Vitamin C prevents cigarette smoke induced atherosclerosis in guinea pig model.
OBJECTIVE
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.


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.


CONCLUSIONS
Exposure of guinea pigs to cigarette smoke causes the development of atherosclerosis, which can be prevented by vitamin C supplement.
Ray
Tanusree
T
Department of Microbiology, University of Calcutta, Kolkata, WB, India.
Maity
Palash Chandra
PC
Banerjee
Sumana
S
Deb
Suryyani
S
Dasgupta
Anjan Kumar
AK
Sarkar
Srimonti
S
Sil
Alok Kumar
AK
D000818:Animals; D000975:Antioxidants / Q000627:therapeutic use*; D001011:Aorta / Q000187:drug effects; D017209:Apoptosis / Q000187:drug effects; D001205:Ascorbic Acid / Q000627:therapeutic use*; D050197:Atherosclerosis / Q000209:etiology / Q000517:prevention & control*; D019587:Dietary Supplements; D004195:Disease Models, Animal; D006168:Guinea Pigs; D007124:Immunoenzyme Techniques; D020287:In Situ Nick-End Labeling; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects; D015539:Platelet Activation / Q000187:drug effects; D012907:Smoking / Q000009:adverse effects*
D000975:Antioxidants; D001205:Ascorbic Acid