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In this work, chitosan/caffeic acid mixtures in the weight ratios of 80/20 and 50/50 were used to obtain thin films enriched with poly(ethylene glycol). It was hypothesized that the presence of caffeic acid indicates the antibacterial properties of the materials (i) and that poly(ethylene glycol) acts as a films modifier (ii). The results showed that by poly(ethylene glycol) addition, the surface free energy as well as mechanical and thermal properties were improved. Moreover, water vapor permeability was observed. All the tested materials showed antioxidant properties in the range of approximately 90%. They also showed antibacterial effectiveness against both Gram-positive and Gram-negative bacteria. The most appropriate material for the application as packaging was composed of chitosan and caffeic acid mixed in a 50/50 weight ratio with 20% PEG addition.

In this work, two-component dialdehyde chitosan/hyaluronic acid scaffolds were developed and characterized. Dialdehyde chitosan was obtained by one-step synthesis with chitosan and sodium periodate. Three-dimensional scaffolds were prepared by the lyophilization method. Fourier transform infrared spectroscopy (FTIR) was used to observe the chemical structure of scaffolds and scanning electron microscopy (SEM) imaging was done to assess the microstructure of resultant materials. Thermal analysis, mechanical properties measurements, density, porosity and water content measurements were used to characterize physicochemical properties of dialdehyde chitosan/hyaluronic acid 3D materials. Additionally, human epidermal keratinocytes (NHEK), dermal fibroblasts (NHDF) and human melanoma cells (A375 and G-361) were used to evaluate cell viability in the presence of subjected scaffolds. It was found that scaffolds were characterized by a porous structure with interconnected pores. The scaffold composition has an influence on physicochemical properties, such as mechanical strength, thermal resistance, porosity and water content. There were no significant differences between cell viability proliferation of all scaffolds, and this observation was visible for all subjected cell lines.

A novel assay for the simultaneous determination of ibuprofen (IBU) and its four probable metabolites, 1-hydroxyibuprofen (1-OH IBU), 2-hydroxyibuprofen (2-OH IBU), 3-hydroxyibuprofen (3-OH IBU) and carboxyibuprofen (CBX IBU) in equine urine samples with the application of Gas Chromatography-Electron Ionization-Mass Spectrometry (GC-EI-MS) has been developed and elaborated. The new approach for sample preparation including minimizing matrix effects by the application of weak cation exchange solid-phase extraction together with strong cation exchange solid-phase extraction has been applied. The GC-EI-MS method was validated to demonstrate specificity, matrix effect, linearity, limit of detection (LOD) and quantification (LOQ), precision, trueness, carry-over and stability by using the matrix-matched quality control samples. Additionally, extraction yield was evaluated. The assay achieved the LOQ of 1.75 μg mL-1, 0.62 μg mL-1, 4.15 μg mL-1, 0.58 μg mL-1 and 4.04 μg mL-1 for IBU, 1-OH IBU, 2-OH IBU, 3-OH IBU and CBX IBU, respectively. The developed method has been successfully applied to the excretion study in horses, in which a single oral IBU dose was administered to twelve horses (mares and geldings) and equine urine samples were collected for 5 or 6 days after the drug administration. Data on the detection and determination of three IBU metabolites, 2-OH IBU, 3-OH IBU and CBX IBU in equine urine samples has been presented for the first time. The obtained results indicated the rapid excretion of IBU and its metabolites that were detectable only in the first day after the drug administration. IBU was mainly the most abundant compound detected in equine urine samples (with two exceptions in the case of samples collected from two horses, for which the highest instrumental responses were obtained for CBX IBU). The received results have indicated that two major IBU metabolites, CBX IBU and 2-OH IBU can be important markers for the IBU abuse in view of doping control in equestrian sports.

In this study, sodium alginate-based thin films were modified by the addition of tannic acid. Materials were obtained by solvent evaporation. They were characterized by the observation of its morphology and its surface by scanning electron microscope and atomic force microscope. The thermal properties were studied by differential scanning calorimetry. The concentration of tannic acid released from the material was determined by the Folin–Ciocalteu method. The material safety for biomedical application was determined by the hemolysis rate study in contact with sheep blood as well as platelet adhesion to the material surface. Based on the obtained results, we assume that proposed films based on sodium alginate/tannic acid are safe and may potentially find application in medicine.

