Parisa Ghorbani - Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
Masoud Homayouni-Tabrizi - Department of Biochemistry and Biophysics, Mashhad Branch, Islamic Azad University, Mashhad, Iran
Mozhgan Soltani - Department of Biology, Mashhad Branch, Islamic Azad University, Mashhad, Iran
Farideh Namvar - Research Center for Animal Development Applied Biology, Mashhad Branch, Islamic Azad University, Mashhad, Iran

Oxidative stress is defined as an imbalance between pro-oxidants and antioxidants. Thisimbalance leads to damage of significant biomolecules such as nucleic acids, thus prooxidantscan induce carcinogenesis process. The regulation of oxidative stress is aconsiderable factor in both tumour growth and responses to anticancer therapies. In thisregard nanoparticles synthesized by green method can be used that show antioxidant andanticancer properties. The aim of this study was to evaluate the potential effects of silvernanoparticles synthesized by green method from aqueous extract of sumac fruit on geneexpression of glutathione peroxidase in breast cancer cell line. Glutathione peroxidase is oneof the important enzymes in the cellular defense against oxidative stress and helps to retainredox balance within cells. MCF-7 breast cancer cell line was purchased from National CellBank of Iran (the Pasteur Institute of Iran, Tehran) and cultured in RPMI 1640 supplementedwith 10% Fetal bovine serum and 1% penicillin/streptomycin. They were incubated in a 95%humidified incubator containing 5% CO2 at 37 °C. The cells were divided into two groups:control (untreated) and that treated with 5,10,15 ÂμM of silver nanoparticles synthesized bygreen method from aqueous extract of sumac fruit for 48 hours. At the end of the treatment,total RNA was extracted from the cell cultures with High Pure RNA Isolation Kit. Each sampleof total RNA was subjected to reverse transcription using a cDNA kit (fermentas). The RealtimePCR was performed subsequently. Examined the mRNA expression levels ofglutathione peroxidase (GPx) gene as an antioxidant enzyme in treated cells compared tountreated cells using Real-time PCR method. The results displayed a increasing inexpression of GPx in MCF7 cells that exposed with doses of 5 (3.1 fold), 10 (4.9 fold) and 15(7.1 fold) μM/ml in comparison to untreated cells. The present study indicated that silvernanoparticles synthesized by green method from aqueous extract of sumac fruit induced anincrease in glutathione peroxidase gene expression and they can be useful in therapy ofcancer and diseases caused by oxidative stress.

Oxidative Stress, Cancer, Silver Nanoparticles, Sumac Fruit, Glutathione Peroxidase