Effects of Aflatoxin-Contaminated Feed on Immunological Parameters of Common Carp (Cyprinus carpio)

Background: Aflatoxin contamination is a common natural phenomenon that is difficult to avoid or control and it can occur during pre and post-harvest periods under high humidity and temperature conditions, and are potentially dangerous to fish. In the present study, a feeding trial evaluated the effects of diets contaminated with aflatoxin on certain immunological parameters of common carp. Methods: The immunotoxicity assessment of juvenile common carp was performed on 180 fish divided into five groups with triplicate: Control group received normal feed (Group I); group II was fed diets contaminated with extraction solution (methanol, acetone and diluted water) as a positive control. Group III-V was respectively fed diets contaminated with 0.5, 0.7 and 1.4 mg kg-1 feed for 3 wk. Results: Lysozyme activities, total immunoglobulin contents, complement C3 and C4 activities in plasma of common carp fed with different concentrations of aflatoxins significantly decreased when compared to that of the control fish. Although plasma ACH50 contents remained unchanged in 0.5 mg kg-1 aflatoxins, ACH50 contents decreased in 0.7 and 1.4 mg kg-1 groups after 21 d of aflatoxin treatment. No significant changes were observed in immunological parameters between the control positive and control groups throughout the experimental periods. Conclusion: Oral exposure to aflatoxin (0.5 mg kg-1≤) could adversely affect immunological parameters of common carp.