Assessment of haematological, serum biochemical and histopathological effects of subchronic dietary fumonisin b₁ in rats

Abstract

Context: Fumonisin B₁ (FB₁), a mycotoxin produced by Fusarium verticillioides and other Fusarium species that grow on maize worldwide, has been documented to cause various physiological responses in animals. Consumption of lesser amounts of fumonisins at levels below those that cause overt toxicity may exert haematological, serum biochemical and/or histopathological effects in animals.  

Objective: The effects of dietary FB₁ on haematology, serum biochemistry and histopathology were assessed in female Wistar rats in a short-term toxicity study.  

Materials and Methods: Thirty-nine mature female Wistar rats (Rattus norvegicus) weighing between 167.5 – 170.5 g were used in the study. The rats were assigned to diets containing 0.2, 10.0 and 20.0 mg FB₁/kg constituting diets 1, 2 and 3, respectively. After 14 days of feeding, blood samples were obtained from four rats per treatment. The rats were sacrificed by cervical dislocation, eviscerated for organ collections and subsequently processed for histology.  

Results: Significant differences in feed consumption and body weight gains were not observed. The final live weight of the rats, however, seemed to decline with an increase in dietary FB₁ levels. Significant (P<0.05) alterations were observed in the haematological and serum biochemical parameters with increasing levels of dietary FB₁. Diets containing different FB₁ concentrations, the decreased values of PCV, Hb, erythrocyte and monocyte counts could be attributed to the FB₁ effects on the blood-forming tissues in animals placed on diets 2 and 3 as compared to those fed diet 1. Also, histopathological changes were observed in the livers, kidneys, spleens and hearts of rats fed diets 2 and 3.  

Conclusion: This study revealed that the No-observable adverse effect level (NOAEL) of dietary FB₁ above which may cause significant physiological changes without overt toxicity for short-term toxicity study in female Wistar rats is <0.74 mg/kg bw per day.  

Keywords: Blood; Rat; Mycotoxin; Fusarium verticillioides; Fumonisin B_1; Histopathology.

DOI: http://dx.doi.org/10.3329/jbs.v18i0.8779

JBS 2010; 18(0): 74-83