The Antioxidant Activity and Cytotoxic Effects of Amaranthus cruentusBiosynthesized Silver Nanoparticles Toward MCF7 Breast Cancer Cell Line

Introduction: Silver nanoparticles (AgNPs) have grabbed special attention owing to their exclusive structural features. Green synthesis (i.e., plantmediated) of AgNPs is an efficient and costeffective method with widespread clinical applications. Therefore, the present study aimed to synthesize AgNPs based on green synthesis method employing the seed extracts of Amaranthus cruentus and to investigate the antioxidant and cytotoxic activities of the biosynthesized AgNPs. Methods: The AgNPs were biologically synthesized using the A. cruentus extract which served as a reducing agent. Then, the synthesized AgNPs were visualized by transmission electron microscopy. Next, the antioxidant activity of the synthesized AgNPs was evaluated by DPPH and ABTS methods. Finally, the cytotoxicity of AgNPs was investigated against MCF7 breast cancer cell line using MTT assay. Results: The mean diameter of the synthesized AgNPs ranged from 20 to 40 nm. In addition, the IC50 of free radical scavenging activity of the AgNPs were obtained as 500 µg/mL (DPPH) and 400 µg/mL (ABTS). Further, the AgNPs showed time and dosedependent cytotoxicity against MCF7 cells. Eventually, at the 24hour exposition to the 80 µg/mL dose of AgNPs, the viability of cancerous cells was 19% plunging to 2.03% and 1.9% after 48 hours and 72 hours, respectively. Conclusion: In general, plant extracts can serve as facile and ecofriendly alternatives to hazardous methods for synthesizing the metal nanoparticles. Therefore, the A. cruentus biosynthesized AgNPs can be utilized in medicine for various purposes due to their low toxicity and appropriate antioxidant activity.