J Korean Med Sci.  2007 Apr;22(2):283-289. 10.3346/jkms.2007.22.2.283.

Promotive Effect of Minoxidil Combined with All-trans Retinoic Acid (tretinoin) on Human Hair Growth in Vitro

• Kwon OS
• Pyo HK
• Oh YJ
• Han JH
• Lee SR
• Chung JH
• Eun HC
• Kim KH

• KMID: 1713189
• DOI: http://doi.org/10.3346/jkms.2007.22.2.283

Abstract

Minoxidil induces hair growth in male pattern baldness and prolongs the anagen phase. All-trans retinoic acid (ATRA) has been reported to act synergistically with minoxidil in vivo: they can enhance more dense hair regrowth than either compound alone. We evaluated the effect of minoxidil combined with ATRA on hair growth in vitro. The effect of co-treatment of minoxidil and ATRA on hair growth was studied in hair follicle organ culture. In cultured human dermal papilla cells (DPCs) and normal human epidermal keratinocytes, the expressions of Erk, Akt, Bcl-2, Bax, P53 and P21 were evaluated by immunoblot analysis. Minoxidil plus ATRA additively promoted hair growth in vitro, compared with minoxidil alone. In addition, minoxidil plus ATRA elevated phosphorylated Erk, phosphorylated Akt and the ratio of Bcl-2/Bax, but decreased the expressions of P53 and P21 more effectively than by minoxidil alone. Our results suggest that minoxidil plus ATRA would additively enhance hair growth by mediating dual functions: 1) the prolongation of cell survival by activating the Erk and Akt signaling pathways, and 2) the prevention of apoptosis of DPCs and epithelial cells by increasing the ratio of Bcl-2/Bax and downregulating the expressions of P53 and P21.

Keyword

Minoxidil; Tretinoin; Hair Follicle; Hair Growth; Dermal Papilla Cell; Keratinocytes

MeSH Terms

Tretinoin/*administration & dosage
Minoxidil/*administration & dosage
Keratolytic Agents/administration & dosage
Humans
Hair/cytology/*drug effects/*growth & development
Drug Combinations
Dose-Response Relationship, Drug
Cells, Cultured
Cell Proliferation/drug effects