Saponins are natural substances produced by a large number of plants, one of which is Tribulus terrestris L. (TT). They have been reported to possess an antitumor activity exerted by regulating various signaling pathways in the cell. Although the mechanisms of action of saponin extracts from various plants have been widely studied, limited data are available about TT. The present study aimed to analyze the impact of saponin extract from TT on cell processes in breast carcinoma cell lines. The variations in expression of a group of 32 selected genes were examined by real-time PCR after saponin treatment of MCF7 and MCF10A cell lines. Only three genes -CXCR4, CCR7 and BCL2, showed changes in their mRNA levels after the application of the herb extract. While CXCR4 expression was reduced in both cell lines, CCR7 and BCL2 levels decreased only in tumorigenic MCF7 cells, implying cell-specificity of the saponin action. Our results suggested that TT extract containing saponins was likely to affect the processes of apoptosis and metastasizing of cancer cells. Further in vivo studies will show its applicability as an anticancer therapeutic agent.