Haruyo Yamanishi    Department   Kawasaki Medical School  Kawasaki Medical School, Department of Anatomy,    Position   Assistant Professor
Article types	原著
Language	English
Peer review	Peer reviewed
Title	The topical penta-peptide Gly-Pro-Ile-Gly-Ser increases the proportion of thick hair in Japanese men with androgenetic alopecia.
Journal	Formal name：Journal of cosmetic dermatology ISSN code：14732165/14732130
Domestic / Foregin	Foregin
Volume, Issue, Page	15,pp.176-84
Author and coauthor	Iwabuchi T, Takeda S, Yamanishi H, Ideta R, Ehama R, Tsuruda A, Shibata H, Ito T, Komatsu N, Terai K, Oka S
Publication date	2016/06
Summary	BACKGROUND: A penta-peptide, Gly-Pro-Ile-Gly-Ser (GPIGS), promotes proliferation of mouse hair keratinocytes and accelerates hair growth in mice. AIM OF THIS STUDY: This study focused on the ability of the peptide to promote human hair growth. METHODS: We used a human hair keratinocyte proliferation assay and organ cultures of human hair follicle as in vitro systems. The lotions with and without the penta-peptide were administered to 22 Japanese men with androgenetic alopecia (AGA) for 4 months in a double-blind and randomized clinical study. RESULTS: The penta-peptide significantly stimulated the proliferation of human hair keratinocytes at a concentration of 2.3 μm (P < 0.01), and 5.0 μm of this peptide had a marked effect on hair shaft elongation in the organ culture (P < 0.05). The change in the proportion of thick hair (≥60 μm) compared to baseline in patients that received the peptide was significantly higher than in the placebo (P = 0.006). The change in the proportion of vellus hair (<40 μm) was also significantly lower in the peptide group than in the placebo (P = 0.029). The penta-peptide also significantly improved the appearance of baldness (P = 0.020) when blinded reviewers graded photographs of the participants according to a standardized baldness scale. No adverse dermatological effects due to treatment were noted during this clinical study. CONCLUSIONS: This penta-peptide promotes proliferation of human hair keratinocytes and hair shaft elongation of human hair follicles, in vitro. This peptide increases thick hair ratio in vivo, and this compound is useful for the improvement of AGA.