Assessment of in vitro mutagenicity in Salmonella and in vivo genotoxicity in mice of the mycotoxin fumonisin B(1).

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