TOCOTRIENOLS; EFFECTS ON INTIMAL THICKENING IN ASCENDING AORTA OF CHOLESTEROL-FED RABBITS

Abstract

Objective: To evaluate the effect of tocotrienols on intimal thickening in ascending aorta of cholesterol-fed rabbits. Study Design: Randomized control trial. Place and duration of study: The Anatomy department of Army Medical College, Rawalpindi, from March 2009 to February 2010. Material and Methods: Thirty, male, New Zealand white rabbits were randomly divided into three equal groups. Group- I was fed normal lab diet for six weeks. For the similar period, group-II & III were given 2% high cholesterol diet. However, group-III diet was also supplemented with tocotrienols (6 mg/kg body weight/day). By the end of study, aorta was removed from each animal. Cross sections from ascending aorta were processed and embedded in paraffin. Light microscopic examination was performed in H & E and Verhoeff elastic stained slides. Results: Tunica intima in group-I appeared as single layer of squamous endothelial cells, lying on a thin layer of loose connective tissue. High cholesterol diet in group-II induced marked atherosclerotic changes which were characterized by extensive intimal thickening with raised fatty streaks, pools of extracellular lipids, proliferation of smooth muscles and deposition of connective tissue matrix. Intimal thickening was also observed in group-III, but lesions were of lesser degree than group-II (P<0.05). Histomorphometric analysis revealed significantly (P<0.001) higher thickness of intima in group-II and in group-III when either was compared with group-I. However, thickness of intima was 35% lesser (P<0.05) in group-III than group-II. Conclusions: Tocotrienols has significant potential in suppressing the intimal thickening of aorta in cholesterol-fed rabbits.