P-11   MECHANISM OF HAIR GROWTH PROMOTING BY -3, 4’-DIMETYL-3-HYDROXYFLAVANONE

M. Sasajima, M. Hotta, Y. Takema Biological Science Laboratories, Kao Corporation, Tochigi, Japan.

Trans-3, 4’-dimethyl-3-hydroxyflavanone (t-flavanone), is a novel hair growth promoter that improves male pattern baldness. In order to clarify the cellular basis of the efficacy, we have here examined the effect of t-flavanone on TGFbeta production. TGF-beta is a critical growth factor in hair growth that has a high activity to induce catagen in hair cycle. We found that t-flavanone significantly decreased the amount of active TGF-beta2, but not the total amount of TGF-beta2, in the co-culture of human keratinocyte (KC)/human dermal papilla cell (DPC). It was considered that KC activates latent TGF-beta2 secreted by DPC in the co-culture of KC/DPC, so we studied the effect of t-flavnone on TGF-beta activating potential of KC. We obtained the fraction rich in latent TGF-beta2 of conditioned medium from DPC, and added this fraction to KC whether treated with t-flavanone or non-treated. It was found that t-flavanone downregulated TGF-beta activating potential of KC. In this study we revealed that t-flavanone suppressed the TGF-beta activation cascade of KC and then decreased active TGF-beta2 in the co-culture of KC/DPC. These results suggest that t-flavanone promoted hair growth by controlling the TGF-beta signal transduction in hair follicles.