Effect Of Soybean Extract Research Articles

The Effect of Soybean Extracts on Serum Lipid Profile and the Accumulation of Free Cholesterol and Cholesteryl Ester in the Aorta, Carotid Artery and Iliac Artery-Experimental Study

Background: We evaluated the effect of soybean extracts on serum lipoprotein profile and cholesterol accumulation on the arterial walls. Objective and design: Sixty-four female Sprague-Dawley rats were randomly divided into eight groups. Soybean extracts were given to the rats via oral gavage every day for eight weeks, after which serum was collected. In the thoracic aorta, left carotid artery, and right iliac artery, we measured the lipoprotein fractions in the serum and the accumulation of free cholesterol and cholesteryl ester, which are predictors of subclinical atherosclerosis. Results: After eight weeks of a continuous soybean diet, only two groups showed a lipid-lowering effect (n-hexane extract for 200 mg/kg dose and ethyl acetate extract for 200 mg/kg dose). We found lower free cholesterol and cholesteryl ester accumulation in the aortas and iliac arterial walls only in these two groups. Conclusion: The results indicated that soybean extract intake leads to weight change and may influence lipid metabolism. The positive effects of the soybean diet involved not only serum lipids but also aortic wall cholesterol accumulation.

Fermented soy bean extract suppresses differentiation of 3T3-L1 preadipocytes and facilitates its glucose utilization

Obesity is a serious health problem which may continuously increase the morbidity and mortality associated with a variety of acute and chronic diseases.This study aimed to examine the antiobesity effect of soy bean extract fermented by Bacillus subtilis MORI (BTD-1) and to elucidate the mechanisms underlying such effects using 3T3-L1 preadipocytes. Lipid accumulations were significantly inhibited by BTD-1 treatment, which were accompanied by the decreased expression of CCAAT element binding protein α (C/EBPα) and the increased phosphorylation of acetyl-CoA carboxylase (ACC) protein expression. In addition, BTD-1 treatment increased the expression of glucose transporter 4 (GLUT4) along with significantly increasing glucose uptake into the adipocytes based on results of a 2-deoxy-D-[3H] glucose uptake assay. Our findings suggest that BTD-1 may suppress the differentiation of 3T3-L1 adipocytes and greatly facilitate glucose uptake into the adipocytes. Therefore, BTD-1 has a potential as a functional food ingredient in improving obesity and related metabolic disorders.

Biotransformed Soybean Extract Induces Cell Death of Estrogen-Dependent Breast Cancer Cells by Modulation of Apoptotic Proteins

The process of soybean biotransformation increases the quantity of isoflavones (daidzein and genistein), which besides being considered an alternative to estroprogestive hormone replacement therapy (HRT), are able of hindering the growth and development of tumor cells. We investigated the effects of soybean extract biotransformed by fungus on estrogen-dependent (MCF-7) and nondependent (SK-BR-3) breast cell lines. Cells were treated with different concentrations of biotransformed (BSE) and nonbiotransformed soybean extract (SE), or daidzein (D) and genistein (G) patterns isolated and in combination (D + G). Afterwards, we analyzed cell viability by MTT assay, phosphatidylserine exposure and cell permeability by flow cytometry; expression of apoptotic proteins by Western blotting. BSE promoted reduction in cell viability and increase in DNA degradation in both cell lines. In addition, we verified increase in cell permeability and in the expression of phosphatidylserine, as well as modulation in the expression of apoptotic proteins in MCF-7 cells. The cells did not show any signs of cell death when incubated with the controls (D, G, and D + G). Unknown components found in the BSE induce cell death by apoptosis and necrosis, mainly in MCF-7 cells. These processes depend on the activation of caspase-3 and involve an increase in the expression of proapoptotic molecules.

Cognitive dysfunction and amyloid β accumulation are ameliorated by the ingestion of green soybean extract in aged mice

The effects of soybean extracts were investigated in senescence-accelerated (SAMP10) mice, a mouse model of brain senescence with cognitive dysfunction. Mature soybeans are usually yellow. However, the green soybean retains green color after being ripened. Cognitive functions were significantly better-preserved in aged mice fed green soybean than age-matched control mice with or without yellow soybean feeding. Molecular mechanisms of the beneficial effect of green soybean on brain functions were examined through transcriptome analysis of SAMP10 hippocampus. The high expression of Ptgds was significantly associated with green soybean diet, which encodes lipocalin-type prostaglandin D2 synthase, a putative endogenous amyloid β(Αβ)-chaperone. In consonance, Aplp1 expression was significantly reduced, a member of amyloid precursor proteins. Furthermore, the amount of Aβ 40 and 42 was reduced in the insoluble fraction of cerebral cortex. These results suggest that the intake of green soybean ameliorates cognitive dysfunction of aged mice through the reduction of Aβ accumulation.

