MAIN METHODS: A curcumin derivative (Z)-3-hydroxy-1-(2-hydroxyphenyl)-3-phenylprop-2-en-1-one (DK1) was synthesized and its cytotoxicity was tested on breast cancer cell MCF-7 and normal cell MCF-10A using MTT assay. Meanwhile, cell cycle regulation and apoptosis on MCF-7 cell were evaluated using flow cytometry. Regulation of cell cycle and apoptosis related genes expression was investigated by quantitative real time polymerase chain reaction (qRT-PCR), western blot and caspases activity analyses. Activation of oxidative stress on MCF-7 were evaluated by measuring ROS and GSH levels.
KEY FINDINGS: DK1 was found to possess selective cytotoxicity on breast cancer MCF-7 cell than normal MCF-10A cell. Flow cytometry cell cycle and AnnexinV/PI analyses reported that DK1 effectively arrested MCF-7 at G2/M phase and induced apoptosis after 72 h of incubation than curcumin. Upregulation of p53, p21 and downregulation of PLK-1 subsequently promote phosphorylation of CDC2 which were found contributed to the arrest of G2/M phase. Moreover, increased of reactive oxygen species and reduced of antioxidant glutathione level correlate with apoptosis observed with raised of cytochrome c and active caspase 9.
SIGNIFICANCE: DK1 was found to be more effective in inducing cell cycle arrest and apoptosis against MCF-7 cell with much higher selectivity index of MCF-10A/MCF-7 than curcumin, which might be contributed by the overexpression of p53 protein.
RESULTS: Twenty-four curcumin derivatives have synthesized, which comprises cyclohexanone 1-10, acetone 11-17 and cyclopentanone 18-24 series. All the curcuminoids were synthesized by the acid or base catalyzed Claisen Schmidt condenstion reactions, in which β-diketone moiety of curcumin was modified with mono-ketone. These curcuminoids 1-24 were screened against HeLa, K562, MCF-7 (an estrogen-dependent) and MDA-MB-231 (an estrogen-independent) cancer cell lines. Among them, acetone series 11-17 were found to be more selective and potential cytotoxic agents. The compound 14 was exhibited (IC50 = 3.02 ± 1.20 and 1.52 ± 0.60 µg/mL) against MCF-7 and MDA-MB-231 breast cancer cell lines. Among the cyclohexanone series, the compound 4 exhibited (IC50 = 11.04 ± 2.80, 6.50 ± 01.80, 8.70 ± 3.10 and 2.30 ± 1.60 µg/mL) potential cytotoxicity against four proposed cancer cell lines, respectively. All the curcucminoids were characterized with the detailed1H NMR, IR, UV-Vis, and mass spectroscopic techniques. The structure of compound 4 was confirmed by using the single X-ray crystallography. Additionally, we are going to report the first time spectral data of (2E,6E)-2,6-bis(2-methoxybenzylidene)cyclohexanone (1). Structure-activity relationships revealed that the mono-carbonyl with 2,5-dimethoxy substituted curcuminoids could be an essential for the future drugs against cancer diseases.
CONCLUSIONS: Curcuminoids with diferuloyl(4-hydroxy-3-methoxycinnamoyl) moiety with mono carbonyl exhibiting potential cytotoxic properties. The compound 14 was exhibited (IC50 = 3.02 ± 1.20 and 1.52 ± 0.60 µg/mL) against MCF-7 and MDA-MB-231 breast cancer cell lines.