Antioxidants protect against increased risk of atherosclerosis induced by exposure to cigarette smoke: Histological and biochemical study.

BACKGROUND AND OBJECTIVES: This study aimed to assess the dose-dependent effect of antioxidants in protection against cardiovascular changes induced by exposure to cigarette smoke. DESIGN AND SETTING: This was an experimental study, conducted at King Fahd Medical Research Center, King Abdulaziz University. MATERIALS AND METHODS: This study was carried out on 57 male albino rats divided into nine groups. Rats of experimental groups were exposed to cigarette smoke from a total of 100 cigarettes per week for four weeks in a specially designed chamber. The antioxidants used (vitamin C, E, and B-carotene) were administrated at low (9, 7.2, and 0.27 mg/day) and high doses (18, 14.4, and 0.54 mg/day), respectively, through gastric feeding tubes. The lipid profile was estimated, and the carotids and heart were removed, weighed, and then processed, and the carotid intima-media thickness was measured. Statistical analysis was performed using the Statistical Package for Social Sciences. RESULTS: The lipid profile was significantly improved in all groups treated with low or high doses of antioxidants after or during the exposure to cigarette smoke. Improvement was marked in the group treated with a high dose of antioxidants. The histological changes, as well as the intima-medial thickness of the carotid artery induced by exposure to cigarette smoke, have been improved by treatment with antioxidants (at either low or high doses), either after or during exposure to cigarette smoke. Improvement was marked in the group treated with a low dose of antioxidant. Treatment with antioxidants could not improve degenerated cardiac muscle fibers, while they could reduce the thickness of the branches of the coronary vessels. CONCLUSION: These results indicated that antioxidants ameliorated the cigarette smoke contribution to atherosclerosis, but they could not completely reverse the changes induced by cigarette smoke. Simultaneous intake of antioxidants could ameliorate the cigarette-smoke-induced changes apart from those of the heart.