Toxicity of gamma aluminium oxide nanoparticles in the Mediterranean mussel ( Mytilus galloprovincialis ): histopathological alterations and antioxidant responses in the gill and digestive gland.

Purpose: Accumulation of Gamma aluminium oxide nanoparticles γ-Al ₂ O ₃ NPs significant impact on aquatic ecosystems. However, the toxicity of γ-Al ₂ O ₃ NPs in aquatic organisms has been limited investigated. This study investigated histopathological changes and antioxidant responses induced by different concentrations of γ-Al ₂ O ₃ NPs in Mytilus galloprovincialis .
Material and Methods: In this study, mussels were exposed to different concentrations of 5 nm γ-Al ₂ O ₃ NPs (0, 5, 20 and 40 mg/L) for 96 h under controlled laboratory conditions. Gill and digestive gland from mussels were assessed to histopathological (light microscopy, histopathological condition indices, digestive gland tubule types), SOD, CAT, GPx activities.
Results: Histopathological indices calculated higher, and significantly different in all exposure groups compared to the control group in gill and digestive gland ( p  < 0.05). Atrophic phase tubules proportion very high in 20 and 40 mg/L γ-Al ₂ O ₃ NPs exposure groups. No significant changes in CAT activities in the gill and digestive gland ( p  > 0.05). Superoxide dismutase (SOD) activities significantly different ( p  ≤ 0.05) in the digestive gland from 20 mg/L γ-Al ₂ O ₃ NPs exposures, and GPx activities significantly different ( p  < 0.05) in gill from 40 mg/L γ-Al ₂ O ₃ NPs exposures.
Conclusion: These results indicate that contamination of γ-Al ₂ O ₃ NPs negatively affects the aquatic organism.