Tannic acid protects neuroblastoma cells against hydrogen peroxide - triggered oxidative stress by suppressing oxidative stress and apoptosis.

ABSTRACT

Recent investigations indicate that tannic acid is associated with a decrease in oxidative damage. Growing evidence supports the protective effects of tannic acid on the central nervous system (CNS). However, uncertainties persist regarding its influence on hydrogen peroxide (H2O2)-triggered oxidative impairment in nerve cells and its interaction with apoptosis. Hence, the objective of this work was to examine the neuroprotective impact of tannic acid on SH-SY5Y cell impairment following H2O2-induced oxidative stress, particularly concerning apoptotic pathways. The control group received no treatment, while the H2O2 group underwent treatment with 0.5 mM H2O2 for a duration of 24 h. The tannic acid group received treatment with different concentrations of tannic acid for a duration of 24 h. Meanwhile, the tannic acid + H2O2 group underwent pre-treatment with tannic acid for one hour and was subsequently subjected to 0.5 mM H2O2 for one day. Within the tannic acid + H2O2 group, the cell viability in SH-SY5Y cells was notably enhanced by tannic acid at concentrations of 2.5, 5, and 10 µM. It also resulted in a considerable rise in TAS (Total Antioxidant Status) levels and a concurrent decline in TOS (Total Oxidant Status) levels, serving as indicators of reduced oxidative stress. Additionally, tannic acid treatment resulted in decreased levels of apoptotic markers (Bax, cleaved PARP, and cleaved caspase 3) and oxidative DNA damage marker (8-oxo-dG), while increasing the anti-apoptotic marker Bcl-2. The findings from flow cytometry also revealed a significant reduction in the apoptosis rate following pretreatment with tannic acid. In summary, tannic acid demonstrates protective effects on SH-SY5Y cells in the face of H2O2-triggered oxidative damage by suppressing both oxidative stress and apoptosis. Nevertheless, additional research is warranted to assess the neuroprotective potential of tannic acid.