P#49  The extract of Thujae Occidentalis semen (TOS) inhibited 5a-reductase (type 2) and androchronogenetic alopecia of B6CBAF1/j hybrid mouse

Won-seok Park, Chang-hoon Lee, Won-hee Cho, Byeong-gon Lee and Ih-seop Chang. Skin Research Team, Skin Research Institute, Amore Pacific Corp. R&D Center, Yongin-si, Korea

The conversion of testosterone to DHT(dihydrotestosterone; 5a-androstan-17b-ol-3-one) by 5a-reductase plays a crucial role in hair baldness and prostatomegaly. Recent approach showed specific inhibitors for 5a-reductase type 2 such as finasteride promoted hair growth in male pattern alopecia. In order to search for effective plants applied topically for androgen alopecia, we screened numerous plant extracts having inhibition activity of 5a-reductase. We evaluated the inhibition activity by contact cell metabolic method using constructed a stable HEK 293 cell line expressing human 5a-reductase(type 2). To elucidate the biological activity in vivo, the TOS extract was topically applied to fuzzy rat and androchronogenetic alopecia (AGA) mouse, respectively. The secreted sebum and sebaceous glands of fuzzy rat was measured after 6 weeks. Also, during subcutaneous injecting testosterone (1mg/mice/day) followed by treating TOS extract and androgen receptor antagonist (cyproterone acetate), hair loss patterns of female B6CBAF1/J hybrid mouse were observed. TOS extract showed higher inhibition activity of 5a-reductase type 2(IC50 value = 2.6µg/ml) than that of
g-linolenic acid, but lower than that of finasteride. When applied to fuzzy rat, the amount of sebum and sebaceous gland size decreased remarkably.
In androchronogenetic alopecia model, alopecia degrees of two groups, treated with TOS extract (p<0.015) or cyproterone acetate (p<0.01), were lower than that of vehicle (propylene glycol: ethanol = 7:3) and there was no difference between above two groups. TOS extract would be used as an effective agent for male pattern baldness by regulating androgen conversion.