Anti-toxoplasma activity and DNA-binding of copper(II) and zinc(II) coordination compounds with 5-nitroimidazole-based ligands

Tetrahedral copper(II) and zinc(II) coordination compounds from 5-nitroimidazole derivatives, viz. 1-(2-chloroethyl)-2-methyl-5-nitroimidazole (cenz) and ornidazole 1-(3-chloro-2-hydroxypropyl)-2-methyl-5-nitroimidazole (onz), were synthesized and spectroscopically characterized. Their molecular structures were determined by X-ray diffraction studies. The complexes [Cu(onz)2X2], [Zn(onz)2X2], [Cu(cenz)2X2] and [Zn(cenz)2X2] (X- = Cl, Br), are stable in solution and exhibit positive LogD7.4 values that are in the range for molecules capable of crossing the cell membrane via passive difussion. Their biological activity against Toxoplasma gondi was investigated, and IC50 and lethal dose (LD50) values were determined. The ornidazole copper(II) compounds showed very good antiparasitic activity in its tachyzoite morphology. The interaction of the coordination compounds with DNA was examined by circular dichroism, fluorescence (using intercalating ethidium bromide and minor groove binding Hoechst 33258) and UV-Vis spectroscopy. The copper(II) compounds interact with the minor groove of the biomolecule, whereas weaker electrostatic interactions take place with the zinc(II) compounds. The spectroscopic data achieved for the two series of complexes (namely with copper(II) and zinc(II) as metal center) agree with the respective DNA-damage features observed by gel electrophoresis.

Vitamin E (α-Tocopherol) Does Not Ameliorate the Toxic Effect of Bisphenol S on the Metabolic Analytes and Pancreas Histoarchitecture of Diabetic Rats

This study investigated whether the coadministration of vitamin E (VitE) diminishes the harmful effects provoked by plasticizer bisphenol S (BPS) in the serum metabolites related to hepatic and renal metabolism, as well as the endocrine pancreatic function in diabetic male Wistar rats. Rats were divided into five groups (n = 5-6); the first group was healthy rats (Ctrl group). The other four groups were diabetic rats induced with 45 mg/kg bw of streptozotocin: Ctrl-D (diabetic control); VitE-D (100 mg/kg bw/d of VitE); BPS-D (100 mg/kg bw/d of BPS); The animals from the VitE + BPS-D group were administered 100 mg/kg bw/d of VitE + 100 mg/kg bw/d of BPS. All compounds were administered orally for 30 days. Body weight, biochemical assays, urinalysis, glucose tolerance test, pancreas histopathology, proximate chemical analysis in feces, and the activity of antioxidants in rat serum were assessed. The coadministration of VitE + BPS produced weight losses, increases in 14 serum analytes, and degeneration in the pancreas. Therefore, the VitE + BPS coadministration did not have a protective effect versus the harmful impact of BPS or the diabetic metabolic state; on the contrary, it partially aggravated the damage produced by the BPS. VitE is likely to have an additive effect on the toxicity of BPS.

Toxicity Evaluation of a Novel Rapamycin Liposomal Formulation After Subconjunctival and Intravitreal Injection

Purpose: Safety and toxicity evaluation of a novel, liposome-encapsulated rapamycin formulation, intended for autoimmune ocular disorders. Methods: The formulation was assessed by micronucleus polychromatic erythrocyte production, irritability by Hen's Egg Test-Chorioallantoic Membrane (HET CAM), sterility, and pyrogenicity testing. Subconjunctival (SCJ) and intravitreal (IVT) administration of the formulation were performed to evaluate subacute and acute toxicity, respectively. Differences between groups in biochemical and hematological parameters were evaluated by analysis of variance and t-tests. Numeric score was assigned to histopathological classification. Electroretinography (ERG) testing was also performed. Data were analyzed by a 1 way no parametric Kruskal-Wallis and the Mann-Whitney tests. Significance was considered when P < 0.05. Results: No significant toxicity directly related to the preparation was detected. Micronucleus count, mucous irritation score, and pyrogenicity results were negative. Pathology demonstrated no damage related to the formulation after SCJ injection. After IVT injection, only lens injury associated with technique was observed. Retinal function was also conserved in ERG. Conclusions: The preparation evaluated offers a good toxicity and safety profile when injected in a SCJ or IVT manner in an animal model. A clinical trial conducted in humans is highly warranted, as it could reveal an alternative immunosuppressive treatment for ophthalmological immune-mediated pathologies.

Exposure to bisphenol A: current levels from food intake are toxic to human cells

In the present work, cell lines of different origin were exposed to BPA levels from food intake reported elsewhere. Specifically, we used an in vitro assay to determine cytotoxicity of BPA in three cell lines: MCF7 (breast cancer), PC3 (prostate cancer) and 3T3-L1 (mouse fibroblast). Cytotoxic effects were observed at concentrations higher than 50 μg/mL which is above the involuntary exposure level of BPA described before in fresh, canned and frozen foods and beverages. Furthermore, medial inhibitory concentrations (IC50) of 85.17 μg/mL and 88.48 μg/mL were observed for PC3 and 3T3-L1, respectively, and a slightly lower IC50 of 64.67 μg/mL for MCF7. These results highlight BPA's toxicity potential at current levels from food intake. The cell line-dependent divergent response to BPA reported herein is discussed.