Soybean flour induces a greater increase of the antioxidant defenses in rats fed with a normocaloric diet compared with a hypercaloric diet.

BACKGROUND: Soybeans, due to their antioxidant properties, present beneficial health effects. The objective was to evaluate if replacing casein with soy flour, modifies antioxidant defenses in rat liver, compared to animals that continued being fed with casein based diets (normocaloric and hypercaloric). RESULTS: Four groups of rats were used: CC (control casein), CS (control soy), HC (hypercaloric casein) and HS (hypercaloric soy). Malondialdehyde, in serum and liver, did not present differences. In liver, when comparing CS vs. CC: increased superoxide dismutase 1 (P < 0.001), catalase (P < 0.01) and glutathione reductase (P < 0.05) activities, the total glutathione (P < 0.001) and reduced glutathione (P < 0.05) content and decreased oxidized glutathione content (P < 0.05). In HS vs. HC: increased carbonyl groups (P < 0.01) and superoxide dismutase 1 activity (P < 0.05), and decreased glutathione peroxidase activity (P < 0.01), total glutathione (P < 0.05) and oxidized glutathione content (P < 0.001). In HS vs. CS: decreased glutathione reductase activity (P < 0.01), total glutathione (P < 0.001) and reduced glutathione (P < 0.01) content, and increased oxidized glutathione content (P < 0.05). CONCLUSION: Replacing casein by soybean flour improves antioxidant defenses, mainly in normocaloric diets.

Biochemical and molecular study of the influence of Amaranthus hypochondriacus flour on serum and liver lipids in rats treated with ethanol.

Hyperlipidemia and hepatic steatosis are frequent alterations due to alcohol abuse. Amaranth is a pseudocereal with hypolipidemic potential among other nutraceutical actions. Here we study the effect of Amaranthus hypochondriacus (Ah) seeds on serum and liver lipids, and the expression of genes associated to lipid metabolism and liver histology in male Wistar rats intoxicated with ethanol. The animals were divided into four groups; two groups were fed the American Institute of Nutrition 1993 for maintenance diet (AIN-93M), and the other two with AIN-93M containing Ah as protein source. One of each protein group received 20% ethanol in the drinking water, thus obtaining: CC (control casein), EC (ethanol casein), CAh (control Ah) and EAh (ethanol Ah). When comparing EAh vs . EC, we found a positive effect of Ah on lipids, preventing the increment of serum cholesterol (p <0.001), through the higher expression of the LDL receptor (p <0.001); and it also decreased free (p < 0.05) and esterified cholesterol (p <0.01) in liver, probably via the reduction of the 3-hydroxy-3-methylglutaryl coenzyme A reductase expression (p <0.001). We also observed that amaranth contributed to the decrease of fat deposits in liver, probably through the decrease in acetyl-CoA carboxylase alpha (p <0.01), glycerol-3-phosphate acyltransferase 1 (p <0.01) and diacylglycerol O-acyltransferase 2 (p <0.05) expression. The histological study showed a decrease in the fat deposits in the amaranth group when compared to casein; this is consistent with the biochemical and molecular parameters studied in this work. In conclusion, amaranth could be recommended to avoid the alterations in the lipid metabolism induced by alcohol and other harmful agents.