Dose-Dependent Toxicological Effects of Smoked Fish Extract on Liver and Kidney Function in Albino Rats: Implications for Human Health
Wokocha Peter Gift *
Department of Medical Biochemistry, Faculty of Basic Medical Sciences, Rivers State University, Nkpolu Oroworukwo, Port Harcourt, Nigeria.
Opusunju Mandu Boma
Department of Surgery, Faculty of Clinical Sciences, College of Medical Sciences, Rivers State University, Nkpolu Oroworukwo, Port-Harcourt, Nigeria.
Opusunju Boma Harris
Department of Medical Biochemistry, Faculty of Basic Medical Sciences, Rivers State University, Nkpolu Oroworukwo, Port Harcourt, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
This study evaluated the toxicological effects of smoked fish extract on liver and kidney function in albino rats, with emphasis on oxidative stress and hematological changes. Twenty adult male rats (180–220 g) were randomized into four groups: a control and three treatment groups receiving 50, 100, and 200 mg/kg body weight of smoked fish extract intraperitoneally for 28 days. Gas Chromatography-Mass Spectrometry (GC-MS) analysis revealed the presence of key polycyclic aromatic hydrocarbons (PAHs) including benzo[a]pyrene and chrysene at concentrations exceeding EU maximum limits (e.g., benzo[a]pyrene: 4.6 µg/kg vs. 2 µg/kg limit), establishing a direct link between extract composition and observed toxicity. Biochemical assays showed dose-dependent increases in liver enzymes—alanine aminotransferase (ALT) and aspartate aminotransferase (AST)—and kidney biomarkers (urea, creatinine) with statistical significance (P < 0.0001). Oxidative stress markers revealed significantly elevated malondialdehyde (MDA) levels and suppressed superoxide dismutase (SOD) activity (P < 0.05). Hematological evaluations demonstrated anemia (↓ RBC, HGB, HCT) and leukocytosis (↑ WBC, PLT) in treated groups. Histopathological analysis confirmed progressive hepatic and renal damage with statistically significant necrosis severity scores (p < 0.01), particularly at the 200 mg/kg dose.
These pathological changes are attributed to PAHs and heavy metals present in the extract. The study highlights the potential health risks of chronic consumption of traditionally smoked fish, especially from informal sources. Follow-up recovery studies and mechanistic investigations into PAH–metal synergism are recommended.
Keywords: Smoked fish extract, liver toxicity, kidney injury, oxidative stress, PAHs, heavy metals, GC-MS, hematotoxicity