Multiple Biomarker Responses in Female Catfish (Clarias Gariepinus) Exposed to Acetaminophen

Abstract

Acetaminophen is one of the most commonly detected Analgesics and pain killer drug in freshwater environments. This study evaluated the possible multi-toxic effects of environmentally relevant concentrations (15.5, 25.5, 35.5 and 45.5µg/L) of acetaminophen in Clarias gariepinus fish exposed for 28 days using multiple biomarkers. Hepatosomatic index (HIS) and condition factor (K) of acetaminophen–exposed group were not different from the control. The superoxide dismutase (SOD) activity increased significantly at 15.5 and 35.5µg/L and Catalase (CAT) activity in all acetaminophen-exposed groups barely showed an upward trend. The concentration of glutathione S-transferase (GST) activities was not different from the control. Glutathione peroxidase (GPx) activities increased at all concentrations when compared to the control group. There were general inhibitions of Acetylcholinesterase (AChE) activities in all exposed groups including the control. Total antioxidant capacity (TAC) increased significantly at 25.5 and 45.5µg/L and Interluekin-6 (IL-6) showed non-significant increases in all exposed concentrations. Acetaminophen exposure caused non-significant increases in the activities of C reactive protein (CRP). White blood cells (WBC) and lymphocytes (LYM counts) were significant reduced. Acetaminophen induced significant changes in hormones of the hypothalamic-pituitary-gonad (HPG) axis (17β-Estradiol and Testosterone) and vitellogenin (Vtg) synthesis at 45.5µg/L. Histopathological alterations in the liver was evident of apoptotic hyperplasia, sinusoidal congestion and necrosis of the hepatocytes and was concentration dependent. Acetaminophen exposure to the fish gills enhanced the fusion and shortening of some filaments, hyperplasia of the epithelia gills cells, aneurism, congestion and epithelia rupture of the gills. Gonad examination showed acetaminophen exposure triggered the occurrence of intersex in 25.5, 35.5 and 45.5µg/L. The collaborative biomarkers used in this study showed the multiple impacts of acetaminophen on the physiology of C. gariepinus. Multivariate statistical analysis indicated that fish in the control groups exhibited a distinctly response from the acetaminophen-exposed fish and that over 95% of the biomarkers significantly contribute to discriminate between the acetaminophen-exposed fish and the control group. Our research provides evidence supporting the use of multiple-biomarker approach to evaluate the health status of C. gariepinus in future studies.