Titanium dioxide and gold nanoparticles toxicity in albino rats: Biochemical, anatomical, histopathological, and immunohistochemical studies

The current research is aimed to synthesize, characterize, investigate, and compare the effect of Gold (Au) and titanium dioxide (TiO₂) nanoparticles-mediated hepatorenal toxicity in adult male albino rats demonstrating which one of them is more secure for future use. Acute toxicity and LD₅₀ studies were assessed. For the hepatorenal toxicity study, thirty albino rats were assigned into three groups (n = 10): Group I (control) was administered distilled water, groups II (Au-NPs), Au-NPs were given daily for four weeks at oral dose of 31 mg/kg, and in group III (TiO₂-NPs), TiO2-NPs were administered daily for four weeks at oral dose of 33 mg/kg. After the experiment was over, blood, liver, and kidney specimens were collected and processed for biochemical, anatomical, histopathological, and immunohistochemical studies. Results revealed that LD₅₀ was found to be (310 mg/kg body weight) for Au-NPs and (330 mg/kg body weight) for TiO₂ NPs. Au-NPs substantially elevated the concentrations of serum hepatic markers (AST and ALT) and serum kidney markers (urea and creatinine) compared to TiO2 NPs. Hepato-renal tissues showed increase in MDA concentration, but decreased SOD activity in Au-NPs exposed group compared to TiO₂ NPs-exposed group. Macroscopically, TiO₂ NPs and Au NPs-caused obvious gross effects in both hepato-renal organs compared to control group. Liver and kidney of rats administered Au-NPs showed marked histopathological alterations plus a significant increase in the caspase-3 positive renal cells and hepatocytes compared to TiO₂-NPs group. In conclusion, Au-NPs have a harmful effect on the liver and kidney functions proved by histopathological, immunohistochemical, and biochemical parameters, which was more injurious than TiO₂-NPs.