Discovery of thirteen cobalt(II) and copper(II) salicylaldehyde Schiff base complexes that induce apoptosis and autophagy in human lung adenocarcinoma A549/DDP cells and that can overcome cisplatin resistance in vitro and in vivo.

In this study, 13 transition metal complexes, namely, [Cu(L1H)(H2O)2]·(H2O)·NO3 (1), [Cu(LnH2)2]·(NO3)·(H2O)2 (2, n = 2; 3, n = 3; 4, n = 4; 5, n = 5), [Co(LnH)2]2·(H2O)0.5 (6, n = 2; 7, n = 3; 8, n = 4; 9, n = 5), [Cu(L6H)0.5(L10H)0.5(phen)]·(CH3OH)0.25 (10), [Cu(L11H) (phen)]4·(H2O)9 (11), [Cu(L8H)0.27(L12H)0.73(phen)]4·(H2O)5.5(CH3OH) (12), and [Cu(L9H) (phen)]3·(H2O)7·(CH3OH) (13), were synthesized using Schiff base ligands and characterized by elemental analysis (EA), infrared spectroscopy (IR), and single-crystal X-ray diffraction (SC-XRD). Compared with complexes 1-9, complexes 10-13 displayed stronger cytotoxic activities against the tested A549/DDP cancer cells (IC50 = 0.97-3.31 µM), with differences greater than one order of magnitude. Moreover, complexes 11 and 13 could induce apoptosis and autophagy in A549/DDP cells via the mitochondrial dysfunction pathway that affects the regulation of autophagy- and mitochondrial-related proteins. Importantly, the results indicate that the two novel salicylaldehyde Schiff base analogs, 11 and 13, exhibited pronounced and selective activity against A549/DDP xenografts in vivo.

Solvent and Copper Ion-Induced Synthesis of Pyridyl-Pyrazole-3-One Derivatives: Crystal Structure, Cytotoxicity.

Five novel compounds, methyl 5-(acetyloxy)-1-(6-bromo-2-pyridinyl)-1H-pyrazole-3-carboxylate (1), methyl 1-(6-bromo-2-pyridinyl)-5-hydroxy-1H-pyrazole-3-carboxylate (2), Trimethyl 1,1',1''-tris(6-bromo-2-pyridinyl)-5,5''-dihydroxy-5'-oxo-1',5'-dihydro-1H,1''H-4,4': 4',4''-terpyrazole-3,3',3''-tricarboxylate (H2L¹, 3), [Cu2(L²)2]·CH3OH (4), H2L2A·CH3CN (5) were synthesized. Compounds 1-5 characterized by elemental analysis, IR, and X-ray single-crystal diffraction. And 1-3 were also characterized by ¹H NMR, 13C NMR and ESI-MS. The H2L¹, H2L² were formed by in-situ reaction. H2L² and H2L2A are mesomer compounds which have two chiral carbons. The antitumor activity of compounds 1-5 against BEL-7404, HepG2, NCI-H460, T-24, A549 tumor cell lines were screened by methylthiazolyl tetrozolium (MTT) assay. The compounds 1, 2 showed weakly growth inhibition on the HepG2 cell lines. The HepG2 and A549 cell lines showed higher sensitivity to compound 4, while the IC50 values are 10.66, 28.09 µM, respectively. It is worth noting that compounds 1-5 did not show cytotoxicity to human normal liver cell line HL-7702, suggesting its cytotoxic selectivity on these tumor cell lines.

[Synergism inhibition of curcumin combined with cisplatin on T24 bladder carcinoma cells and its related mechanism].

OBJECTIVE: To investigate the synergism inhibition of curcumin combined with cisplatin on T24 bladder carcinoma cells and the down-regulating effect of curcumin on the Keapl-Nrf2 pathway, a well recognized anti-drug pathway in almost drugged tumor cells. METHODS: T24 cells were cultured and treated with increasing concentrations of curcumin(5 ,10 and 20 µmol/mL) combined with cisplatin(30 µg/mL) for 24 hours. The inhibitory effects on T24 cells were tested with MTI colorimetric assay. Nuclear Nrf2 and Keapl , cytoplasmic Keapl and two typical phase II enzymes (GSTP1 and NQOl) were checked with Western blotting. RESULTS: The proliferation of T24 cells was significantly inhibited by different concentrations of curcumin combined with cisplatin. After the treatment with different concentrations of curcumin, Nuclear Nrf2 was decreased but Keapl was increased, and GSTP1 and NQO1 were decreased. CONCLUSION: Synergism inhibition of curcumin combined with cisplatin on T24 bladder carcinoma cells is observed in this research. The Keapl-Nrf2 pathway in T24 cells is down-regulated by curcumin. The expression of typical phase I enzymes (GSTP1 and NQO1) mediated by Nrf2 are decreased by curcumin. The sensitivity of tumor cells to chemotherapeutic drugs is then enhanced. These may be the mechanism of synergism effect of curcumin combined with cisplatin.