DNA SINGLE AND DOUBLE-STRAND BREAKS INDUCED BY ALIPHATIC AND AROMATIC-ALDEHYDES IN COMBINATION WITH COPPER(II)

The aliphatic n-butyr- and n-valeraldehyde as well as the aromatic ben z- and anisaldehyde induced DNA strand breaks in PM2 DNA in the presen ce of CuCl2. Neither aldehydes nor CuCl2 alone showed DNA breakage pro perties. The maximum of single strand breaks (SSBs) induced by the com bination of CuCl2 and aldehydes was dependent on the CuCl2-concentrati on. The aliphatic aldehydes induced SSBs and double strand breaks (DSB s) at lower concentrations than aromatic aldehydes when optimal CuCl2 concentration were used. Catalase and neocuproine nearly completely in hibited strand break formation induced by aromatic aldehydes/CuCl2. Th e prevention of strand breaks induced by aliphatic aldehydes/CuCl2 was less effective. While the inhibition by neocuproine was only 25%, cat alase was totally ineffective. In all aldehydes/CuCl2 mixtures the for mation of Cu(I) was observed. The results point to different DNA damag ing species produced during redox reactions of aromatic and aliphatic aldehydes in combination with CuCl2.