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Quercetin (Qe) plays an important role in inflammation, antibacterial, anticancer, and aging. However, Qe has extremely low water solubility, which is a major challenge in drug absorption. In this study, we described a simple method for synthesis of Qe/CdSe/ZnS nanoparticles (QCZ NPs). The QCZ NPs had an average diameter of 10nm and prominent yellow emission under UV irradiation. We investigated the antibacterial activity of QCZ NPs against drug-resistant Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) in vitro. Results showed that QCZ NPs had considerably more effective antibacterial activities than Qe or CdSe nanoparticles (CdSe NPs). Antibacterial experiment results showed that QCZ NPs acted against E. coli and B. subtilis by disrupting the bacterial cell wall and membrane. In vivo study, the QCZ NPs could cure inflammation and lesion which caused by E. coli. In anticancer assays, the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] cell proliferation assays exhibited the cytotoxicity of QCZ NPs increased approximately 2-6 fold compared to raw Qe and CdSe NPs. Moreover, by using RT-CES (real-time cell electronic sensing) studies, we had demonstrated QCZ NPs have also an effect on migration and proliferation of BGC-823 cells. CdSe NPs loaded with Qe, these QCZ NPs exhibited excellent antibacterial (E. coli and B. subtilis) and anticancer (BGC-823) activities., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Although cadmium (Cd) is a widespread environmental contaminant and human carcinogen, our studies indicate an organic Cd complex to be a potent inhibitor of proteasomal chymotrypsin-like (CT-like) activity, further capable of inducing apoptosis in a cancer cell-specific manner. It has been reported that the ligands indole-3-butyric acid (L1) and indole-3-propionic acid (L2) have cancer-fighting effects when tested in a rat carcinoma model. In addition, 3, 5-diaminobenzoic acid o-vanillin Schiff bases (L3) have high antimicrobial activity and a large number of Schiff base complexes have been reported to have proteasome-inhibitory activity. We therefore hypothesized that synthetic forms of Cd in combination with L1, L2 and L3 may have proteasome-inhibitory and apoptosis-inducing activities, which would be cancer cell-specific. To test this hypothesis, we have synthesized three novel Cd-containing complexes: [Cd2(C12H12O2N)4(H2O)2]·2H2O (Cd1), [Cd2(C11H10O2N)4(H2O)2]·2H2O (Cd2) and [Cd(C7H4N2O2)(C8H6O2)2]·2H2O (Cd3), by using these three ligands. We sought out to characterize and assess the proteasome-inhibitory and anti-proliferative properties of these three Cd complexes in human breast cancer cells. Cd1, Cd2 and Cd3 were found to effectively inhibit the chymotrypsin-like activity of purified 20S proteasome with IC50 values of 2.6, 3.0 and 3.3 μΜ, respectively. Moreover, inhibition of cancer cell proliferation also correlated with this effect. As a result of proteasomal shutdown, the accumulation of ubiquitinated proteins and the proteasome target IκB-α protein as well as induction of apoptosis were observed. To account for the cancer specificity of this effect, immortalized, non-tumorigenic breast MCF10A cells were used under the same experimental conditions. Our results indicate that MCF10A cells are much less sensitive to the Cd1, Cd2 and Cd3 complexes when compared to MDA MB 231 breast cancer cells. Therefore, our study suggests that these Cd organic complexes are capable of inhibiting tumor cellular proteasome activity and consequently induce cancer cell-specific apoptotic death., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Three new Cd(II) complexes with the Schiff base ligand derived from the condensation 1+2 of 2,6-diacetylpyridine and 5,6-diamino-1,3-dimethyluracil have been "in template" synthesized. The molecular structures of complexes were determined by single-crystal X-ray diffraction. The metal center shows a very distorted mer-bis-tridentate CdN(6) octahedral geometry as consequence of the reduced bite angles of the ligand and the existence of long-distanced interactions with donor atoms in the neighbourhood. The luminescent properties of complexes in CH(3)CN solution were investigated showing the emission energies depend on the uracil part of the ligand. The evaluation of their biological properties against C6 glioma cell line indicates that cadmium(II) complexes could be an interesting tools to treat drug-resistant brain tumors.