[Effects of polyphenols on activity of glycosyl hydrolases in the cecum of rats fed obesity inducing diets]

Abstract

The results of experimental studies indicate that the preventive and therapeutic effects of polyphenols in obesity are accompanied by a significant decrease in the severity of dysbiosis caused by the predominance of fats and simple carbohydrates in the diet, especially fructose, and the restoration of the functional state of the microbiota. The aim of the work was to study the effect of quercetin and resveratrol - polyphenols, widely represented in the daily human diet, on the activity of bacterial glycosidases in rats receiving diets high in fructose or fat and fructose. Material and methods. Using spectrophotometric analysis, the activity of β-galactosidase (Gal), β-glucosidase (Glu) and β-glucuronidase (Gluс) was studied in the content of the cecum of Wistar rats receiving a semi-synthetic diet and a 20% solution of fructose instead of drinking water (hfr diet) or a semi-synthetic diet with a high (30%) fat content and a 20% solution of fructose instead of drinking water (hf/hfr diet). Results and discussion. Feeding rats with the hfr diet for 20 weeks led to the suppression of Gal activity by 35, Glu by 46 and Gluс by 31%. With the inclusion of quercetin in the hfr diet at a dose of 34 mg/kg b.w. enzyme activity was restored to the control values and exceeded the level of activity in rats fed hfr ration without quercetin by 60, 100 and 47%, respectively, for Gal, Glu, and Gluс. Feeding rats with the hf/hfr diet for 10 weeks did not have a significant impact on the activity of bacterial enzymes. The inclusion of resveratrol in the hf/hfr diet at a dose of 10 mg/kg b.w. resulted in a decrease in Glu activity by 58 and Gluс by 28%, and an increase in resveratrol dose to 100 mg/kg b.w. caused further suppression of Gal activity by 30, Glu by 76 and Gluc by 64% comparative to the activity in rats on the hf/hfr diet without resveratrol. Conclusion. The obtained data suggest that quercetin restores reduced by hfr diet activity of glycosyl hydrolases of the cecum microflora of rats, most likely due to an increase in the representation of the types of enzyme activity carriers. The suppressive effect of resveratrol on the activity of glycosyl hydrolases of the cecum microflora of rats fed a hf/hfr diet may be the result of its direct action on enzymes and is not associated with the effect on the composition of the intestinal microbiota.

Keywords: bacterial glycosyl hydrolases; high-fat high-fructose diet; high-fructose diet; intestinal microbiota; quercetin; resveratrol.