[Anti-atherosclerotic efficacy of quercetin and sodium phenylbutyrate in rabbits].

The aim of the study was to evaluate the antiatherosclerotic efficacy of a natural bioflavonoid--quercetin and sodium phenylbutyrate (tributyrate) in rabbits. Fifty male mixed-breed rabbits were randomly assigned to 5 equal groups: I--control; II--fat-rich diet (FRD); III--FRD and sodium phenylbutyrate; IV--FRD and quercetin; V--FRD, quercetin and sodium phenylbutyrate. The whole study lasted 12 weeks and the following tests were performed: 1) biochemical analysis of cholesterol--total cholesterol (TCh), low density lipoprotein cholesterol (LDL-Ch), and high density lipoprotein cholesterol (HDL-Ch)) and triglycerides (TG); 2) pathomorphologic (microscopic and macroscopic) evaluation of aorta and coronary arteries. A significant reduction in total cholesterol and LDL-cholesterol was observed in animals given sodium phenylbutyrate. The hypolipemic effect of quercetin was limited, with a significant decrease in LDL-Ch and increase in HDL-Ch. Quercetin and sodium phenylbutyrate administered together were least effective, insignificantly lowering TCh, LDL-Ch, and TG and increasing HDL-Ch (Tab. 1). Macroscopic and microscopic evaluation of aorta revealed that the area covered by atherosclerotic plaques was smallest and the atherosclerotic changes thinnest in animals on FRD and quercetin (Tab. 2, Fig. 1-2). There was no significant reduction in aortic plaque area in the groups III and V in comparison with group II. Coronary arteries displayed more advanced atherosclerotic changes than aorta and were more resistant to the administered substances (Fig. 3-4). The following conclusions were drawn: 1) Sodium phenylbutyrate and quercetin have an antiatherosclerotic activity in rabbits. 2) Combination of hypolipemic drugs does not always give the expected prophylactic and therapeutic effect. 3) Severity of atherosclerotic changes and the effect of quercetin or phenylbutyrate were not identical in the aorta and coronary arteries. 4) Antiatherosclerotic properties of sodium phenylbutyrate and quercetin are worth further clinical investigations.