Apoptosis-mediated antiproliferation of A549 lung cancer cells mediated by Eugenia aquea leaf compound 2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone and its molecular interaction with caspase receptor in molecular docking simulation.

In a previous study, 2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone (ChalcEA) isolated from the leaves of Eugenia aquea was reported to inhibit proliferation of the breast adenocarcinoma MCF7 cell line and to promote apoptosis via activation of poly(adenosine diphosphate-ribose) polymerase protein. The present study aimed to evaluate the inhibitory effect of ChalcEA on the proliferation of A549 lung cancer cells using a 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxylmethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay, and to examine the ability of ChalcEA to induce apoptosis through activation of the caspase cascade signaling pathway in a western blotting assay. The results revealed that ChalcEA inhibited proliferation of the A549 lung cancer cell lines in a time- and dose-dependent manner with IC₅₀ values of 25.36 and 19.60 µM for 24 and 48 h treatments, respectively. Western blot analysis indicated that ChalcEA exerted its anti-proliferative effects by promoting apoptosis via the activation of caspase-9 and caspase-3. Based on in silico results, ChalcEA with the binding energy of -6.53 kcal/mol could compete better than 4-methyl benzenesulfonamide (-6.43 kcal/mol) as an inhibitor of caspase-3 (PDB: 2XYG). ChalcEA has potential since it has three hydrophobic features. These results provided a basis for further study of ChalcEA as an active compound for anticancer therapeutics.