Urtica dioica Induces Cytotoxicity in Human Prostate Carcinoma LNCaP Cells: Involvement of Oxidative Stress, Mitochondrial Depolarization and Apoptosis

Purpose: To evaluate the cytotoxic mechanisms of an extract from the leaves of the Urtica dioica (UD) plant in LNCaP prostate cancer cells.Methods: LNCaP cells were exposed to the UD extract for 24hrs and cell viability assessed using the MTT assay. Reactive oxygen species generation was assessed using the NBT assay and mitochondrial membrane potential using JCI-aggregation. DNA fragmentation patterns and cleavage of poly (ADPribose) polymerase were assessed using western blot and caspase activation via colorimetric assay.Results: The viability of LNCaP cells was significantly decreased in a dose-dependent manner following 24-h treatment with the UD extract. The reactive oxygen species levels were also significantly increased and mitochondrial depolarization was evident. DNA fragmentation, PARP cleavage and an increase in the activities of caspases 3 and 9 were observed in cells treated with the UD extract and this confirmed the induction of apoptosis as the major cytotoxic modality for this extract.Conclusion: The results confirm that the cytotoxic activity of UD aqueous extract in LNCaP cells is mediated through oxidative stress and apoptosis. These findings could hold positive implications for the potential use of UD extract in prostate cancer therapy.Keywords: Urtica dioica, Cytotoxicity, DNA fragmentation, PARP cleavage, Caspases, Prostate cance