Cytotoxicity and Characterization of Zinc Oxide Nanoparticles Synthesized using Saraca Asoca Bark Extract

Abstract

ZnO NPs have of late garnered interest for their biomedical and theranostic applications, however, all such applications would involve exhaustive toxicological testing for their safe use. This paper reports on the green synthesis of ZnO NPs by the reduction of cytotoxicity during production from Saraca Asoca bark extract. The ZnO NPs obtained were characterized through UV visible spectroscopy by observing the peak at 326 nm. The scanning electron microscopy is done to assess the particle size range, which ranges from 50 to 100 nm. The LC50 of the toxin, formula was established through an in-vivo Brine Shrimp Lethality Assay. Lethal effects at various concentrations of ZnO NPs including 5, 10, 20, 40, 80, and 100 µg/mL were tested on nauplii of brine shrimp while maintaining time constant at 24 hours. All nauplii survived at 5, 10, 20, and 40 µg/mL; at 80 µg/mL nine survived, while eight survived at 100 µg/mL, indicating a high level of nontoxicity at higher concentrations. LC50 estimation provides evidence that the ZnO NPs synthesized through the bark extract of Saraca Asoca reveal very low cytotoxicity and, therefore, would act as a promising candidate for biomedical applications. The green synthesis route here may find an alternative, non-toxic nanoparticle production technique instead of the toxic ones shown here.