Effect of essential oil of onion and garlic on experimental atherosclerosis in rabbits

Abstract

The effects of the essential oils of onion (extracted from 2 g of raw onion per kg body weight) and garlic (extracted from 1 g of raw garlic per kg body weight) have been observed on experimental atherosclerosis produced by cholesterol feeding, (0.5 g/kg) in rabbits. The rise in serum cholesterol and serum triglycerides was significantly reduced by both onion and garlic during the 4-month period of study. Cholesterol feeding significantly increased β-( P < 0.01) and pre-β ( P < 0.001) lipoproteins while decreasing the α-fraction ( P < 0.001). Onion and garlic both prevented these changes. The β α ratio, which was initially 1.3 : 1, rose to 4.5 : 1 and 5.7 : 1 at the end of 2 months and 4 months of cholesterol feeding. However, this ratio did not increase significantly, both at the 2-month and 4-month period, when onion and garlic were added. Fibrinolytic activity significantly increased with onion ( P < 0.001) and garlic ( P < 0.001) while feeding only cholesterol actually decreased it ( P < 0.001). Onion and garlic reduced aortic atheroma by about half. It is suggested that the essential oils. of onion and garlic protect against experimental atherosclerosis by preventing the fall in the alpha lipoprotein fraction and by enhancing fibrinolytic activity, as well as by lowering the serum cholesterol and tri-glyceride levels.