NanoNEXT 2(3) (2021) 8-19 DOI: 10.34256/nnxt2132 Page 8 of 19 In vitro biological activity of synthesized silver nanoparticles using Myrtus extract Neda Mohamadi a , Mohsen Doostmohammadi b , Iraj Sharifi c , Mehdi Bamorovat c , Ahmad Khosravi c , Razieh Tavakoli Oliaee c , Abbas Aghaei Afshar c , Maryam Sharifi d , Fatemeh Sharifi e, * a Herbal and Traditional Medicines Research Center, Kerman University of Medical Sciences, Kerman, Iran b Department of Pharmaceutics, Faculty of Pharmacy, Kerman Medical Sciences University, Kerman, Iran c Leishmaniasis Research Center, Kerman University of Medical Sciences, Kerman, Iran d Department of Pediatric Dentistry, School of dentistry, Kerman University of Medical Sciences, Kerman, Iran e Research Center of Tropical and Infectious Diseases, Kerman University of Medical Sciences, Kerman, Iran *Corresponding author Email: fatemeh7267@gmail.com DOI: https://doi.org/10.34256/nnxt2132 Received: 25-06-2021; Revised: 08-07-2021; Accepted: 20-09-2021; Published: 24-09-2021 Abstract: This study aimed to synthesize and characterize silver nanoparticles (AgNPs) from M. communis laves, and determine their potential activity against human cancer cells as well as leishmanial and bacterial cells. The UV- visible spectroscopy showed an absorption peak at 430 nm wavelengths which is one of the characteristic features of AgNPs. The FESEM image showed irregular shape with a size range of 20-70 nm. MTT results in A172 and MCF- 7 cell lines exposed to 5-240 g/mL for 48 hours revealed that M. communis-AgNPs were cytotoxic, with IC50 values of 93.2 g/mL for A172 cell lines and 89.1 g/mL for MCF-7 cell lines, respectively. DCFH-DA analysis showed that 24 h exposure to 25- 200 μg/mL concentrations of AgNPs significantly increased ROS production in cells t hat indicate oxidative stress induction by AgNPs. M. communis-AgNPs showed overexpression of BCL-2 and Bax genes compared with Glucantime ® and negative control (p<0.001) as a potent leishmanicidal and bactericidal activity. The primary modes of action seem to be involved by promotion of the ROS production and up-regulation of BCL-2 and Bax against cancer cell lines. As a result, M. communis-AgNPs formulation should be regarded as a promising agent for potential anti-cancer, anti-leishmanial, and anti-bacterial drugs in therapeutic control programs. Keywords: Nanotechnology, Nanoparticles, Nanobiomaterial, Biomedicine 1. Introduction Nanotechnology is a multidimensional field that includes the synthesis of nanoparticles (NPs) and associated events. Noble elements including silver (Ag), gold (Au), palladium (Pd), and to a lower extent, other metal elements have been used as the most potent, emergent, and advanced agents to design nanobiotechnology materials as innovative diagnostic and therapeutic tools to control serious complications such as cancers and many types of infectious diseases [1]. The unique feature properties of NPs, including multi-functionalization, high surface Plasmon resonances, vast surface area, easy processing, phenotypic nature, and high stability property, make them productive entities as promising metal-based NPs for drug delivery, diagnostic and therapeutic means against major diseases [2]. This multifunctional mechanistic nature has fascinated the consideration of diverse investigators towards their potential bioengineering and biomedical applications [3, 4]. Cancer is the second major cause of death globally and kills millions of people each year in many countries [5]. Conventional medication for cancer involves the use of surgery, radiation and chemotherapy. Unfortunately, most of the therapeutic agents are toxic and harmful to the patients [6]. Leishmaniasis, a vector-borne disease caused by 22 human parasitic species, is present in 98 countries, more prevalently in tropics and sub-tropics [7]. To date, efforts to control all forms of visceral, cutaneous, and muco-cutaneous leishmaniasis have been inconclusive. Due to the complexity of the life cycle, unavailability of confirmed vaccines, numerous vector and reservoir species, biological measures against the disease is not practical. At present, the only universal control measure against this diverse disease is chemotherapy using pentavalent antimony derivatives Research Article