Cinnamic Acid Promotes Hair Growth

To investigate the effects of cinnamic acid on hair growth, DP cells (5 × 10³ cells) and epithelial cells (5 × 10³ cells) were suspended in 0.2 mL advanced Dulbecco's Modified Eagle Medium/Nutrient Mixture F-12 (DMEM/F-12; Thermo Fisher Scientific) containing 2% (v/v) Matrigel (Corning Inc.) and seeded into the wells of a non-cell-adhesive round-bottom 96-well plate (Primesurface^® 96U plate; Sumitomo Bakelite Co., Ltd., Japan). DMEM/F-12 medium was supplemented with 10 μM cinnamic acid for 4–10 days after seeding. Then, 0.1 mL of the spent medium was replaced with fresh medium every 2 days. Hair sprout lengths were observed using an all-in-one fluorescence microscope (BZ-X810; Keyence).