BACKGROUND: The prevalent disease known as breast cancer has a significant impact on both men's and women's health and quality of life. AIM: The aim of this study was to explore the potential roles of (planch.) extract and triterpenoid- derived gold nanoparticles (AuNPs) in cancer therapy, specifically targeting MCF-7 breast cancer cell lines. METHODS: Gold nanoparticles were synthesized utilizing triterpenoid (ZJ-AuNPs) and leaf extract from (LC-AuNPs). Fourier transform infrared spectroscopy (FTIR), Dynamic light scattering (DLS), High-resolution transmission electron microscopy (HRTEM), and UV-vis spectroscopy were employed to characterize the nanoparticles. Additionally, the MTT assay was used to assess the impact of AuNPs on cancer cell viability using MCF-7 breast cancer cell lines. RESULTS: Analysis of ZJ-AuNPs and LC-AuNPs revealed DLS zeta potentials of -31.8 and -35.8 mV, respectively, and a corresponding UV-vis absorption maxima at 540 and 550 nm. Also, the ZJ-AuNPs and LC-AuNPs had respective zeta-sizes that ranged from 25.84 to 35.98 nm and polydispersive index values between 0.2360 and 0.773. Furthermore, the presence of the chemical groups -OH and -NH was shown to be necessary for the green method of capping and reducing the gold nanoparticles. Nevertheless, a significant decrease in cell viability percentages was noted in the MTT experiment, accompanied by an increase in the quantity or concentration of the nanoparticles for both ZJ-AuNPs and LC-AuNPs. CONCLUSION: Given the data obtained in this study, the biosynthesized ZJ-AuNPs and LC-AuNPs were shown to possess potent cytotoxic effects on breast cancer cells. Hence, they may be valuable tools in the development of new cancer chemotherapy drugs.