A potential suppressor of TGF-β delays catagen progression in hair follicles

TGF-beta plays important roles in the induction of catagen during the hair cycle. We examined whether TGF-beta2 could activate a caspase in human hair follicles. Using active caspase-9 and -3 specific antibodies, we found that TGF-beta2 activated these caspases in two regions, the lower part of the hair bulb and the outer layer of the outer root sheath. In addition, we searched for a plant extract that can effectively suppress TGF-beta action. We found that an extract of Hydrangea macrophylla reduced synthesis of a TGDbeta-inducible protein. We con-firmed that the extract has a potential to promote hair elongation in the organ culture system. Furthermore, it delayed in vivo progression of catagen in a mouse model. Our results suggest that the induction of catagen by TGF-beta is mediated via activation of caspases and that a suppressor of TGF-beta could be effective in preventing male pattern baldness.