Effects of capsaicin and menthol on oral thermal sensory thresholds

Kalantzis, Athanasios; Robinson, P.P.; Loescher, Alison R.

doi:10.1016/j.archoralbio.2006.09.001

Cited by 19 publications

(16 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this study, we applied menthol to both ventral hindpaws, which constitute a significantly larger percentage of the overall body surface area of a rat, as compared to a restricted region of the volar forearm skin treated with menthol in tests on humans [14,44,46,72]. Moreover, dermal absorption of chemicals, which is a function of the total area of application and of the concentration [76][77][78][79], is greater in rats vs humans [80]. For example, permeation of L-menthol through the stratum corneum was four times more intense in rats after elimination of the hair, as compared to the human skin [81].…”

Section: Discussionmentioning

confidence: 99%

Behavioral Testing of the Effects of Thermosensitive TRP Channel Agonists on Touch, Temperature, and Pain Sensations

Tsagareli¹

2011

Neurophysiology

View full text Add to dashboard Cite

It was recently found that transient receptor potential (TRP) channels play an important role in the transduction of thermal, mechanical, and chemical stimuli underlying the somatic sensation. Several types of TRP channels exhibit sensitivity to increases or decreases in temperature, as well as to the action of chemical ligands that elicit similar thermal or painful sensations. These agents include menthol, mustard oil, cinnamaldehyde (CA), gingerol, capsaicin, camphor, eugenol, and others. Cinnamaldehyde is a pungent chemical obtained from cinnamon, which acts as an agonist of the TRPA1 channels; these channels were originally reported to be activated by cold temperatures (below 18°C). TRPA1 is also implicated in cold nociception. However, its role in the formation of cold pain is more controversial, with discrepant reports that TRPA1s do or do not respond to intense cooling. Menthol derived from plants of the mint family enhances the feeling of coldness by interacting with the cold-sensitive TRPM8 channels, but its effect on pain is less well understood. Using behavioral methods, we showed that unilateral intraplantar injection of CA (5 to 20%) induced a significant concentration-dependent decrease in the latency for ipsilateral paw withdrawal from a noxious heat stimulus, i.e., heat hyperalgesia. Cinnamaldehyde also significantly reduced mechanical withdrawal thresholds for the injected paw, i.e., evoked mechanical allodynia. Bilateral intraplantar injections of CA resulted in a significant cold hyperalgesia (cold plate test) and a weak enhancement of innocuous cold avoidance (thermal preference test). In contrast to CA, menthol in a dose-dependent manner increased the latency for noxious heat-evoked withdrawal, i.e., exerted an antinociceptive effect. Menthol did not affect mechanosensation except for a weak allodynic effect when applied in the highest concentration used (40 %), indicating that it did not exert a local anesthetic effect. Menthol had a biphasic effect on cold avoidance. High concentrations of menthol reduced cold avoidance, i.e., induced cold hypoalgesia, while low menthol concentrations significantly intensified cold avoidance. The highest menthol concentration provided cold hypoalgesia (cold plate test), while lower concentrations had no effect. Taken together, our data support the idea that TRPA1 and TRPM8 channels represent promising peripheral targets for pain modulation.

show abstract

Section: Discussionmentioning

confidence: 99%

Behavioral Testing of the Effects of Thermosensitive TRP Channel Agonists on Touch, Temperature, and Pain Sensations

Tsagareli¹

2011

Neurophysiology

View full text Add to dashboard Cite

show abstract

“…decreased temperatures (Granot & Nagler, ; Kalantzis et al . ), or (3) are more sensitive to cooling than to warming (Green, ; Renton et al . ).…”

Section: Discussionmentioning

confidence: 99%

Oral thermosensing by murine trigeminal neurons: modulation by capsaicin, menthol and mustard oil

