Biosynthesized silver nanoparticles of Cissus woodrowii inhibit proliferation of cancer cells through induction of apoptosis pathway

Abstract

The purpose of this study was biogenic synthesis of silver nanoparticles using aqueous leaf extract of Cissus woodrowii (CW-AgNPs) and exploration of their role in inhibition cell proliferation of breast cancer cells. Inhibitory effect of biogenic CW-AgNPs on cell proliferation of MCF-7 cells was determined by MTT assay. Apoptotic cell death was demonstrated by caspase-3 assay, DNA fragmentation assay, Annexin-V-FITC/PI staining assay and cell cycle arrest assay by flow cytometry. Expression of apoptosisrelated genes including caspase-3, p53 and Bcl2 was studied by western blot analysis and semi-quantitative RT-PCR. Results of UV-Vis spectrum of colloidal solution of CW-AgNPs showed surface plasmon resonance peak at 430 nm. TEM and XRD results confirmed spherical shaped, 20-30 nm sized nanoparticles. Cell proliferation results showed inhibitory effects of CW-AgNPs on MCF-7 with IC 50 (24 h) 8.48 µg/ mL and (48 h) 7.11 µg/mL. The CW-AgNPs altered cell morphology of MCF-7 cells and induced apoptosis significantly which was evidenced through caspase-3 activation and nuclear DNA fragmentation. The results were supported by the observation of Annexin-V-FITC/PI staining and cell cycle arrest assays. The up-regulated expression of both p53 and caspase-3 genes and down-regulation of Bcl2 at both protein and mRNA level supported their role in induction of apoptosis in MCF-7 cells in response to CW-AgNPs. The findings obtained in current study supported the role of biogenic CW-AgNPs in inhibition of cell proliferation in breast cancer cells through induction of apoptosis.