The action of metronidazole on DNA

Abstract

Reduced metronidazole affects the melting proffle of DNA by decreasing the T_m value and increasing the melting range, but has no effect on the cooling profile. The reduced drug also causes single and double strand breaks in T2 and calf-thymus DNA, but does not break single stranded DNA. None of these effects are observed with the unreduced drug. The effects may explain the biological basis of its action not only as an antimicrobial agent, but also as a radiosensitizer, and may be relevant to its reported mutagenic and carcinogenic activity.