The promotion of hair regrowth by topical application of a Perilla frutescens extract through increased cell viability and antagonism of testosterone and dihydrotestosterone

This study investigated the potential hair regrowth effects associated with a plant extract of Perilla frutescens, which was selected due to its putative hair regrowth activity. Extracts were prepared from dried P. frutescens suspended in distilled water, where the resultant aqueous suspension was fractionated sequentially using hexane, ethyl acetate, n-butanol, and distilled water. We observed that the n-butanol fraction resulted in the highest hair regrowth activity. The n-butanol soluble fraction of P. frutescens extract (BFPE) was further separated using AB-8 macroporous resin and silica gel chromatography to obtain rosmarinic acid (RA), which demonstrated effective hair growth regeneration potential. BFPE also showed in vivo anti-androgenic activity following the use of a hair growth assay in testosterone-sensitive male C57Bl/6NCrSlc mice. Furthermore, the effects of cell viability promotion were investigated following an in vitro analysis in primary hair follicle fibroblast cells (PHFCs) treated with RA. The results suggested that RA was the active compound in P. frutescens that triggers hair growth, and RA could be a potential therapeutic agent for the promotion of hair growth and prevention of androgenetic alopecia (AGA).