The protective effects of vitamin C on common carp (Cyprinus carpio) exposed to titanium oxide nanoparticles (TiO2-NPs)

The aim of this study was to investigate the hematological, biochemical, immunological, oxidative and mucosal changes in common carp (Cyprinus carpio) (15.18 ± 0.22 g) exposed to titanium oxide nanoparticles (TiO2-NPs), as well as the possible role of vitamin C in counteracting undesirable effects. Six experimental groups were examined for 21 days. T1: Control- basal diet; T2: TiO2-NPs (0.125 mg L−1) + basal diet; T3: basal diet + vitamin C (500 mg kg−1 of food); T4: basal diet + vitamin C (1000 mg kg−1 of food); T5: basal diet + vitamin C (500 mg kg−1 of food) + TiO2-NPs (0.125 mg L−1); T6: basal diet + vitamin C (1000 mg kg−1 of food) + TiO2-NPs (0.125 mg L−1). The results showed that TiO2-NPs alone significantly elevated the level of biomarkers for stress (glucose, cortisol) and liver damage (ALT, AST, ALP) and significantly declined immune parameters of serum (TP, Ig, ACH50, LYZ) and mucus (Ig, LYZ) due to increased oxidative stress and lower activity of antioxidant enzymes compared to the control group. In addition, TiO2 caused some histological damages to liver, however the severity of these damages was lower in fish supplemented with 1000 mg kg−1 vitamin C compared to other TiO2 exposed groups. Vitamin C supplementation considerably prevented TiO2-NPs-induced changes and attenuated the intensity of liver damages. In conclusion, although TiO2-NPs produced toxicity in Cyprinus carpio, supplementation of diet with vitamin C at a level of 500 to 1000 mg kg−1 of feed could effectively prevent oxidative stress and undesirable effects of TiO2-NPs exposure. •TiO2-NPs exposure induced indices of oxidative stress in common carp.•Vitamin C supplementation enhanced antioxidant capacity and immune responses in common carp.•Vitamin C supplementation protected the common carp from TiO2-NPs exposure.