METHODS: Isolation of compounds from G. segetum leaves was conducted using vacuum liquid chromatography (VLC) and column chromatography (CC). Two new compounds, namely 4,5,4'-trihydroxychalcone and 8,8'-(ethene-1,2-diyl)-dinaphtalene-1,4,5-triol, together with stigmasterol and β-sitosterol were isolated from G. segetum methanol extract and their structures were determined spectroscopically. The presence of gallic acid and rutin in the extract was determined quantitatively by a validated HPLC method. G. segetum methanol extract and its constituents were investigated for their effects on chemotaxis, phagocytosis, β2 integrin (CD18) expression, and reactive oxygen species (ROS) of polymorphonuclear leukocytes (PMNs), lymphocytes proliferation, cytokine release and nitric oxide (NO) production of phagocytes.
RESULTS: All the samples significantly inhibited all the innate immune responses tested except CD 18 expression on surface of leukocytes. Among the samples, 8,8'-(ethene-1,2-diyl)-dinaphtalene-1,4,5-triol exhibited the strongest inhibitory on chemotaxis, phagocytosis, ROS and NO production. The compound exhibited exceptionally strong inhibitions on ROS and chemotaxis activities with IC50 values lower than the positive controls, aspirin and ibuprofen, respectively. 4,5,4'-Trihydroxychalcone revealed the strongest immunosuppressive activity on proliferation of lymphocytes (IC50 value of 1.52 μM) and on release of IL-1β (IC50 value of 6.69 μM). Meanwhile rutin was the most potent sample against release of TNF-α from monocytes (IC50, 16.96 μM).
CONCLUSION: The extract showed strong immunosuppressive effects on various components of the immune system and these activities were possibly contributed mainly by 4,5,4'-trihydroxychalcone, 8,8'-(ethene-1,2-diyl)-dinaphtalene-1,4,5-triol and rutin.
METHODS: MCF-7 and MDA-MB231 cells were treated with several concentrations of FKA. The apoptotic analysis was done through the MTT assay, BrdU assay, Annexin V analysis, cell cycle analysis, JC-1 mitochondrial dye, AO/PI dual staining, caspase 8/9 fluorometric assay, quantitative real time PCR and western blot. For the metastatic assays, the in vitro scratch assay, trans-well migration/invasion assay, HUVEC tube formation assay, ex vivo rat aortic ring assay, quantitative real time PCR and western blot were employed.
RESULTS: We have investigated the effects of FKA on the apoptotic and metastatic process in two breast cancer cell lines. FKA induces apoptosis in both MCF-7 and MDA-MB231 in a dose dependent manner through the intrinsic mitochondrial pathway. Additionally, FKA selectively induces a G2/M arrest in the cell cycle machinery of MDA-MB231 and G1 arrest in MCF-7. This suggests that FKA's anti-cancer activity is dependent on the p53 status. Moreover, FKA also halted the migration and invasion process in MDA-MB231. The similar effects can be seen in the inhibition of the angiogenesis process as well.
CONCLUSIONS: FKA managed to induce apoptosis and inhibit the metastatic process in two breast cancer cell lines, in vitro. Overall, FKA may serve as a promising candidate in the search of a new anti-cancer drug especially in halting the metastatic process but further in vivo evidence is needed.