Fibroblast cell, which synthesizes and secretes collagen and other ECM in dermis, plays an important role in the structural formation of connective tissue. Bupleuri radix, the root of Bupleurum falcatum L. Apiaceae (Figure 19), one of the widely used crude drugs in Traditional Chinese Medicine (TCM) or Kampo medicine, which is Japanese study and adaptation of TCM, revealed fibroblast proliferative activity and hyaluronan production. Furthermore, saikosaponin derivatives (Figure 20), oleanane saponins derived from B. falcatum L., were evaluated for fibroblast proliferative effect. As shown in Figure 21, saikosaponin b1 (SSb1) and saikosaponin b2 (SSb2) showed the effect in a dose-dependent manner. On the other hand, saikosaponin a (SSa), saikosaponin d (SSd), and saikosaponin c (SSc) were inactive. Adding epidermal growth factor (EGF) stimulated the fibroblast proliferative effect of SSb1 and SSb2. Consequently, fibroblast proliferative effect appears to be associated with the presence of a double bond at C-13 or hydroxymethylene group at C-17 within the chemical structure of those five saikosaponins, as SSb1 and SSb2 were metabolized by the cleavage of the 13-ether bond of SSa and SSd respectively.