In this study, we assessed the toxic effects of sub lethal concentration (0.1 mg l−1) 4-nonylphenol (4-NP) on
serum biochemical parameters, liver lipid peroxidation (LPO) and antioxidant enzymes of the African catfish
Clarias gariepinus for 14 days and the ability of the quince leaf extract to alleviate the effects of (4-NP). Fish were
categorized into four groups: control, exposure to 0.1 mg l−1 4-NP, exposure to 0.1 mg l−1 4-NP with quince leaf
extract (10 ml/30 L water), and exposure to 0.1 mg l−1 4-NP with quince leaf extract (20 ml/30 L water). 4-NP
exposure induced a significant (p<0.05) increase in the levels of glucose, AST, ALT, creatinine, urea, uric acid,
cholesterol, and G6PDH as well as, the percentages of hepatic LPO level, DNA fragmentation, and apoptotic
erythrocytes (p<0.05). A significant (p<0.05) decrease in alkaline phosphatase (ALP), total protein, albumin,
globulin, total lipids, and LDH were also recorded. Liver enzyme activities (SOD, CAT and TAC) were increased.
Addition of the quince leaf extract into the water was able to reinstate the alterations in biochemical parameters,
antioxidant biomarkers, apoptotic level and hepatic DNA damage induced by 4-NP.