β-carotene treatment alters the cellular death process in oxidative stress-induced K562 cells

Oxidizing agents (e.g., H₂ O₂ ) cause structural and functional disruptions of molecules by affecting lipids, proteins, and nucleic acids. As a result, cellular mechanisms related to disrupted macro molecules are affected and cell death is induced. Oxidative damage can be prevented at a certain point by antioxidants or the damage can be reversed. In this work, we studied the cellular response against oxidative stress induced by H₂ O₂ and antioxidant-oxidant (β-carotene-H₂ O₂ ) interactions in terms of time, concentration, and treatment method (pre-, co-, and post) in K562 cells. We showed that co- or post-treatment with β-carotene did not protect cells from the damage of oxidative stress furthermore co- and post-β-carotene-treated oxidative stress induced cells showed similar results with only H₂ O₂ treated cells. However, β-carotene pre-treatment prevented oxidative damage induced by H₂ O₂ at concentrations lower than 1,000 μM compared with only H₂ O₂ -treated and co- and post-β-carotene-treated oxidative stress-induced cells in terms of studied cellular parameters (mitochondrial membrane potential [Δψ_m ], cell cycle and apoptosis). Prevention effect of β-carotene pre-treatment was lost at concentrations higher than 1,000 μM H₂ O₂ (2-10 mM). These findings suggest that β-carotene pre-treatment alters the effects of oxidative damage induced by H₂ O₂ and cell death processes in K562 cells.