Investigating antioxidant effects of hamamelitannin-conjugated zinc oxide nanoparticles on oxidative stress-Induced neurotoxicity in zebrafish larvae model.

Background: An excessive amount of reactive oxygen species triggers oxidative stress, leading to an imbalance in cellular homeostasis. Antioxidant therapy is an effective tool for lowering the oxidative stress and associated ailments. Recently, green nano-based drug formulations have demonstrated promising antioxidant activity and neutralizing oxidative stress. In this study, a tannin molecule Hamamelitannin (HAM), was utilized to synthesize zinc oxide nanoparticles HAM-ZnO NPs, to mitigate oxidative stress and associated ailments .

Methodology: The HAM-ZnO NPs were synthesized and characterized by XRD, SEM, and FTIR. The antioxidant potentials of HAM-ZnO NPs were analyzed by in vitro antioxidant assays. Zebrafish embryos and larvae were used as in-vivo models to assess the toxicity and antioxidant protective mechanism. Hydrogen peroxide (1mM) was employed to induce oxidative stress and treated with HAM-ZnO NPs to study the cognitive impairment and antioxidant enzyme levels. Levels of reactive oxygen species and cell death due to oxidative stress induction were studied by 2',7'-dichlorodihydrofluorescein diacetate and Acridine orange staining methods. Additionally, expression of Antioxidant genes such as SOD, CAT, GPx, and GSR were studied. .

Results: HAM-ZnO NPs exhibited a spherical morphology and size ranges between 48 and 53 nm. In vitro antioxidant studies revealed the antioxidant properties of HAM-ZnO NPs. Furthermore, in vivo studies indicated that HAM-ZnO NPs don't possess any cytotoxic effects in zebrafish larvae at concentrations between (5-25 µg/ml), The study also observed that HAM-ZnO NPs significantly reduced Hydrogen Peroxide-induced stress and increased antioxidant activity in zebrafish larvae. Also, the antioxidant gene expression was upregulated in the HAM-ZnO NPs zebrafish larvae.

Conclusion: Findings in this study showed that HAM-ZnO NPs might be a potential intervention for diseases linked to oxidative stress.