Unravelling the Molecular Interaction of Pentoxifylline with Calf Thymus DNA: A Multitechnique Approach

Abstract

The drug-DNA interaction studies provide vital insights for designing and developing effective chemotherapeutic agents used in treatment of different cancers. Thus, the interaction of potential anticancer agent pentoxifylline and calf thymus DNA was analysed by various spectroscopic and electrochemical methods under physiological condition. The absorption spectra of pentoxifylline with calf thymus DNA revealed the formation of complex by hyperchromic effect with a binding constant of 1.461 × 10 4 M À 1 . Fluorescence studies, further showed that pentoxifylline binds to calf thymus DNA and form a stable complex with a static quenching mechanism. Thermodynamic analysis further confirms that the interaction process is spontaneous with Vander Waals force or hydrogen bonding playing a major role. The electrochemical studies and circular dichroism spectra signify that pentoxifylline interacts by groove binding mode. Based on electrochemical and spectroscopic results, the mode of pentoxifylline binding to calf thymus DNA is mainly established through groove binding.

Novel Azapodophyllotoxin Induces DNA Cleavage via Groove Binding: An Advancement in Exploration of Anticancer Activity of a Known Inhibitor of Tubulin Polymerization and Topoisomerase

“…However, with a view to determine any conformational changes in DNA due to binding of HTDQ, circular dichroism studies were implemented The CD spectrum of pure calf thymus DNA helix consists of two characteristic bands: 245 nm (negative) and 275 nm (positive), which are regarded as marker bands for B‐conformation of DNA [64] . Besides, the peak at 245 nm represents helicity of DNA and the stacking of DNA gives rise to peak at 275 nm [65] . The alterations in conformation of DNA is evident from the changes in the intensity and position of these peaks.…”

“…[64] Besides, the peak at 245 nm represents helicity of DNA and the stacking of DNA gives rise to peak at 275 nm. [65] The alterations in conformation of DNA is evident from the changes in the intensity and position of these peaks. The intercalators on binding with DNA usually leads to significant perturbations of both negative and positive bands while the groove binders induce very little or no perturbations in the spectra.…”

Elucidating the significance of molecular interaction between sulphur doped zinc oxide nanoparticles and serum albumin using multispectroscopic approach

“…Thus, if the binding affinity between nanoparticles and protein increases, the K b also increases and vice versa. For an equilibrium, the binding interaction of BSA with ZnO/S NPs is described as follows 39 where n is the number of binding site and K b represents the binding constant.…”

“…For an equilibrium, the binding interaction of BSA with ZnO/S NPs is described as follows. 39 BSA þ n ZnO S NPs ,…”

“…The type of binding force involved between ZnO/S NPs-BSA interaction is described by the sign and magnitude of thermodynamic parameters: (i) the positive values for both ΔS and ΔH refer to the involvement of hydrophobic forces, (ii) the negative values for both ΔS and ΔH refer to van der Waals and hydrogen bonding interactions and (iii) the positive value of ΔS and the negative value of ΔH indicate electrostatic interaction. 39 From the results summarized in Table 1, the negative sign of ΔG and ΔH indicates that the binding process is spontaneous and exothermic. The negative sign of ΔH and ΔS indicates the involvement of van der Waals force or hydrogen bonding interaction in ZnO/S NPs-BSA complex formation.…”