J. Pharm. Biomed. Sci., 5(1)1-9, 2015 © 2015, TextRoad Publication ISSN 2090 – 424X Journal of Pharmaceutical and Biomedical Sciences www.textroad.com *Corresponding Author: Amel F. M. Ismail, Drug Radiation Research Department, National Center for Radiation Research and Technology (NCRRT).P.O. Box 29, Atomic Energy Authority, Nasr City, Cairo, Egypt. Tel./Fax: +202 2274 9298, email: afmismail@gmail.com Biosynthesis of Silver Nanoparticles Using Mushroom Extracts: Induction of Apoptosis in HepG2 and MCF-7 Cells via Caspases Stimulation and Regulation of BAX and Bcl-2 Gene Expressions Amel F. M. Ismail 1,* , Mahgoub M. Ahmed 2 and Asmaa A. M. Salem 3 1 Drug Radiation Research Department, National Center for Radiation Research and Technology (NCRRT).P.O. Box 29, Atomic Energy Authority, Nasr City, Cairo, Egypt. 2 Molecular Drug Evaluation Department, National Organization for Drug Control and Research (NODCAR), Giza 12553, Egypt 3 Regional Center for Food and Feed (RCFF), Agriculture Research Center, Giza, Egypt. ABSTRACT Green synthesis of metal nanoparticles is a rapidly growing field due to their potential applications in the medical and search fields. This study was conducted for the silver nanoparticles biosynthesis; using Pleurotus ostreatus edible mushroom extracts and investigating the anticancer activity against human liver (HepG2) and breast (MCF-7) adenocarcinoma cancer cell lines. The formation of silver nanoparticles (Ag-NPs) was confirmed by Fourier transform infrared (FTIR), Ultraviolet-visible spectroscopy and Transmission Electron Microscopy (TEM). The data showed that spherical Ag-NPs with a mean diameter size of 17.5 nm and absorption maxima at 450 nm were produced. The anticancer activity of Ag-NPs on HepG2 and MCF-7 cancer cell lines was assessed using the MTT method. The results demonstrated that Ag-NPs showed cytotoxicity against HepG2 and MCF-7 cancer cells, with the median growth inhibitory concentrations (IC50) 20.0±1.15 and 37.0±1.15 µg/ml, as compared to the anticancer drug doxorubicin (IC50: 18.67±1.20 and 30.33±0.88 µg/ml, respectively. Further, the apoptotic effect of Ag-NPs was investigated by DNA damage. Furthermore, the transcriptional expression of Bcl-2 (B-cell lymphoma 2), BAX (Bcl2-Associated X Protein), caspase-3, -8,-9, cytochrome c and P53 were also evaluated by RT-PCR. The Ag-NPs induced DNA fragmentation and apoptosis in HepG2 and MCF-7 via suppressing of bcl-2 gene expression, up-regulation of BAX, down-regulation of Bcl2, simulation of caspases, P53 and cytochrome c gene expression. In conclusion: Ag-NPs prepared by Pleurotus ostreatus edible mushroom extracts showed antitumor cytotoxicity against HepG2 and MCF-7 via caspase-dependent apoptosis, associated with the activation of p53 and the down-regulation of Bcl-2. KEYWORDS: Silver nanoparticles, Pleurotus ostreatus extract, apoptosis, human liver HepG2 adenocarcinoma cell line and Breast cancer MCF-7 adenocarcinoma cell lines. INTRODUCTION The discovery and identification of new antitumor drugs with low side effects on the immune system has become an essential target in many studies [1]. Even though there is an extensive range of cytotoxic agents used in the cancer therapy, such as doxorubicin, cisplatin and bleomycin, their use have shown drawbacks and are not as efficient as expected [2]. Nowadays, great efforts have been enforced to develop bio-active antitumor nanomaterials. Nanoparticles are used for solid tumor treatment via their selective accumulation in the tumor tissues due to the passive targeting effects [3]. Numerous microorganisms from bacteria to fungi have been documented to synthesize inorganic materials either intra- or extracellularly and thus to be potentially exploited as eco-friendly nano-factories [4-6]. Some naturally occurring edible mushroom extracts were efficiently used for the biosynthesis of gold (Au-NPs), Silver (Ag- NPs) and Au-Ag nanoparticles in water [6]. In particular, several researchers used Pleurotus ostreatus mushroom extract for Ag-NPs biosynthesis [7,8]. Silver nanoparticles had a broad spectrum of biological activities as anti-bacterial, anti-fungal, and anti-viral activities [9]. Kovács et al [10] demonstrate that Ag-NPs have anti-proliferative effect and induce apoptosis mediated cell death, both in drug sensitive and in multidrug resistant cancer cells. A recent study showed that, silver nanoparticles prepared by Mora leaf had in vitro cytotoxicity on hepatic cancer cell line (Hep-G2) and in vitro antioxidant efficiency [11]. Mushrooms have many different bioactive compounds with various biological activities. The content and bioactivity of these compounds depend on the preparation and consumption of mushroom [8]. It is well known that mushrooms are rich in proteins, vitamins and amino acids. Edible mushrooms have antitumor, anti-inflammatory, cardiovascular, antiviral and antibacterial [12,13]. In addition, the progress of green synthesis of Ag-NPs and their applications in the medical field are of important [14]. The antibacterial, antioxidant and antitumor activities of Ag-NPs have been reported previously that depend on the size, shape and stability of the nanoparticles [15-19]. 1