Repeated dose 28-day oral toxicity study of moniliformin in rats

• The subacute oral toxicity of synthetic moniliformin in rats was assessed according to an adaption of OECD guideline 407.
• The clinical signs included death and acute cardiac distress in 2 out of 5 rats in the highest dose group (15 mg/kg b.w.).
• Moniliformin reduced the phagocytic activity of the rat neutrophils indicating an adverse effect on innate immunity.
• Excretion of moniliformin into urine was rapid, with no indication of accumulation post-exposure.
• Based on our findings, we suggest a LOAEL of 3 mg/kg b.w.

Moniliformin is a Fusarium mycotoxin mainly produced by several species infecting grains in different climatic conditions. According to our previous studies, it is acutely toxic to rats, with an LD50 cut-off value of 25 mg/kg b.w. To further assess the possible health risks of low dose exposure to moniliformin, a subacute oral toxicity study was conducted in Sprague-Dawley rats, adapting OECD guideline 407. Five dose groups and two satellite groups, each consisting of five male rats, were daily exposed to moniliformin by gavage. Two rats in the highest dose group, showed decreased activity followed by acute heart failure and death. The rats of the lower doses (<9 mg/kg b.w.) showed no signs of toxicity. The daily intake of moniliformin strongly reduced the phagocytic activity of neutrophils in all dose groups. The decrease continued in the satellite group during the follow-up period, indicating a severe impact on the immune system and a LOAEL value of 3 mg/kg b.w. for moniliformin. Moniliformin was rapidly excreted into urine, ranging between 20.2 and 31.5% daily and showed no signs of accumulation. The concentration of moniliformin in faeces was less than 2%, which suggests efficient absorption from the gastrointestinal tract.