BIOLOGICAL SYNTHESIS OF ZINC OXIDE NANOPARTICLES USING DATURA METEL: EVALUATION OF ANTIMICROBIAL, ANTI-INFLAMMATORY, CYTOTOXIC EFFECTS, AND ZEBRAFISH EMBRYONIC TOXICOLOGY

Abstract

This study examined the antimicrobial properties and toxicity profiles of Datura metel Zinc Oxide Nanoparticles (ZnO NPs). Characterisation of the nanoparticles was performed using UV and SEM studies, while FTIR analysis was used to identify functional groups. Well-diffusion assays assessed antimicrobial effectiveness against Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, and Pseudomonas sp. Findings indicated that ZnO NPs exhibited a concentration-dependent effect against these pathogens, with the maximum inhibition zones measured at 100 µg/ml. The nanoparticles' ability to prevent protein denaturation was evaluated through Bovine Serum Albumin (BSA) and Egg Albumin (EA) denaturation assays, which demonstrated significant inhibition, reflecting potent anti-inflammatory properties. Additionally, the membrane stabilisation assay suggested possible cytoprotective effects, as notable inhibition was seen in the lysis of red blood cells. Toxicological evaluations included the Brine Shrimp Lethality Assay and a zebrafish embryonic toxicity study, revealing that while ZnO NPs were non-toxic at lower concentrations, higher doses (≥40 µg/mL) resulted in in vitro cytotoxicity and significant embryotoxicity in zebrafish. This was evidenced by decreased viability and various developmental abnormalities, including pericardial edema and spinal malformations. These findings underscore the dual role of ZnO NPs as potential antimicrobial agents and underscore the need for caution regarding their biological and environmental safety at elevated concentrations. It is crucial to consider the dose-responsive therapeutic and toxic effects associated with any application of ZnO NPs in medical and environmental settings.