Diethyl phthalate and dibutyl phthalate disrupt sirtuins expression in the HepG2 cells

Background Phthalates are additives used as plasticizers among other uses, classified as endocrine disruptors and may contribute to some metabolic disorders. The aim of this work was to determine the effect of the exposure of diethyl phthalate (DEP) and dibutyl phthalate (DBP) on cell viability and reactive oxygen species (ROS) production, as well as the regulation of sirloins in HepG2 cells.Methods HepG2 cells were exposed to DEP or DBP at 0.1, 1, 10 and 100 mu g/mL, and after 48 or 72 h the gene and protein expression of sirtuins was quantified by qRT-PCR and Western-Blot, respectively.Results Results showed that even at a low concentration of 0.1 mu g/mL DEP affected the expression of Sirt3 and Sirt4, whereas DBP at 0.1 mu g/mL affected Sirt3 and Sirt5 gene expression. Protein analysis showed a reduction in Sirt1 levels at a DEP concentration of 1 mu g/mL and higher, while DBP at higher dose (100 mu g/mL) decreased Sirt3 protein levels. Cell viability decreased by 20% only at higher dose (100 mu g/mL) and ROS production increased at 10 and 100 mu g/mL for both phthalates.Conclusion These findings indicate that exposure to low concentrations (0.1 mu g/mL) of DEP or DBP can negatively influence the expression of some sirtuins.