Identification of novel thiazolidine-4-one based hits as potential PPARγ modulators through in silico workflow and validation through in vitro studies

Abstract

Full PPARγ agonists like thiazolidinediones have shown notable antidiabetic efficacy but are associated with significant side effects. Partial PPARγ agonists offer superior efficacy with minimized side effects. Based on the extensive literature review, a novel library of C-2 and C-5 disubstituted thiazolidine-4-one analogs was designed as synthetically feasible PPARγ modulators. A multi-step computational workflow, including molecular docking, MM-GBSA calculations, ADMET predictions, MD simulations, and DFT analysis, guided the selection of promising candidates. Among the various promising designed compounds, compounds 1 (-8.189 kcal/mol) and 106 (-8.383 kcal/mol) emerged as the most potent hits, outperforming rosiglitazone (-7.057 kcal/mol) and pioglitazone (-7.381 kcal/mol) in docking studies. Further, ADMET profiling confirmed drug-likeness, and MD simulations highlighted stable interactions with key residues, notably Ser342, a crucial residue linked to the partial PPARγ agonism which may help in reducing the side effects. These two potential hits 1 & 106 were synthesized, characterized and evaluated in vitro for PPARγ agonistic activity wherein they displayed EC₅₀ values of 8.71±2.0 µM and 13.1±2.2 µM, respectively compared to pioglitazone (0.65±0.19 µM) and rosiglitazone (0.35±0.08 µM). In vitro glucose uptake assay also confirmed good hypoglycemic action of the identified hits 1 and 106 comparable to pioglitazone. Furthermore, in vitro cytotoxicity assay against HEK-293 cells demonstrated IC₅₀ values of 751.1 µM and 2869 µM for 1 and 106, respectively suggesting low toxicity and high tolerance to increasing drug concentration with a favorable safety margin for further development.