Investigação de vias de estresse oxidativo em ratos wistar hipercolesterolêmicos suplementados com extrato dos frutos de Vaccinium ashei R.

Abstract

The hypercholesterolemy is characterized by the total circulating cholesterol increase. A diet rich in cholesterol increase the levels of lipoprotein of low density (LDL), that acts as a proatherogenic, triggering inflammatory process that leads to the formation of the atherosclerotic plaque. The dietetic effects of the plants on the lipid profile, have been documented and show to be useful in the plasmatic cholesterol levels reduction, preventing the atherosclerosis. The blueberry fruit is an important source of food rich in polyphenols, anthocyanins, flavonoids, and it has antioxidant action, giving to it the title of functional food. The objective of this study was to investigate ways of oxidative stress in hypercholesterolemic Wistar rats, supplemented with lyophilized extract from the Vaccinium ashei R fruits. The hypercholesterolemic rats were divided into six groups (n=6): group 1: control (saline); group 2: simvastatin (10mg/Kg) as positive control; group 3: blueberry extract (25mg/Kg); group 4: blueberry extract (50mg/Kg); group 5: blueberry extract (25mg/Kg) and simvastatin and the group 6: blueberry extract (50mg/Kg) and simvastatin. After 14 consecutive days of administration, the animals were euthanized and the total blood and arteries were removed to be analyzed later. The group that received the blueberry extract shown statistically significant reduction of the lipid profile (total cholesterol, LDL-cholesterol and triglycerides) and an increase of the HDL-cholesterol. The presence of polyphenols in the blueberry extract contributed to hypolipidemic effect what is more evident when the extract is associated with to the simvastatin. The hypercholesterolemic diet increased the serum levels of creatine kinase and homocysteine, nevertheless, the administration of the extract decrease significantly the levels of these makers when they are compared to the group that did not received the extract. Moreover, the extract at a dose of 50mg/kg associated with simvastatin showed protection against the aorta thickening, it reduced the lipid peroxidation and oxidative damage to DNA, induced by hypercholesterolemia.The contents of vitamin C and serum polyphenols increased after 14 days of the extracts administration, as the activity of the oxidant enzymes, superoxide dismutase, catalase and glutathione peroxidase. In this manner, the results point that the lyophilized extract of Vaccinium ahei R. shows an antiatherogenic effect, besides the antioxidant and hypocholesterolemic activities.