Isoflavones have drawn attention due to their potential therapeutic use. Isoflavones are the important chemical components of the seeds and sprouts of chickpea and higher isoflavones in sprouts than in seeds. However, there have been no previous reports of the estrogenic activity of isoflavones extracted from chickpea Cicer arietinum L sprouts (ICS) in vitro. In this study, which incorporated several in vitro bioassays methods, we systematically evaluated the estrogenic properties of ICS. MTT assay showed that ICS at the low concentration ranges (10(-3)-1mg/L) promoted MCF-7 cell growth, while at high concentrations, (>1mg/L) inhibited cell proliferation, indicating ICS worked at a diphasic mechanism. Flow cytometric analysis further calculated the proliferation rate of ICS at low concentration (1mg/L). ER/Luc trans-activation assay and then semi-quantitative RT-PCR analysis indicated that ICS at low concentrations induced ER-mediated luciferase activity in MCF-7 cells and promoted the ER downstream target gene pS2 and PR trans-activation. These effects were inhibited by ICI 182,780, a special antagonist of ER, indicating that an ER-mediating pathway was involved. Alkaline phosphatase (AP) expression in Ishikawa cells showed that ICS at low concentrations stimulated AP expression. Our current study is the first to demonstrate that ICS has significant estrogenic activity in vitro. ICS may be useful as a supplement to hormone replacement therapy and in dietary supplements. Copyright (c) 2012 John Wiley & Sons, Ltd.