Introduction In current days most of Tilapia Nilotica (Oreochromis Nilotica) in Egyptian market comes from Monosex farming by using 17 α- Methyltestosterone (MT) sometimes misuse of this hormone cause harmful effect on a human who consumed fish containing MT hormone residues as it cause problems in puberty for girls and boys, liver tumors, carcinoma and increases embryo mortality.
Aim To assess the presence of MT residues in Tilapia Nilotica and to examine the effect of the exposure to this hormone on rat liver.
Subject and methods Tilapia Nilotica samples were collected from Kafr EL-sheikh monosex farms and MT residues were measured by ELISA then an experiment was done on 40 male rats divided to 4 groups 10 in each one control group, F group which take with its ration mixed fish flesh about two kilograms contain MT residues, A group take oral doses of MT 20mg/ kg body weight for 30 days and A group which take 80 mg /kg body weight for 30 days then blood samples collected for biochemical parameters (Alt, Ast, albumin, globulin, total protein, A/G ratio, total cholesterol, and HDL-c) and liver collected for monitoring CYP P450 E1 gene expression and TNF-α gene expression and histopathological examination of liver tissue.
Results We noticed the presence of hormone residues in Tilapia Nilotica Flesh by ELISA as the mean of hormone concentration was about 2.55 ppb which was above permissible limit and oral dosing of MT. The exposure of rats to MT leads to significant induction of gene expression of CYP P 450 E1 gene as the fold change on control group was one on both genes while in F group, A group, and B group (2.07 ± 0.13, 6.96 ± 0.19 and 13.2 ± 0.41) respectively and also TNF-α gene as F group, A group and B group was (2.85 ± 0.05, 8.84 ± 0.19, and 15.4 ± 0.32) respectively (P ≤ 0.05). Liver functions tests reveal increased ALT and AST values in group B. Histopathology reveals hydropic changes in the B group. MT caused hypocholesterolemic effect as there is a significant decrease in total cholesterol value from 70.5 ± 2.63 mg/dl in the control group to 46.2 ± 2.32 mg/dl in the B group and HDL-c also, decreased significantly from 46.2 ± 2.32 mg/dl in the control group to 40.0 ± 2.65 mg/dl (P ≤ 0.05).
Conclusion MT is a hepatotoxic substance as exposure to MT caused induction of some inflammatory mediators as CYT. P450 E1 and TNF-α genes.MT may be needs a long term of exposure to show hepatic dysfunction, necrosis and carcinoma as high oral dose(80mg/kg) for one month causes only hydropic changes.MT decrease total cholesterol in a bad way decreasing lipoprotein HDL which may lead to atherosclerosis.