An experimental study of the interaction of glibenclamide,, a sulfonylurea drug, with DNA

Detecting the binding mode of glibenclamide to DNA and the factors involved is highly important to generally find out DNA binding. In this study, the biological properties of glibenclamide were studied under physiological conditions (Tris–HCl buffer solutions, pH ۷.۴) by experimental methods (emission titration, UV-Vis spectroscopy, viscometry, and circular dichroism techniques). Based on experimental methods, because of the intercalation of the complex into the DNA base pairs, a variation in the structural parameters was observed. Hypochromism in UV absorption, a strong fluorescence quenching of glibenclamide, competition experiment with methylene blue, and increasing viscosity indicated that glibenclamide might intercalate between DNA nucleic bases. Two linear ranges observed with adding DNA concentration at ۲۵-۴۵۰ μM indicated different interactions in low and high DNA concentration ranges. The thermodynamic parameters, entropy change (ΔS) and enthalpy change (ΔH), indicated that hydrophobicinteractions are the main elements involved in the binding of glibenclamide to ct-DNA. Methylene blue (MB) displacement assessment showed that glibenclamide could eplace MB probe in the MB -DNA complex, indicating the intercalation binding.

Keywords:

Sulfonylurea drug , Glibenclamide , Intercalative , Hydrophobic interaction , Fluorescence quenching