Abstract
Nivalenol (NIV) is considered to be an important trichothecene mycotoxin produced by Fusarium species because of its frequent contamination in wheat and barley worldwide. The present study examined the subchronic toxicity of NIV in male and female F344 rats fed diets containing 0, 6.25, 25 and 100 mg kg−1 of the toxin for 90 days. During the experimental period there was a decrease in the white blood cell count at 100 mg kg−1 in males and at ≥6.25 mg kg−1 in females. Histopathologically, treatment-related changes were observed in the haematopoietic and immune systems in both sexes and in the female reproductive system at 100 mg kg−1. Flow cytometric analysis of splenic cells revealed an elevation in the ratio of helper/cytotoxic T-lymphocytes at 100 mg kg−1. In summary, NIV targets the female reproductive system as well as haematopoietic and immune systems in rats fed NIV for 90 days. Based on a significant decrease in white blood cells in female rats relative to controls, the lowest observable effect level was calculated as 0.4 mg kg−1 body weight day−1.
Acknowledgements
This work was supported by Health and Labour Sciences Research Grants (Research on Food Safety) from the Ministry of Health, Labour and Welfare of Japan. The authors are also grateful to Dr Onji (Nara Prefectural Institute for Hygiene and Environment) for providing de-epoxy NIV standard.