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Administration of capsaicin and isoflavone promotes hair growth


#1

Administration of capsaicin and isoflavone promotes hair growth by increasing insulin-like growth factor-I production in mice and in humans with alopecia

Growth Horm IGF Res. 2007 Oct;17(5):408-15

OBJECTIVE:
Insulin-like growth factor-I (IGF-I) plays an important role in hair growth. Capsaicin activates vanilloid receptor-1, thereby increasing the release of calcitonin gene-related peptide (CGRP) from sensory neurons, and CGRP has been shown to increase IGF-I production.

We recently reported that isoflavone, a phytoestrogen, increases production of CGRP by increasing its transcription in sensory neurons. These observations raise the possibility that administration of capsaicin and isoflavone might promote hair growth by increasing IGF-I production. In the present study, we examined this possibility in mice and humans with alopecia.

DESIGN:
Dermal IGF-I levels, immunohistochemical expression of IGF-I in the skin and hair regrowth were examined after capsaicin and isoflavone administration to wild-type (WT) mice and CGRP-knockout mice. Plasma levels of IGF-I and promotion of hair growth were evaluated in 48 volunteers with alopecia after administration of capsaicin and isoflavone for 5 months.

RESULTS:
Subcutaneous administration of capsaicin significantly increased dermal IGF-I levels at 30 min after administration in WT mice (p < 0.01), but not in CGRP-knockout mice. Dermal levels of IGF-I were significantly higher in WT mice administered capsaicin and isoflavone for 4 wks than in those administered capsaicin alone for 4 wks (p < 0.01) and in those administered neither of them (p < 0.01).

Immunohistochemical expression of IGF-I at dermal papillae in hair follicles was increased in WT mice administered capsaicin and isoflavone and in those administered capsaicin alone at 4 wks. Hair regrowth was clearly more accelerated in WT mice administered capsaicin and isoflavone for 4 wks than in those administered capsaicin alone for 4 wks and in those administered neither of them.

Plasma levels of IGF-I were significantly increased from baseline levels in 31 volunteers with alopecia at 5 months after oral administration of capsaicin (6 mg/day) and isoflavone (75 mg/day) (p < 0.01), while they were not increased in 17 volunteers with alopecia administered placebo.

The number of volunteers with alopecia who showed promotion of hair growth at 5 months after administration was significantly higher among volunteers administered capsaicin and isoflavone (20/31: 64.5%) than among those administered placebo (2/17: 11.8%) (p < 0.01).

CONCLUSIONS:

These observations strongly suggested that combined administration of capsaicin and isoflavone might increase IGF-I production in hair follicles in the skin, thereby promoting hair growth. Such effects of capsaicin and isoflavone might be mediated by sensory neuron activation in the skin.


#2

» Administration of capsaicin and isoflavone promotes hair growth by
» increasing insulin-like growth factor-I production in mice and in humans
» with alopecia

»
» Growth Horm IGF Res. 2007 Oct;17(5):408-15
»
» OBJECTIVE:
» Insulin-like growth factor-I (IGF-I) plays an important role in hair
» growth. Capsaicin activates vanilloid receptor-1, thereby increasing the
» release of calcitonin gene-related peptide (CGRP) from sensory neurons, and
» CGRP has been shown to increase IGF-I production.
»
» We recently reported that isoflavone, a phytoestrogen, increases
» production of CGRP by increasing its transcription in sensory neurons.
» These observations raise the possibility that administration of capsaicin
» and isoflavone might promote hair growth by increasing IGF-I production. In
» the present study, we examined this possibility in mice and humans with
» alopecia.
»
»
» DESIGN:
» Dermal IGF-I levels, immunohistochemical expression of IGF-I in the skin
» and hair regrowth were examined after capsaicin and isoflavone
» administration to wild-type (WT) mice and CGRP-knockout mice. Plasma levels
» of IGF-I and promotion of hair growth were evaluated in 48 volunteers with
» alopecia after administration of capsaicin and isoflavone for 5 months.
»
»
» RESULTS:
» Subcutaneous administration of capsaicin significantly increased dermal
» IGF-I levels at 30 min after administration in WT mice (p < 0.01), but not
» in CGRP-knockout mice. Dermal levels of IGF-I were significantly higher in
» WT mice administered capsaicin and isoflavone for 4 wks than in those
» administered capsaicin alone for 4 wks (p < 0.01) and in those administered
» neither of them (p < 0.01).
»
» Immunohistochemical expression of IGF-I at dermal papillae in hair
» follicles was increased in WT mice administered capsaicin and isoflavone
» and in those administered capsaicin alone at 4 wks. Hair regrowth was
» clearly more accelerated in WT mice administered capsaicin and isoflavone
» for 4 wks than in those administered capsaicin alone for 4 wks and in those
» administered neither of them.
»
» Plasma levels of IGF-I were significantly increased from baseline levels
» in 31 volunteers with alopecia at 5 months after oral administration of
» capsaicin (6 mg/day) and isoflavone (75 mg/day) (p < 0.01), while they were
» not increased in 17 volunteers with alopecia administered placebo.
»
» The number of volunteers with alopecia who showed promotion of hair growth
» at 5 months after administration was significantly higher among volunteers
» administered capsaicin and isoflavone (20/31: 64.5%) than among those
» administered placebo (2/17: 11.8%) (p < 0.01).
»
»
» CONCLUSIONS:
»
» These observations strongly suggested that combined administration of
» capsaicin and isoflavone might increase IGF-I production in hair follicles
» in the skin, thereby promoting hair growth. Such effects of capsaicin and
» isoflavone might be mediated by sensory neuron activation in the skin.

Sounds interesting, but how exactly would this be administered, do you think?