Ginsenoside-Rb1 from Panax ginseng C.A. Meyer activates estrogen receptor-alpha and -beta, independent of ligand binding.
We studied the estrogenic activity of a component of Panax ginseng, ginsenoside-Rb1. The activity of ginsenoside-Rb1 was characterized in a transient transfection system, using estrogen receptor isoforms and estrogen-responsive luciferase plasmids, in COS monkey kidney cells. Ginsenoside-Rb1 activated both alpha and beta estrogen receptors in a dose-dependent manner with maximal activity observed at 100 microm, the highest concentration examined. Activation was inhibited by the estrogen receptor antagonist ICI 182,780, indicating that the effects were mediated through the estrogen receptor. Treatment with 17beta-estradiol or ginsenoside-Rb1 increased expression of the progesterone receptor, pS2, and estrogen receptor in MCF-7 cells and of AP-1-driven luciferase genes in COS cells. Although these data suggest that it is functionally very similar to 17beta-estradiol, ginsenoside-Rb1 failed to displace specific binding of [(3)H]17beta-estradiol from estrogen receptors in MCF-7 whole-cell ligand binding assays. Our results indicate that the estrogen-like activity of ginsenoside-Rb1 is independent of direct estrogen receptor association.
Cho
Jungyoon
J
College of Life Science, Institute of Biotechnology, Department of Bioscience and Biotechnology, Sejong University, Kwang-Jin-Gu, Seoul 143-747, Korea.
Park
Wankyu
W
Lee
Seungki
S
Ahn
Woongshick
W
Lee
Youngjoo
Y
D000818:Animals; D001667:Binding, Competitive; D019556:COS Cells; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000494:pharmacology; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D005786:Gene Expression Regulation / Q000187:drug effects; D017930:Genes, Reporter / Q000187:drug effects; D036145:Ginsenosides / Q000008:administration & dosage / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D008024:Ligands; D008156:Luciferases / Q000235:genetics; D005894:Panax / Q000737:chemistry*; D010957:Plasmids / Q000187:drug effects; D011506:Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D011960:Receptors, Estrogen / Q000187:drug effects / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000235:genetics; D018808:Transcription Factor AP-1 / Q000502:physiology; D000071163:Trefoil Factor-1; D025521:Tumor Suppressor Proteins
D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D036145:Ginsenosides; D008024:Ligands; D011506:Proteins; D012333:RNA, Messenger; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C051838:TFF1 protein, human; D018808:Transcription Factor AP-1; D000071163:Trefoil Factor-1; D025521:Tumor Suppressor Proteins; D004958:Estradiol; C442759:ginsenoside Rb1; D008156:Luciferases