Potential inhibitors for FKBP51: an in silico study using virtual screening, molecular docking and molecular dynamics simulation.

Over the years, FK506-binding proteins have been targeted for different pharmaceutical interests. The FK506-binding protein, encoded by the FKBP5 gene, is responsible for stress and metabolic-related disorders, including cancer. In addition, the FKBD-I domain of the protein is a potential target for endocrine-related physiological diseases. In the present study, a set of natural compounds from the ZINC database was screened against FKBP51 protein using in silico strategy, namely pharmacophore modeling, molecular docking, and molecular dynamic simulation. A protein-ligand-based pharmacophore model workflow was employed to identify small molecules. The resultant compounds were then assessed for their toxicity using ADMET prediction. Based on ADMET prediction, 4768 compounds were selected for molecular docking to elucidate their binding mode. Based on the binding energy, 857 compounds were selected, and their Similarity Tanimoto coefficient was calculated, followed by clustering according to Jarvis-Patrick clustering methods (Jarp). The clustered singletons resulted in 14 hit compounds. The top 05 hit compounds and 05 known compounds were then subjected to 100 ns MD simulation to check the stability of complexes. The study revealed that the selected complexes are stable throughout the 100 ns simulation; for FKBD-I (4TW6), crystal structure compared with FKBP-51 (1KT0) crystal structure. Finally, the binding free energies of the hit complexes were calculated using molecular mechanics energies combined with Poisson-Boltzmann. The data reveal that all the complexes show negative BFEs, indicating a good affinity of the hit compounds to the protein. The top five compounds are, therefore, potential inhibitors for FKBP51. Communicated by Ramaswamy H. Sarma.

Phyllanthus maderaspatensis, a dietary supplement for the amelioration of adriamycin-induced toxicity and oxidative stress in mice.

The effect of ethanol extract of Phyllanthus maderaspatensis (PME), a popular south Indian dietary supplement, was studied for its chemoprotective property on adriamycin (ADR)-induced toxicity and oxidative stress in mice. Adriamycin toxicity was evaluated biochemically by measuring the serum concentration of lactate dehydrogenase (LDH) and creatinine phosphokinase (CPK). Genotoxicity was evaluated by measuring the frequency of micronucleated polychromatic erythrocytes (MNPCEs) in bone marrow cells. Oxidative stress in the heart tissue was estimated by measuring the glutathione (GSH) levels in the homogenate. The treatment of mice with different doses of PME (400 mg/kg and 600 mg/kg body weight, p.o.,) for 7 days before the administration of a single i.p. dose of ADR (15 mg/kg) exhibited significant protection in a dose-dependent manner. The results clearly indicate that PME has a protective effect against ADR-induced toxicity, as revealed by the decrease in the concentrations of LDH, CPK, and the frequency of MNPCEs. The increased levels of GSH are indicative of the antioxidant property of PME.