Allicin and propolisbenzofuran B: Interaction pattern with ATP-binding cassete B1 (ABCB1) transporter

Natural products have been the mainstay of chemotherapy for years. Drug resistance in tumor cells is a major cause of failure in chemotherapy treatment. Several factors support this resistance and one of the main factors is the presence of drug efflux pumps such as ABCB1 transporters. The search for molecules capable of blocking the efflux by ABCB1 is important to increase the success of chemotherapy treatment. The Allicin (ALC) is one of the most biologically active compounds in freshly crushed garlic and the propolis-benzofuran B (PBB), a bioactive natural product isolated from honeybee propolis resin. ALC and PBB have already demonstrated anti-tumor effects, so they could block ABCB1. Comparing the binding pattern of ALC and PBB with ABCB1 through molecular docking was the main objective of this study. The docking simulation by AutoDock Vina demonstrated a binding energy with the ABCB1 more negative for PBB (-9.2 Kcal/mol) and less negative for ALC (-4.7 Kcal/mol). ALC linked to an extracellular region of ABCB1, whereas PBB bounded close to the nucleotide binding domain (intracellular portion) of ABCB1. The ALC established 02 and PBB 03 Hydrogen bonds with ABCB1. The number of hydrophobic interactions with ABCB1 was the same (10 interactions) for both molecules. Considering the more negative binding energy and the higher number of hydrogen bonds (evidence of greater affinity and stability) PBB appears to be a better ABCB1 inhibitor. However, it is necessary to continue in vitro and in vivo studies.