Neurotoxic effects of titanium dioxide nanoparticles on the brain of male sprague dawley rats

Abstract

Titanium dioxide nanoparticles have diverse applications in many fields and are used in cosmetics, sterilization, paints, tooth paste, food products, air cleaning, sunscreens and waste water treatment plants due to their unique properties. But on the other hand, the wide use of titanium dioxide nanoparticles raises concerns to the upcoming challenges of human health. This study assessed the neurotoxic effect of titanium dioxide nanoparticles by histology, cell viability, oxidative stress and acetylcholine esterase level. For this purpose, 28 days old, post weaning male Sprague Dawley rats (n=25) were procured from the animal house of the Government College University, Faisalabad. Rats were randomly divided into five groups with five rats in each group and designated as Control (C) without treatment, Placebo group (S) treated with 0.9% normal saline and three nanoparticles treated groups (Group 1 of 80 mg/kg, Group 2 of 120 mg/kg and Group 3 of 160 mg/kg body weight of rat). Nanoparticles were injected intraperitonealy on alternate days for 28 days. On 29th day, rats were sacrificed and brain was isolated from all groups. Accumulation of titanium in the brain was assessed by inductively coupled plasma mass spectrometry (ICP-MS) and its increase in concentration was observed in a dose dependent manner. Cell viability, acetylcholine esterase and glutathione activities were significantly (P<0.05) decreased in Group 2 and Group 3 treated groups as compared to control and placebo groups. Histological alterations were also reported in brain exposed to titanium dioxide nanoparticles treated groups. This study revealed that titanium dioxide nanoparticles are neurotoxic as expressed by histological alterations, reduced cell viability, reduced acetylcholine esterase activity and induced oxidative stress by reducing glutathione activity in male Sprague Dawley rats.