Protein hydrolysates from beta-conglycinin enriched soybean genotypes inhibit lipid accumulation and inflammation in vitro

Consumption of different soymilk formulations differentially affects the gut microbiomes of overweight and obese men

The effects of consuming foods on the intestinal microbiome of obese individuals remain unclear. The objective of this study was to compare the effects of consuming low glycinin soymilk (LGS, 49.5% β-conglycinin/6% glycinin), conventional soymilk (S, 26.5% β-conglycinin/38.7% glycinin) or bovine milk (M, 0% β-conglycinin/0% glycinin) on the intestinal microbiome in overweight and obese men. In a randomized double-blind study, participants (64 men, BMI > 25, 20-45 y old), organized in three groups, consumed 500 mL of LGS, S or M daily for 3 mo. Three fecal samples were collected before (baseline) and after 3 mo of consumption. Dietary energy and macronutrient intake were monitored monthly and remained constant throughout the study (p > 0.05). Microbial composition was analyzed with qPCR and bTEFAP. Within groups, qPCR analysis showed that the total bacteria increased in all treatments over time (p < 0.001). Bacteroides-Prevotella (p = 0.001) and Lactobacillus (p < 0.001) increased in LGS and M, respectively. Bifidobacterium was significantly reduced in LGS (p = 0.003) and S (p < 0.001). Bacterial diversity decreased for LGS, S and M (p = 0.004, 0.005, 0.001; respectively). Unweighted UniFrac analysis revealed that the microbial communities were more similar within than between individuals. The Firmicutes to Bacteroidetes ratio decreased in both LGS and S groups and remained relatively unchanged in the M group (Time p = 0.012; Interaction p = 0.059). Indicator analysis revealed several genera that were indicative of each treatment including Lactobacillus and Prevotella. Consumption of the three beverages differentially altered the microbiota in overweight and obese men including a potentially beneficial alteration of the Firmicutes to Bacteroidetes ratio in both soymilk groups.

Antioxidant and antiinflammatory properties of germinated and hydrolysed Brazilian soybean flours

The effect of germination in combination with Alcalase hydrolysis of Brazilian soybean cultivar BRS 133 on the production of soybean flours with bioactive peptides as modulators of oxidative stress and markers of inflammation was monitored. The electrophoretic profile showed a weak protein breakdown during germination. However, a strong breakdown of the proteins can be observed after the first hour of hydrolysis with Alcalase. MALDI-TOF-MS analysis of the protein extracts showed differences in the intensity and profile of peptide mass fingerprint due to germination and hydrolysis. Germinated flour showed higher soluble protein concentration and antioxidant capacity. All soybean protein extracts and protein hydrolysates produced (G0, G18 and G72) showed a significant (p<0.05) inhibition on inflammatory markers such as nitric oxide (20.5-69.3%), iNOS (22.8-93.6%), PGE(2) (64.0-88.3%), COX-2 (36.2-76.7%), and TNF-α (93.9-99.5%) in LPS-induced RAW 264.7 macrophages. However, protein extracts of flours with 18 h of germination were more potent in inhibiting pro-inflammatory responses when compared to 72 h. It can be concluded that a combination of 72 h of soybean BRS 133 germination and 1h Alcalase hydrolysis resulted in the formation of bioactive compounds with more potent antioxidant activity, and improvement in the reduction of some of the markers of inflammation.

RGD-peptide lunasin inhibits Akt-mediated NF-κB activation in human macrophages through interaction with the αVβ3 integrin

SCOPE

Cardiovascular disease is the leading cause of mortality in the United States and regulation of aberrant macrophage activity under inflammatory conditions is critical for its prevention. The objective was to determine the effect of lunasin on the inhibition of Akt-mediated activation of nuclear factor-kappa B (NF-κB)-dependent markers of inflammation and to characterize the physical interaction of lunasin with the αVβ3 integrin receptor in lipopolysaccharide (LPS)-induced human THP-1 macrophages.

METHODS AND RESULTS

The effect of lunasin was evaluated in vitro in LPS-induced THP-1 human macrophages using immunoassays, co-immunoprecipitation (Co-IP), and fluorescence confocal microscopy. Lunasin (50 μM) reduced cyclooxygenase-2, inducible nitric oxide synthase, and NO levels by 57.9, 64.5, and 76.2%, respectively, and inhibited the activation of phosphorylated Akt and NF-κB p65 by 59.5 and 74.5%, respectively. Lunasin (50 μM) reduced exogenous release of prostaglandin E(2) and tumor necrosis factor-α by 92.5 and 94.9%, respectively. Vitronectin (10 μg/mL), an integrin ligand, increased expression of proinflammatory markers, whereas lunasin (50 μM) attenuated them. Co-IP of lunasin-treated cells confirmed direct interaction with αVβ3 integrin and LC/MS/MS verified its identity. Lunasin was detected within intracellular vesicles and reduced total αVβ3 intensity as observed by fluorescence microscopy.

