Protective effects of thymoquinone and avenanthramides on titanium dioxide nanoparticles induced toxicity in Sprague-Dawley rats.

The protective effect of thymoquinone (TQ), the major active ingredient of Nigella sativa seeds, and avenanthramides (AVA) enriched extract of oats on titanium dioxide naonparticles (TiO2 NPs) induced toxicity and oxidative stress in Sprague-Dawley (SD) rats was investigated. Sixty rats were divided into 6 equal groups. The first, second, third, fourth and fifth groups received TiO2 NPs, TiO2 NPs and TQ, TiO2 NPs and AVA, TQ only, or AVA only for 6 weeks. The sixth group served as the control. Exposure to TiO2 NPs resulted in increased liver enzyme markers, oxidative stress indices, tumor necrosis factor alpha (TNF-α) and DNA damage. Histopathological alterations were also observed in the liver, brain, lung, kidney, heart and testes. Co-administration of TQ and AVA with TiO2 NPs decreased the level of liver enzymes, oxidative stress, TNF-α and DNA damage. Furthermore, TQ and AVA increased the total antioxidant and glutathione (GSH) levels. In conclusion, TiO2 NPs induce hazardous effects in different organs and are closely related to oxidative stress. TQ and AVA have antioxidative and anti-inflammatory effect against the detrimental effect of TiO2 NPs.