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.

leaves

During a previous study that aimed to identify anticancer agents within primate-consumed plants, the present group identified that Eugenia aquea (E. aquea) possessed potential as a source of anticancer agents. The ethanol extract of E. aquea leaves exhibited strong inhibitory activity against the proliferation of the human breast adenocarcinoma MCF-7 cell line. The inhibition of proliferation was determined using an MTT assay. The present study was performed to isolate the active compound within the E. aquea leaves that generated the aforementioned activity, and resulted in the isolation of 2',4'-dihydroxy-6-methoxy-3,5-dimethylchalcone, which was identified through the analysis of spectroscopic data. This compound was examined for its inhibitory activity against the MCF-7 cell line using a MTT assay, and the ability of 2',4'-dihydroxy-6-methoxy-3,5-dimethylchalcone to induce apoptosis through the activation of the poly(adenosine diphosphate-ribose) polymerase (PARP) protein was also investigated. The results of the present study revealed that the isolated compound inhibited cell proliferation in a dose-dependent manner, possessed an IC₅₀ of 74.5 µg/ml (250 µM) and promoted apoptosis via the activation of PARP. It was concluded that these results indicated a requirement for additional investigations into 2',4'-dihydroxy-6-methoxy-3,5-dimethylchalcone in order to provide a basis for the use of this compound in the management of cancer.