Influence of beta cyclodextrin on amlodipine-BSA interaction: A spectroscopic and molecular docking study

Abstract

• Thermodynamic study revealed the static quenching mechanism and Van der Waals force, hydrogen bond and hydrophobic interactions are involved in the ALDP-BSA binding • Spectroscopic and molecular docking results demonstrated that β-CD incorporates ALDP, within its moiety thereby reducing its interaction with BSA • β-CD-ALDP inclusion complex enhanced solubility and bioavailability of ALDP • Inclusion complex interaction with BSA leads to increased therapeutic effect of ALDP Interaction behaviour of amlodipine (ALDP) with bovine serum albumin (BSA) in beta cyclodextrin (β-CD) environment has been studied in this work. Absorbance, steady-state fluorescence, three-dimensional fluorescence, circular dichroism and molecular docking techniques have been followed to monitor the BSA-(β-CD-ALDP) interaction. Thermodynamic study by steady-state fluorescence has shown spontaneous reaction between BSA-ALDP with static quenching, involving Van der Waals forces and hydrogen bonding interaction. Stern-Volmer equation has been employed to compute quenching constant and binding constant values for BSA-ALDP system in β-CD media. Reduction in the binding constant values for BSA-ALDP in β-CD media compared to BSA-ALDP suggests the formation of an inclusion complex. Spectroscopic experimental results are found to be in good agreement with molecular docking, which has demonstrated that β-CD incorporates ALDP within its moiety thereby reducing its interaction with BSA.