Hair loss and reduction of hair volume are hallmarks of hair disorders, such as telogen effluvium, or male or female pattern hair loss, and hair aging, which can cause severe distress in both men and women. Common anti-hair loss drugs carry some side-effects, therefore, novel, safer approaches targeting milder phenotypes are highly advocated. In this context, we investigated an extract of the alpine plant Edelweiss, Leontopodium alpinum var. Helvetia, for its ability to modulate hair follicle (HF) growth ex vivo and inhibit hair loss while increasing hair regeneration in vivo.
Human amputated HFs were micro-dissected from three donors, two females and one male, and cultured ex vivo for 6 days. After treatment with 0.001% Edelweiss extract (EWDE), we investigated hair shaft production, and anagen/catagen conversion, and measured known parameters associated with hair growth, i.e., hair matrix keratinocyte proliferation and apoptosis, dermal papilla inductivity, and growth factors, by quantitative (immuno-) histomorphometry. To assess the anti-hair loss potential of the alpine plant compound, we performed a randomized, placebo-controlled human study enrolling Caucasian women and men, aged 18 to 65 years, with normal hair loss. After five months' daily use of an extract containing leave-on serum, we analysed hair density and anagen to catagen/telogen ratio by Trichogram analysis.
Our results revealed a significant prolongation in the anagen phase in HFs treated with 0.001% Edelweiss, as indicated by an increase in HFs remaining in anagen and a significant decrease in hair cycle score. In line with this effect, EWDE significantly stimulated hair matrix (HM) keratinocyte proliferation, and dermal papilla inductivity, as shown by a significant up-regulation of versican expression and alkaline phosphatase activity, and a tendential increase in FGF7 immunoreactivity in the dermal papilla of all HFs or only anagen VI HFs. Corroborating the ex vivo results, we observed a significant increase in growing hair shaft numbers (hair density) after treatment with Edelweiss extract formulation, and a tendential up-regulation in the anagen to catagen-telogen ratio.
We show here, through several lines of evidence, that the selected extract of the alpine plant Leontopodium alpinum var Helvetia (Edelweiss) inhibits premature catagen induction, possibly by stimulating dermal papilla inductivity. It is therefore worth exploiting this extract clinically as an anti-hair loss agent, both for preventing aging-associated hair shedding and as an adjuvant therapy for hair loss disorders.