Leijon

Neves

Breza

et al. 2019

The Journal of Physiology

View full text Add to dashboard Cite

Key points Orosensory thermal trigeminal afferent neurons respond to cool, warm, and nociceptive hot temperatures with the majority activated in the cool range. Many of these thermosensitive trigeminal orosensory afferent neurons also respond to capsaicin, menthol, and/or mustard oil (allyl isothiocyanate) at concentrations found in foods and spices. There is significant but incomplete overlap between afferent trigeminal neurons that respond to oral thermal stimulation and to the above chemesthetic compounds. Capsaicin sensitizes warm trigeminal thermoreceptors and orosensory nociceptors; menthol attenuates cool thermoresponses. Abstract When consumed with foods, mint, mustard, and chili peppers generate pronounced oral thermosensations. Here we recorded responses in mouse trigeminal ganglion neurons to investigate interactions between thermal sensing and the active ingredients of these plants – menthol, allyl isothiocyanate (AITC), and capsaicin, respectively – at concentrations found in foods and commercial hygiene products. We carried out in vivo confocal calcium imaging of trigeminal ganglia in which neurons express GCaMP3 or GCAMP6s and recorded their responses to oral stimulation with thermal and the above chemesthetic stimuli. In the V3 (oral sensory) region of the ganglion, thermoreceptive neurons accounted for ∼10% of imaged neurons. We categorized them into three distinct classes: cool‐responsive and warm‐responsive thermosensors, and nociceptors (responsive only to temperatures ≥43–45 °C). Menthol, AITC, and capsaicin also elicited robust calcium responses that differed markedly in their latencies and durations. Most of the neurons that responded to these chemesthetic stimuli were also thermosensitive. Capsaicin and AITC increased the numbers of warm‐responding neurons and shifted the nociceptor threshold to lower temperatures. Menthol attenuated the responses in all classes of thermoreceptors. Our data show that while individual neurons may respond to a narrow temperature range (or even bimodally), taken collectively, the population is able to report on graded changes of temperature. Our findings also substantiate an explanation for the thermal sensations experienced when one consumes pungent spices or mint.

show abstract

“…Previous human studies have generally reported cold hyperalgesia and/or a decrease in cold pain threshold following topical menthol application [24, 29, 33, 44, 66, 68]. However, thresholds for cold pain are more variable compared to heat pain [46], so that overall subjective ratings of cold pain might include a component of innocuous cold that is also enhanced by menthol.…”

Section: Discussionmentioning

confidence: 99%

Topical application of l-menthol induces heat analgesia, mechanical allodynia, and a biphasic effect on cold sensitivity in rats

Klein

Sawyer

Carstens

et al. 2010

Behavioural Brain Research

View full text Add to dashboard Cite

Menthol is used in analgesic balms and also in foods and oral hygiene products for its fresh cooling sensation. Menthol enhances cooling by interacting with the cold-sensitive thermoTRP channel TRPM8, but its effect on pain is less well understood. We presently used behavioral methods to investigate effects of topical menthol on thermal (hot and cold) pain and innocuous cold and mechanical sensitivity in rats. Menthol dose-dependently increased the latency for noxious heatevoked withdrawal of the treated hindpaw with a weak mirror-image effect, indicating antinociception. Menthol at the highest concentration (40%) reduced mechanical withdrawal thresholds, with no effect at lower concentrations. Menthol had a biphasic effect on cold avoidance. At high concentrations (10 and 40%) menthol reduced avoidance of colder temperatures (15 and 20°C ) compared to 30°C, while at lower concentrations (0.01-1%) menthol enhanced cold avoidance. In a −5°C cold-plate test, 40% menthol significantly increased the nocifensive response latency (cold hypoalgesia) while lower concentrations were not different from vehicle controls. These results are generally consistent with neurophysiological and human psychophysical data and support TRPM8 as a potential peripheral target of pain modulation.

show abstract

Effects of capsaicin and menthol on oral thermal sensory thresholds

Cited by 19 publications

References 35 publications

Behavioral Testing of the Effects of Thermosensitive TRP Channel Agonists on Touch, Temperature, and Pain Sensations

Behavioral Testing of the Effects of Thermosensitive TRP Channel Agonists on Touch, Temperature, and Pain Sensations

Oral thermosensing by murine trigeminal neurons: modulation by capsaicin, menthol and mustard oil

Topical application of l-menthol induces heat analgesia, mechanical allodynia, and a biphasic effect on cold sensitivity in rats

Contact Info

Product

Resources

About