In vitro characteristics of 1-phenyl-3-methyl-4-acylpyrazol-5-ones iron chelators

(±)-Catechin-A Mass-Spectrometry-Based Exploration Coordination Complex Formation with FeII and FeIII

Catechin is an extensively investigated plant flavan-3-ol with a beneficial impact on human health that is often associated with antioxidant activities and iron coordination complex formation. The aim of this study was to explore these properties with FeII and FeIII using a combination of nanoelectrospray-mass spectrometry, differential pulse voltammetry, site-specific deoxyribose degradation assay, FeII autoxidation assay, and brine shrimp mortality assay. Catechin primarily favored coordination complex formation with Fe ions of the stoichiometry catechin:Fe in the ratio of 1:1 or 2:1. In the detected Fe-catechin coordination complexes, FeII prevailed. Differential pulse voltammetry, the site-specific deoxyribose degradation, and FeII autoxidation assays proved that coordination complex formation affected catechin's antioxidant effects. In situ formed Fe-catechin coordination complexes showed no toxic activities in the brine shrimp mortality assay. In summary, catechin has properties for the possible treatment of pathological processes associated with ageing and degeneration, such as Alzheimer's and Parkinson's diseases.

Oxidoperoxidomolybdenum(vi) complexes with acylpyrazolonate ligands: synthesis, structure and catalytic properties

Oxidoperoxido–molybdenum(vi) complexes Ph₄P[Mo(O)(O₂)₂(Q^R)] and [Mo(O)(O₂)(Q^R)₂] (Q^R = acylpyrazolonate ligands) were synthesised and tested as catalysts in epoxidation, sulphoxidation and epoxide deoxygenation.

Synthesis, characterization and anticancer activity of kaempferol-zinc(II) complex

According to the previous studies, the anticancer activity of flavonoids could be enhanced when they are coordinated with transition metal ions. In this work, kaempferol-zinc(II) complex (kaempferol-Zn) was synthesized and its chemical properties were characterized by UV-VIS, FT-IR, (1)H NMR, elemental analysis, electrospray mass spectrometry (ES-MS) and fluorescence spectroscopy, which showed that the synthesized complex was coordinated with a Zn(II) ion via the 3-OH and 4-oxo groups. The anticancer effects of kaempferol-Zn and free kaempferol on human oesophageal cancer cell line (EC9706) were compared. MTT results demonstrated that the killing effect of kaempferol-Zn was two times higher than that of free kaempferol. Atomic force microscopy (AFM) showed the morphological and ultrastructural changes of cellular membrane induced by kaempferol-Zn at subcellular or nanometer level. Moreover, flow cytometric analysis indicated that kaempferol-Zn could induce apoptosis in EC9706 cells by regulating intracellular calcium ions. Collectively, all the data showed that kaempferol-Zn might be served as a kind of potential anticancer agent.

Antiproliferative activity and therapeutic implications of potassium tris(4-methyl-1-pyrazolyl) borohydride in hepatocellular carcinoma

The study of iron chelators as cancer chemotherapeutic agents is still in its infancy. Accordingly, there is a need to optimize new chelating molecules for iron chelation therapy and cancer treatment. Previous studies have demonstrated that the ligand tris(1-pyrazolyl) borohydride and its derivates were able to chelate ferrous iron, but very little research focused on their biological properties and applications in cancer treatment. So, in this study, several boron-pyrazole derivatives were chosen for the examination of their effects on the proliferation of human hepatocellular carcinoma (HCC) cell lines. The results suggested that potassium tris(4-methyl-1-pyrazolyl) borohydride (KTp(4-Me)) exhibited the most potent anti-tumor activities among the candidates. Hence, the antiproliferative activity and the iron chelating capacity of the iron chelator KTp(4-Me) in HCC cell lines HepG2 and Hep3B were characterized. KTp(4-Me) could disrupt cell iron uptake and affect signaling pathways of iron regulation in HCC cell lines and induced the expression of TfR1 and HIF-1α in a concentration-dependent manner, which was a typical cell response to iron deficiency. Moreover, KTp(4-Me) arrested cell cycle in S phase and induced cell apoptosis in both Hep3B and HepG2 cells. Overall, our results provide a promising starting point and the possibility of the future development and applications of KTp(4-Me) in HCC therapy.

Dexrazoxane provided moderate protection in a catecholamine model of severe cardiotoxicity

Positive effects of dexrazoxane (DEX) in anthracycline cardiotoxicity have been mostly assumed to be associated with its iron-chelating properties. However, this explanation has been recently questioned. Iron plays also an important role in the catecholamine cardiotoxicity. Hence in this study, the influence of DEX on a catecholamine model of acute myocardial infarction (100 mg/kg of isoprenaline by subcutaneous injection) was assessed: (i) the effects of an intravenous dose of 20.4 mg/kg were analyzed after 24 h, (ii) the effects were monitored continuously during the first two hours after drug(s) administration to examine the mechanism(s) of cardioprotection. Additional in vitro experiments on iron chelation/reduction and influence on the Fenton chemistry were performed both with isoprenaline/DEX separately and in their combination. DEX partly decreased the mortality, reduced myocardial calcium overload, histological impairment, and peripheral haemodynamic disturbances 24 h after isoprenaline administration. Continuous 2 h experiments showed that DEX did not influence isoprenaline induced atrioventricular blocks and had little effect on the measured haemodynamic parameters. Its protective effects are probably mediated by inhibition of late myocardial impairment and ventricular fibrillation likely due to inhibition of myocardial calcium overload. Complementary in vitro experiments suggested that iron chelation properties of DEX apparently did not play the major role.