| | - Kevin Loniewski
- Faculty of Health, York University, Toronto, Ontario, Canada
| | - Jared E Dookie
- Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Muhammad Muneeb Ahmed
- Michael G. Degroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Brian Y Hong
- Division of Plastic and Reconstructive Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Chris Hong
- Health Research Methods, Evidence, and Impact, University of Toronto Faculty of Medicine, Toronto, Ontario, Canada
| | - Patrick Hong
- Department of Anesthesiology and Pain Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Rachel Couban
- Michael G. DeGroote Institute for Pain Research and Care, McMaster University, Hamilton, Ontario, Canada
| | - Thomas Agoritsas
- Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada
- Division of General Internal Medicine & Division of Epidemiology, University Hospitals Geneva, Geneve, Switzerland
| | - Jason W Busse
- Anesthesia, McMaster University, Hamilton, Ontario, Canada
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Cifelli P, Ruffolo G, Ceccanti M, Cambieri C, Libonati L, Palma E, Inghilleri M. Classical and Unexpected Effects of Ultra-Micronized PEA in Neuromuscular Function. Biomolecules 2022; 12:biom12060758. [PMID: 35740883 PMCID: PMC9221058 DOI: 10.3390/biom12060758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 05/23/2022] [Accepted: 05/27/2022] [Indexed: 02/06/2023] Open
Abstract
Recently, the endocannabinoid system has attracted growing attention from the scientific community for its involvement in homeostatic and pathological processes as they pertains to human physiology. Among the constituents of the endocannabinoid system, the molecule palmitoyl ethanolamide has particularly been studied for its ability to reduce several inflammatory processes involving the central nervous system. Here, we reviewed published literature and summarized the main targets of the palmitoyl ethanolamide, along with its unique possible mechanisms for restoring correct functioning of the central nervous system. Moreover, we have highlighted a less-known characteristic of palmitoyl ethanolamide, namely its ability to modulate the function of the neuromuscular junction by binding to acetylcholine receptors in different experimental conditions. Indeed, there are several studies that have highlighted how ultra-micronized palmitoyl ethanolamide is an interesting nutraceutical support for the treatment of pathological neuromuscular conditions, specifically when the normal activity of the acetylcholine receptor is altered. Although further multicentric clinical trials are needed to confirm the efficacy of ultra-micronized palmitoyl ethanolamide in improving symptoms of neuromuscular diseases, all the literature reviewed here strongly supports the ability of this endocannabinoid-like molecule to modulate the acetylcholine receptors thus resulting as a valid support for the treatment of human neuromuscular diseases.
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Affiliation(s)
- Pierangelo Cifelli
- Department of Applied Clinical and Biotechnological Sciences, University of L’Aquila, 67100 L’Aquila, Italy
- Correspondence: (P.C.); (M.I.)
| | - Gabriele Ruffolo
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, 00185 Rome, Italy; (G.R.); (E.P.)
- IRCCS San Raffaele Roma, 00163 Rome, Italy
| | - Marco Ceccanti
- Department of Human Neuroscience, University of Rome Sapienza, 00185 Rome, Italy; (M.C.); (C.C.); (L.L.)
| | - Chiara Cambieri
- Department of Human Neuroscience, University of Rome Sapienza, 00185 Rome, Italy; (M.C.); (C.C.); (L.L.)
| | - Laura Libonati
- Department of Human Neuroscience, University of Rome Sapienza, 00185 Rome, Italy; (M.C.); (C.C.); (L.L.)
| | - Eleonora Palma
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, 00185 Rome, Italy; (G.R.); (E.P.)
| | - Maurizio Inghilleri
- Department of Human Neuroscience, University of Rome Sapienza, 00185 Rome, Italy; (M.C.); (C.C.); (L.L.)
- Correspondence: (P.C.); (M.I.)
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Clayton P, Hill M, Bogoda N, Subah S, Venkatesh R. Palmitoylethanolamide: A Natural Compound for Health Management. Int J Mol Sci 2021; 22:5305. [PMID: 34069940 PMCID: PMC8157570 DOI: 10.3390/ijms22105305] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/06/2021] [Accepted: 05/06/2021] [Indexed: 01/23/2023] Open
Abstract
All nations which have undergone a nutrition transition have experienced increased frequency and falling latency of chronic degenerative diseases, which are largely driven by chronic inflammatory stress. Dietary supplementation is a valid strategy to reduce the risk and severity of such disorders. Palmitoylethanolamide (PEA) is an endocannabinoid-like lipid mediator with extensively documented anti-inflammatory, analgesic, antimicrobial, immunomodulatory and neuroprotective effects. It is well tolerated and devoid of side effects in animals and humans. PEA's actions on multiple molecular targets while modulating multiple inflammatory mediators provide therapeutic benefits in many applications, including immunity, brain health, allergy, pain modulation, joint health, sleep and recovery. PEA's poor oral bioavailability, a major obstacle in early research, has been overcome by advanced delivery systems now licensed as food supplements. This review summarizes the functionality of PEA, supporting its use as an important dietary supplement for lifestyle management.
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Affiliation(s)
- Paul Clayton
- Institute of Food, Brain and Behaviour, Beaver House, 23-28 Hythe Bridge Street, Oxford OX1 2EP, UK
| | - Mariko Hill
- Gencor Pacific Limited, Discovery Bay, Lantau Island, New Territories, Hong Kong, China; (M.H.); (N.B.); (S.S.)
| | - Nathasha Bogoda
- Gencor Pacific Limited, Discovery Bay, Lantau Island, New Territories, Hong Kong, China; (M.H.); (N.B.); (S.S.)
| | - Silma Subah
- Gencor Pacific Limited, Discovery Bay, Lantau Island, New Territories, Hong Kong, China; (M.H.); (N.B.); (S.S.)
