Computational identification of potential modulators of heme-regulated inhibitor (HRI) for pharmacological intervention against sickle cell disease

Abstract

Sickle cell disease (SCD) poses a significant health challenge and therapeutic approaches often target fetal hemoglobin (HbF) to ameliorate symptoms. Hydroxyurea, a current therapeutic option for SCD, has shown efficacy in increasing HbF levels. However, concerns about myelosuppression and thrombocytopenia necessitate the exploration of alternative compounds. Heme-regulated inhibitor (HRI) presents a promising target for pharmacological intervention in SCD due to its association with HbF modulation. This study screened compounds for their potential inhibitory functions against HRI. Small-molecule compounds from 17 folkloric plants were subjected to <i>in silico</i> screening against HRI. Molecular docking was performed, and free binding energy calculations were determined using molecular mechanics with generalized born and surface area (MMGBSA). Lead compounds were subjected to molecular dynamics simulation at 100 ns. Computational quantum mechanical modeling of the lead compounds was subsequently performed. We further examined the pharmacodynamics, pharmacokinetic and physiological properties of the identified compounds. Five potential HRI inhibitors, including kaempferol-3-(2G-glucosyrutinoside), epigallocatechin gallate, tiliroside, myricetin-3-O-glucoside and cannabiscitrin, with respective docking scores of -16.0, -12.17, -11.37, -11.56 and 11.07 kcal/mol, were identified. The MMGBSA analysis of the complexes yielded free-binding energies of -69.76, -71.17, -60.44, -53.55 and -55 kcal/mol, respectively. The identified leads were stable within HRI binding pocket for the duration of the 100 ns simulation. The study identified five phytoligands with potential inhibitory effects on HRI. This finding holds promise for advancing SCD treatment strategies. However, additional preclinical analyses are warranted to validate the chemotherapeutic properties of the lead compounds.