Soybean Flour Improves Fatty Acid Profile and Decreases Hepatic Triglyceride Deposition in Rats Fed with Normocaloric and Hypercaloric Diet

Abstract

This study investigated the effects of replacing casein with soy flour on the fatty acids profile and triglycerides metabolism in the liver of rats that were previously fed with normocaloric and hypercaloric diets based on casein. Wistar male rats were used; one group was fed with control diet (AIN-93) and another with hypercaloric diet (AIN-93 with 34.15% sucrose, 42% fat calories) for 9 weeks. Each group was then divided into two subgroups and casein was replaced with soybean in one of them, obtaining CC (control casein), CS (control soy), HC (hypercaloric casein) and HS (hypercaloric soy), which were fed for 6 weeks. We measured triglycerides in serum, and triglycerides, total lipids, fatty acids profile, the expression of apolipoprotein B (Apo B), acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), sterol-regulatory element-binding protein 1c (SREBP1c), mitochondrial glycerol-3-phosphate acyltransferase (mGPAT), diacylglycerol acyltransferase 2 (DGAT-2), carnitine palmitoyltransferase 1 (CPT-1) and peroxisome proliferator-activated receptors alpha (PPARα) in liver. Histological studies were also performed. When comparing HS vs. HC, a positive effect of soybean flour on hepatic triglycerides deposits was found, possibly through the reduction in DGAT-2 expression (P < 0.01) and the increase in Apo B (P < 0.001) expression. Soybean flour also decreased fat deposits in control diets when compared with casein, decreasing the DGAT-2 (P < 0.001) expression and increasing Apo B (P < 0.001), CPT-1 (P < 0.05) and PPARα (P < 0.01) expressions. Both soy diet subgroups increased unsaturated fatty acids respect to casein diets (P < 0.01). Hepatocytes showed few lipid droplets in HS, whereas a fat deposit in HC was ob-* Corresponding author.G. S. Razzeto et al. 1246 served. These results suggest that replacing casein with soybean flour in normocaloric and hypercaloric diets reduces triglycerides and improves fatty acids profile in rat liver.

تأثیر دقیق فول الصویا، زیت جوز الهند، و الماغنسیوم علی الفئران التى تعانى من مرض الکبد الدهنى غیر الکحولی

“…Treating NAFLD rats with a soybean diet containing coconut oil, magnesium and their combination improved lipid profile, as compared to the positive control groups. In this respect (Razzeto et al, 2015) suggest that replacement of soybean flour instead of casein in normocaloric and hypercaloric diets decreased triglycerides and improved fatty acids profile in liver of rats. The results coincided with that reported by Ascencio et al (2004) whom suggested that hepatic triglycerides were decreased by feeding on soy protein or elevated-fat diets that contain soy protein in contrast to rats fed casein or elevated-fat diets that contain casein.…”

Soybean Seed Compounds as Natural Health Protectors

“…Hepatic lipid metabolism is partially controlled by transcription factors: sterol regulatory element binding proteins (SREBPs) and peroxisome proliferator-activated receptors (PPARs) [38]. Soybean intake decreases the expression of SREBP-1c and increases the expression of SREBP-2.…”

“…In contrast, PPARα regulates genes involved in hepatic fatty acid oxidation. For example, carnitine palmitoyltransferase-1 (CPT-1) is an enzyme that regulates fatty acid β-oxidation [37,38]. In conclusion, SREBP is associated with the regulation of hepatic lipogenesis and reduction of cholesterol synthesis [39].…”

“…Interactions between soy components are believed to improve fatty acid oxidation in the liver by increasing the expression of peroxisome proliferator activated receptor α (PPARα) regulated genes, thus decreasing lipid accumulation in the liver [38]. Another nuclear receptor involved in lipid metabolism is peroxisome proliferator-activated receptor (PPAR)γ2, whose expression is greatly increased in response to a high fat (HF) diet, especially a diet high in saturated and unsaturated fatty acids [36].…”