Abstract

Titanium dioxide nanoparticles are one of the famous widely produced nanoparticles in the world that are widely used in paints, cosmetics, plastics, pharmaceutical preparations, water treatment and purification and filtration of air. Beta carotene is provitamin A carotenoid with antioxidant and anti-apoptotic activities. The aim of this study is to evaluate the histopathological changes that occur in the testicular tissue of adult albino rats after intraperitoneal injection of titanium dioxide nanoparticles and to clarify possible protective role of beta carotene against this toxicity. 48 adult male albino rats weighing 180 to 200 g was divided into 4 groups: (I) Control group which consisted of 24 rats divided into 3 equal subgroups (Subgroup Ia (negative control): Received balanced diet for 14 days; Subgroup Ib (positive control): received intraperitoneal injection of distilled water for 14 days; Subgroup Ic: received corn oil by gastric gavage for 21 days (positive control)). Beta carotene group (positive control) which consisted of 8 rats received oral beta carotene 10 mg/kg once daily by gastric gavage for 21 days. The treated group which consisted of 8 rats received intraperitoneal (IP) injection of TiO2 nanoparticles (300 mg/kg) daily for 14 days. The protective group which consisted of 8 rats received 10 mg/kg beta carotene for 7 days by gavage then intraperitoneal (IP) injection of TiO2 nanoparticles (300 mg/kg) for 14 days together with10 mg/kg beta carotene by gavage. Testicular sections were stained with H&E, Masson’s trichrome, vimentin immunohistochemical staining. Serum testosterone level along with quantitative real-time PCR for TNFα gene was measured and statistical analysis was done. Results revealed that marked histopathological changes in testicular tissue was observed in TDN treated group which was improved by co-administration of beta carotene. In addition, statistically significant difference in TNFα expression in testicular tissue, testosterone level, body weights, testes weights and sperm count, motility, tubular dimensions, thickness of capsule in TDN treated group compared to the control group and protective group which showed significant improvement. Thus, titanium dioxide nanoparticles have hazardous effect on testis and that can be improved by beta carotene co-administration.

Key words: Adult albino rats, testes, titanium dioxide nanoparticles, β-carotene and gene expression.