Cancer is ranks second in causing death worldwide (Uthman, 2016). Cancer, with its updated definition, is a disease caused by the uncontrolled proliferation of transformed cells that evolve through natural selection (Brown et al., 2023). Breast cancer remains a leading cause of malignancy-related death in women. As the global incidence of this disease continues to rise, understanding its multifaceted nature is essential for developing effective treatment strategies (Xiong et al., 2025). Traditional treatments for breast cancer include surgery, kemoterapy, radiation therapy etc. (Waks and Winer, 2019). However, the survival benefits of traditional treatment strategies have been limited. Additional treatment options beyond the current standard options are still needed to improve patient recovery, survival, and quality of life (Wang and Wu, 2023).

The significant advancements made possible by nanoscience and nanotechnology are encouraging in many areas, including diagnosis and treatment. As a result of research and studies on new synthesis methods that are environmentally friendly, have low toxic substance contents, and are based on the production of NPs from living cells, the term ‘Green Nanotechnology’ has emerged in response to the limitations and drawbacks of physical and chemical synthesis methods (Duncan, 2011, Ahmad et al., 2019, Rajoriya et al., 2024). The called green synthesis method is more cost-effective and easier to synthesise. Additionally, it removes pointless processes from the synthesis of NPs while lowering the chemical load on the environment (Patra and Baek, 2015, Samuel et al., 2022). AgNPs exhibit distinctive characteristics like highly effective antibacterial, antifungal, antiviral, and anti-inflammatory activity. Because of these properties, it is used in wound healing ointments and silver-based medicinal products, delaying and preventing bacterial infections (Sironmani and Daniel, 2011, Bruna et al., 2021, Maduray et al., 2022, Alissa, 2025). In addition to each of these potential applications, numerous earlier studies have documented the anti-cancer properties of nanoparticles made through green synthesis (Krishnan et al., 2016, Venugopal et al., 2017, Alahmad et al., 2021, Jabir et al., 2021). According to the information gathered from these studies, AgNPs made using the green synthesis technique have the power to increase apoptosis and decrease cell viability in a variety of cancer types (Sankar et al., 2013, Vasanth et al., 2014, Aghebati-Maleki et al., 2020, Arslan et al., 2025).

This study is the first report in literature demonstrating the cytotoxic effects of silver nanoparticles (AgNPs) synthesised from Betula pendula Roth extract (BpE.) specifically on MCF-7 breast cancer cells. This novel finding provides a strong basis for evaluating these nanoparticles as innovative therapeutic agents in cancer treatment. In our study, the cytotoxic effects of both BpE. and AgNPs synthesised via BpE. were comprehensively investigated using MCF-12A normal breast cells compared to MCF-7 breast cancer cells. The obtained results strongly support the importance of plant-based nanomaterials not only for their biocompatible and environmentally friendly properties but also for their potential as leading candidates in cancer nanomedicine research.