Introduction: Since Di-(2-ethylhexyl) phthalate (DEHP) is used in polyvinyl chloride products, it has been found to reduces osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) due to induction of oxidative stress. Curcumin, having antioxidant properties, was proposed to compensate adverse effects of DEHP. Methods: BMSCs were extracted from Wistar rats and treated with DEHP (100 μM) and curcumin (0.1 μM) individually and simultaneously in osteogenic media for 20 days. The viability, total protein concentration, bone matrix production, ALP activity, MDA level, total antioxidant capacity, activity of superoxide dismutase and catalase and expression of osteogenic related gene were evaluated. Results: following DEHP treatment, we observed a significant decrease in bone matrix production based on alizarin red and calcium analysis. On the other hand, the expression of ALP, RUNX2 and alkaline phosphatase enzyme activity decreased. In addition, MDA increased significantly, while the activity of antioxidant enzymes and the level of total antioxidant decreased. Although, simultaneous treatment showed curcumin could improve the toxic effect of DEHP but could not completely compensate its adverse effect compared to the control group. Conclusion: AS curcumin is highly insoluble in aqueous situation, we propose its encapsulation in delivery system to improve its antioxidant action.
