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

Oxidizing agents (e.g., H 2 O 2 ) 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 H 2 O 2 and antioxidant–oxidant (β‐carotene–H 2 O 2 ) 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 H 2 O 2 treated cells. However, β‐carotene pre‐treatment prevented oxidative damage induced by H 2 O 2 at concentrations lower than 1,000 μM compared with only H 2 O 2 ‐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 H 2 O 2 (2–10 mM). These findings suggest that β‐carotene pre‐treatment alters the effects of oxidative damage induced by H 2 O 2 and cell death processes in K562 cells.