Effects of garlic extract supplementation on blood lipid and antioxidant parameters and atherosclerotic plaque formation process in cholesterol-fed rabbits.

OBJECTIVE

Possible effects of garlic extract supplementation on blood oxidant/antioxidant status, blood lipid profile and coronary plaque formation process were investigated in cholesterol-fed rabbits.

METHODS

Thirty-one male rabbits of New Zealand strain were used. Twenty-two animals were given cholesterol for 4 months. Seven of them were sacrificed to investigate plaque formation and to measure blood parameters. Seven of the remaining 15 animals were fed on normal laboratory diet and others normal diet plus garlic extract for additional 3 months. Blood antioxidant and lipid parameters were measured and histological examination was made.

RESULTS

Total, HDL and LDL cholesterol levels were found to be significantly higher in the Cholesterol Group relative to controls. In the histological investigation, a dense atherosclerotic plaque formation was observed in the aortas of this group. In the Normal Diet Group, total, HDL and LDL cholesterol levels were higher relative to the control group. No significant differences were observed between plaque surface areas of the Cholesterol and Normal Diet Groups. In the Extract Group however, there were differences with regard to all the analysis parameters. Total, HDL and LDL cholesterol levels were found to be decreased in this group. There was significant reduction in the plaque surface area in the aortas of this group. Blood antioxidant potential (AOP) was higher than the other groups but, malondialdehyde (MDA) level and, value of susceptibility to oxidation (SO) were lower in the Extract Group relative to the other groups. There were however no significant differences between MDA and SO values of the Control and Extract Groups.

CONCLUSIONS

Our results demonstrate that cholesterol supplementation leads to dense plaque formation in the aortas of the rabbits. Garlic extract supplementation ameliorates blood lipid profile and, increases antioxidant potential. Extract treatment can significantly reduce plaque surface area in the aorta. Our results suggest that increased blood antioxidant potential due to extract supplementation might be one of the factors leading to this end.