The invention relates to active principles which are capable of inducing the conversion of inactive TGFb-Latent into active TGFb. The invention relates in particular to the use of such an extract for the manufacture of a composition for increasing the concentration of active TGFb1 in the skin, notably in the dermis. The present invention also relates to the uses which are derived from said use, as well as to cosmetic or pharmaceutical compositions which comprise said extract.