mtt-formazan and Lymphoma--B-Cell

Complexes of lanthanum (III) with bis-coumarins: bis(4-hydroxy-2-oxo-2H-chromen-3-yl)-piridin-2-yl-methane; bis(4-hydroxy-2-oxo-2H-chromen-3-yl)-piridin-3-yl-methane and bis(4-hydroxy-2-oxo-2H-chromen-3-yl)-piridin-4-yl-methane were synthesized by reaction of lanthanum (III) salt and the ligands, in amounts equal to metal/ligand molar ratio of 1:2. The complexes were prepared by adding an aqueous solution of lanthanum (III) salt to an aqueous solution of the ligand subsequently raising the pH of the mixture gradually to ca. 5.0 by adding dilute solution of sodium hydroxide. The lanthanum (III) complexes with bis-coumarins were characterized by different physicochemical methods-elemental analysis, IR-, (1)H- and 13C-NMR spectroscopies and mass-spectral data. The spectral data of lanthanum (III) complexes were interpreted on the basis of comparison with the spectra of the free ligands. This analysis showed that in the La (III) complexes the ligands coordinated to the metal ion through both deprotonated hydroxyl groups. On the basis of the nu(C=O) red shift observed, participation of the carbonyl groups in the coordination to the metal ion was also suggested. Cytotoxic screening by MTT assay was carried out. In the present study, we performed comparative evaluation of the cytotoxic effects of the three newly synthesized lanthanum complexes against the acute myeloid leukemia derived HL-60 and the chronic myeloid leukemia (CML)-derived BV-173. In addition the cytotoxic effects of La (III) complex with bis(4-hydroxy-2-oxo-2H-chromen-3-yl)-piridin-2-yl-methane were evaluated on the SKW-3 cells. In order to elucidate some of the mechanistic aspects of the observed cytotoxic effects we evaluated the ability of this complex to trigger programmed cell death (apoptosis by means of agarose gel electrophoretic analysis of DNA), isolated from the cytosolic fraction of treated SKW-3 cells. In addition, microscopic morphological evaluation of the treated cells was carried out in order to establish morphological features indicative for programmed cell death.

Topics: Antineoplastic Agents; Apoptosis; Cell Survival; Coumarins; DNA Fragmentation; Drug Screening Assays, Antitumor; Formazans; HL-60 Cells; Humans; Inhibitory Concentration 50; Lanthanum; Lymphoma, B-Cell; Magnetic Resonance Spectroscopy; Mass Spectrometry; Molecular Structure; Organometallic Compounds; Spectrophotometry, Infrared; Tetrazolium Salts

Coriolus versicolor (CV), also known as Yunzhi, is one of the commonly used Chinese medicinal herbs. Although recent studies have demonstrated its antitumour activities on cancer cells in vitro and in vivo, the exact mechanism is not fully elucidated. Hence, the objective of this study was to examine the in vitro cytotoxic activities of a standardized aqueous ethanol extract prepared from Coriolus versicolor on a B-cell lymphoma (Raji) and two human promyelocytic leukemia (HL-60, NB-4) cell lines using a MTT cytotoxicity assay, and to test whether the mechanism involves induction of apoptosis. Cell death ELISA was employed to quantify the nucleosome production resulting from nuclear DNA fragmentation during apoptosis. The present results demonstrated that CV extract at 50 to 800 microg/ml dose-dependently suppressed the proliferation of Raji, NB-4, and HL-60 cells by more than 90% (p < 0.01), with ascending order of IC50 values: HL-60 (147.3 +/- 15.2 microg/ml), Raji (253.8 +/- 60.7 microg/ml) and NB-4 (269.3 +/- 12.4 microg/ml). The extract however did not exert any significant cytotoxic effect on normal liver cell line WRL (IC50 > 800 microg/ml) when compared with a chemotherapeutic anticancer drug, mitomycin C (MMC), confirming the tumour-selective cytotoxicity. Nucleosome productions in HL-60, NB-4 and Raji cells were significantly increased by 3.6-, 3.6- and 5.6-fold respectively upon the treatment of CV extract, while no significant nucleosome production was detected in extract-treated WRL cells. The CV extract was found to selectively and dose-dependently inhibit the proliferation of lymphoma and leukemic cells possibly via an apoptosis-dependent pathway.

Topics: Antineoplastic Agents; Apoptosis; Cell Division; Cell Line, Tumor; Cell Survival; DNA Fragmentation; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Drugs, Chinese Herbal; Formazans; Humans; Leukemia, Promyelocytic, Acute; Liver; Lymphoma, B-Cell; Medicine, Chinese Traditional; Mitomycin; Nucleosomes; Plants, Medicinal; Tetrazolium Salts