title: Isoflavone content and estrogenic activity of different batches of red clover (Trifolium pratense L.) extracts: an in vitro study in MCF-7 cells.
abstract: The estrogenicity of different batches of red clover (Trifolium pratense L., Fabaceae; RCL) extracts and its relationship with the isoflavone content were assessed by measuring MCF-7 cell proliferation by flow cytometry and propidium iodide staining. RCL extracts were compared to estradiol (E2) and to the main RCL isoflavones biochanin A, daidzein, genistein and formononetin. Isoflavone content in the extracts was assayed by HPLC. E2 and isoflavones increased MCF-7 proliferation in a concentration-dependent fashion, with the following potency order: E2>>>genistein>biochanin A=daidzein>formononetin. Extracts increased MCF-7 proliferation with different potencies, which in four out of five extracts correlated with the ratios 5,7-dihydroxyisoflavones/7-hydroxyisoflavones. The efficacy of all extracts increased with decreasing genistein contents. A solution containing the main isoflavones at the average concentration of RCL extracts increased MCF-7 proliferation with higher potency and steeper concentration-response curve. The effects of E2, of RCL extracts and of the isoflavone solution were inhibited by the estrogen receptor antagonist 4-hydroxytamoxifen. Flow cytometric analysis of MCF-7 proliferation is a suitable bioassay for the estrogenicity of RCL extracts, thus expanding the characterization of individual batches beyond assessment of chemical composition and contributing to improved standardization of quality and activity.
authors: Center for Research in Medical Pharmacology, University of Insubria, Varese, Italy.
authors: Paola
authors: P
authors: Spagnuolo
authors: Center for Research in Medical Pharmacology, University of Insubria, Varese, Italy.
authors: Emanuela
authors: E
authors: Rasini
authors: Center for Research in Medical Pharmacology, University of Insubria, Varese, Italy.
authors: Alessandra
authors: A
authors: Luini
authors: Center for Research in Medical Pharmacology, University of Insubria, Varese, Italy.
authors: Massimiliano
authors: M
authors: Legnaro
authors: Linnea SA, Riazzino, TI Switzerland.
authors: Marcello
authors: M
authors: Luzzani
authors: Linnea SA, Riazzino, TI Switzerland.
authors: Enrico
authors: E
authors: Casareto
authors: Linnea SA, Riazzino, TI Switzerland.
authors: Massimiliano
authors: M
authors: Carreri
authors: Linnea SA, Riazzino, TI Switzerland.
authors: Silvano
authors: S
authors: Paracchini
authors: Center for Research in Medical Pharmacology, University of Insubria, Varese, Italy.
authors: Franca
authors: F
authors: Marino
authors: Center for Research in Medical Pharmacology, University of Insubria, Varese, Italy. Electronic address: marco.cosentino@uninsubria.it.
authors: Marco
authors: M
authors: Cosentino
mesh_terms: D049109:Cell Proliferation; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D004965:Estrogen Antagonists / Q000494:pharmacology; D004967:Estrogens / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D020128:Inhibitory Concentration 50; D007529:Isoflavones / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D061986:MCF-7 Cells; D015394:Molecular Structure; D048789:Phytoestrogens / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D013629:Tamoxifen / Q000031:analogs & derivatives / Q000494:pharmacology; D029921:Trifolium / Q000737:chemistry*
chemical_list: D004965:Estrogen Antagonists; D004967:Estrogens; D007529:Isoflavones; D048789:Phytoestrogens; D010936:Plant Extracts; D013629:Tamoxifen; C016601:afimoxifene
keywords: 4-Hydroxytamoxifen (PubChem CID: 449459); Biochanin A; Biochanin A (PubChem CID: 5280373); Daidzein; Daidzein (PubChem CID: 5281708); Estradiol; Estradiol (PubChem CID: 5757); Estrogenicity; Formononetin; Formononetin (PubChem CID: 5280378); Genistein; Genistein (PubChem CID: 5280961); MCF-7; Red clover; Tamoxifen (PubChem CID: 2733526); Trifolium pratense