Curcumin protects against hydrogen peroxide-induced oxidative stress and cellular injury in human embryonic kidney cells

Background and Objectives: Oxidative stress plays a major role in the pathogenesis of various diseases including renal injury. Curcumin has been shown to exert antioxidant activity in various experimental models. Thus, the objectives of this study are to standardize and establish an in vitro model of hydrogen peroxide (H₂O₂)-induced renal cell injury using human embryonic kidney cells (HEK293), and to evaluate the cytoprotective role and antioxidant properties of curcumin against the established in vitro model. Methods: HEK293 cells were incubated at 37°C with different concentrations of H₂O₂ (ranging from 100 µM to 100 mM) over 15-45 minutes. Cell viability was assessed by trypan blue exclusion assay using a hemocytometer to select an optimal concentration of H₂O₂ for our study. Cells were then divided into four different groups: control, H₂O₂-treated, curcumin-treated, and curcumin + H₂O₂ treated. The cytoprotective role and antioxidant properties of curcumin were assessed by measuring cell viability and superoxide dismutase (SOD) activity (using native gel electrophoresis) respectively. Results: Compared to the control, 2.5 mM H₂O₂ treatment in HEK293 cells caused a significant decrease in cell viability (98.55% vs. 68.8% respectively; P value <0.05), and loss of SOD activity. Interestingly, cells pretreated with curcumin were protected from H₂O₂-induced cell injury (83.15% vs. 68.8% cell viability in H₂O₂ treated group) and showed an active SOD band, similar to that of control. Conclusions: Curcumin acts as an antioxidant and protects HEK293 cells against H₂O₂-induced cellular injury. Further investigations are required to establish the potential therapeutic role of curcumin in kidney diseases.