Research Article

The first clinical trial of topical application of procyanidin B-2 to investigate its potential as a hair growing agent
Tomoya Takahashi 1 *, Ayako Kamimura 1, Yoshiharu Yokoo 1, Shinkichi Honda 2, Yasushi Watanabe 3
1Tsukuba Research Laboratories, Kyowa Hakko Kogyo Co., 2, Miyukigaoka, Tsukuba, Ibaraki 305-0841, Japan
2Development Department, Biochemicals Division, Kyowa Hakko Kogyo Co., 1-6-1, Ohtemachi, Chiyoda, Tokyo 100-8185, Japan
3Watanabe Dermatological Clinic, 1-32-16, Shinjuku, Shinjuku-ku, Tokyo 160-0022, Japan
email: Tomoya Takahashi (tomoya.takahashi@kyowa.co.jp)
*Correspondence to Tomoya Takahashi, Tsukuba Research Laboratories, Kyowa Hakko Kogyo Co., 2, Miyukigaoka, Tsukuba, Ibaraki 305-0841, Japan.

Abstract
Procyanidin B-2 is a compound we have identified in apple which acts as a growth-promoting factor on murine hair epithelial cells. This report describes our investigation of the hair-growing effects of 1% procyanidin B-2 tonic after sequential use for 4 months. A double-blind clinical trial was performed, involving a total of 29 subjects (procyanidin B-2, 19 men; placebo, 10 men). No adverse side effects were observed in either group. In the procyanidin B-2 group, 78.9% showed an increased mean value of hair diameter, whereas only 30.0% in the placebo group showed any increase (p < 0.02, Fisher's exact probability test). The increased ratio of hairs measuring more than 40 m in diameter after 4 months of procyanidin B-2 treatment was significantly higher than that of the placebo controls (p < 0.05, two-sample t-test). The increase in number of total hairs in the designated scalp area (0.25 cm2) of procyanidin B-2 subjects after a 4 month trial was significantly greater than that of the placebo controls (procyanidin B-2, 3.67 ± 4.09 (mean ± SD)/0.25 cm2; placebo, -2.54 ± 4.00/0.25 cm2; p < 0.001, two-sample t-test). Procyanidin B-2 therapy shows potential as a promising cure for male pattern baldness. Copyright © 2001 John Wiley & Sons, Ltd.

Keywords
androgenetic alopecia; condensed tannin; external application; Malus pumila; proanthocyanidins; scalp