Effects of Hypolip (Simvastatin) on Lipid Profile and Renal Functions in an induced hypercholesterolemic rats

Abstract

The present study was carried out to investigate the biochemical effects of hypolip (simvastatin) on serum total cholesterol and low density lipoproteincholesterol (LDL-c) and to assess its effects on renal profile, hematological and histopathological parameters.Twenty- five Wister albino rats were divided into five groups. Group A was fed basal diet only (control group) and the other four groups (B, C, D and E) were fed 1% cholesterol diet for two weeks to induce hypercholesterolemia.After two weeks, groups C, D and E (treated groups) were orally administrated hypolip at a dose rate of 10, 40 and 80 mg/kg Bwt respectively,for four weeks. Blood samples were obtained from the orbital plexus veinand collected in heparinized tubes every two weeks to investigate serum lipid profile, serum constituents and hematological parameters. Specimens from kidney, aorta, brain and intestine were immediately removed after the ratswere slaughtered, and fixed in 10% neutral formalin, for histopathological investigations. There was a significant (P<0.05)increase in the serum totalcholesterol and LDL-c concentrations in groups B, C, D and E compared with group A after two weeks. Also, there was a significant increase in body weights in induced hypercholesterolemic rats. Two weeks after administration of hypolip, there was no significant changes in serum total cholesterol concentration in groups C,D and E compared with group B. However, there was a significant decrease in LDL-c in groups D and E, compared with group B and a significant decrease in high density lipoprotein-cholesterol (HDL-c) in groups D and E and triglycerides in group E compared with group B. Four weeks after administration of hypolip, there was a significant decrease in serum total-cholesterol in groups C and D and a highly significant (P<0.01) decrease in group E. There was a significant increase in serum HDL-c in groups D and E and a significant decrease in serum triglycerides in groups D and E compared with group B. There was a significant decrease in blood urea ingroups C, D and E compared with group B after four weeks of administration of hypolip. There were no significant changes in levels of serum creatinine, potassium and sodium between treated groups (C, D and E) and group B throughout the experimental period. Hematological findings demonstrated that there were no significant differences in red blood cell counts between treated groups (C, D, and E) and group B. However, there was a significant decrease in white blood cell counts in group D compared with group B. Hemoglobin concentrations and PCV showed a significant decrease in group E compared with group B; but, there were no significant changes on platelets concentrations betweentreated groups (C, D and E) and group B. Histopathologically, the aortal wall was thickened with a precipitation of cholesterol clefts, particularly in group B. Renal tissues showed hemorrhage, congestion, infiltration of inflammatorycells in group B. In the treated groups, kidneys showed hemorrhage, segmented golmeruli and infiltration of inflammatory cells surrounding blood arteriole. The intestine showed hemorrhage, necrosis of epithelial cells, increasing number of goblet cells and infiltration of inflammatory cells in treated groups. The brain showed congestion, vaculation, demyelation of neurons, congestion and infiltration of microglaialcells in treated groups.