Potential toxic effects of titanium oxide (TiO2) nanoparticles on the biological, biochemical, and histological aspects of the land snail Helix aspersa
Hoda H. Abdel‐Azeem, Gamalat Y. Osman, Azza H. Mohamed
Abstract
Abstract Nanotechnology has come a long way in our lives. However, it maintains some negative effects on the environment. This study aims to use the land snail Helix aspersa as a bioindicator. Titanium dioxide nanoparticles (TiO 2 NPs) had been used at 70 and 140 µg/L for two weeks by the spraying method. The oxidative biomarkers, condition index (CI), DNA damage, hemocyte count, and phagocytic activity were estimated. The toxicity of TiO 2 NPs was determined (LC 50 = 544 µg/L). The exposure to TiO 2 NPs caused a significant reduction of the activities of superoxide dismutase (SOD) and catalase (CAT) in the digestive gland of Helix aspersa (the activity of CAT was 3.4 ± 0.1 ( P = 0.001), SOD was 11 ± 1 ( P = 0.0002) at concentration 140 µg/L after two weeks). The activity of glutathione peroxidase (GPX) was (1.13 ± 0.01 µ/mg protein at 140 µg/L compared with controls (5.47 ± 0.01 µ/mg protein). The treatment caused DNA damage in the hemocytes (tail DNA % = 8.66 ± 0.02 and tail moment = 52.99 ± 0 at140 µg/L ( P = 0.002)). In the digestive gland, both tail DNA % and tail moment increased (tail moment = 78.38 ± 0.08 compared with control = 2.29 ± 0.09 ( P = 0.0001)). The total count of hemocytes significantly decreased after two weeks (the average number was 71 ± 1.5 compared with controls 79 ± 1.1 at 140 µg/L). Furthermore, TiO 2 NPs caused histological alterations in the digestive gland of Helix aspersa . It can be concluded that the Helix aspersa can be used as environmental pollution bioindicator. A comprehensive evaluation of toxic effects induced by TiO 2 NPs in vivo assays must be investigated.