Green fabrication of silver nanoparticles mediated by Bistorta officinalis aqueous extract: putative mechanism for apoptosis-inducing properties

Abstract

Green synthesis of silver nanoparticles using water extract of Bistorta officinalis (BO/Ag-NPs) and evaluation of toxicity and its pro-apoptotic effects. BO/Ag-NPs were synthesized and characterized by DLS, FTIR, XRD, EDX, TEM and FESEM. Then, toxicity and apoptotic effect of BO/Ag-NPs were assessed by MTT, qPCR, flow cytometry and AO/PI methods. Spherical BO/Ag-NPs with a size of 29 nm, PDI of 0.3 and ζ potential of −27.06 mV were synthesized. Medium concentrations of BO/Ag-NPs on MDA-mb231 and HDF cells were reported about 6.1 and >50 µg.ml respectively. Increase the rate of apoptotic cells in AO/PI staining and flow cytometry and upregulation of caspase 3,9 and Bax genes and down regulation of Bcl-2 gene confirmed the activated of intrinsic pathway in BO/Ag-NPs treated cells. Due to the biological effects of BO/Ag-NP, these nanoparticles could be a promising factor in cancer therapy.

Keywords:

• Apoptosis
• Bistorta officinalis
• breast cancer
• cytotoxicity
• silver nanoparticles

Acknowledgment

This study was performed in the Mashhad Branch, Islamic Azad University, Iran and the authors have special thanks to the central lab of this university.

Conflict of interest

No conflict of interest was declared by the authors.

Abbreviations
DLS	=	dynamic light scattering
FTIR	=	Fourier transform infrared spectroscopy
XRD	=	x-ray diffraction
EDX	=	energy dispersive x-ray
TEM	=	transmission electron microscopy
FESEM	=	field emission scanning electron microscopy
MTT	=	([3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide)
AO/PI	=	acridine orange/propidium iodide
Bax	=	Bcl-2-associated X protein
Bcl-2	=	B-cell lymphoma-2
HDF	=	human dermal fibroblasts
MDA-MB-231	=	a type of breast cancer cell line
ζ potential	=	zeta potential
PDI	=	Polydispersity Index
FBS	=	fetal bovine serum
DMEM	=	Dulbecco’s Modified Eagle Medium
DW	=	distilled water