Cell Toxicity Effect of the Extract of Medicinal Plants against Human Breast (MCF7 and KBR3) Cancer Cell Lines

Background: Breast cancer is the most lethal cancer causing death among women, especially in developed countries. Using medicinal plants and natural resources to control and prevent different types of cancer in human has been the focus of attention. Objectives: The current study aimed to investigate the possible effects of hydroalcoholic extracts from some plant species such as Lavandula angustifolia, Ephedra major, and Scenedesmus obliquus on cell viability of two breast cancer MCF7 and SK-BR3 cell lines. Methods: MTT assay and gene expression analysis were performed adopting qRT-PCR method. Target cells were treated with different concentrations of plant extracts in a 24-hour period. Data were analyzed using Graphpad Prism version 8.3.0. Differences among means were determined using Student’s t-test or one-way ANOVA with Dunnett’s Multiple Comparison Test. Results: An indirect relationship was detected between extract concentration and cell viability. The result of the cell viability (IC-50) showed that the extract of S. obliquus had the maximum effect on both tested cells at concentrations above 100 µg/mL. A high cell death rate was observed in MCF-7 cell line compared to SK-BR3 cell line 24 h after the treatment. According to results from gene expression analysis, Caspase 3 gene increased in all treated cells, while the bcl-xl gene expression declined in the tested cells. Conclusions: It was concluded that the extracts from three plants had both positive and dose-related effects on MCF-7 and SK-BR3 cell line. However, it was recommended that future complementary studies should be conducted in order to evaluate the cell viability effect of these plants on human cancer.