None listed
Conditions
Brief summary
The trichomes of the New Zealand endemic nettle ongaonga, Urtica ferox, may contain a novel compound with therapeutic potential. When skin is exposed to the liquid in the Urtica ferox trichomes, a suite of chemicals including acetylcholine, histamine and serotonin cause an immediate painful response. However, there is also potentially a yet-to-be identified compound that affects the peripheral nervous system causing anaesthesia, spontaneous and cold-induced paraethesias and allodynia and which appears to be exclusive to the New Zealand Urtica species. This compound may provide insight into the fundamental scientific neurobiology of the mechanisms whereby chemicals interact with dermal pain receptors and could potentially lead to a new therapeutic for treatment of neuropathic pain from disorders such as diabetic neuropathy, leprosy, or excessive alcohol consumption. Despite the reports that there is an unidentified compound that affects the peripheral nervous system functioning as an analgesic these assumptions have never been clinically tested. Through controlled exposure to Urtica ferox and comparision to 4% lidocaine, this study aims to assess if exposure to Urtica ferox results in increased thermal sensation and thermal pain thresholds.
Interventions
Exposure to Urtica ferox will be topically administered once in a single exposure on the volar forearm in an area identified with a 15mm diameter circle denoted with indelible ink at time=0.
100 ug of standardised extract (equivelent to 5-10 trichromes by weight) will be placed on the skin and a skin scratched performed.
Immediately prior to administration the sensory testing will be performed in triplicate at the three test sites. Subsequent to administration of the intervention testing wi
Exposure to Urtica ferox will be topically administered once in a single exposure on the volar forearm in an area identified with a 15mm diameter circle denoted with indelible ink at time=0. 100 ug of standardised extract (equivelent to 5-10 trichromes by weight) will be placed on the skin and a skin scratched performed. Immediately prior to administration the sensory testing will be performed in triplicate at the three test sites. Subsequent to administration of the intervention testing will be performed at 1, 3, 24, 48 and 72 hours.
Sponsors
Nelson Marlborough Institute of Technology
Study design
Allocation
Non-randomised trial
Intervention model
Other
Primary purpose
Treatment
Masking
Blinded (masking used) (Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
Age over 18
Exclusion criteria
Smoker Known condition that causes neuropathy, particularly diabetes and excess alcohol intake. Loss of hand Loss of feeling in hand Allergy to lidocaine or Urtica ferox
Outcome results
None listed