Toxicological Influence of Dietary Fumonisin B, on Blood Profile of Adult Rabbits

Abstract

An experiment was conducted to assess the toxicological effects of dietary fumonisin B_1, a mycotoxin produced by F. verticillioides in the culture, on haematology and serum biochemistry of rabbits exposed to fumonisin-contaminated diets. Forty-eight 7 to 8 weeks old male crossbred rabbits were used. The animals were randomly assigned to four treatment diets formulated with F. verticillioides cultured maize that produced approximately 5.0, 7.5 and 10.0 mg/kg fumonisin B₁ (FB₁) constituting diets 2, 3 and 4 respectively, while diet 1 (control) contained no cultured maize in a 210 days feeding trial. Blood samples were collected from the animals through the ear vein, after the feeding trial, for haematology and serum biochemistry. Results revealed that rabbits fed 7.5 and 10.0 mg/kg FB₁ showed significantly (P<0.05) reduced erythrogenesis and concentration of red blood cells, and consequent anaemia. Their leukocyte counts also indicate a condition of leukocytosis. Serum protein synthesis in same animals indicates both hypoproteinemia and hypoalbuminemia conditions. Cholesterol level significantly increases among dietary treatments with increase in the FB₁ level in the diets. Rabbits exposed to 7.5 and 10.0 mg/kg FB₁ showed a hypercholesterolemia condition. Activities of aspartate amino transferase, alanine amino transferase and alkaline phosphatase were significantly (P<0.05) elevated in the serum of treated animals, which is an indication of liver and kidney toxicity and cell damage. This study indicates that prolonged exposure to a concentration of at least 7.5 mg FB₁/kg in rabbit diets will depress erythrogenesis and protein synthesis; altered serum biochemical variables and induced leukocytosis, liver and kidney toxicity as well as hypercholesterolemia in rabbits.

Key words: Dietary fumonisin B₁, toxicity, blood profile, rabbits.