On the basis of a literature survey, the effects of methanol extracts of 80 herbs on hair regrowth were investigated. Hair regrowth-promoting activity was measured by Ogawa's method using 9-week-old C3H/He mice, in which the anagen hair regrowth after removal of back telogen hair is evaluated. On the 13th day after topical application, 18 kinds of herb extracts showed apparent hair regrowth promotion on the mice. Bioassay-guided fractionation of two potent herbs, Polygara senega var. latifolia and Polyporus umbellatus, afforded eight active principles, 1〜8, by combination of column chromatography (Amberlite XAD-2, Sephadex LH-20, silica gel and HPLC). The structures of these compounds were determined by physicochemical data, as senegose A, senegin II, III, desmethoxysenegin II, 3,4-dihydroxybenzaldehyde, polyporusterone-A and B, and acetosyringone. The structure of polyporusterone A, which showed an apparent activity at a dose of 0.1μg/mouse, was determined to be (+)-2b,3b,14a,20b,(22R)-pentahydroxy-(24S)-methyl-5b-cholest-7-ene-6-one by X-ray crystallographic analysis. 14 analogs to the active principles promoted hair regrowth on the mice.
