DNA damage induced by a chromium(III) Schiff base complex is reversible under physiological condition

[Cr(naphen)(H2O)2]+, where naphen is 1,2-bis(naphthylideneamino)ethane having the basic salen moiety, has been characterized structurally. [Cr(naphen)(H2O)2]+, which has an extended aromatic system and binds with calf thymus DNA (CT DNA) intercalatively, has been found to promote DNA cleavage in the presence of biological reductant such as ascorbate and oxidant like hydrogen peroxide. Results of electron paramagnetic resonance (EPR) experiments suggest involvement of hydroxyl radicals in the oxidative cleavage of DNA in the presence of the Cr(III) complex and hydrogen peroxide. The cell viability study on nicked DNA by [Cr(naphen)(H2O)2]+ has shown that the damage brought about to DNA could be repaired by Escherichia coli DNA repair enzymes.