The aversive action of the pharmacological properties of ethanol was studied in selectively bred Warsaw Alcohol High-Preferring (WHP) and Warsaw Alcohol Low-Preferring (WLP) rats. For this study, a conditioned-taste aversion test was used. Male WHP and WLP rats were submitted to daily 20-min sessions for 5 days, in which a saccharin solution (1.0 g/L) was available (pre-conditioning phase). Next, this drinking was paired with the injection of ethanol (0, 0.5, 1.0 g/kg), intraperitoneally [i.p.] immediately after removal of the saccharin bottle (conditioning phase). Afterward, the choice between the saccharin solution and water was extended for 18 subsequent days for 20-min daily sessions (post-conditioning phase). Both doses of ethanol did not produce an aversion to saccharin in WLP and WHP rats in the conditioning phase. However, injection of the 1.0 g/kg dose of ethanol produced an aversion in WLP rats that was detected by a decrease in saccharin intake at days 1, 3, 7, and 10 of the post-conditioning phase, with a decrease in saccharin preference for 16 days of the post-conditioning phase. Conditioned taste aversion, measured as a decrease in saccharin intake and saccharin preference, was only visible in WHP rats at day 1 and day 3 of the post-conditioning phase. This difference between WLP and WHP rats was apparent despite similar blood ethanol levels in both rat lines following injection of 0.5 and 1.0 g/kg of ethanol. These results may suggest differing levels of aversion to the post-ingestional effects of ethanol between WLP and WHP rats. These differing levels of aversion may contribute to the selected line difference in ethanol preference in WHP and WLP rats.

Fast, simple in use and highly effective voltammetric enantiosensor dedicated for determination of thalidomide (TD) enantiomers (especially towards the toxic (S)-enantiomer) in blood plasma is still desirable. Here we have proven that newly synthesized chiral naphthalene diimide (NDI) derivatives are excellent electroactive materials for TD enantiosensors. The recognition process relies on the specific interaction between the chiral NDI receptor and the thalidomide enantiomer of the opposite configuration. This unique specific interaction between (S)-thalidomide and (R)-NDI derivative counterparts, evident in the DPV voltammograms, was confirmed by molecular modeling. The demonstrated voltammetric enantiosensors are characterized by the low detection limit at the level of μg·L−1, wide analytical range from 5·10−4 – 10 mg·L−1, high selectivity and long lifetime. The results of the recovery rates showed a very good degree of accuracy towards the determination of (S)-thalidomide in the blood samples, so it can be successfully used in the analysis of clinical samples.

Ethyl glucuronide (EtG) is a direct ethanol metabolite. The presence of EtG in urine can be used as a laboratory test to detect recent alcohol consumption. Several earlier studies in humans and in rats revealed that the same amount of ethanol ingested at different concentrations results in different blood ethanol concen- trations. The effect of different concentrations of ingested ethanol on the resulting EtG levels in urine was tested in WHP rats. The EtG concentration was also measured in rat hair. A significant (p0.05) decrease in the total amount of urine EtG after administration of the higher concentration (50%) ethanol solution as compared to 30% ethanol at the same dose of ethanol (3 g/kg) was observed. Median EtG concentration in rat hair of 1.5 ng/mg (range: 0.7-2.3 ng/mg) was observed. Our results demonstrate that EtG production and excretion in WHP rats is dependent on alcohol concentration administered orally. EtG levels in hair closely reflect the fate of EtG in the rat.

