Supplemental role of Alzheimer's disease drugs as reversal agents for oxidative stress in DNA

The detrimental effect of oxidative stress on biological systems has been the primary cause of many neurological, gastrointestinal and cardiovascular disorders. The possible conformational alterations in the structure of deoxyribonucleic acid (DNA) due to oxidative stress induced by reactive oxygen species (ROS) in the DNA backbone are known to be the underlying cause of many life-threatening diseases. A clear understanding of the interactions between therapeutic drugs and DNA is essential to quantify the possibility of any change in DNA that might take place during the administration of these drugs. In this study, the interactions of four FDA approved drugs used in the treatment of Alzheimer's disease (AD), namely donepezil (DON), tacrine (TAC), eserine (ESE) and (-) huperzine (HuPA), with calf thymus DNA (ct-DNA) were investigated through several in vitro spectroscopic, PCR based assay (with plasmid DNA) and molecular modelling studies. It is intriguing to note that all the four drugs bind at the minor groove of ct-DNA base pairs, thus, ruling out the possibility of any damage to DNA