[Therapeutic effect of Impatiens balsamina, Lawsonia inermis L. and Henna on androgenetic alopecia in mice].

To investigate the therapeutic effect of Impatiens balsamina, Lawsonia inermis L. and Henna in a C57BL/6 mouse model of androgenetic alopecia and explore the mechanisms.

Forty-eight male C57BL/6 mice were randomized equally into blank control group, androgenetic alopecia model group, Impatiens balsamina group, Lawsonia inermis L. group, Henna group and minoxidil group. In all but those in the blank control group, the mice were subjected to dorsal subcutaneous injection of testosterone propionate solution (daily dose 5 mg/kg) to establish models of androgenetic alopecia and received subsequent treatment with topical application of the corresponding drugs on a daily basis for 35 days. The concentrations of testosterone, dihydrotestosterone and 5α reductase type Ⅱ in the serum and skin tissue were measured, and the histopathological changes of the skin tissues were observed.

All the tested drugs were capable of promoting new hair growth in the dorsal skin lesions of the mice. Among these drugs, Henna produced the most pronounced therapeutic effect and resulted in the highest dorsal hair density and a color change of the dorsal skin into gray; Lawsonia inermis L. showed the poorest therapeutic effect and resulted in the lowest dorsal hair density. The total number of follicles and the number of terminal hair follicles in a given field were significantly higher in all the drug treatment groups than in the model group (P < 0.05). In Impatiens balsamina group and Henna group, the contents of testosterone and dihydrotestosterone in the skin were significantly lower than those in the model group (P < 0.05). No significant difference was found in serum testosterone and dihydrotestosterone levels or skin 5α reductase type Ⅱ level between the drug treatment groups and the model group.

Impatiens balsamina, Lawsonia inermis L., and Henna all have therapeutic effects on androgenetic alopecia in C57BL/6 mice. The therapeutic effect of Impatiens balsamina and Henna is possibly achieved by reducing androgen content in local skin tissue.