Hexavalent chromium-induced toxic effects on the hematology, redox state, and apoptosis in Cyprinus carpio

In recent years, hexavalent chromium [Cr (VI)]has been widely used in the electrochemical industry, posing potential threat to aquatic animals The objective of this study was to investigate the toxic effects of waterborne Cr (VI) on hematology, digestive enzyme, redox state, and apoptosis in Cyprinus carpio. In this study, 300 C. carpio were randomly divided into four groups and exposure to 0 (Control), 0.5, 1 and 2 mg/L Cr (VI) for 28 days, respectively. The result showed that Cr (VI) exposure exerted significant toxic effects by reducing in the levels of hematology parameters (hemoglobin, erythrocytes) and serum calcium, increasing serum biochemistry (glucose, cholesterol and ALT), decreasing digestive enzyme (lipase and amylase). The waterborne Cr (VI) exposure significantly increased oxidative stress levels by increasing the levels of MDA, ROS and PC, interfering with the enzyme activities of antioxidant system (SOD, CAT, AHR, GSH, GSH-Px, GR and GST) and finally breaking the redox state in C. carpio. Additionally, our study found that waterborne Cr (VI) exposure induced intestinal and liver apoptosis in different ways was mainly related to death receptor pathway and mitochondrial pathway, respectively. Our results suggest that exposed to waterborne Cr (VI) above 0.5 mg/L has potential toxic effects in C. carpio.