Electrochemical studies and spectroscopic investigations on the interaction of an anticancer drug flutamide with DNA and its analytical applications

Flutamide (Flu) is a chemotherapeutic drug, used for the treatment of prostate cancer. It functions by interfering DNA in fast growing cells and preventing them from reproducing. The present work is focused on the interaction of Flu with single and double stranded DNA at different temperatures and at physiological pH 7.4 (human blood pH). Cyclic voltammetry, square wave voltammetry and UV-visible spectroscopy were used to analyze the interaction of Flu with DNA. The voltammetric results indicate Flu gets intercalated between dsDNA bases and the strength of interaction is independent on the ionic strength. The hyperchromic effect in absorption spectra of Flu-dsDNA complex affirmed the intercalative mode of binding between Flu and dsDNA. Comparison of the mode interaction of Flu with dsDNA and ssDNA was discussed. The binding constants, stoichiometric coefficients and thermodynamic parameters of Flu-dsDNA and Flu-ssDNA complexes were evaluated. The association between Flu and dsDNA is maximum at 308 K which depicts the most stable complexes are formed at near human body temperature. The decrease in the peak current of Flu resulting from its interaction with DNA was employed for determination of dsDNA and ssDNA concentration. The detection limits of dsDNA and ssDNA were found to be 4.27 x 10(-7) M and 1.87 x 10(-7) M, respectively. (C) 2014 Elsevier B.V. All rights reserved.