Effect of selenium on the interaction between daunorubicin and cardiac myosin

Effect of Selenium on the Levels of Cytokines and Trace Elements in Toxin-Mediated Oxidative Stress in Male Rats

Selenium is an essential cofactor in the key enzymes involved in cellular antioxidant defense. This study was designed to investigate the protective effects of selenium on mercury chloride (HgCl2)-induced toxicity. Male Wistar rats were randomly divided into four groups of six animals each. The first group was control; the second group was treated with mercuric chloride (HgCl2: 50 mg/kg/bw). The third group was treated with sodium selenite (Se 0.2 mg/kg/bw), and the fourth group received Se (0.2 mg/kg/bw) plus HgCl2 (50 mg/kg for 24 h). The influence of Se on mercury induced levels of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) and zinc, copper, and iron in serum of rats were observed. The serum MDA, SOD, zinc, and iron concentrations were found to be statistically different among the control and toxin-treated group. The serum levels of IL-6, IL-10, and TNF-α were also measured. There was a significant decrease in the levels of TNF-α, IL-6, and IL-10 in toxin-treated group II compared with that of the control group (p < 0.05). A significant increase in the serum levels of inflammatory cytokines IL-6, TNF-α, and IL-10 after administration of Se seemed to counteract some of the damage, as indicated by differences in the serum concentrations of major elements.

Synthesis and characterization of tumor-targeted copolymer nanocarrier modified by transferrin

To increase the encapsulation of hydrophilic antitumor agent daunorubicin (DNR) and multidrug resistance reversal agent tetrandrine (Tet) in the drug delivery system of nano-particles (NPs), a functional copolymer NP composed of poly(lactic-co-glycolic acid) (PLGA), poly-L-lysine (PLL), and polyethylene glycol (PEG) was synthesized and then loaded with DNR and Tet simultaneously to construct DNR/Tet–PLGA–PLL–PEG-NPs using a modified double-emulsion solvent evaporation/diffusion method. And to increase the targeted antitumor effect, DNR/Tet–PLGA–PLL–PEG-NPs were further modified with transferrin (Tf) due to its specific binding to Tf receptors (TfR), which is highly expressed on the surface of tumor cells. In this study, the influence of the diversity of formulation parameters was investigated systematically, such as drug loading, mean particle size, molecular weight, the concentration of PLGA–PLL–PEG–Tf, volume ratio of acetone to dichloromethane, the concentration of polyvinyl alcohol (PVA) in the external aqueous phase, the volume ratio of the internal aqueous phase to the external aqueous phase, and the type of surfactants in the internal aqueous phase. Meanwhile, its possible effect on cell viability was evaluated. Our results showed that the regular spherical DNR/Tet–PLGA–PLL–PEG–Tf-NPs with a smooth surface, a relatively low polydispersity index, and a diameter of 213.0±12.0 nm could be produced. The encapsulation efficiency was 70.23%±1.91% for DNR and 86.5%±0.70% for Tet, the moderate drug loading was 3.63%±0.15% for DNR and 4.27%±0.13% for Tet. Notably, the accumulated release of DNR and Tet could be sustained over 1 week, and the Tf content was 2.18%±0.04%. In cell viability tests, DNR/Tet–PLGA–PLL–PEG–Tf-NPs could inhibit the proliferation of K562/ADR cells in a dose-dependent manner, and the half maximal inhibitory concentration value (total drug) of DNR/Tet–PLGA–PLL–PEG–Tf-NPs was lower than that of DNR, a mixture of DNR and Tet, and DNR/Tet–PLGA–PLL–PEG-NPs. These results clearly indicate that the PLGA–PLL–PEG formulation is a potential drug delivery system for hydrophilic and hydrophobic drugs, and that Tf modification may increase its targeting properties.

Administration of chromium(III) and manganese(II) as a potential protective approach against daunorubicin-induced cardiotoxicity: in vitro and in vivo experimental evidence

Daunorubicin (DNR) is a widely used antitumor drug, but its application is limited because of its cardiotoxic side effects. The present study was designed to investigate the interaction between DNR and cardiac myosin (CM) in the presence of chromium(III) (Cr(3+)) and manganese(II) (Mn(2+)) using fluorescence spectrometry under simulative physiological conditions with the aim of exploring the influence of metal ion on DNR-CM complex and finding out an aggressive approach to abrogate of DNR-induced cardiotoxicity. In detail, the quenching and binding constant of ternary system, including metal ion, DNR, and CM, were measured and compared with the DNR-CM. The data from in vitro experiments indicate that the presence of Cr(3+) or Mn(2+) distinctly decreased the binding force between DNR and CM, and alleviated the cardiac toxicity caused by DNR. In addition, the variations in mice body weight and myocardial enzyme level were examined by in vivo experiments. Animals receiving Cr(3+) or Mn(2+) supplementation of DNR showed preservation of the normal pattern of the heart, especially 2.0 mg Cr(3+)/kg body wt or 50.0 mg Mn(2+)/kg body wt exhibited an obviously protective effect accompanied with body weight raise when compared with the mice treated with DNR alone, decreased the ratio of heart to body weight (BW) and the ratio of left ventricular mass to BW to the normal levels, and inhibited the leak of myocardial enzyme caused by DNR. As a result, this study suggests that pretreatment of lower dose of Cr(3+) (2 mg/kg wt) and moderate dose of Mn(2+) (50 mg/kg wt) might be useful and play an important role in ameliorating the cardiotoxicity of DNR treatment in cancer patients.