Inhibitory Effects of Polyacetylene Compounds from Panax ginseng on Neurotrophin Receptor-Mediated Hair Growth.

Neurotrophins play an important role in the control of the hair growth cycle. Therefore, neurotrophin receptor antagonists have therapeutic potential for the treatment of hair growth disorders. In this study, we investigated the inhibitory effect of Panax ginseng, a medicinal plant commonly used to treat alopecia, on the binding of neurotrophins to their receptors. In addition, we isolated and characterized the bioactive compounds of P. ginseng extracts. P. ginseng hexane extracts strongly inhibited brain-derived neurotrophic factor (BDNF)-TrkB and ß-nerve growth factor (ß-NGF)-p75 neurotrophin receptor (p75NTR) binding. Furthermore, we identified the following 6 polyacetylene compounds as the bioactive components in P. ginseng hexane extract: panaxynol (1), panaxydol (2), panaxydol chlorohydrin (3), 1,8-heptadecadiene-4,6-diyne-3,10-diol (4), panaxytriol (5), and dihydropanaxacol (6). In particular, compounds 4, 5, and 6 significantly inhibited BDNF-TrkB binding in a dose-dependent manner. To identify the structural component mediating the inhibitory effect, we investigated the effects of the hydroxyl moiety in these compounds. We found that the inhibitory effect of panaxytriol (5) was strong, whereas the inhibitory effect of Ac-panaxytriol (7) was relatively weak. Our findings suggest that P. ginseng-derived polyacetylenes with a hydroxyl moiety might provide therapeutic benefits to patients with hair growth disorders such as alopecia by inhibiting the binding of neurotrophins to their receptors. Although saponins have been proposed to be the primary mediators of the effects of P. ginseng on hair growth, this study revealed that polyacetylene compounds exert similar effects.

Induction of hepatocyte growth factor production in human dermal fibroblasts by caffeic acid derivatives.

Hepatocyte growth factor (HGF) has mitogenic, motogenic, and morphogenic activities in epithelial cells. Induction of HGF production may be involved in organ regeneration, wound healing and embryogenesis. In this study, we examined the effects of caffeic acid derivatives including 4,5-di-O-caffeoylquinic acid (1) and acteoside (2) on HGF production in Neonatal Normal Human Dermal Fibroblasts (NHDF). Both 4,5-di-O-caffeoylquinic acid (1) and acteoside (2) significantly induced HGF production dose-dependent manner. To know the important substructure for HGF production activity, we next investigated the effect of the partial structure of these caffeic acid derivatives. From the results, caffeic acid (3) showed strong activity on the promotion of HGF production, while hydroxytyrosol (4) and quinic acid (5) didn't show any activity. Our findings suggest that the caffeoyl moiety of caffeic acid derivatives is essential for accelerated production of HGF. The compound which has the caffeoyl moiety may be useful for the treatment of some intractable organ disease.

[Efficacy of sweat-antigen-inactivating skin care products on itching of patients with atopic dermatitis].

BACKGROUND: Many patients with atopic dermatitis showed immediate-type hypersensitivity against sweat antigen. Therefore, to deal with sweating is important to prevent itching and aggravations of dermatitis of patient with atopic dermatitis. We had searched a substance that inactivated sweat antigen adopting histamine release test. And we found that tannic acid which selected by screening various natural products inactivated sweat antigen. METHODS: We evaluate skin care products (spray, after-bathing water and aerosol-spray) containing tannic acid for patients with atopic dermatitis. We administered in a tannic acid-containing spray and after-bathing water on 17 patients with atopic dermatitis. RESULTS: After treatment, total clinical assessment score and itching in the afternoon had significantly decreased from that on day 0. To evaluate the effect of tannic acid containing-aerosol spray on itching of patients with AD, we assessed symptoms of atopic dermatitis patients who used a tannic acid containing-aerosol spray every day for 4 weeks in a cross-over, double-blind study. Clinical severity of atopic dermatitis and degrees of itching in daily life of patients were evaluated by physicians and patients themselves, respectively. Degrees of itching in morning and those at night were significantly more largely improved by the use of tannic acid-containing aerosol spray than those by the use of placebo control aerosol spray. The overall efficacy of tannic acid-containing aerosol sprays was also significantly higher than those of tannic acid free spray. CONCLUSION: Sweat antigen inactivating skin care products may be effective to reduce itching of patients with atopic dermatitis.