Lead (Pb) accumulation,oxidative stress and DNA damage induced by dietary Pb in tilapia (Oreochromis niloticus)

With the increasing occurrence of dietary lead (Pb) contamination in aquaculture, a better understanding of the toxic effects of dietary Pb on aquatic animals is needed. Tilapia (Oreochromis niloticus) were exposed to dietary Pb at concentrations of 0, 100, 400 and 800 μg g^?1 dry weight for 60 days, and Pb accumulation in tissues and blood, oxidative stress in posterior kidney and DNA damage in peripheral blood cells were investigated. The results showed that dietary Pb exposure resulted in significant Pb accumulation in tissues and blood, which increased with the dietary Pb concentrations. Pb accumulated in sampled tissues in the following order: posterior kidney>bone>liver>gill>spleen>testis>muscle>brain. Dietary Pb caused a significant increase in the malondialdehyde level and a significant decrease in the total antioxidant capacity content when compared with the control group (P<0.05), accompanied by concentration‐dependent decreases in the glutathione content, glutathione peroxidase and superoxide dismutase activities. Pb dose‐dependent DNA damage was observed in peripheral blood cells of tilapia exposed to dietary Pb. The results suggest that dietary Pb exposure can induce significant Pb accumulation in tissues and blood, followed by oxidative stress in posterior kidney and DNA damage in peripheral blood cells of tilapia.