Effect of eugenol and selected eugenol rich plants on the genomic and proteomic components of A549 lung adenocarcinoma cells

Abstract

The present study focussed on the anticancer activity of eugenol and selected eugenol-rich plant extracts (Piper betle and Syzygium aromaticum) on the lung adenocarcinoma (A549) cells, at the genomic and proteomic level. In order to understand the molecular mechanism of action of eugenol and selected eugenol-rich plant extracts, the study was carried out in four phases. The presence of eugenol in methanolic extracts of P. betle leaf extract and S. aromaticum flower extract was confirmed by HPLC. In the first phase of the study, eugenol and selected eugenol-rich plant extracts, on the viability of A549 lung adenocarcinoma cells, was assessed. The results of Phase I showed that the eugenol and the selected eugenol-rich plant extracts exerted a significant anticancer activity, by killing A549 cells. In addition, it was found that the treatment with eugenol and selected eugenol-rich plant extracts resulted in the arrest of cell cycle at G2/M phase in lung adenocarcinoma A549 cells. In phase II, the functional genomic and proteomic profiles in the A549 cells exposed to eugenol and methanolic extracts of P. betle and S. aromaticum was quantitatively analysed using qRT PCR and 2D gel electrophoresis respectively. The results of Phase II revealed that the eugenol and selected eugenol-rich plant extracts were able to influence the genes in all the cancer-associated pathways studied. The analysis of the pattern of differential gene expression suggested that eugenol exerts its action by increasing cancer cell adhesion, decreasing invasion and metastasis, inducing apoptosis and exerting control over the cell cycle. The treatments also caused profound differences in the pattern of protein spots on the 2D gel. In the third phase of the study, the functional interactions between the proteins coded by the key genes modulated upon eugenol and selected eugenol-rich plant extracts treatment in lung adenocarcinoma A549 cells were studied. Protein interaction maps were constructed and the analysis revealed very strong interactions be