The cytotoxic effect of dwarf stinging nettle (Urtica urens) water extract on human breast cancer cells (MCF-7)

Abstract

Sawsan A. Rahimuddin* and Hala S. Sonbol

Urtica urens or dwarf stinging nettle, is an anticancer herb in many countries. The herb's effect on cell viability, the cytoplasmic and mitochondrial Reactive Oxygen Species (ROS) levels and its effect on the cell cycle in human breast adenocarcinoma cells (MCF-7) were investigated. The malignant cells were incubated with 2 mg/ml extracts of both freeze- dried and freshly dried leaves. After treatment, the antiproliferation changes of cells were measured using Trypan blue and MTT assays. The cytoplasmic and mitochondrial ROS were determined using flow cytometry. Finally, the type of cell death and cell cycle changes were determined using Annexin V and Propidium Iodide (PI). Results showed that both extracts reduced cell viability with reduced cytoplasmic ROS. In addition, an increase in mitochondrial ROS was observed with the freeze-dried extract. Cell cycle analysis revealed that the freshly dried leaves extract increased the early apoptosis population and arrested the cell cycle in S phase. In contrast, a significant increase in late apoptosis and necrosis phase, with cell cycle arrest in G2/M phase, was obtained with the freeze-dried leaves. Findings support that using Urtica urens may help in the reduction of breast cancer cell proliferation, causing apoptosis in different stages depending on the type of preparation.