1996 Volume 29 Issue 4 Pages 411-416
It is well known that hair growth is regulated by many factors. In the male pattern baldness, the hormonal effect due to androgens, such as testosterone (TE) and dihydrotestosterone (DHT), is the most important factor. TE is converted to an active androgen, DHT, by 5α-reductase. It has been considered that the DHT binding to androgen receptors expresses the hormonal effect. Therefore, we searched for active ingredents which possessed 5α-reductase inhibitory activity among 80 kinds of plant extracts. We found that Hop (Humulus lupulus L.) strongly inhibited the activity of 5α-reductase. Furthermore, it was found that Hop extract enhanced the proliferation of hair follicle derived keratinocyte. We demonstrated that Hop showed a potent stimulation of hair growth in the animal tests as well as Minoxidil. Hop extract gave the increase of the hair growth rate in human use test. Finally, the effect of the Hop extract was evaluated by using the 54 volunteers suffering from androgenetic alopecia. Most of the volunteers answered that the tonic was effetive in hair repairing.
We conclude that Hop extract is an excellent ingredient for hair growth products and that hair tonics containing Hop extract can benefit people suffering from androgenetic alopecia.