Green synthesis of silver nanoparticles using Rubia tinctorum extract and evaluation the anti-cancer properties in vitro.

Cancer is one of the leading causes of human death. Nanotechnology could offer new and optimised anticancer agents in order to fight cancer. It was shown that metal nanoparticles, in particular silver nanoparticles (AgNPs) were effective in cancer therapy. In this study, AgNPs were synthesised using Rubia tinctorum L. extract (Ru-AgNPs). Then, cytotoxicity effects of the Ru-AgNPs against MDA-MB-231 carcinoma cell line and human dermal fibroblast as normal cell line were performed. Furthermore, anti-apoptotic effects of Ru-AgNPs on these cancer and normal cell lines were compared using acridine orange/propidium iodide staining, flow cytometry analysis and real-time qPCR in apoptosis gene markers. Results of UV-vis spectroscopy showed that Ru-AgNPs have a peak at 430 nm, which indicated synthesis of AgNPs. Ru-AgNPs had spherical shape and average size of 12 nm. Ru-AgNPs have cytotoxicity on MDA-MB-231 cells and decrease cancerous cell viability (IC50 = 4 µg/ml/48 h). Ru-AgNPs could induce apoptosis in MDA-MB-231 cells through upregulation of Bax and downregulation of Bcl-2 gene expression. The results opened up new avenues to develop Rubia based metal complexes as an anticancer agent.