Binding process evaluation of bovine serum albumin and Lawsonia inermis (henna) through spectroscopic and molecular docking approaches

Abstract Lawsonia inermis L. (Henna) has been widely used in cosmetic, medicine and pharmacy industries. Henna is one of the ancient used plants and it's able to be absorbed into the blood and interact with plasma serum albumin. In this article, we investigated the interaction between henna and bovine serum albumin (BSA) through several spectroscopic techniques, which accompanied with molecular docking approach. According to the results, fluorescence intensity of BSA were decreased upon addition of different concentrations of henna and variation of the intensity illustrates the interaction between henna and BSA. Stern-Volmer quenching analysis along with bimolecular quenching rate results suggested that henna quenched the intensity of BSA through hybrid quenching mechanism, which was confirmed via UV–Vis measurement. As the temperature increase, values of binding constant increased from 5.17 × 102 to 6.17× 102 (M−1) demonstrating that the stability of henna–BSA complex increased with temperature rising. Thermodynamic investigations revealed that the henna molecule bind to BSA via hydrophobic bonds spontaneously. Furthermore, the molecular docking analysis demonstrated that henna has high affinity to bind a cavity in Site II (Domain III, subdomain IIIA) on BSA with binding energy score - 11.37 kcal/mol. Finally, it should be stated that distribution of the henna in the blood circulatory system can be done via BSA, which would accompany us to understand the different medicinal aspects of this natural product especially in drug delivery.