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Fibromyalgia: Pathogenesis, Mechanisms, Diagnosis and Treatment Options Update. Int J Mol Sci 2021; 22:ijms22083891. [PMID: 33918736 PMCID: PMC8068842 DOI: 10.3390/ijms22083891] [Citation(s) in RCA: 168] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 04/06/2021] [Accepted: 04/07/2021] [Indexed: 12/13/2022] Open
Abstract
Fibromyalgia is a syndrome characterized by chronic and widespread musculoskeletal pain, often accompanied by other symptoms, such as fatigue, intestinal disorders and alterations in sleep and mood. It is estimated that two to eight percent of the world population is affected by fibromyalgia. From a medical point of view, this pathology still presents inexplicable aspects. It is known that fibromyalgia is caused by a central sensitization phenomenon characterized by the dysfunction of neuro-circuits, which involves the perception, transmission and processing of afferent nociceptive stimuli, with the prevalent manifestation of pain at the level of the locomotor system. In recent years, the pathogenesis of fibromyalgia has also been linked to other factors, such as inflammatory, immune, endocrine, genetic and psychosocial factors. A rheumatologist typically makes a diagnosis of fibromyalgia when the patient describes a history of pain spreading in all quadrants of the body for at least three months and when pain is caused by digital pressure in at least 11 out of 18 allogenic points, called tender points. Fibromyalgia does not involve organic damage, and several diagnostic approaches have been developed in recent years, including the analysis of genetic, epigenetic and serological biomarkers. Symptoms often begin after physical or emotional trauma, but in many cases, there appears to be no obvious trigger. Women are more prone to developing the disease than men. Unfortunately, the conventional medical therapies that target this pathology produce limited benefits. They remain largely pharmacological in nature and tend to treat the symptomatic aspects of various disorders reported by the patient. The statistics, however, highlight the fact that 90% of people with fibromyalgia also turn to complementary medicine to manage their symptoms.
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della Rocca G, Gamba D. Chronic Pain in Dogs and Cats: Is There Place for Dietary Intervention with Micro-Palmitoylethanolamide? Animals (Basel) 2021; 11:952. [PMID: 33805489 PMCID: PMC8065429 DOI: 10.3390/ani11040952] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 03/23/2021] [Accepted: 03/23/2021] [Indexed: 12/17/2022] Open
Abstract
The management of chronic pain is an integral challenge of small animal veterinary practitioners. Multiple pharmacological agents are usually employed to treat maladaptive pain including opiates, non-steroidal anti-inflammatory drugs, anticonvulsants, antidepressants, and others. In order to limit adverse effects and tolerance development, they are often combined with non-pharmacologic measures such as acupuncture and dietary interventions. Accumulating evidence suggests that non-neuronal cells such as mast cells and microglia play active roles in the pathogenesis of maladaptive pain. Accordingly, these cells are currently viewed as potential new targets for managing chronic pain. Palmitoylethanolamide is an endocannabinoid-like compound found in several food sources and considered a body's own analgesic. The receptor-dependent control of non-neuronal cells mediates the pain-relieving effect of palmitoylethanolamide. Accumulating evidence shows the anti-hyperalgesic effect of supplemented palmitoylethanolamide, especially in the micronized and co-micronized formulations (i.e., micro-palmitoylethanolamide), which allow for higher bioavailability. In the present paper, the role of non-neuronal cells in pain signaling is discussed and a large number of studies on the effect of palmitoylethanolamide in inflammatory and neuropathic chronic pain are reviewed. Overall, available evidence suggests that there is place for micro-palmitoylethanolamide in the dietary management of chronic pain in dogs and cats.
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Affiliation(s)
- Giorgia della Rocca
- Department of Veterinary Medicine, Centro di Ricerca sul Dolore Animale (CeRiDA), Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Davide Gamba
- Operational Unit of Anesthesia, Centro Veterinario Gregorio VII, 00165 Roma, Italy;
- Freelance, DG Vet Pain Therapy, 24124 Bergamo, Italy
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Amorfrutins Relieve Neuropathic Pain through the PPAR γ/CCL2 Axis in CCI Rats. PPAR Res 2021; 2021:8894752. [PMID: 33552153 PMCID: PMC7846402 DOI: 10.1155/2021/8894752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 12/29/2020] [Accepted: 01/04/2021] [Indexed: 11/17/2022] Open
Abstract
Neuropathic pain is a public health problem. Although many pharmaceuticals are used to treat neuropathic pain, effective and safe drugs do not yet exist. In this study, we tested nociceptive responses in CCI rats, and ELISA assay was performed to examine the expression of proinflammatory cytokines. We found that amorfrutins significantly reduce the pain behaviors in CCI rats and suppress the expression of proinflammatory cytokines (TNFα, IL-6, and IL-1β) and chemokines (CCL2/CCR2) in the spinal cord. However, concurrent administration of a PPARγ antagonist, GW9662, reversed the antihyperalgesic effect induced by amorfrutins. The results indicate that amorfrutins inhibit the inflammation and chemokine expression by activating PPARγ, thus relieving neuropathic pain in CCI rats. Therefore, PPARγ-CCL2/CCR2 pathway might represent a new treatment option for neuropathic pain.
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D’Amico R, Impellizzeri D, Cuzzocrea S, Di Paola R. ALIAmides Update: Palmitoylethanolamide and Its Formulations on Management of Peripheral Neuropathic Pain. Int J Mol Sci 2020; 21:ijms21155330. [PMID: 32727084 PMCID: PMC7432736 DOI: 10.3390/ijms21155330] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 07/23/2020] [Accepted: 07/24/2020] [Indexed: 02/06/2023] Open
Abstract
Neuropathic pain results from lesions or diseases of the somatosensory nervous system and it remains largely difficult to treat. Peripheral neuropathic pain originates from injury to the peripheral nervous system (PNS) and manifests as a series of symptoms and complications, including allodynia and hyperalgesia. The aim of this review is to discuss a novel approach on neuropathic pain management, which is based on the knowledge of processes that underlie the development of peripheral neuropathic pain; in particular highlights the role of glia and mast cells in pain and neuroinflammation. ALIAmides (autacoid local injury antagonist amides) represent a group of endogenous bioactive lipids, including palmitoylethanolamide (PEA), which play a central role in numerous biological processes, including pain, inflammation, and lipid metabolism. These compounds are emerging thanks to their anti-inflammatory and anti-hyperalgesic effects, due to the down-regulation of activation of mast cells. Collectively, preclinical and clinical studies support the idea that ALIAmides merit further consideration as therapeutic approach for controlling inflammatory responses, pain, and related peripheral neuropathic pain.
