Vitamin C prevents cigarette smoke induced atherosclerosis in guinea pig model

Aim: cigarette smoking is a major risk for developing atherosclerosis; however,the underlying mechanism is poorly understood. this paucity of knowledge is largely attributed to the lack of an animal model; therefore,our efforts were targeted towards establishing cigarette smoke (cs)-induced atherosclerosis in guinea pig. to understand the mechanism,we investigated apoptosis,an event implicated in atherosclerosis,in the aorta of cs-exposed animals. since a major deleterious effect of cs is oxidative stress,we also examined the effect of vitamin c,an antioxidant,on cs- induced atherosclerosis. &methods and results: guinea pigs on a diet with or without vitamin c supplement were exposed to cs for different time periods. aortal sections from these animals were examined for atherosclerotic changes by staining with h&e and oil red o. atherogenic changes were observed in sections obtained from cs-exposed guinea pigs only. tunel assay showed the occurrence of apoptosis in cs-exposed guinea pig aorta. our results revealed that cs-induced apoptosis could contribute to the progression but not to the initiation of the disease. immunohistochemical analysis documents that cs-induced apoptosis in aortal sections is mediated at least in part by an increased bax/bcl2 ratio. in contrast,cs-exposed guinea pigs fed with vitamin c-supplemented diet exhibit little or no atherogenic changes. this anti-atherosclerotic activity of vitamin c can be attributed partly to its ability to inhibit cs-induced apoptosis and platelet activation. &conclusion: exposure of guinea pigs to cigarette smoke causes the development of atherosclerosis,which can be prevented by vitamin c supplement.