Effect of furfural on plasmid DNA.

Furfural is a dietary mutagen and is present in various food products and beverages. We have previously shown that it induces single strand breaks in double stranded DNA that occur mainly in AT sequences. In this paper, we have examined the mutagenic effect of furfural induced lesions in the plasmid pBR322. Plasmid DNA was treated with furfural before transformation in E. coli. There was a progressive decrease in the transformation capacity of the plasmid both as a function of furfural concentration and time of reaction. Several mutants were isolated from plasmid preparations whose transforming capacity had been decreased by treatment with furfural. Depending on the concentration of furfural used, these were found to have undergone DNA alterations including deletions. Experiments on the conservation of EcoRI cleavage site in mutant plasmids indicated that repair of furfural damaged plasmid DNA takes place on propagation in host cells.