Protective effects of N-acetylcysteine against titanium dioxide nanoparticles-induced kidney damage in rats

The objective of this study was to evaluate the potential protective effect of N-acetylcysteine (NAC) against kidney damage induced by titanium dioxide nanoparticles (TiO₂NP) through biochemical, histological, and immunohistochemical analyses. Forty rats were randomly divided into four groups of 10 animals each. Saline was administered intragastrically to control group for 14 days. In NAC group, 150 mg/kg NAC was injected intraperitoneally for 21 days. In TiO₂NP group, TiO₂NP at a dose of 50 mg/kg/day, dissolved in saline, was administered intragastrically for 14 days. TiO₂NP + NAC group received 50 mg/kg/day TiO₂NP for 14 days and 150 mg/kg NAC for 21 days, starting 7 days before TiO₂NP administration. At the end of experiment, rats were anesthetized, serum samples were collected for biochemical analysis, and kidney tissue was removed for histological and immunohistochemical analyses. There was no significant change in body weight, kidney weight, or serum urea-creatinine levels between the groups. TiO₂NP caused a significant increase in vacuolization and brush border loss scores in tubular cells, as well as scores for congestion and leukocyte infiltration. However, NAC supplementation significantly ameliorated these impairments. Additionally, TiO₂NP significantly increased NF-kB, TNF-α, and caspase-3 immunoreactivities, as well as the number of PCNA-positive and TUNEL-positive cells. NAC treatment decreased all immunoreactivities and TUNEL-positive cells, but did not change the number of PCNA-positive cells after TiO₂NP exposure. The results of the study showed that the toxic effects of TiO₂NP on the kidneys, commonly encountered in daily life, can be mitigated by the anti-inflammatory and anti-apoptotic properties of NAC.