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Affiliation(s)
- Ramona D’Amico
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno D’Alcontres 31, 98166 Messina, Italy; (R.D.); (D.I.); (R.D.P.)
| | - Daniela Impellizzeri
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno D’Alcontres 31, 98166 Messina, Italy; (R.D.); (D.I.); (R.D.P.)
| | - Salvatore Cuzzocrea
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno D’Alcontres 31, 98166 Messina, Italy; (R.D.); (D.I.); (R.D.P.)
- Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, 1402 South Grand Blvd, St Louis, MO 63104, USA
- Correspondence: ; Tel.: +39-90-6765208
| | - Rosanna Di Paola
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno D’Alcontres 31, 98166 Messina, Italy; (R.D.); (D.I.); (R.D.P.)
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Ultramicronized Palmitoylethanolamide and Paracetamol, a New Association to Relieve Hyperalgesia and Pain in a Sciatic Nerve Injury Model in Rat. Int J Mol Sci 2020; 21:ijms21103509. [PMID: 32429243 PMCID: PMC7278943 DOI: 10.3390/ijms21103509] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 05/12/2020] [Accepted: 05/13/2020] [Indexed: 12/20/2022] Open
Abstract
Inflammation is known to be an essential trigger of the pathological changes that have a critical impact on nerve repair and regeneration; moreover, damage to peripheral nerves can cause a loss of sensory function and produces persistent neuropathic pain. To date, various potential approaches for neuropathic pain have focused on controlling neuroinflammation. The aim of this study was to investigate the neuroprotective effects of a new association of ultramicronized Palmitoylethanolamide (PEAum), an Autacoid Local Injury Antagonist Amide (ALIAmide) with analgesic and anti-inflammatory properties, with Paracetamol, a common analgesic, in a rat model of sciatic nerve injury (SNI). The association of PEAum-Paracetamol, in a low dose (5 mg/kg + 30 mg/kg), was given by oral gavage daily for 14 days after SNI. PEAum-Paracetamol association was able to reduce hyperalgesia, mast cell activation, c-Fos and nerve growth factor (NGF) expression, neural histological damage, cytokine release, and apoptosis. Furthermore, the analgesic action of PEAum-Paracetamol could act in a synergistic manner through the inhibition of the NF-κB pathway, which leads to a decrease of cyclooxygenase 2-dependent prostaglandin E2 (COX-2/PGE2) release. In conclusion, we demonstrated that PEAum associated with Paracetamol was able to relieve pain and neuroinflammation after SNI in a synergistic manner, and this therapeutic approach could be relevant to decrease the demand of analgesic drugs.
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Cordaro M, Cuzzocrea S, Crupi R. An Update of Palmitoylethanolamide and Luteolin Effects in Preclinical and Clinical Studies of Neuroinflammatory Events. Antioxidants (Basel) 2020; 9:antiox9030216. [PMID: 32150935 PMCID: PMC7139331 DOI: 10.3390/antiox9030216] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 02/25/2020] [Accepted: 02/26/2020] [Indexed: 02/06/2023] Open
Abstract
The inflammation process represents of a dynamic series of phenomena that manifest themselves with an intense vascular reaction. Neuroinflammation is a reply from the central nervous system (CNS) and the peripheral nervous system (PNS) to a changed homeostasis. There are two cell systems that mediate this process: the glia of the CNS and the lymphocites, monocytes, and macrophages of the hematopoietic system. In both the peripheral and central nervous systems, neuroinflammation plays an important role in the pathogenesis of neurodegenerative diseases, such as Parkinson’s and Alzheimer’s diseases, and in neuropsychiatric illnesses, such as depression and autism spectrum disorders. The resolution of neuroinflammation is a process that allows for inflamed tissues to return to homeostasis. In this process the important players are represented by lipid mediators. Among the naturally occurring lipid signaling molecules, a prominent role is played by the N-acylethanolamines, namely N-arachidonoylethanolamine and its congener N-palmitoylethanolamine, which is also named palmitoylethanolamide or PEA. PEA possesses a powerful neuroprotective and anti-inflammatory power but has no antioxidant effects per se. For this reason, its co-ultramicronization with the flavonoid luteolin is more efficacious than either molecule alone. Inhibiting or modulating the enzymatic breakdown of PEA represents a complementary therapeutic approach to treating neuroinflammation. The aim of this review is to discuss the role of ultramicronized PEA and co-ultramicronized PEA with luteolin in several neurological diseases using preclinical and clinical approaches.
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Affiliation(s)
- Marika Cordaro
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Via Consolare Valeria 1, 98100 Messina, Italy;
| | - Salvatore Cuzzocrea
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Via F. Stagno D’Alcontres 31, 98166 Messina, Italy;
- Department of Pharmacology and Physiology, Saint Louis University, St. Louis, MO 63103, USA
- Correspondence: ; Tel.: +390-906-765-208
| | - Rosalia Crupi
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Via F. Stagno D’Alcontres 31, 98166 Messina, Italy;
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Davis MP, Behm B, Mehta Z, Fernandez C. The Potential Benefits of Palmitoylethanolamide in Palliation: A Qualitative Systematic Review. Am J Hosp Palliat Care 2019; 36:1134-1154. [PMID: 31113223 DOI: 10.1177/1049909119850807] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Palmitoylethanolamide (PEA) is a nutraceutical endocannabinoid that was retrospectively discovered in egg yolks. Feeding poor children with known streptococcal infections prevented rheumatic fever. Subsequently, it was found to alter the course of influenza. Unfortunately, there is little known about its pharmacokinetics. Palmitoylethanolamide targets nonclassical cannabinoid receptors rather than CB1 and CB2 receptors. Palmitoylethanolamide will only indirectly activate classical cannabinoid receptors by an entourage effect. There are a significant number of prospective and randomized trials demonstrating the pain-relieving effects of PEA. There is lesser evidence of benefit in patients with nonpain symptoms related to depression, Parkinson disease, strokes, and autism. There are no reported drug-drug interactions and very few reported adverse effects from PEA. Further research is needed to define the palliative benefits to PEA.
