The effect of exposure to polystyrene nanoplastics on cytokine levels and reproductive system of male tilapia

Abstract

Several studies demonstrated adverse effects associated with exposure to polystyrene nanoplastics (NPs), such as toxicity, inflammation, or other health-related concerns. This study aims to analyse the impact of NPs exposure on pro-inflammatory cytokine levels and testicular histology in tilapia gonads. Twenty-four male tilapias were used in this study and divided into four groups, including a control (commercial pellets only) and three treatment groups (commercial feed mixed 0.5, 1.0 and 2.0 μL/kg of NPs, respectively) for 25 days. Blood sample was used to tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-ɣ) levels analysis. Histology of testicular tissue was prepared with hematoxylin and eosin (HE) staining. The results showed that NPs exposure has no significant influence of TNF-α and IFN-ɣ levels. The levels of TNF-α on the control (1.6 ± 0.3 ng/mL) and the treatment groups from low to high concentration (1.7± 0.4; 1.7 ± 0.4; and 1.6 ± 0.3 ng/mL) and the levels of IFN-γ control (16.7 ± 2.8 ng/mL) and the treatment groups (19.1 ± 5.3; 18.7 ± 4.2; and 19.8 ± 3.5 ng/mL). Polystyrene nanoplastics exposure can reduce the number of spermatogenic cells. Spermatogonia cells was decreased from 27.5 ± 0.9 to 13.1 ± 1.1 cells/cyst. Spermatocyte cell was decreased from 57.6 ± 0.6 to 18.5 ± 0.3 cells/cyst. Spermatid cells was decreased from 86.8 ± 2.7 to 38.5 ± 2.7. In conclusion, exposure to multiple doses of NPs for 25 days did not increase pro-inflammatory cytokines levels in the blood serum of tilapia, but it caused histological changes in the gonads of fish.