Condensed tannins alleviate aflatoxin B1-induced injury in Chinese sea bass (Lateolabrax maculatus)

Abstract

A 56-day feeding trial was conducted to evaluate the protective mechanism of condensed tannins (CT) on the dietary aflatoxin B1 (AFB1)-induced changes in body compositions, intestinal digestive enzyme activities, antioxidant and immune parameters, liver histomorphology, and the AFB1 residue contents in the liver and muscle of Chinese sea bass (Lateolabrax maculatus) (initial body weight 2.9 ± 0.1 g). Three diets were formulated to contain 0 mg/kg of AFB1 and 0 g/kg of CT (T1), 1.0 mg/kg of AFB1 and 0 g/kg of CT (T2), and 1.0 mg/kg of AFB1 and 1.0 g/kg of CT (T3), respectively. Each diet was randomly assigned to three tanks with 40 fish per tank. Fish were fed to apparent satiation twice daily. Results indicated that the survival rate, whole body compositions of dry matter, crude protein and crude lipid contents, and intestinal digestive enzyme activities of amylase, lipase and trypsin were not significantly different among diets (P > 0.05). Fish fed T2 had lower (P < 0.05) albumin, high density lipoprotein cholesterol, superoxide dismutase, catalase and glutathione peroxidase, but higher (P < 0.05) triacylglycerol, aspartate aminotransferase, malondialdehyde, alkline phosphatase, lysozyme and immunoglobulin M than those of fish fed T1 and T3. As compared with T1, hepatocytes in T2 and T3 had obvious and slight vacuolar degeneration, some white spots of necrosis and inflammatory cell infiltration, respectively. T2 had higher (P < 0.05) AFB1 residue contents in the liver and muscle than T1, and the AFB1 residue contents in liver and muscle were not significantly different (P > 0.05) between T1 and T3. In conclusion, inclusion of 1.0 mg/kg AFB1 in L. maculatus diet induced liver injury and lipid dysmetabolism, caused imbalance of liver antioxidant and immune system, and increased AFB1 residue contents in liver and muscle of fish. Supplementation of 1.0 g/kg CT protected against AFB1-induced injury and reduced AFB1 residue contents in L. maculatus.