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A double-blind randomized placebo controlled study assessing safety, tolerability and efficacy of palmitoylethanolamide for symptoms of knee osteoarthritis. Inflammopharmacology 2019; 27:475-485. [PMID: 30927159 DOI: 10.1007/s10787-019-00582-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 03/06/2019] [Indexed: 12/20/2022]
Abstract
BACKGROUND The aim of the study was to assess the safety, tolerability and efficacy of palmitoylethanolamide (PEA) when dosed at 300 mg and 600 mg per day on symptoms of knee osteoarthritis. METHODS This was a single site, comparative, double-blind placebo controlled study in adults with mild to moderate knee osteoarthritis with 111 participants randomized to receive 300 mg PEA, 600 mg PEA or placebo each day, in divided doses b.i.d, for 8 weeks. The primary outcome was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). The secondary outcomes were the Numerical Rating Scales (NRS) for pain, the Depression Anxiety Stress Scale (DASS), the Perceived Stress Scale (PSS), the Pittsburg Sleep Quality Index (PSQI), the Short Form Health Survey (SF-36), the use of rescue pain medication and clinical safety assessment. RESULTS There was a significant reduction in the total WOMAC score in the 300 mg PEA (p = 0.0372) and the 600 mg PEA (p = 0.0012) groups, the WOMAC pain score (300 mg PEA, p = 0.0074; 600 mg PEA, p = < 0.001), the WOMAC stiffness score (PEA 300 mg, p < 0.0490; 600 mg PEA, p = 0.001) and in the WOMAC function score in the 600 mg PEA group (p = 0.033) compared to placebo. The NRS pain evaluations for "worst pain" and "least pain" were significantly reduced in the 300 mg PEA group (p < 0.001, p = 0.005) and the 600 mg PEA group (p < 0.001, p < 0.001) compared to placebo. There was a significant reduction in anxiety (DASS) in both active treatment groups (300 mg PEA, p = 0.042; 600 mg PEA group (p = 0.043) compared to placebo. There were no changes in the clinical markers and the product was well tolerated. CONCLUSIONS The study demonstrated that palmitoylethanolamide may be a novel treatment for attenuating pain and reducing other associated symptoms of knee osteoarthritis. Further studies on the pharmacological basis of this anti-inflammatory effect are now required.
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Cruccu G, Di Stefano G, Marchettini P, Truini A. Micronized Palmitoylethanolamide: A Post Hoc Analysis of a Controlled Study in Patients with Low Back Pain - Sciatica. CNS & NEUROLOGICAL DISORDERS DRUG TARGETS 2019; 18:491-495. [PMID: 31269891 PMCID: PMC7132032 DOI: 10.2174/1871527318666190703110036] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 05/20/2019] [Accepted: 06/18/2019] [Indexed: 12/22/2022]
Abstract
BACKGROUND Despite being widely prescribed, relatively few controlled trials have been conducted on the class of neurotrophic/antinociceptive nutraceuticals. While performing a search in the literature, we came across an old registration study on micronized palmitoylethanolamide in patients with low back pain - sciatica by Guida and colleagues. METHODS We contacted the authors of the article and obtained all the original material, which allowed us to reanalyze the study. We assessed its clinical relevance by calculating the numbers needed to treat for pain (visual analog scale) and function (Roland-Morris Questionnaire). After excluding patients for whom the information available was insufficient, we assigned each patient to one of the five categories of increasing probability of neuropathic pain: pure lumbago, lumbago with projecting pain to surrounding regions (e.g. gluteus or groin), lumbago with projecting pain to the thigh or leg, pure sciatica and radiculopathy, and investigated any correlations (Spearman) between the improvement in pain and function with these five classes. RESULTS Compared with placebo, palmitoylethanolamide 600 mg/die yielded a number needed to treat of 1.7 (95% confidence interval: 1.4-2) for pain, and 1.5 (95% confidence interval: 1.4-1.7) for function. The correlation between the five categories was highly significant for pain relief (P <0.0001), though not significant for reduced dysfunction. CONCLUSION Palmitoylethanolamide was extremely effective on pain and function in a large cohort of patients with low back pain - sciatica. Although, the multiple mechanisms of action of palmitoylethanolamide are ideal for mixed pain conditions such as low back pain - sciatica, the correlation between pain relief and the likelihood of neuropathic pain suggests that this drug exerts a predominant action on the neuropathic pain component.
