Protective effect of soybeans as protein source in the diet against cadmium-aorta redox and morphological alteration

We investigated the effects of cadmium exposition on thoracic aorta redox status and morphology, and the putative protective effect of soybeans in the diet. Male Wistar rats were separated into 6 groups: 3 fed with a diet containing casein and 3 containing soybeans, as protein source. Within each protein group, one was given tap water (control) and the other two tap water containing 15 and 100ppm of Cd2+, respectively, for two months. In rats fed with casein diet, 15ppm of Cd induced an increase of thiobarbituric acid-reactive substances (TBARS), and of the catalase (CAT) and glutathione peroxidase (GPx) activities, which were even higher with 100ppm of Cd2+, in aorta. Also, 100ppm Cd2+ exposure increased superoxide dismutase (CuZnSOD) activity; CAT, GPX, SOD, Nrf2 and metallothioneine II mRNA expressions and CAT, GPx and NOX-2 protein levels, compared with control. Aorta endothelial and cytoplasmic alterations were observed. However, with the soybeans diet, 15 and 100ppm of Cd2+ did not modify TBARS levels; CAT, GPX and Nrf2 mRNA expressions; CAT, GPx and NOX-2 protein; and the aorta morphology, compared with control. The soybean diet attenuates the redox changes and protects against morphological alterations induced, in a dose-dependent way, by Cd in aorta. •Under casein diet, 100ppm Cd2+ in drinking water induces oxidative stress in aorta.•Under casein diet, 100ppm Cd2+ increases Nrf2, MT II and NOX2 expressions in aorta.•Under casein diet, 100ppm Cd2+ induces morphological changes in rat aorta.•The soybean diet attenuates the redox changes induced by Cd in rat aorta.•The soybean diet attenuates morphological alterations induced by Cd in rat aorta.