Connarus semidecandrus Jack Exerts Anti-Alopecia Effects by Targeting 5α-Reductase Activity and an Intrinsic Apoptotic Pathway

There is a growing demand for hair loss treatments with minimal side effects and recurrence potential. Connarus semidecandrus Jack has been used as a folk medicine for fever in tropical regions, but its anti-alopecia effects remain unclear. In this study, the anti-androgenic alopecia effect of an ethanol extract of Connarus semidecandrus Jack (Cs-EE) was demonstrated in a testosterone-induced androgenic alopecia (AGA) model, in terms of the hair–skin ratio, hair type frequency, and hair thickness. The area of restored hair growth and thickened hair population after Cs-EE treatment showed the hair-growth-promoting effect of Cs-EE. Histological data support the possibility that Cs-EE could reduce hair loss and upregulate hair proliferation in mouse skin by shifting hair follicles from the catagen phase to the anagen phase. Western blotting indicated that Cs-EE reduced the expression of the androgenic receptor. Cs-EE treatment also inhibited programmed cell death by upregulating Bcl-2 expression at the mRNA and protein levels. The anti-alopecia effect of Cs-EE was confirmed by in vitro experiments showing that Cs-EE had suppressive effects on 5-α reductase activity and lymph node carcinoma of the prostate proliferation, and a proliferative effect on human hair-follicle dermal papilla (HDP) cells. Apoptotic pathways in HDP cells were downregulated by Cs-EE treatment. Thus, Cs-EE could be a potential treatment for AGA.