zahra aliyari babolghani

Diethylhexyl phthalate (DEHP) is leaching form polyvinyl chloride to cause animal toxicity. In our previous study, DEHP caused osteoblasts mortality in vitro, since rat bone marrow mesenchymal stem cells (MSCs) is the cellular back up for osteoblasts; therefore its effect on MSCs was investigated.

MSCs were extracted from Westar rats and treated with 0.5 to 2500μM of DEHP for 12, 24 and 48h to study the viability. Then further investigations, including proliferation, cell morphology, sodium and potassium level, concentration of calcium, total protein, activity of metabolic enzymes (ALT, AST, ALP, LDH), malondialdehyde (MDA) level, total antioxidant capacity, activity of superoxide dismutase (SOD) and catalase (CAT) were measured using selected concentration (100, 500 and 1500μM).

The 100μM of DEHP did not change the viability and biochemical factor after 48h but colony forming assay and population doubling number was significantly affected. Th 500μM only reduced the viability at 24 and 48h, while 1500μM caused the significant reduction at all the periods. These two concentrations, caused significant proliferation reduction as well as significant increase in calcium and sodium level, LDH activity and MDA level. In addition, we observed decrease in potassium, total protein, activity of metabolic enzymes and activity of CAT and SOD significantly.

DEHP has reduced viability and proliferation of MSCs through metabolic change, alteration in cellular ultrastructure, ionic imbalance and induction of oxidative stress.

Blood contamination of di-2-ethyl hexyl phthalate (DEHP) has been reported due to its release following medical procedures such as blood transfusion and vital liquid injection. We investigated the effect of DEHP on osteogenic differentiation of mesenchymal stem cells and their viability.

The rat bone marrow mesenchymal cells (MSCs) were cultured three times, and the third passage kept in the differentiation medium with the presence of DEHP. The viability of differentiated cells, sodium and potassium level, calcium concentration, total protein concentration, and the activity of lactate dehydrogenase, alkaline phosphatase, alanine transaminase, and aspartate transaminase were determined. Also, the concentration of malondialdehyde, total antioxidant capacity, the activity of superoxide dismutase and catalase were estimated. Finally, the level of matrix deposition and expression of alkaline phosphatase (ALP) and runt-related transcription factor 2 (RUNX2) genes were evaluated.

We observed a concentration-dependent and significant reduction of matrix mineralization based on alizarin red and calcium analysis. Besides, the expression of ALP and RUNX2 gene was down-regulated, and alkaline-phosphatase activity reduced significantly. Also, we observed cell viability reduction but the elevation of lactate dehydrogenase activity and malondialdehyde level. Sodium level was elevated too, whereas the activity of transaminases, oxidative stress enzymes, potassium level, and total antioxidants decreased.

DEHP contamination reduced matrix mineralization due to the down-regulation of the genes involved in osteogenic differentiation and viability reduction via electrolyte and metabolic imbalance as well as induction of oxidative stress.