A proportion of sensory C-fibres is characterized by sensitivity to the pungent agent in hot peppers, capsaicin. Upon stimulation by capsaicin, co-stored peptides including calcitonin gene-related peptides (CGRP), are released from the peripheral terminals of these fibres. 

In addition to capsaicin other noxious/painful stimuli and conditions such as low pH, ischaemia, nicotine and bradykinin can cause release of CGRP from capsaicin - sensitive afferent nerves.  CGRP - immuno-reactive nerve fibres occur throughout the cardiovascular system, including the heart where the highest amounts of CGRP have been detected along the coronary arteries and in the atria. 

In various species and experimental models, CGRP has proven to be the most potent vasodilator yet discovered.

Goran Kallner
Royal Karolinska Medico
Chirurgiska Institutet

EXPRESSION CLONING AND CHARACTERIZATION OF THE CAPSAICIN RECEPTOR

Capsaicin is the principle pungent ingredient found in hot chili peppers.  Exposure to capsaicin initially leads to the sensation of pain but upon repeated application, it leads to the desensitization of painful stimuli.

This paradoxical effect underlies the use of capsaicin containing compounds as tipical analgesics.  Because capsaicin selectively activates nociceptors, the "capsaicin receptor" has been suggested to play a role in the transduction and maintenance of pain.

We have recently characterized a cDNA clone encoding a "capsaicin receptor" (Nature 389: 816-824, 1997). The capsaicin receptor (vaniloid receptor type 1) VR1 recapitulates many of the properties described for capsaicin receptors in pain sensing neurons.

In addition, we demonstrated that VR1 can transduce noxious thermal stimuli into an inward current response supporting the hypothesis that it may function as a transducer of painful thermal stimuli in vivo.

Mark A Schumacher Ph.D, M.D.
Assistant Professor
Department of Anesthesia and Perioperative Care
University of California, San Francisco

Capsaicin, the active ingredient in red peppers, has been shown to have efficacy in the relief of pain associated with arthritis.  Structurally analogous to prostaglandins, capsaicin could be a lead-compound for drug discovery products with a similar mode of action. 

The Mcg human light chain dimer has been shown to have affinity for other anti-inflammatory compounds as well as prostagladin H2. Ongoing research with this well-characterized protein in providing structural information to a number of protein-ligand complexes.

from A Capsaicin-Immune Protein Complex: Structure and Binding Studies.
B.L. Hanson, C. Dewitt, A.B. Edmundson
University of Tennessee - Oak Ridge Graduate School of Bio-Medical Sciences and Oklahoma Medical Research Foundation

Effect of Coapplication of Capsaicin and Minoxidil on the Murine Hair Growth

  Won-Soo Lee, Hyung Jin Ahn, Young Hee Kim Department of Dermatology. Yonsei University Wonju College of Medicine, Wonju. Korea

Capsaicin induces the release of substance P(SP) which is believed to play an important role in murine hair growth and cycle. Minoxidil, the only approved topical hair drug having direct hair growth effect, has therapeutic limitation because it stimulates mainly vellus hair regrowth, not thick coarse terminal hairs.

So, we hypothesize that combined use of capsaicin and minoxidil may exert positive effects in terms of hair growth than minoxidil alone. We evaluated the effects of coapplication of capsaicin and minoxidil on the hair growth and cycle, compared with application of capsaicin or minoxidil alone.

We induced the anagen phase of the hair of back skin of ICR mice by depilation. We devied the mice into 4 groups, i.e., control group, capsaicin group, minoxidil group, and coapplied group. And then, we examined the hair growth macroscopically, and the percentage of the area of hair regrowth by image analysis using phototrichogram at the 0, the 5th, 10th, 15th, 20th, 25th, and 30th day.

Also we examined the morphologic changes of hair follicles and subcutis, and the number of mast cells by microscopy, and[methyl-3H] thymidine uptake by scintillation counter.

In this study, we observed that capsaicin can not only induce the anagen phase quickly, but also sustain constant effect on the linear hair growth. Minoxidil also induced the anagen phase fast, and prolong the anagen phase of the hair cycle.

Therefore, it is concluded that the coapplication of capsaicin and minoxidil can grow hair quickly and steadily.
 

Capsaicin for Hair Loss