Effect of shark liver oil on renal cortical structure in hypercholesterolemic rats

ABSTRACT

Numerous studies reported the association between hypercholesterolemia and renal damage. Elevated plasma cholesterol is involved in the onset and progression of renal diseases. Shark liver oil is reported to be an antioxidant and hypolipidemic. This study was conducted to investigate the possible effects of two different doses of shark liver oil in reducing renal cortical changes associated with high cholesterol diet feeding in correlation with serum lipids. Forty rats were divided into two groups control group [group 1 = 1 0 rats] and high cholesterol diet-fed group [group 2 = 30 rats]. Group 2 was further subdivided into three subgroups group 2a, nonsupplemented with shark liver oil; group 2b, supplemented with 1 0% shark liver oil; and group 2c supplemented with 20% shark liver oil. Kidney samples were processed for general histological, immunohistochemical, and ultrastructural study of the renal cortex. Blood samples were collected for assessment of serum lipids. High cholesterol diet-fed group showed prominent podocyte injury characterized by de novo desmin staining and flattening and fusion of foot processes. Some renal corpuscles exhibited thickening and distortion of the glomerular basement membrane. Renal tubular cells showed intracellular vacuoles and mitochondrial degeneration. These structural changes were associated with altered serum lipids. Shark liver oil dietary supplement noticeably ameliorated renal cortical damage and corrected the changes in serum lipids with better improvement in the 20% shark liver oil-supplemented group. This study reveals the beneficial effect of shark liver oil, as a health supplement, in ameliorating the structural renal cortical damage and hypercholesterolemia associated with high cholesterol diet feeding