Effect of dietary garlic supplementation on lipid profile, oxidant-antioxidant status and aortic mechanical properties in experimental atherosclerosis

ABSTRACT

Experimental atherosclerosis was induced in a group of chicken [1 day old] by feeding a standard chicken diet supplemented with 1% cholesterol for twelve weeks. Another group was given the same diet supplemented with garlic [80 mg/kg body weight/day] for twelve weeks. The third group received standard poultry diet and served as controls. The alterations of lipids, lipid peroxidation products and antioxidant parameters of plasma and liver as well as the changes in the mechanical properties of the arterial walls were investigated. Hypercholesterolemia, a significant increase in low density lipoprotein cholesterol [LDL-C], triglycerides [TG] and phosphatidylcholine phospholipid fraction [PC] together with the significant decrease in high density lipoprotein cholesterol [HDL-C], very low density lipoprotein cholesterol [VLDL-C], total phospholipids and lysophosphatidylcholine [LPC] percent, induced by cholesterol feeding, were almost corrected by garlic administration. Lipid peroxidation products concentrations were significantly higher in atherosclerotic chicken and returned to almost control values by dietary garlic supplementation. In a corollary fashion, pronounced effect of garlic on antioxidants including liver glutathione [GSH], glutathione peroxidase [GPx], glucose-6-phosphate dehydrogenase [G6PDH], superoxide dismutase [SOD] and plasma antioxidant activity, expressed as D[max] was clearly noticed through restoration of their levels towards normal values after impairment under hypercholesterolaemia. As regards the mechanical properties, ultimate strain [U.S] of the thoracic aorta was significantly increased in the atherosclerotic group of chicken while the tensile strength [T.S] decreased significantly. The inner diameter of both thoracic and abdominal aortae decreased significantly in atherosclerotic group of chicken. These changes were returned to almost control values by addition of garlic powder to diet. These results suggest that garlic supplemented diet corrected not only pathological, lipids and antioxidant parameters but also the mechanical properties of the aortae