Green Synthesis and in vitro Insights of Zinc Oxide Nanoparticles Using Nutmeg and Flaxseed Extracts

Background: Among various nanomaterials, Zinc Oxide Nanoparticles (ZnO NPs) have gained significant attention due to their unique properties. Traditional methods for synthesizing ZnO NPs often involve hazardous chemicals and energy-intensive processes, raising environmental and health concerns. In response to these issues, green synthesis methods have been developed as an eco-friendly alternative. Nutmeg and flaxseed are 2 plant sources known for their rich phytochemical content. This study aims to assess the cytotoxic, antimicrobial, anti-inflammatory and antioxidant properties of ZnO NPs synthesized with nutmeg and flaxseed. Materials and Methods: 5 mg of nutmeg and flaxseed powder were dissolved in 0.1 L of distilled water. This mixture was boiled at 60ºC for 10 min and then filtered. 0.1 g of ZnO was added to 100 mL of filtered extract. After centrifugation, the concentrated nutmeg and flaxseed extract-mediated ZnO NPs were reduced to 100 mL. Various extract concentrations (25 μL, 50 μL and 100 μL) were then subjected to cytotoxic, antimicrobial, anti-inflammatory and antioxidant assays. Results: Nauplii lethality was assessed over 2 days. At 25 μL, no mortality was observed on either day. However, on day 2, mortality increased by 10% at both 50 μL and 100 μL extract concentrations. The antimicrobial action of nutmeg and flaxseed extract-mediated ZnO NPs against S. aureus, S. mutans and E. faecalis increased with concentrations from 25 μL to 100 μL. Additionally, the anti-inflammatory and antioxidant activities of the NPs also increased with higher concentrations, from 25 μL to 100 μL. Conclusion: The synthesized nutmeg and flaxseed extract-mediated ZnO NPs exhibited significant bioactivity, including antibacterial, anti-inflammatory and antioxidant effects and were non-cytotoxic.