This study represents an original work aimed to recognize the main constitution of Trigonella berythea. The total phenolic content and total flavonoid content of leaves and stems of T. berythea have been estimated. An extraction and purification of phenolic mixture compounds from the leaves and stems of this plant have been performed and their antioxidant potential using the DPPH, H2O2 and chelating of ferrous ions tests has been evaluated. Then, their cytotoxicity on the MCF7 breast cancer cell line by the XTT Cell Viability technique has been studied. Our results demonstrated that leaves of T. berythea had higher total phenolic content and total flavonoid content than stems. On the other hand, the six extract from leaves and stems of this plant demonstrated a high antioxidant potential reaches more than 80%. Also, extracts from leaves of T. berythea had the highest inhibitory effect on MCF7 and U937 cell growth than that of stems. This inhibition was more than 60% for all extracts. These results provide new insight into the health functions of leaves and stems and demonstrate that T. berythea extracts can potentially have health benefits.