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Affiliation(s)
- Giorgio Cruccu
- Department of Human Neuroscience, Sapienza University, Rome, Italy
| | | | - Paolo Marchettini
- Pain Medicine Center of Scientific Institute H. San Raffaele in Milan, Milan, Italy
| | - Andrea Truini
- Department of Human Neuroscience, Sapienza University, Rome, Italy
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19
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Production of PEA composite microparticles with polyvinylpyrrolidone and luteolin using Supercritical Assisted Atomization. J Supercrit Fluids 2019. [DOI: 10.1016/j.supflu.2018.07.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Passavanti MB, Fiore M, Sansone P, Aurilio C, Pota V, Barbarisi M, Fierro D, Pace MC. The beneficial use of ultramicronized palmitoylethanolamide as add-on therapy to Tapentadol in the treatment of low back pain: a pilot study comparing prospective and retrospective observational arms. BMC Anesthesiol 2017; 17:171. [PMID: 29258432 PMCID: PMC5735888 DOI: 10.1186/s12871-017-0461-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Accepted: 12/10/2017] [Indexed: 11/10/2022] Open
Abstract
Background This pilot study was designed to compare the efficacy of ultramicronized palmitoylethanolamide (um-PEA) as add-on therapy to tapentadol (TP) with TP therapy only in patients suffering from chronic low back pain (LBP). Methods This pilot observational study consists in two arms: the prospective arm and the retrospective one. In the prospective arm patients consecutively selected received um-PEA as add-on therapy to TP for 6 months; in the retrospective arm patients were treated with TP only for 6 months. Pain intensity and neuropathic component were evaluated at baseline, during and after 6 months. The degree of disability and TP dosage assumption were evaluated at baseline and after 6 months. Results Statistical analysis performed with generalized linear mixed model on 55 patients (30 in the prospective group and 25 in the retrospective group) demonstrated that um-PEA as add-on treatment to TP in patients with chronic LBP, in comparison to TP alone, led to a significantly higher reduction in pain intensity, in the neuropathic component, the degree of disability and TP dosage assumption. No serious side effects were observed. Conclusion Overall, the present findings suggest that um-PEA may be an innovative therapeutic intervention as add-on therapy to TP for the management of chronic LBP with a neuropathic component, as well as to improve patient quality of life. Additionally, this combination treatment allowed a reduction in TP dose over time and did not show any serious side effects.
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Affiliation(s)
- Maria Beatrice Passavanti
- Department of Women, Child and General and Specialized Surgery, University of Campania "Luigi Vanvitelli", 80138, Naples, Italy
| | - Marco Fiore
- Department of Women, Child and General and Specialized Surgery, University of Campania "Luigi Vanvitelli", 80138, Naples, Italy.
| | - Pasquale Sansone
- Department of Women, Child and General and Specialized Surgery, University of Campania "Luigi Vanvitelli", 80138, Naples, Italy
| | - Caterina Aurilio
- Department of Women, Child and General and Specialized Surgery, University of Campania "Luigi Vanvitelli", 80138, Naples, Italy
| | - Vincenzo Pota
- Department of Women, Child and General and Specialized Surgery, University of Campania "Luigi Vanvitelli", 80138, Naples, Italy
| | - Manlio Barbarisi
- Department of Medical, Surgical, Neurological, Metabolic and Aging Sciences, University of Campania "Luigi Vanvitelli", Piazza L. Miraglia, 2, 80138, Naples, Italy
| | - Daniela Fierro
- Department of Women, Child and General and Specialized Surgery, University of Campania "Luigi Vanvitelli", 80138, Naples, Italy
| | - Maria Caterina Pace
- Department of Women, Child and General and Specialized Surgery, University of Campania "Luigi Vanvitelli", 80138, Naples, Italy
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Wu J, Wang JJ, Liu TT, Zhou YM, Qiu CY, Shen DW, Hu WP. PPAR-α acutely inhibits functional activity of ASICs in rat dorsal root ganglion neurons. Oncotarget 2017; 8:93051-93062. [PMID: 29190977 PMCID: PMC5696243 DOI: 10.18632/oncotarget.21805] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 08/29/2017] [Indexed: 12/29/2022] Open
Abstract
Peroxisome proliferator-activated receptor-α (PPAR-α), a lipid activated transcription factor of nuclear hormone receptor superfamily, can relieve pain through a rapid-response mechanism. However, little is known about the underlying mechanism. Herein, we report that PPAR-α activation acutely inhibits the functional activity of acid-sensing ion channels (ASICs), key sensors for extracellular protons, in rat dorsal root ganglion (DRG) neurons. Pre-application of PPAR-α agonist GW7647 for 2 min decreased the amplitude of proton-gated currents mediated by ASICs in a concentration-dependent manner. GW7647 shifted the concentration-response curve for proton downwards, with a decrease of 36.9 ± 2.3% in the maximal current response to proton. GW7647 inhibition of proton-gated currents can be blocked by GW6471, a selective PPAR-α antagonist. Moreover, PPAR-α activation decreased the number of acidosis-evoked action potentials in rat DRG neurons. Finally, peripheral administration of GW7647 dose-dependently relieved nociceptive responses to injection of acetic acid in rats. These results indicated that activation of peripheral PPAR-α acutely inhibited functional activity of ASICs in a non-genomic manner, which revealed a novel mechanism underlying rapid analgesia through peripheral PPAR-α.
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Affiliation(s)
- Jing Wu
- Research Center of Basic Medical Sciences, School of Basic Medical Sciences, Hubei University of Science and Technology, Xianning 437100, Hubei, P.R. China
| | - Jia-Jia Wang
- Research Center of Basic Medical Sciences, School of Basic Medical Sciences, Hubei University of Science and Technology, Xianning 437100, Hubei, P.R. China
| | - Ting-Ting Liu
- Research Center of Basic Medical Sciences, School of Basic Medical Sciences, Hubei University of Science and Technology, Xianning 437100, Hubei, P.R. China.,Department of Physiology, School of Basic Medical Sciences, Hubei University of Science and Technology, Xianning 437100, Hubei, P.R. China
| | - Yi-Mei Zhou
- Research Center of Basic Medical Sciences, School of Basic Medical Sciences, Hubei University of Science and Technology, Xianning 437100, Hubei, P.R. China
| | - Chun-Yu Qiu
- Department of Pharmacology, Hubei University of Science and Technology, Xianning 437100, Hubei, P.R. China
| | - Ding-Wen Shen
- Research Center of Basic Medical Sciences, School of Basic Medical Sciences, Hubei University of Science and Technology, Xianning 437100, Hubei, P.R. China
| | - Wang-Ping Hu
- Research Center of Basic Medical Sciences, School of Basic Medical Sciences, Hubei University of Science and Technology, Xianning 437100, Hubei, P.R. China.,Department of Physiology, School of Basic Medical Sciences, Hubei University of Science and Technology, Xianning 437100, Hubei, P.R. China
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Nestmann ER. Safety of micronized palmitoylethanolamide (microPEA): lack of toxicity and genotoxic potential. Food Sci Nutr 2017; 5:292-309. [PMID: 28265364 PMCID: PMC5332261 DOI: 10.1002/fsn3.392] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 05/05/2016] [Accepted: 05/13/2016] [Indexed: 01/01/2023] Open
Abstract
Palmitoylethanolamide (PEA) is a natural fatty acid amide found in a variety of foods, which was initially identified in egg yolk. MicroPEA of defined particle size (0.5-10 μm) was evaluated for mutagenicity in Salmonella typhimurium, for clastogenicity/aneuploidy in cultured human lymphocytes, and for acute and subchronic rodent toxicity in the rat, following standard OECD test protocols, in accordance with Good Laboratory Practice (GLP). PEA did not induce mutations in the bacterial assay using strains TA1535, TA97a, TA98, TA100, and TA102, with or without metabolic activation, in either the plate incorporation or liquid preincubation methods. Similarly, PEA did not induce genotoxic effects in human cells treated for 3 or 24 h without metabolic activation, or for 3 h with metabolic activation. PEA was found to have an LD50 greater than the limit dose of 2000 mg/kg body weight (bw), using the OECD Acute Oral Up and Down Procedure. Doses for the 90-day rat oral toxicity study were based on results from the preliminary 14-day study, that is, 250, 500, and 1000 mg/kg bw/day. The No Effect Level (NOEL) in both subchronic studies was the highest dose tested.
