Abstract:

Objective To screen phytoestrogens and investigate their effect on collagen synthesis in skin fibroblasts. Methods Sixty-four kinds of plant extracts were screened for phytoestrogens by determining their effect on estrogen receptor (ER)positive MCR-7 cell proliferation with MTT assay. ER-negative MDA-MB-231 cells and ER antagonist ICI 182780 were used to validate if the stimulatory effect on MCF-7 cell proliferation was mediated by ER. By using dot blot method, the effect on procollagen-1 (PC-1) synthesis in neonatal foreskin fibroblasts was also assessed. Results Among the selected 64 plant extracts and active fractions, soybean isoflavonoids and the ethanol extracts of Radix Puerariae, Spica Humuli Lupuli, Semen Cassiae, Folium Mori and Radix Glycyrrhizae effectively induced the proliferation of MCF-7 cells, but showed no effect on MDA-MB-231 cells. Moreover, their effect on MCF-7 cell proliferation was inhibited by ICI 182780. Genistein and puerarin significantly increased PC-1 synthesis in skin fibroblasts (P<0.01), and puerarin showed more potent effect than genistein. In contrast, daidzein significantly reduced PC-1 synthesis (P<0.01). Conclusion The extracts of Radix Puerariae and soybean isoflavnoids have relatively potent estrogenic activity. Puerarin and genistein, their main active ingredients, stimulate collagen synthesis of human skin fibroblasts, suggesting their potential anti-wrinkle and anti-skin aging effect.

Key words: puerarin, soy isoflavonoid, genistein, daidzein, phytoestrogen, fibroblast, procollagen-1