Antioxidant system biomarkers of freshwater mussel (Unio tigridis) respond to nanoparticle (Al₂O₃, CuO, TiO₂) exposures

Abstract

Purpose

Mussels are known as the natural filters of the aquatic systems and are accepted as one of the best bioindicator organism. There is no data on the response of Unio tigridis to metal-oxide nanoparticle (NP) exposures. This study aimed to investigate the response of the antioxidant enzymes of U. tigridis following exposure to NPs.

Materials and methods

The mussels were exposed to different concentrations (0, 1, 3, 9 mg NP/L) of Al₂O₃, CuO and TiO₂ NPs for 14 days and subsequently, the activities of CAT (catalase), SOD (superoxide dismutase), GPx (glutathione peroxidase), GST (glutathione S-transferase) and GR (glutathione reductase) were measured in the gill and digestive gland. Mussels were fed with cultured unicellular algae (Chlorella vulgaris) during experiments.

Results

Data showed that algae consumptions of mussels were not significantly (p>0.05) altered by NPs. However, all enzyme activities in the digestive gland and gill altered significantly (p<0.05) after NP exposures. The activities of CAT and SOD decreased, while the activities of enzymes belonging to glutathione metabolism (GPx and GST) increased in both tissues.

Conclusion

This study representing the first record on the antioxidant system response of U. tigridis toward NP exposures suggests that NP toxicity should be investigated thoroughly in organisms and some regulations must be done on their usages.

Keywords:

• Nanoparticle
• mussel
• antioxidant
• biomarker
• toxicity

Acknowledgements

This study was supported by the Scientific and Technological Research Council of Turkey (Tubitak, 120Y016). We thank Dr Uslu for help on algae culturing.

Disclosure statement

No potential conflict of interest was reported by the author(s).