Fresh soy oil protects against vascular changes in an estrogen-deficient rat model: an electron microscopy study.
OBJECTIVE
To observe the effects of consuming repeatedly heated soy oil on the aortic tissues of estrogen-deficient rats.


METHODS
Thirty female Sprague Dawley rats (200-250 g) were divided equally into five groups. One group served as the normal control (NC) group. The four treated groups were ovariectomized and were fed as follows: 2% cholesterol diet (OVXC); 2% cholesterol diet + fresh soy oil (FSO); 2% cholesterol diet + once-heated soy oil (1HSO); and 2% cholesterol diet + five-times-heated soy oil (5HSO). After four months, the rats were sacrificed, and the aortic tissues were obtained for histological studies.


RESULTS
After four months of feeding, the NC, FSO and 1HSO groups had a lower body weight gain compared to the OVXC and 5HSO groups. The tunica intima/media ratio in the 5HSO group was significantly thicker (p < 0.05) compared to the NC, OVXC and FSO groups. Electron microscopy showed that endothelial cells were normally shaped in the FSO and NC groups but irregular in the 1HSO and 5HSO groups. A greater number of collagen fibers and vacuoles were observed in the 5HSO group compared to the other treatment groups.


CONCLUSIONS
Fresh soy oil offered protection in the estrogen-deficient state, as these rats had similar features to those of the NC group. The damage to the tunica intima and the increase in the ratio of tunica intima/media thickness showed the deleterious effect of consuming repeatedly heated soy oil in castrated female rats.
Adam
Siti Khadijah
SK
Universiti Kebangsaan Malaysia, Department of Pharmacology, Faculty of Medicine - Kuala Lumpur, Malaysia. s_khad@yahoo.com
Das
Srijit
S
Othman
Faizah
F
Jaarin
Kamsiah
K
D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects* / Q000648:ultrastructure; D050197:Atherosclerosis / Q000473:pathology / Q000517:prevention & control*; D004042:Dietary Fats, Unsaturated / Q000494:pharmacology; D004195:Disease Models, Animal; D004967:Estrogens / Q000172:deficiency*; D005260:Female; D006358:Hot Temperature; D010052:Ovariectomy; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013024:Soybean Oil / Q000494:pharmacology*; D017539:Tunica Intima / Q000648:ultrastructure
D004042:Dietary Fats, Unsaturated; D004967:Estrogens; D013024:Soybean Oil