Angelica sinensis induces hair regrowth via the inhibition of apoptosis signaling.

Hair loss is accompanied by keratinocyte apoptosis-regression during catagen and prolonged telogen. Angelica sinensis was reported to promote hair growth in vitro. Based on previous studies, we explored the hair growth effect and the mechanism of A. sinensis related to keratinocyte apoptosis-regression during catagen in mice. The 70% Ethanol extract of A. sinensis was applied topically at doses of 1 and 100 mg/mL to the dorsa of C57BL/6 mice for 2 weeks. The A. sinensis-treated group showed noticeable hair regrowth. Treatment with A. sinensis restored the lengths of hair shafts and size of hair follicles. In addition, mice treated with A. sinensis showed notably decreased apoptotic cells, along with a significant change in the expression of cleaved caspase-3 and the ratio of a pair of apoptosis-associated proteins: Bcl-2 and Bax. Also, A. sinensis inhibited the nuclear translocation of NF-κB, the phosphorylation of IκB-α, the phosphorylation of three mitogen-activated protein MAP kinases, and the activation of c-Jun with decreased TNF-α. These findings reveal a role of A. sinensis as an alternative treatment for hair loss that acts through hair cycle pathways associated with apoptosis regression during catagen.