The hair growth promoting effect of Asiasari radix extract and its molecular regulation.

Background: Hair loss is a distressing condition for an increasing number of men and women. It is of great importance; therefore, to develop new therapies for the treatment of hair loss.

Objective: We examined the effects of 45 plant extracts that have been traditionally used for treating hair loss in oriental medicine in order to identify potential stimulants of hair growth.

Methods: Six-week-old female C57BL/6 and C3H mice were used for evaluating the hair growth-promoting effects of the plant extracts. Topical application onto the backs of the C57BL/6 and C3H mice was performed daily for 30 days and 45 days, respectively. Protein synthesis was measured by the cysteine uptake assay, using cultured murine vibrissae follicles. Proliferation of the immortalized human keratinocyte cell line (HaCaT) and human dermal papilla (DP) cells was evaluated by the MTT and thymidine incorporation assays. The mRNA levels of several growth factors that have been implicated in hair growth control were measured by reverse transcription-polymerase chain reaction (RT-PCR).

Results: Among the tested plant extracts, the extract of Asiasari radix showed the most potent hair growth stimulation in C57BL/6 and C3H mice experiments. In addition, this extract markedly increased the protein synthesis in vibrissae follicle cultures and the proliferation of both HaCaT and human DP cells in vitro. Moreover, the A. radix extract induced the expression of VEGF in human DP cells that were cultured in vitro.

Conclusion: These results suggest that the A. radix extract has hair growth-promoting potential, and that this effect may be due to its regulatory effects on both cell growth and growth factor gene expression.