Soybean Extracts Facilitate Bacterial Agglutination and Prevent Biofilm Formation on Orthodontic Wire

Soybean is an essential food ingredient that contains a class of organic compounds known as isoflavones. It is also well known that several plant agglutinins interfere with bacterial adherence to smooth surfaces. However, little is known about the effects of soybean extracts or genistein (a purified isoflavone from soybean) on bacterial biofilm formation. We evaluated the effects of soybean (Glycine max) extracts, including fermented soybean and genistein, on streptococcal agglutination and attachment onto stainless steel orthodontic wire. After cultivating streptococci in biofilm medium containing soybean extracts and orthodontic wire, the viable bacteria attached to the wire were counted. Phase-contrast microscopy and scanning electron microscopy (SEM) analyses were conducted to evaluate bacterial agglutination and attachment. Our study showed that soybean extracts induce agglutination between streptococci, which results in bacterial precipitation. Conversely, viable bacterial counting and SEM image analysis of Streptococcus mutans attached to the orthodontic wire show that bacterial attachment decreases significantly when soybean extracts were added. However, there was no significant change in pre-attached S. mutans biofilm in response to soybean. A possible explanation for these results is that increased agglutination of planktonic streptococci by soybean extracts results in inhibition of bacterial attachment onto the orthodontic wire.

Soybean extract showed modulation of retinoic acid‐related gene expression of skin and photo‐protective effects in keratinocytes

Soy extracts are well known as medicinal and nutritional ingredients, and exhibit benefits towards human skin including depigmenting or anti-ageing effects. Despite the wrinkle decreasing effects of retinoids on skin as an anti-ageing ingredient, retinoid application can causes photo-sensitive responses such as skin irritation. Thus, their daytime usage is not recommended. The aim of this study is the investigation into the activities of soybean extract as an anti-ageing ingredient and their comparison to retinoids in this respect. Soybean extract decreased the relative ratio of MMP-1/TIMP-1 mRNA to the same degree as retinoic acid in normal human fibroblasts. It also affected mRNA levels of HAS2 and CRABP2 in normal human keratinocytes. Furthermore, we investigated its effect on mRNA expression of histidase, an enzyme that converts histidine into urocanic acid, the main UV light absorption factor of the stratum corneum. Unlike the complete inhibition of histidase exhibited by the mRNA expression of retinoic acid, the effect of soybean extract on histidase gene expression was weaker in normal human keratinocytes. Also, soybean extract pretreatment inhibited UVB-induced cyclobutane pyrimidine dimer formation dose-dependently in normal human keratinocytes. In this study, we found that soybean extract modulated retinoic acid-related genes and showed photo-protective effects. Our findings suggest that soybean extract could be an anti-ageing ingredient that can be safely used under the sunlight.

The Effect of Glycine max Extract Diets on Changes in NR2B Gene Expression, Cognitive Vitality and Neurotoxicity in High Concentrate Consumption

The effects of soybean extract (Glycine max) on NR2B expression, cognitive vitality and neurotoxicity have not been exclusively reported. Here, we examined the correlation between Glycine max concentration and the N-methyl-D-aspartate (NMDA) receptor NR2B. We observed the brain weight, bodyweight and body movement in animals that received soybean extract in their food. Brain tissues from five groups of rats treated with five different concentration of soybean extract (5-50% of total diet calories) were collected. Rats without treatment served as the control group. NR2B expression was determined using RT-PCR. Average values of escape latency (EL) on day four in the control. 5%, 10% and 20% groups were 34.5, 29.67, 27.2 and 33.83 seconds, respectively. The EL of the 10% group was significantly shorter than that of the control. The low (5-10%) and moderate (20%) extract concentrations were not found to induce any abnormality in body movements, whereas the high concentration (40-50%) groups were found to have some movement disorders after four weeks of administration. The cerebellum weight of the high concentration group (50%) was decreased 18% from the pre-treatment weight, and this decrease might be related to the movement abnormality, which was possibly due to a defect of the CNS in this group. Specifically, we speculated that this abnormality might be due to damage in the cerebellum. These events might be initiated by an increase of NR2B as an adaptive process in the low and high soybean extract groups (5-40%), followed by a sudden decrease in NR2B in the 50% group due to the possibility of brain injury. The low percentage Glycine max extract diet (<5%) is recommended, and 5-10% can be tolerated, but more than 20% is not recommended. High concentrations (40-50%) of soybean extract were found to have neurotoxicilogical effects.

