Design, Synthesis, Molecular docking, and biological evaluation of novel 2,3-diaryl-1,3-thiazolidine-4-one derivatives as potential anti-inflammatory and cytotoxic agents

•Three series of thiazolidin-4-one-based derivatives 4a-m, 5a-e, and 6a,b were designed and synthesized.•Compounds 4 k and 4j exhibited the highest inhibitory activities against COX-2 at IC50 values of 0.05 and 0.06 μM, respectively.•Compound 4j exhibited the highest antioxidant activity with IC50 of 45.27 μM comparable to torolox (IC50 = 62.03 μM).•The cytotoxic activity of all the synthesized compounds 4a-m, 5a-e, and 6a, b was evaluated against four cancer cell lines.•Results revealed that compounds 4b, 4j, 4 k, and 6b exhibited antiproliferative activities with IC50 range 2.31–27.19.•Molecular docking was performed illustrating good fitting and correlation with the results of in vitro COX‑2 inhibition assay.