Thalassemia is a group of anemias that result from inherited defects in the production of the beta chain of hemoglobin. It is stabilized by gamma globin, which combines to form fetal hemoglobin. One therapeutic approach is to target histone deacetylase (HDAC), which plays an important role in controlling beta thalassemia. This study sought to identify a natural inducer for treating this disease.
Twenty-five Andrographis paniculata compounds were screened using Schrödinger Suite 2020 (Maestro 12.3) for ligand preparation, grid generation, glide extra precision docking and molecular mechanics/generalized born surface area scoring. The HDAC2 crystal structure (Protein Data Bank ID: 4LXZ) was prepared by removing crystallographic water molecules and performing restrained minimization. Top-scoring complexes were subjected to 5-ns molecular dynamics simulations in GROMACS 2019 using the optimized potentials for liquid simulations force field, three interaction site point charge solvation, and standard neutralization and equilibration protocols. Absorption, distribution, metabolism, and excretion properties were predicted using QikProp.
Among the twenty five screened compounds, SRJ09 derivative of andrographolide, ranked among the top candidates based on glide extra precision docking and molecular mechanics/generalized born surface area scores and was therefore selected for further analysis. SRJ09 showed favorable binding to the HDAC2 active site, with interactions comparable to the reference inhibitor 20Y. Absorption, distribution, metabolism, and excretion predictions indicated acceptable drug-likeness, and molecular dynamics simulations demonstrated stable SRJ09–HDAC2 complex behavior over 5 ns.
We concluded that beta thalassemia may benefit from the use of andrographolide, and SRJ 09 as prospective HDAC2 inhibitor drugs that are favourable and efficacious and that generate fetal hemoglobin. Therefore, this bioactive compound is worth further investigation using in vitro and in vivo studies.
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