AIM OF THE STUDY: This study aimed to investigate the in vitro antiproliferative effects and apoptotic events of the ionic liquid extract of Graviola fruit (IL-GFE) on MCF-7 breast cancer cells and their cytokinetics behaviour to observe their potential as a therapeutic alternative in cancer treatment.
MATERIALS AND METHODS: The cell viability assay of the extract was measured using tetrazolium bromide (MTT assay) to observe the effects of Graviola fruit extract. Then the cytokinetics behaviour of MCF-7 cells treated with IL-GFE is observed by plotting the growth curve of the cells. Additionally, the cell cycle distribution and apoptosis mechanism of IL-GFE action on MCF-7 cancer cells were observed by flow cytometry.
RESULTS: IL-GFE exhibited anti-proliferative activity on MCF-7 with the IC50 value of 4.75 μg/mL, compared to Taxol with an IC50 value of 0.99 μg/mL. IL- GFE also reduced the number of cell generations from 3.71 to 1.67 generations compared to 2.18 generations when treated with Taxol. Furthermore, the anti-proliferative activities were verified when the growth rate was decreased dynamically from 0.0077 h to 1 to 0.0035 h-1. Observation of the IL-GFE-treated MCF-7 under microscope demonstrated detachment of cells and loss of density. The growth inhibition of the cells by extracts was associated with cell cycle arrest at the G0/G1 phase, and phosphatidylserine externalisation confirms the anti-proliferation through apoptosis.
CONCLUSIONS: ionic liquid Graviola fruit extract affect the cytokinetics behaviour of MCF-7 cells by reducing cell viability, induce apoptosis and cell cycle arrest at the G0/G1 phase.
METHODS: The three variants expressed by bacteria were investigated using substrate (omeprazole and 3- cyano-7-ethoxycoumarin[CEC]) and inhibitor (ketoconazole, fluoxetine, sertraline and loratadine) probes in enzyme assays along with molecular docking.
RESULTS: All alleles exhibited very low enzyme activity and affinity towards omeprazole and CEC (6.1% or less in intrinsic clearance). The inhibition studies with the four inhibitors, however, suggested that mutations in different variants have a tendency to cause enhanced binding (reduced IC50 values). The enhanced binding could partially be explained by the lower polar solvent accessible surface area of the inhibitors relative to the substrates. Molecular docking indicated that G91R, R335Q and F448L, the unique mutations in the alleles, have caused slight alteration in the substrate access channel morphology and a more compact active site cavity hence affecting ligand access and binding. It is likely that these structural alterations in CYP2C19 proteins have caused ligand-specific alteration in catalytic and inhibitory specificities as observed in the in vitro assays.
CONCLUSION: This study indicates that CYP2C19 variant selectivity for ligands was not solely governed by mutation-induced modifications in the active site architecture, but the intrinsic properties of the probe compounds also played a vital role.