An In Vitro Study of Antioxidant, Anti-inflammatory, and Cytotoxic Effects of Echinacea-Mediated Zinc Oxide Nanoparticles.

ABSTRACT

Background Plant extracts, such as Echinacea, are preferred in the pharmaceutical industry for their natural availability and minimal adverse effects. Echinacea is known for its anti-inflammatory and other biological properties. Zinc oxide nanoparticles (ZnONPs) are cost-effective, safe, and easily synthesized, making them prominent in nanoparticle research. This study aims to determine the anti-inflammatory, cytotoxic, and antioxidant properties of ZnONPs synthesized using Echinacea. Methodology In this study, 5 mg of powdered Echinacea was mixed with 100 mL of distilled water, heated at 44°C until vaporization, cooled, and filtered twice. The extract was mixed with 0.1 g of zinc oxide and exposed to sunlight for two weeks for nanoparticle synthesis. After centrifugation at 3,500 rpm for eight minutes, nanoparticles were collected. Scanning electron microscope analysis was done to determine nanoparticle formation. Cytotoxicity analysis was conducted using the brine shrimp method, with surviving nauplii counted after exposure to different nanoparticle concentrations. Antioxidant activity was assessed via 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and ferric-reducing antioxidant power (FRAP) assay. Anti-inflammatory activity was assessed using membrane stabilization assay and bovine serum albumin (BSA) assay. Using SPSS Statistics Version 23 (IBM Corp., Armonk, NY, USA), the mean and standard deviation between the prepared extract and the standard were compared for all assays. Results In the cytotoxicity assessment, at 5 µL, the mortality of nauplii remained unchanged from the control. However, at 10 and 20 µL, a 10% increase in mortality was observed, which then stabilized at 40 and 80 µL with 20%. Regarding antioxidant activity, as nanoparticle concentration increased from 10 to 50 µL in the DPPH and FRAP assays, their effectiveness also increased accordingly. According to the anti-inflammatory assay, the membrane stabilization and BSA assay showed an increase in activity with increasing concentrations of 10 to 50 µL extract against similar concentrations of standard diclofenac sodium. Conclusions Echinacea-based ZnONPs demonstrated effective antioxidant and anti-inflammatory properties with low cytotoxicity, suggesting their potential use in future pharmaceutical or therapeutic applications.