[Comparative analysis of the total content of polyphenols in some types of industrial juice products].

Fruits are the most important source of polyphenols, substances that have a positive effect on human health. Modern technologies for the industrial processing of fruits into juice are aimed at preserving the useful components of the raw material in it. The issue of the content of polyphenols in industrial juice products, and, especially, changes in their concentration over time, is important for understanding the nutritional value of juice products and requires further study. The purpose of the work is to study the total content of polyphenols depending on the type of juice products and the time elapsed since the product was manufactured. Material and methods. The total content of polyphenols in terms of gallic acid was determined by the Folin-Ciocalteu method in four popular types of juice products (orange, grapefruit and apple juice, cherry nectar), various brands and with different production dates. The results of the determination in 60 product samples selected from Russian retail chains were analyzed. Results. Polyphenols are found in all types of products in significant amounts: in orange juices from 678 to 870 mg/kg, in grapefruit juices from 447 to 798 mg/kg, in apple juices from 264 to 1320 mg/kg, in cherry nectars from 696 to 1090 mg/kg. The highest average content was found in cherry nectars (859±106 mg/kg), followed by orange (781±54 mg/kg) and grapefruit juices (634±91 mg/kg). In apple juices, there is a significant variation in the content of polyphenols depending on the method of juice production - the highest content of polyphenols was found in straight-pressed apple juices (1119±124 mg/kg). The content of polyphenols in products stored for six months or more does not show any significant differences from the content in fresher products, which suggests a consistently high content of polyphenols in juice products throughout the entire shelf life. Conclusion. The study showed the presence of high concentrations of common polyphenols in juice products. The dependence of total polyphenol content on the time elapsed since the production of juice product was not found. Juice products of industrial production can make a significant contribution to the intake of polyphenols in the human body.

Levetiracetam effect on behavioral and electrophysiological parameters in rat model of global brain ischemia.

Post-stroke paroxysmal activity is a neurophysiological indicator of epileptogenesis and increase of seizure susceptibility, so treatments with neuroprotective activity and anti-paroxysmal activity can be more beneficial during post-ischemic period. The goal of this study was evaluation of levetiracetam (100 mg/kg, 7 days of administration) effect on behavior and brain bioelectric activity changes in the post-ischemic period. Global ischemia model was carried out with bilateral ligation of carotid arteries in rats. Neurological deficit and electrophysiological changes of brain structures (striatum, cortex, hypothalamus, hippocampus) were analyzed during 28 days. Paroxysmal activity was not observed on the 1st day after ischemia and had early (2nd day) and late (28th day) onsets. Spectral analysis showed that rats, that died by the 10th day, had delta wave increase and theta decrease on the 1st day and delta activity reduction on the 2-7th days. LEV did not affect survival rate, however, it contributed to neurological disorder regression towards lighter forms on the 1st day after ischemia. It suppressed paroxysmal activity with an early onset and affected delta and theta waves on the 1st day in all structures except hippocampus. On the 7th and 28th days LEV increased delta activity due to 1-3 Hz frequency. Thus, LEV eliminates early onset post-ischemic paroxysmal activity and contributes to normalization of delta waves activity on the 1st day after ischemia, that positively affects neurological status of animals in post-ischemic period. It allows one to make a conclusion about possible LEV application in the post-ischemic period.