Assessment of in vitro mutagenicity in Salmonella and in vivo genotoxicity in mice of the mycotoxin fumonisin B1

Fumonisin B-1 (FB1), a mycotoxin produced by Fusarium moniliforme, is a contaminant of cereals with various and complex cellular effects. FB1 induces liver cancer in rats and has been linked to esophageal cancer in South Africa and China. The mechanisms of FB1-induced carcinogenesis are uncertain and the information on FB1 mutagenic properties is limited and controversial. FB1 contamination levels in maize and wheat from Chile were found to be similar to those in other countries. FB1 was devoid of activity in gene mutation assays with Salmonella typhimurium strains TA100, TA102 and TA98. However, i.p. injection of FB1 induced an increased frequency of micronuclei in mouse bone marrow polychromatic erythrocytes at 25 and 100 mg/kg. We conclude that FBI induces in vivo genotoxicity in the absence of in vitro mutagenicity in Salmonella.