Spectroscopic analysis on the resveratrol-DNA binding interactions at physiological pH

Area of Science:

• Biochemistry
• Molecular Biology
• Pharmacology

Background:

• Resveratrol, a natural polyphenol, exhibits diverse biological activities.
• Deoxyribonucleic acid (DNA) is the primary target for many therapeutic agents.
• Understanding drug-DNA interactions is crucial for drug development.

Purpose of the Study:

• To investigate the binding mechanism of resveratrol with calf thymus deoxyribonucleic acid (ctDNA).
• To determine the binding affinity, mode, and thermodynamic parameters of the resveratrol-ctDNA complex.
• To elucidate the fluorescence quenching mechanism of acridine orange-ctDNA by resveratrol.

Main Methods:

• Spectroscopic analysis (UV-Vis absorption and fluorescence spectroscopy).
• Viscosity measurements.
• Thermodynamic parameter calculations using the double reciprocal method.

Main Results:

• Resveratrol forms a complex with ctDNA, with binding constants K(17°C) = 5.49×10^3 L mol⁻¹ and K(37°C) = 1.90×10^4 L mol⁻¹.
• The interaction involves static fluorescence quenching of acridine orange-ctDNA by resveratrol.
• Thermodynamic parameters (ΔH = 4.64×10^4 J mol⁻¹, ΔS = 231.8 J K⁻¹ mol⁻¹, ΔG = -2.54×10^4 J mol⁻¹ at 37°C) indicate a spontaneous binding process.
• Evidence suggests an intercalation mode of binding.

Conclusions:

• Resveratrol interacts with ctDNA through intercalation.
• The binding is thermodynamically favorable and increases with temperature.
• These findings provide insights into the molecular interactions of resveratrol with DNA, relevant for its biological functions and therapeutic potential.