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Petrosino S, Di Marzo V. The pharmacology of palmitoylethanolamide and first data on the therapeutic efficacy of some of its new formulations. Br J Pharmacol 2016; 174:1349-1365. [PMID: 27539936 DOI: 10.1111/bph.13580] [Citation(s) in RCA: 200] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 08/01/2016] [Accepted: 08/05/2016] [Indexed: 02/06/2023] Open
Abstract
Palmitoylethanolamide (PEA) has emerged as a potential nutraceutical, because this compound is naturally produced in many plant and animal food sources, as well as in cells and tissues of mammals, and endowed with important neuroprotective, anti-inflammatory and analgesic actions. Several efforts have been made to identify the molecular mechanism of action of PEA and explain its multiple effects both in the central and the peripheral nervous system. Here, we provide an overview of the pharmacology, efficacy and safety of PEA in neurodegenerative disorders, pain perception and inflammatory diseases. The current knowledge of new formulations of PEA with smaller particle size (i.e. micronized and ultra-micronized) when given alone or in combination with antioxidant flavonoids (i.e. luteolin) and stilbenes (i.e. polydatin) is also reviewed. LINKED ARTICLES This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc.
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Affiliation(s)
- Stefania Petrosino
- Endocannabinoid Research Group, Istituto di Chimica Biomolecolare, Consiglio Nazionale delle Ricerche, Pozzuoli (NA), Italy.,Epitech Group S.p.A., Saccolongo (PD), Italy
| | - Vincenzo Di Marzo
- Endocannabinoid Research Group, Istituto di Chimica Biomolecolare, Consiglio Nazionale delle Ricerche, Pozzuoli (NA), Italy
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Karwad MA, Macpherson T, Wang B, Theophilidou E, Sarmad S, Barrett DA, Larvin M, Wright KL, Lund JN, O'Sullivan SE. Oleoylethanolamine and palmitoylethanolamine modulate intestinal permeability in vitro via TRPV1 and PPARα. FASEB J 2016; 31:469-481. [PMID: 27623929 DOI: 10.1096/fj.201500132] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 08/15/2016] [Indexed: 12/26/2022]
Abstract
Cannabinoids modulate intestinal permeability through cannabinoid receptor 1 (CB1). The endocannabinoid-like compounds oleoylethanolamine (OEA) and palmitoylethanolamine (PEA) play an important role in digestive regulation, and we hypothesized they would also modulate intestinal permeability. Transepithelial electrical resistance (TEER) was measured in human Caco-2 cells to assess permeability after application of OEA and PEA and relevant antagonists. Cells treated with OEA and PEA were stained for cytoskeletal F-actin changes and lysed for immunoassay. OEA and PEA were measured by liquid chromatography-tandem mass spectrometry. OEA (applied apically, logEC50 -5.4) and PEA (basolaterally, logEC50 -4.9; apically logEC50 -5.3) increased Caco-2 resistance by 20-30% via transient receptor potential vanilloid (TRPV)-1 and peroxisome proliferator-activated receptor (PPAR)-α. Preventing their degradation (by inhibiting fatty acid amide hydrolase) enhanced the effects of OEA and PEA. OEA and PEA induced cytoskeletal changes and activated focal adhesion kinase and ERKs 1/2, and decreased Src kinases and aquaporins 3 and 4. In Caco-2 cells treated with IFNγ and TNFα, OEA (via TRPV1) and PEA (via PPARα) prevented or reversed the cytokine-induced increased permeability compared to vehicle (0.1% ethanol). PEA (basolateral) also reversed increased permeability when added 48 or 72 h after cytokines (P < 0.001, via PPARα). Cellular and secreted levels of OEA and PEA (P < 0.001-0.001) were increased in response to inflammatory mediators. OEA and PEA have endogenous roles and potential therapeutic applications in conditions of intestinal hyperpermeability and inflammation.-Karwad, M. A., Macpherson, T., Wang, B., Theophilidou, E., Sarmad, S., Barrett, D. A., Larvin, M., Wright, K. L., Lund, J. N., O'Sullivan, S. E. Oleoylethanolamine and palmitoylethanolamine modulate intestinal permeability in vitro via TRPV1 and PPARα.
