• J Pain · Aug 2016

    High-concentration L-menthol exhibits counter-irritancy to neurogenic inflammation, thermal and mechanical hyperalgesia caused by TRPA1-agonist trans-cinnamaldehyde.

    • Hjalte H Andersen, Parisa Gazerani, and Lars Arendt-Nielsen.
    • Center for Sensory-Motor Interaction (SMI), Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Aalborg, Denmark.
    • J Pain. 2016 Aug 1; 17 (8): 919-29.

    UnlabelledThe transient receptor potential cation channel subfamily M 8 (TRPM8) agonist L-menthol has been used traditionally for its topical counterirritant properties. Although the use of topical L-menthol for pain is casuistically established, evidence regarding its efficacy is negligible. This study aimed to characterize the effect of L-menthol as a counterirritant on cutaneous pain and hyperalgesia provoked by topical application of the transient receptor potential cation channel, subfamily A, member 1 (TRPA1) agonist trans-cinnamaldehyde (CA). In a randomized, double-blinded study CA was applied to a 3 × 3-cm area of the volar forearm evoking neurogenic inflammation, pain, mechanical, and thermal hyperalgesia in 14 healthy volunteers. In different sessions, 10% CA alone or 40% L-menthol applied simultaneously with 10% CA were administered for 20 minutes, throughout which the subjects rated the pain intensity on a visual analogue scale of 0 to 10. Extensive quantitative sensory testing was conducted and superficial blood flow (neurogenic inflammation) was recorded. Administration of CA evoked spontaneous pain, neurogenic inflammation, thermal hyperalgesia, and primary and secondary mechanical hyperalgesia. Coadministration of topical L-menthol reduced spontaneous pain intensity (P < .01), neurogenic inflammation (P < .01), primary mechanical hyperalgesia (P < .05), secondary mechanical hyperalgesia (P < .05), and heat hyperalgesia (P < .05), but not cold hyperalgesia. L-menthol exhibited inhibitory effects on simultaneously established pain, hypersensitivity, and neurogenic inflammation in a human TRPA1-induced pain model. Potent TRPM8 agonists could be useful as topical antihyperalgesics. The study and the trial protocol is registered and approved by the local research ethics committee under the jurisdiction of the Danish Medicines Agency number N-20130005. The protocol also is registered at Clinicaltrials.gov under NCT02653703.PerspectiveDrugs interacting with transient receptor potential channels are of great therapeutic potential. In the present study we established cutaneous pain and hyperalgesia using the TRPA1 agonist CA. Subsequently, we showed that the frequently used topical counterirritant and TRPM8 agonist, L-menthol, decreased evoked pain, hyperalgesia, and inflammation, indicating direct and indirect antinociceptive mechanisms.Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.

      Pubmed     Full text   Copy Citation     Plaintext  

      Add institutional full text...

    Notes

     
    Knowledge, pearl, summary or comment to share?
    300 characters remaining
    help        
    You can also include formatting, links, images and footnotes in your notes
    • Simple formatting can be added to notes, such as *italics*, _underline_ or **bold**.
    • Superscript can be denoted by <sup>text</sup> and subscript <sub>text</sub>.
    • Numbered or bulleted lists can be created using either numbered lines 1. 2. 3., hyphens - or asterisks *.
    • Links can be included with: [my link to pubmed](http://pubmed.com)
    • Images can be included with: ![alt text](https://bestmedicaljournal.com/study_graph.jpg "Image Title Text")
    • For footnotes use [^1](This is a footnote.) inline.
    • Or use an inline reference [^1] to refer to a longer footnote elseweher in the document [^1]: This is a long footnote..

    hide…

What will the 'Medical Journal of You' look like?

Start your free 21 day trial now.

We guarantee your privacy. Your email address will not be shared.