Nano-sized titanium dioxide toxicity in rat prostate and testis: Possible ameliorative effect of morin

This study investigated the effect of short-term oral exposure to nano-sized titanium dioxide (nTiO₂) on Wistar rat prostate and testis, and the associating reproductive-related alterations. The study also evaluated the potential ameliorative effect of the natural flavonoid, morin, on nTiO₂-induced aberrations. Intragastric administration of nTiO₂ (50mg/kg/day for 1, 2 and 3weeks) increased testicular gamma-glutamyltransferase (γ-GT) activity and decreased testicular steroidogenic acute regulatory protein (StAR) and c-kit gene expression, serum testosterone level and sperm count. nTiO₂-treated rats also exhibited prostatic and testicular altered glutathione levels, elevated TNF-α levels, up-regulated Fas, Bax and caspase-3 gene expression, down-regulated Bcl-2 gene expression and enhanced prostatic lipid peroxidation. Sperm malformation and elevated testicular acid phosphatase (ACP) activity and malondialdehyde level, serum prostatic acid phosphatase activity, prostate specific antigen (PSA), gonadotrophin and estradiol levels occurred after the 2 and 3week regimens. Morin (30mg/kg/day administered intragastrically for 5weeks) mitigated nTiO₂-induced prostatic and testicular injury as evidenced by lowering serum PSA level, testicular γ-GT and ACP activities and TNF-α level, along with hampering both intrinsic and extrinsic apoptotic pathways. Moreover, morin alleviated prostatic lipid peroxidation, raised prostatic glutathione level, and relieved testicular reductive stress. Additionally, morin increased testicular StAR and c-kit mRNA expression, raised the sperm count, reduced sperm deformities and modified the altered hormone profile. Histopathological evaluation supported the biochemical findings. In conclusion, morin could ameliorate nTiO₂-induced prostatic and testicular injury and the corresponding reproductive-related aberrations via redox regulatory, anti-inflammatory and anti-apoptotic mechanisms, promoting steroidogenesis and spermatogenesis, and improving sperm count and morphology.