Regulation of Male Sex Hormone Levels by Soy Isoflavones in Rats

Several studies have suggested that soybean intake is associated with a lower risk of prostate cancer. However, the mechanism of prostate cancer prevention by soybeans remains unclear. Because prostate cancer is reported to have an association with an increased level of dihydrotestosterone (DHT) and soybean isoflavones are known to inhibit 5a-reductase, which is involved in the conversion of testosterone to DHT, the effects of soybean extract and isoflavones on the plasma levels of male sex hormones were investigated using male rats. In Experiment I, Sprague-Dawley rats were fed diets with and without soy flour; in Experiment II, rats were fed diets containing 2% soy methanol extract or 0.2% semipurified isoflavones or a control diet. The study showed a reduction of plasma DHT along with an increase in total plasma androgen in rats fed soy flour or semipurified isoflavones for 1 wk. These results suggest that soy isoflavone intake may reduce plasma DHT level.

Effects of Soybean Extract on Morphology and Survival of Caco-2, SW620, and HT-29 Cells

Soybean consumption may be beneficial to prevention of certain human cancers. Low incidence of colon cancer in Asian countries is associated with consumption of soybean products. A limited number of human and animal studies suggested that soybean consumption might prevent colon cancer; other studies did not support this conclusion. Therefore, it is important to understand the biological effects of soybeans on colon cells. In the present study, cultures of Caco-2, SW620, and HT-29 cells were treated with soybean extract, the soluble fraction of a soybean product. The crude extract contains proteins and many soluble components of soybeans. After incubation with soybean extract (1-6%, vol/vol) for 24 h, most Caco-2 cells were found to contain numerous vacuoles within the cytoplasm and to become very flat. Exposure to >6% soybean extract resulted in cell death and giant vacuoles. Soybean extract (0.25-2%) induced small vacuoles within the cytoplasm of SW620 cells. SW620 cells detached from culture dishes at >2% soybean extract. Exposure to 0.5-2% soybean extract produced vacuoles within HT-29 cells similar to those observed in SW620 cells. Soybean extract significantly reduced density of Caco-2, SW620, and HT-29 cells. Reducing protein content of soybean extract reduced but did not abolish its effects on colon cells. Purified genistein (12.5 μg/ml) was capable of producing morphological changes similar to those observed after treatment of colon cells with soybean extract. Assays using annexin V-propidium iodide demonstrated that treatment of Caco-2 and SW620 cells with soybean extract increased cell death. Membranes of vacuoles in soybean-treated Caco-2 and SW620 cells were labeled with Texas red-conjugated wheat germ agglutinin, a cytological marker for the Golgi apparatus. Exposure to soybean extract enhanced protein levels of Rab6, a small GTP-binding protein that is involved in regulation of membrane traffic of the Golgi apparatus. Data from this study suggest that exposure to soybean extract or isoflavones affects morphology and survival of colon cancer cells and that the response to soybean extract varies depending on the cell lines examined.

Effect of soybean extract on nitrosamines formation. In vitro study

Soybean (SB) extracts markedly inhibit formation of diphenylnitrosamine (DPNA) from the precursors diphenylamine (DPA) and nitrite (NO2-). SB extracts interact with nitrite, as shown by the decrease in the nitrite level. The rate of interaction between SB extracts and nitrite was lower than the rate of inhibition of DPNA formation. Thus the reduction of DPNA yield by SB extracts is not caused mainly through their competition for the available nitrite, but it might be due to the adsorption of the DPNA formed to the SB proteins, internitrosation between SB constituents and DPNA formed, or through the breakdown of the DPNA.