A multiparameter investigation into adverse effects of aflatoxin on Oreochromis niloticus health status

Abstract

Aflatoxin is a common contaminant of foods, particularly in the staple diets of many developing countries. To evaluate adverse effects of aflatoxin B1 (AFB1) toxicity on health status in the Nile tilapia Oreochromis niloticus, fish were fed diet contaminated with either 20 or 100 ppb AFB1 for 6 or 12 weeks. Growth indices, survival rate and hepatosomatic index (HSI) were assessed. Blood samples were collected for hematological profiles (e.g. RBCs and WBC count, Hb content). Liver enzyme activity; aspartate aminotransferase (AST), alanine aminotransferase (ALT) as well as alkaline phosphatase (ALP), were evaluated and toxin residues in the liver and musculature were detected. Liver histopathological investigations were carried out, whereas antioxidant glutathione peroxidase (GPx) and glutathione S-transferase (GST) gene expression were determined in this tissue by semi-quantitative RT-PCR. Furthermore, to test the fish immune status, challenge against Aeromonas hydrophila was conducted. Results indicated that 100 ppb AFB1 negatively impacted O. niloticus weight gain, feed efficiency, hematological profiles, HSI as well as liver histopathology, while increase in AST, ALT, ALP liver enzymes activity was evidenced. Further, the expression of liver GPx and GST down-regulated and AFB1 residues were always detected in the liver and only in the musculature in fish fed 100 ppb AFB1 for 12 weeks. The ability of fish to withstand A. hydrophila infection was remarkably lowered. Overall, the results herein demonstrate the toxic effects of AFB1 in O. niloticus. The observed alterations in fish status, especially in the liver coincide well with the expected oxidative stress resulting from the AFB1 toxicity. ª 2015 The Egyptian German Society for Zoology. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Evaluation of Nephrotoxic Effects of Aflatoxins on Common Carp (Cyprinus carpio)

“…The same problem has been reported in varied species of farmed aquaculture [3]. Aflatoxins are polyketide secondary-derived metabolites produced by strains of Aspergillus flavus and Aspergillus parasiticus [1].…”

“…Thus, the increased activity of AST and ALT could be an appropriate mechanism to increase free amino acids to accelerate detoxification process. An increase in AST and ALT is reported in various tissues of rats [32,33] and Nile tilapia, Oreochromis niloticus, [3] treated with aflatoxin B1.…”

Effects of Toxin Binder Biotox on Growth Performance Survival, Enzymatic Activity, Hematologichal and Biochemical Parameters of Fingerlings Rainbow Trout (Oncorhynchus mykiss) Fed Diets- Contaminated with Aflatoxin

“…Our result showed no change on hematological parameters (RBC, WBC, PCV, Hb and MCV ) as well as the percentage of Lymphocytes, Neutrophils and Monocytes. Mahfouz and Sherif [39] demonstrated that hematological profiles and monocytes, esinophils, and lymphocytes were influenced by the dose and duration of exposure to AFB1 contaminated diet. As RBC, WBC, PCV, Hb and MCV levels were significantly decreased in the high AFB1 exposed group.…”

“…An increase of these enzyme activities in the extracellular fluid or serum is a sensitive indicator of even minor cellular damage [41] in which cellular enzymes are released from the cells into the blood serum, which in turn indicates stress-based tissue impairment. Mahfouz and Sherif [39] showed that the activity of serum AST, ALT and ALP liver enzymes significantly increased in tilapia exposed to 100 ppb AFB1. Also, Mahfouz and Sherif [39] verified that AST, ALT and ALP were significantly increased in the serum of rats administered AFB1 (250 μg/kg/day for 2 weeks) indicating the presence of damaged and dysfunctional liver cells.…”

“…Mahfouz and Sherif [39] showed that the activity of serum AST, ALT and ALP liver enzymes significantly increased in tilapia exposed to 100 ppb AFB1. Also, Mahfouz and Sherif [39] verified that AST, ALT and ALP were significantly increased in the serum of rats administered AFB1 (250 μg/kg/day for 2 weeks) indicating the presence of damaged and dysfunctional liver cells. Our result showed that dosages of 1 mg AFB1/kg feed had no effect on ALP of fingerlings rainbow trout.…”