Effects of a Subchronic Intoxication with Cadmium in the Hippocampus of Rats Fed a Soybean-Based Diet
Plateo Pignatari MG, Della Vedova MC, Perez Díaz MF, Navigatore L, Sanchez SI, Giménez MS, Ramírez DC
1Laboratory of Nutrition, Metabolism and Environment, IMIBIO-SL-CONICET-National University of San Luis. 5700 San Luis,
San Luis, Argentina
2Laboratory of Experimental and Translational Medicine, IMIBIO-SL-CONICET-National University of San Luis. 5700 San
Luis, San Luis, Argentina
Experimental and population studies have shown that sub chronic exposure to cadmium (Cd) causes severe toxic effects in several organs including in the brain, but information on the effects in the hippocampus (Hp) is rare. Soybean is an important source of protein and isoflavones. Herein we hypothesized that a sub chronic cadmium-intoxication throughout the drinking water can cause oxidative/ inflammation changes and apoptosis in the Hp; and that a soybean-based diet (SBD) can modulate these effects. To accomplish this goal, we fed 4 groups of female Wistar-rats for 60 days as follows: casein-based diet + tap water (CBD); CBD + tap water with 15 ppm Cd (CBD + Cd); soybean-based diet + tap water (SBD); and SBD + tap water with 15 ppm Cd (SBD + Cd). After the treatment, molecular markers of oxidative stress, inflammation, and apoptosis were measured in serum and Hp tissue. Compared to the Hp of CBD fed rats, the Hp of CBDCd showed an apoptotic profile (high p53 and high Bax / Bcl-2 ratio). However, an SBD caused a pro-apoptosis pattern, i.e, increased p53 and Bax expression, reduced Bcl-2 expression and increased Bax / Bcl-2 ratio. Regardless increased antioxidant enzymes, Cd exposure in SBD fed rats had a synergistic effect in lipid peroxidation and protein oxidation in the Hp. Taking together our data suggest that an SBD and Cd-exposure have a synergistic effect on oxidative stress/inflammation and apoptosis in Hp. Caution may be taken on using soybean as a source of protein in patients exposed to Cd.
Soy-based diet; Cadmium sub chronic intoxication; Hippocampus; Oxidative stress; Inflammation; Apoptosis