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Affiliation(s)
- Mustafa A Karwad
- School of Medicine, Royal Derby Hospital, University of Nottingham, Nottingham, United Kingdom
| | - Tara Macpherson
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom
| | - Bo Wang
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom
| | - Elena Theophilidou
- School of Medicine, Royal Derby Hospital, University of Nottingham, Nottingham, United Kingdom
| | - Sarir Sarmad
- Centre for Analytical Bioscience, School of Pharmacy, University of Nottingham, Nottingham, United Kingdom; and
| | - David A Barrett
- Centre for Analytical Bioscience, School of Pharmacy, University of Nottingham, Nottingham, United Kingdom; and
| | - Michael Larvin
- Graduate Entry Medical School, University of Limerick, Limerick, Ireland.,Health Research Institute, University of Limerick, Limerick, Ireland
| | - Karen L Wright
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom
| | - Jonathan N Lund
- School of Medicine, Royal Derby Hospital, University of Nottingham, Nottingham, United Kingdom
| | - Saoirse E O'Sullivan
- School of Medicine, Royal Derby Hospital, University of Nottingham, Nottingham, United Kingdom;
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Marcucci M, Germini F, Coerezza A, Andreinetti L, Bellintani L, Nobili A, Rossi PD, Mari D. Efficacy of ultra-micronized palmitoylethanolamide (um-PEA) in geriatric patients with chronic pain: study protocol for a series of N-of-1 randomized trials. Trials 2016; 17:369. [PMID: 27473188 PMCID: PMC4966710 DOI: 10.1186/s13063-016-1496-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 07/02/2016] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Chronic pain in older people is highly prevalent, often underestimated, and associated with adverse outcomes. Most available analgesic drugs are often either ineffective or not tolerated, with many side effects. Palmitoylethanolamide (PEA) is an endogenous widely distributed N-acylethanolamina involved in neuroinflammation and pain-generating processes. Formulations containing ultra-micronized palmitoylethanolamide (um-PEA) are available but their effectiveness on chronic pain in highly heterogeneous geriatric patients is not clear and probably not generalizable. We planned to adopt the N-of-1 trial approach to test the effectiveness of um-PEA objectively at the individual level in our older outpatients. METHODS/DESIGN Persons 65 years or older referring to the Geriatric Unit of the Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico of Milan complaining of noncancer chronic pain of any origin will be eligible. Each trial will be a placebo-controlled randomized crossover trial including two um-PEA (600 mg twice a day) and placebo treatment pairs. The um-PEA or placebo 3-week periods will be separated by 2-week washout intervals to overcome possible carryover effects. Pain intensity, need of on-demand analgesic medications, and impact on daily activities will be evaluated. Cognitively impaired patients will be eligible as long as an expression of pain can be recognized and its frequency assessed by a caregiver. Trial results will be discussed with the patient or caregiver and the treating physician to decide whether to continue the treatment. The impact of the N-of-1 approach on the physician's management plan and confidence will be assessed. We will secondarily meta-analyze the performed N-of-1 trials to obtain an estimate of the average effect of um-PEA compared with placebo using a frequentist and Bayesian approach. DISCUSSION While pursuing an ultimate clinical objective, i.e. to empirically and objectively decide the best treatment choice for an individual older patient with chronic pain, these series of geriatric N-of-1 trials on PEA will bring the principles of evidence-based medicine into the care of patients not usually represented in conventional randomized controlled trials, and realize a patient-centered outcome approach necessary to improve appropriate prescribing in elderly patients with multimorbidity and polypharmacy. TRIAL REGISTRATION ClinicalTrials.gov NCT02699281 . Registered on 3 March 2016.
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Affiliation(s)
- Maura Marcucci
- Geriatric Unit, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Via Pace 9, 20122, Milan, Italy. .,Department of Clinical Sciences and Community Health, Università degli Studi di Milano, via Francesco Sforza 35, 20122, Milan, Italy.
| | - Federico Germini
- Geriatric Unit, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Via Pace 9, 20122, Milan, Italy
| | - Anna Coerezza
- Geriatric Unit, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Via Pace 9, 20122, Milan, Italy.,Department of Clinical Sciences and Community Health, Università degli Studi di Milano, via Francesco Sforza 35, 20122, Milan, Italy
| | - Luca Andreinetti
- Department of Clinical Sciences and Community Health, Università degli Studi di Milano, via Francesco Sforza 35, 20122, Milan, Italy
| | - Lorenzo Bellintani
- Geriatric Unit, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Via Pace 9, 20122, Milan, Italy.,Department of Clinical Sciences and Community Health, Università degli Studi di Milano, via Francesco Sforza 35, 20122, Milan, Italy
| | - Alessandro Nobili
- Laboratory for Quality Assessment of Geriatric Therapies and Services, IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", via Giuseppe La Masa 19, 20156, Milan, Italy
| | - Paolo Dionigi Rossi
- Geriatric Unit, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Via Pace 9, 20122, Milan, Italy
| | - Daniela Mari
- Geriatric Unit, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Via Pace 9, 20122, Milan, Italy.,Department of Clinical Sciences and Community Health, Università degli Studi di Milano, via Francesco Sforza 35, 20122, Milan, Italy
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Gabrielsson L, Mattsson S, Fowler CJ. Palmitoylethanolamide for the treatment of pain: pharmacokinetics, safety and efficacy. Br J Clin Pharmacol 2016; 82:932-42. [PMID: 27220803 PMCID: PMC5094513 DOI: 10.1111/bcp.13020] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 05/19/2016] [Accepted: 05/22/2016] [Indexed: 12/11/2022] Open
Abstract
Palmitoylethanolamide (PEA) has been suggested to have useful analgesic properties and to be devoid of unwanted effects. Here, we have examined critically this contention, and discussed available data concerning the pharmacokinetics of PEA and its formulation. Sixteen clinical trials, six case reports/pilot studies and a meta‐analysis of PEA as an analgesic have been published in the literature. For treatment times up to 49 days, the current clinical data argue against serious adverse drug reactions (ADRs) at an incidence of 1/200 or greater. For treatment lasting more than 60 days, the number of patients is insufficient to rule out a frequency of ADRs of less than 1/100. The six published randomized clinical trials are of variable quality. Presentation of data without information on data spread and nonreporting of data at times other than the final measurement were among issues that were identified. Further, there are no head‐to‐head clinical comparisons of unmicronized vs. micronized formulations of PEA, and so evidence for superiority of one formulation over the other is currently lacking. Nevertheless, the available clinical data support the contention that PEA has analgesic actions and motivate further study of this compound, particularly with respect to head‐to‐head comparisons of unmicronized vs. micronized formulations of PEA and comparisons with currently recommended treatments.
