Obesity, a major health problem worldwide, is associated with increased cardiovascular risk factors, such as dyslipidemia, glucose intolerance, and hypertension. We investigated the antioxidative capacity of the ethanol extract of propolis (EEP) and its effect on the lipid profile, the hepatorenal function, and the atherogenic indices in mice fed with a high-fat diet (HFD). EEP (50 mg/kg) was given orally to mice for 30 days. After the treatments, levels of the serum total triglyceride and cholesterol, the high density lipoprotein (HDL-c) and low density lipoprotein (LDL-c) cholesterols, the serum enzymes, and the metabolites were measured, and atherogenic indices [atherogenic index of plasma (AIP); cardiac risk ratio (CRR); cardioprotective index (CPI); atherogenic coefficient (AC)] were calculated and compared with the antioxidant, the reducing power, the radical-scavenging, and the chelating activity of EEP. The HFD diet with EEP significantly reduced the negative lipid profile and lowered AIP, CRR, and AC and increased CPI in animals on a HFD. In addition, EEP reduced the weight of mice and lipid accumulation in the liver, and it had significant in vitro antioxidative activities. The EEP possesses anti-hyperlipidemic and antioxidant activity and exhibits protective action on the cardiovascular system and hepatorenal functions. Our results contribute towards the validation of the traditional use of propolis as a food supplement in aiding hyperlipidemic disorders.

Studies of polyphenols in various natural products have shown their variability and often low amounts. Thus, we aimed to investigate the bioaccessibility of the main polyphenolic groups extracted from two poplar types of propolis collected in continental Croatia. The propolis complex, in the form of water-soluble powder of propolis extract with the carrier 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), was obtained by applying ultrasonic-assisted extraction followed by lyophilization. The in vitro gastrointestinal digestion was conducted on the propolis complex extracts and a mixture of standards (pinocembrin, galangin, chrysin, caffeic acid, and caffeic acid phenylethyl ester). Fractions from the oral, gastric, and intestinal phase samples were analyzed spectrophotometrically by standard methods used to determine the content of total phenols (TPs), flavonols/flavones (TFFs), and flavanones/dihydroflavonols (TFDs). The small-intestinal phase was performed by two models: centrifugation and dialysis. The results of propolis-HP-β-CD extracts demonstrated high polyphenolic bioaccessibility during all three phases of digestion. The bioaccessibility of TPs, TFFs, and TFDs after the intestinal phase with centrifugation was from 0.02 to 8.86 times higher than in the dialysis phase, stressing that it is a better model than dialysis. Our findings show that the inclusion complex of propolis with HP-β-CD enables the good solubility of polyphenol groups.

The aim of the study was to compare the accumulation of β-adrenergic agonist residues clenbuterol (CLB) and salbutamol (SAL) in internal tissues, non-pigmented eyes and hair of laboratory animals repeatedly administered with CLB and SAL during 7 days. Experimental albino guinea pigs (n = 20) were treated with CLB (n = 10) and SAL (n = 10) in anabolic doses of 0.25 and 2.5 mg/kg, whereas the control animal group (n = 10) was left untreated. Methodology validation showed that the ELISA assay to be suitable for β-agonists' semiquantitative determination. The results revealed a significantly higher (P < 0.05) accumulation potential of CLB in comparison with SAL in all investigated tissues. Despite of their lack of pigmentation and the applied dose, the highest residual CLB concentrations were determined in the eyes of the studied animals, followed by their hair, liver, lungs, kidney, heart and adipose and muscle tissue, whereas residual SAL concentrations found in the eyes and hair of the administered animals did not significantly differ (P > 0.05) from those obtained in their internal tissues.

The purpose of this investigation was to prepare a water-soluble complex by encapsulation of propolis extract with the carrier 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) and to examine the influence of in vitro simulated gastrointestinal digestion (GID) on the content of the main polyphenolic groups when administered as aqueous suspension. The research was conducted on two continental samples of propolis from Croatia and a mixture of selected polyphenol standards. By applying UAE followed by a lyophilization procedure, it was possible to obtain a powder with a high content of polyphenols. The content of total phenols (TPs), total flavonols/flavones (TFFs) and total flavanones/dihydroflavonols (TFDs) in the fractions of oral and gastric phase and small intestinal phase performed with two models: centrifugation and dialysis through a semi-permeable membrane, was determined by three UV/Vis spectrophotometric methods: Folin-Ciocalteu, aluminium complexation and 2,4-dinitrophenylhydrazine method. The obtained results for both propolis complexes showed stability in the polyphenol content and high bioaccessibility during all three phases of digestion. The bioaccessibility of TPs, TFFs and TFDs under in vitro conditions after dialysis through a semipermeable membrane was lower compared to the intestinal phase model with centrifugation.

Florfenicol (FF) is a broad-spectrum antibiotic used to treat gastrointestinal and respiratory infections in domestic animals. Considering FF’s rapid elimination via urine after drug treatment, its use increases concerns about environmental contamination. The objective of the study was to establish a sustainable chromatographic method for simple analysis of FF in pig urine to investigate the urinary excretion of FF after a single intramuscular administration of 20 mg FF/kg body weight. The urine sample was prepared using a centrifuge and regenerated cellulose filter, and the diluted sample was analyzed. The method was validated in terms of linearity, the limit of detection (0.005 µg/mL) and quantitation (0.016 µg/mL), repeatability and matrix effect (%RSD ranged up to 2.5), accuracy (varied between 98% and 102%), and stability. The concentration-time profile of pig urine samples collected within 48 h post-drug administration showed that 63% of FF’s dose was excreted. The developed method and previously published methods used to qualify FF in the urine of animal origin were evaluated by the National Environmental Method Index (NEMI), Green Analytical Procedure Index (GAPI) and Analytical GREENness Metric Approach (AGREE). The greenness profiles of published methods revealed problems with high solvents and energy consumption, while the established method was shown to be more environmentally friendly.