DNA Binding Study of Methanolic Extract of Pisonia aculeata Linn. Having Anticancer Activity

Anticancer drugs interact with Deoxyribonucleic acid (DNA) in many different ways. These include intercalation, non-covalent groove binding, covalent binding/cross-linking, DNA cleaving and nucleoside-analog incorporation. As a result of complex formation occurring between DNA and drug, the thermo dynamic stability and the functional properties of DNA change. Understanding how complexation affects both the structural and mechanical properties of DNA is an important step towards elucidating the functional mechanism of binding agents. The present investigation was carried out by performing Spectrophotometric methods, Viscosity measurements and Electrochemical method. In Spectrophotometric methods, Methanolic extract of Pisonia aculeata (MPA) leaves showed analogous spectral changes and Remarkable increasing in the absorbance found around 260 nm. In Viscosity measurements, a classical intercalative mode causes a significant increase in viscosity of DNA due to an increase in separation of base pairs at intercalation sites and hence an increase in overall DNA length and showed slight increase in the flow time of DNA on increasing concentration of extract. Whereas in Electrochemical method, the peak current initially increased due to the absorption of the DNA bound complex onto the electrode surface and then decreased on the addition of DNA to the complex, which is suggestive of an interaction between the complex and DNA. A decrease in the peak-to-peak separation which is consistent with non-coordinating intercalative binding of the complexes through the planar aromatic rings between the DNA base pairs. It can be conclude that MPA showed good anticancer activity.