Background: Different cellular responses influence the progress of cancer. In
this study, the effects of hydrogen peroxide and quercetin induced changes on cell
viability, apoptosis, and oxidative stress in human hepatocellular carcinoma (HepG2)
cells were investigated.
Methods: The effects of hydrogen peroxide and quercetin on cell viability, cell cycle
phases, and oxidative stress related cellular changes were investigated. Cell viability was
assessed by WST-1 assay. Apoptosis rate, cell cycle phase changes, and oxidative stress
were measured by flow cytometry. Protein expressions of p21, p27, p53, NF-Kβ-p50,
and proteasome activity were determined by Western blot and fluorometry, respectively.
Results: Hydrogen peroxide and quercetin treatment resulted in decreased cell viability
and increased apoptosis in HepG2 cells. Proteasome activity was increased by hydrogen
peroxide but decreased by quercetin treatment.
Conclusion: Both agents resulted in decreased p53 protein expression and increased cell
death by different mechanisms regarding proteostasis and cell cycle phases.