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Affiliation(s)
- Linda Gabrielsson
- Department of Pharmacology and Clinical Neuroscience, Umeå University, SE-901 87, Umeå, Sweden
| | - Sofia Mattsson
- Department of Pharmacology and Clinical Neuroscience, Umeå University, SE-901 87, Umeå, Sweden
| | - Christopher J Fowler
- Department of Pharmacology and Clinical Neuroscience, Umeå University, SE-901 87, Umeå, Sweden.
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Del Giorno R, Skaper S, Paladini A, Varrassi G, Coaccioli S. Palmitoylethanolamide in Fibromyalgia: Results from Prospective and Retrospective Observational Studies. Pain Ther 2015; 4:169-78. [PMID: 26334329 PMCID: PMC4676767 DOI: 10.1007/s40122-015-0038-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Indexed: 11/30/2022] Open
Abstract
Introduction Fibromyalgia syndrome (FM) is characterized by persistent pain which is often refractory to common analgesic therapies and is particularly disabling. The objective of this study was to evaluate the therapeutic efficacy of duloxetine (DLX) + pregabalin (PGB) in patients suffering from FM and the possible added benefit of the lipid signaling molecule, palmitoylethanolamide (PEA). PEA is well-documented to exert anti-inflammatory, analgesic, and pain-relieving effects at both the preclinical and clinical level. Methods A total of 80 patients were recruited in two steps. The first was a retrospective observational study comprising 45 patients. This patient group received DLX + PGB for 6 months. The second step was a prospective observational study with 35 patients. Patients in this cohort began treatment with DLX + PGB at the same dosage as for the retrospective study plus micronized PEA (PEA-m®; Epitech Group, Italy) and ultramicronized PEA (PEA-um®; Epitech Group, Italy) for 3 months. Positive tender points (TPs), pain evoked, and pain intensity were evaluated at baseline and after 3 and 6 months in both studies. Statistical analyses were employed for comparison of data within the two studies and between them. Results The retrospective observational study (DLX + PGB), after 3 months of treatment showed a decrease of positive TPs, pain evoked, and pain intensity. After 6 months of treatment, these parameters had further improvement. In the prospective observational study (DLX + PGB + PEA), PEA introduction after 3 months of therapeutic regimen with DLX + PGB provided a significant improvement in pain symptoms, with a further reduction in the number of TPs and significant reduction in pain, compared to combined DLX + PGB only (p < 0.0001 for TPs and Visual Analog Scale comparisons). None of the patients experienced adverse side effects. Conclusion Our study confirms the efficacy of DLX + PGB and demonstrates as well the added benefit and safety of PEA in the treatment of pain in patients affected by FM. Electronic supplementary material The online version of this article (doi:10.1007/s40122-015-0038-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rosaria Del Giorno
- Institute of Internal Medicine, Rheumatology and Medical Therapy of Pain, Perugia University, District of Terni, Perugia, Italy.
| | - Stephen Skaper
- Department of Pharmaceutical and Pharmacological Sciences, Padua University, Padua, Italy
| | - Antonella Paladini
- Institute of Anesthesiology and Pain Therapy, L'Aquila University, L'Aquila, Italy
| | - Giustino Varrassi
- Paolo Procacci Foundation, L'Aquila University, L'Aquila, Italy.,European League Against Pain, Zürich, Switzerland
| | - Stefano Coaccioli
- Institute of Internal Medicine, Rheumatology and Medical Therapy of Pain, Perugia University, District of Terni, Perugia, Italy.,European League Against Pain, Zürich, Switzerland
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Freitag CM, Miller RJ. Peroxisome proliferator-activated receptor agonists modulate neuropathic pain: a link to chemokines? Front Cell Neurosci 2014; 8:238. [PMID: 25191225 PMCID: PMC4138931 DOI: 10.3389/fncel.2014.00238] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 07/28/2014] [Indexed: 11/29/2022] Open
Abstract
Chronic pain presents a widespread and intractable medical problem. While numerous pharmaceuticals are used to treat chronic pain, drugs that are safe for extended use and highly effective at treating the most severe pain do not yet exist. Chronic pain resulting from nervous system injury (neuropathic pain) is common in conditions ranging from multiple sclerosis to HIV-1 infection to type II diabetes. Inflammation caused by neuropathy is believed to contribute to the generation and maintenance of neuropathic pain. Chemokines are key inflammatory mediators, several of which (MCP-1, RANTES, MIP-1α, fractalkine, SDF-1 among others) have been linked to chronic, neuropathic pain in both human conditions and animal models. The important roles chemokines play in inflammation and pain make them an attractive therapeutic target. Peroxisome proliferator-activated receptors (PPARs) are a family of nuclear receptors known for their roles in metabolism. Recent research has revealed that PPARs also play a role in inflammatory gene repression. PPAR agonists have wide-ranging effects including inhibition of chemokine expression and pain behavior reduction in animal models. Experimental evidence suggests a connection between the pain ameliorating effects of PPAR agonists and suppression of inflammatory gene expression, including chemokines. In early clinical research, one PPARα agonist, palmitoylethanolamide (PEA), shows promise in relieving chronic pain. If this link can be better established, PPAR agonists may represent a new drug therapy for neuropathic pain.
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Affiliation(s)
- Caroline M Freitag
- Department of Molecular Pharmacology and Biological Chemistry, Richard J. Miller Laboratory, Northwestern University Chicago, IL, USA
| | - Richard J Miller
- Department of Molecular Pharmacology and Biological Chemistry, Richard J. Miller Laboratory, Northwestern University Chicago, IL, USA
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Palmitoylethanolamide, a naturally occurring disease-modifying agent in neuropathic pain. Inflammopharmacology 2013; 22:79-94. [DOI: 10.1007/s10787-013-0191-7] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 09/10/2013] [Indexed: 02/07/2023]
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