This study has investigated domperidone (DOM) and quinidine (QD) interaction in the Wistar rat experimental model of repeated administration. We used nonconventional administration model consistent with occasional administration method. Difference in administration was related to sequence of domperidone alone or with quinidine dosage. Expected domperidone-quinidine interactions could have its origin both in the ability of quinidine to inhibit P-glycoprotein (P-gp) activity as well as cytochrome P450-mediated metabolism of both compounds. There also were examined kinetics of acetaminophen (PAM) administered (30 mg/kg) with domperidone as an indicator of gastric emptying, showing domperidone prokinetic activity, as well as quinidine anticholinergic activity. Domperidone (30 mg/kg) with PAM and with/without quinidine (25 mg/kg) was administered orally according to the disposition regiment different for six examined rat groups. DOM and PAM concentrations in plasma were assayed by HPLC method. Following changes were observed: domperidone did not modify the duration of the uptake phase of acetaminophen; quinidine prolongs gastric emptying time (as a result of anticholinergic action); quinidine given as the fourth or fifth dose with domperidone promotes growth of its concentration in plasma; analysis of changes in the value of AUC(0-2) at the initial three weeks of experiment suggests intensity of domperidone absorption processes, the following week increase in the value AUC(4-6) suggests inhibition of domperidone hepatic biotransformation and the mechanism of induction of absorption during domperidone administration is different from the absorption - inducing effects of quinidine. Both effects are superimposed and produce large, 2, 3-fold change in domperidone's AUC(0-6).

Background Ethanol and caffeine are the most widely used psychoactive substances in the world, with an observed steady increase in the combined consumption of alcohol and caffeine. Specific signs of ethanol-caffeine interactions have been reported both in humans and in animals. The metabolic effects of these interactions have not been fully elucidated. There are no published reports on the influence of caffeine on ethyl glucuronide (EtG) formation. EtG is a direct metabolite of ethanol and is very often used as a biomarker of alcohol consumption. Here, we investigated the influence of caffeine on the formation of EtG in rat plasma and EtG incorporation into the hair. Methods Studies were conducted on three male Wistar rat groups, each receiving either ethanol at 3 g/kg/day, ethanol (at the same dose) with caffeine at 3 mg/kg/day, or caffeine at 3 mg/kg/day for four weeks. EtG and caffeine levels were evaluated in hair and in blood after the last administration. Results Blood EtG levels after the administration of ethanol together with caffeine were significantly higher than after the administration of ethanol alone. EtG levels in rat hair in the ethanol-and-caffeine group were also higher than in the ethanol-only group, but the difference was not statistically significant. Conclusion This study shows the possible effect of ethanol and caffeine co-administration on EtG formation. Caffeine stimulates EtG synthesis resulting in increased blood and, possibly, hair levels of this metabolite. However, the role of these changes in estimating alcohol consumption requires further studies.

Worldwide, drug-induced liver injury (DILI) is a major cause of hepatic failure. It is also the leading cause of withdrawal, cautionary labeling, and restricted usage of licensed drugs; therefore, European Medicines Agency (EMA) and United States Food and Drug Administration (FDA) warn that the existing methods of assessing DILI are insufficient and that some of the translational biomarkers of hepatotoxicity must be relooked. Magnetic resonance imaging (MRI) seems to be a proper tool in elucidating the effects of DILI in both preclinical and clinical studies, providing excellent visualization of the morphology of the liver parenchyma. Therefore, herein, we propose preclinical MRI assessment of liver injury in experimental paracetamol-treated rats. Quantitative MRI clearly provides evidence of adverse effects in the liver tissue caused by a single overdose of paracetamol (1 g kg−1 and 1.5 g kg−1 b.w.). The results of the MRI were confirmed by the histopathological examination (HE it has a potential to serve as the early diagnostic tool for the prediction of DILI in preclinical evaluation.

Background This study investigated the relationship between ethanol intake in rats and the resulting level of ethyl glucuronide (EtG) in rat hair. Methods Rats (n = 50) consumed a 10% ethanol solution for 4 weeks, then EtG was extracted from samples of their hair using a novel extraction procedure involving freezing and thawing. The EtG concentration was measured using gas chromatography and mass spectrometry. The animals voluntarily drank ethanol, with daily consumption in most rats exceeding 5 g/kg b.w. The silylated EtG was stable for at least 28 h. The limit of detection was 0.03 ng/mg, and the limit of quantification was 0.1 ng/mg. Results Hair samples from rats that consumed ethanol had EtG levels ranging from 0.17–20.72 ng/mg in female rats and 0.15–13.72 ng/mg in males. There was a correlation between the amount of alcohol consumed and the EtG levels in hair from female (p Conclusion The method presented allows detection and quantification of EtG in rat hair. We also observed differences in EtG deposition in male and female rats.