Efficiency of polyphenol-rich grape products for the prevention of metabolic disorders in the experiment

Abstract

The article presents the results of study of the effect of polyphenol-rich materials obtained from grapes on the clinical symptoms, activity of non-specific proteases, and parameters of lipid peroxidation (LPO) of blood of rats with fructose model of metabolic syndrome (MS). White male rats (n=54, with initial body weight of 190-210 g) were randomly divided into five groups: control and 4 experimental groups. Body weight, circumference of the abdomen, blood serum level of glucose, total cholesterol, triglycerides and high density (HDL) lipoproteins were monitored in all animals in dynamics. Also non-specific proteases and their inhibitors were evaluated in rat blood by enzymatic methods, lipid peroxidation profile (malondialdehyde and caeruloplasmin blood serum level, superoxide dismutase blood activity) - by spectrophotometric methods. Modeling of the MS (10% fructose in drinking water) within 8 weeks resulted in statistically significant increase in body mass, abdominal adipose tissue, the activity of elastase-like (ELA) and trypsin-like (TLA) proteinases (20 and 18% respectively), the level of secondary products of LPO (50%), and decrease in activity of superoxide dismutase (15%) compared with the parameters of intact animals. The use of polyphenol-rich materials obtained from grapes with a total content of 1; 1,1 and 4 mg of phenolic compounds (in 0.05 ml) at MS for 4 weeks contributed regression the key clinical signs of MS: significant decrease of glucose and triglyceride levels against the background of increasing the HDL cholesterol were observed. The polyphenol-rich materials obtained from grapes influenced positively on the proteolytic profile (decreased TLA and ELA by 20% at the maximum dosage), contributed to the increase of the level of acid-stable protease inhibitors (by 21%), and reduced the amount of secondary products of LPO (by 34%). The dose-dependent effect of the amount of polyphenol components contained in food concentrates has been revealed.