CONCLUSION

Lunasin inhibited αVβ3 integrin-mediated proinflammatory markers and downregulated Akt-mediated NF-κB pathways through interaction with αVβ3 integrin.

Bowman-Birk and Kunitz protease inhibitors among antinutrients and bioactives modified by germination and hydrolysis in Brazilian soybean cultivar BRS 133

Soybean contains constituents that have antinutritional and bioactive properties. Enzymatic hydrolysis and germination can enhance the biological activity of these compounds in soybean. The objective of this study was to investigate the effect of germination, Alcalase (protease) hydrolysis, and their combination on the concentrations of antinutritional and bioactive compounds in Brazilian soybean cultivar BRS 133. A combination of germination and Alcalase hydrolysis resulted in the degradation of Bowman-Birk inhibitor (BBI), Kunitz trypsin inhibitor (KTI), and lunasin by 96.9, 97.8, and 38.4%. Lectin was not affected by any of the processing treatments when compared to nongerminated and nonhydrolyzed soy protein extract. Total isoflavones (ISF) and total saponins (SAP) increased by 16.2 and 28.7%, respectively, after 18 h of germination, while Alcalase hydrolysis led to the reduction of these compounds. A significant correlation was found between concentrations of BBI and KTI, BBI and lunasin, BBI and ISF, KTI and lunasin, KTI and ISF, KTI and SAP, lunasin and ISF, and ISF and SAP. Germination and Alcalase hydrolysis interacted in reducing BBI, ISF, and SAP. This study presents a process of preparing soy flour ingredients with lower concentrations of antinutritional factors and with biologically active constituents, important for the promotion of health associated with soybean consumption. In conclusion, 18 h of germination and 3 h of Alcalase hydrolysis is recommended for elimination of protease inhibitors, while bioactives are maintained by at least 50% of their original concentrations.

Soy, phytoestrogens and their impact on reproductive health

There is growing interest in the potential health threats posed by endocrine-disrupting chemicals (EDCs) to the reproductive system. Soybean is the most important dietary source of isoflavones, an important class of phytoestrogen. While consumption of soy food or phytoestrogen supplements has been frequently associated with beneficial health effects, the potentially adverse effects on development, fertility, and the reproductive and endocrine systems are likely underappreciated. Here we review the available epidemiological, clinical and animal data on the effects of soy and phytoestrogens on the development and function of the male and female reproductive system, and weigh the evidence as to their detrimental impact.

Soy-derived di- and tripeptides alleviate colon and ileum inflammation in pigs with dextran sodium sulfate-induced colitis

We evaluated the antiinflammatory activity of soy-derived di- and tripeptides in a dextran sodium sulfate (DSS)-induced pig model of intestinal inflammation. In the DSS-positive control (POS) and DSS-positive with soy peptide treatment (SOY) groups (n = 6/group), DSS was administered to piglets via i.g. catheter for 5 d, followed by a 5-d administration of saline or soy-derived peptides, respectively. A negative control (NEG) group received saline in lieu of the DSS and soy peptides. The severity of inflammation was assessed by clinical signs, morphological and histological measurements, gut permeability, and neutrophil infiltration. Local production of TNF and IL6 were measured by ELISA, colonic and ileal inflammatory gene expression were assessed by real-time RT-PCR, and CD4+CD25+ lymphocyte populations were analyzed by flow cytometry. Crypt elongation and muscle thickness, d-mannitol gut permeation, colonic expression of the inflammatory mediators IFNG, IL1B, TNF, RORC, and IL17A as well as the FOXP3 T-regulatory transcription factor, and myeloperoxidase activity were lower (P < 0.05) in the SOY pigs than in POS pigs. Messenger RNA levels of ileal IFNG, TNF, IL12B, and IL17A were lower (P < 0.05) and FOXP3 expression was greater (P < 0.05) in SOY piglets than in the POS group. In the mesenteric lymph nodes, CD4+CD25+ T cells were higher (P < 0.05) in both the POS and SOY groups than in NEG controls. Soy-derived peptides exert antiinflammatory activity in vivo, suggesting their usefulness for the treatment of inflammatory disorders.

Soya protein hydrolysates modify the expression of various pro-inflammatory genes induced by fatty acids in ovine phagocytes

The objective of the present study was to test the hypothesis that fatty acids are the circulating mediators acting in a pro-inflammatory manner towards activated circulating ovine monocyte/macrophages and neutrophils. Furthermore, whether soya protein hydrolysates (SPH) inhibit the fatty acid-induced increase in the production of pro-inflammatory responses by ovine phagocytes was tested in vitro. All the fatty acids tested (myristic, palmitic, palmitoleic, stearic and oleic) increased (P < 0·01; C18>C16>C14) membrane-bound urokinase plasminogen activator (u-PA) and u-PA free binding sites in cell membranes of activated ovine blood monocytes/macrophages, but only the C18 fatty acids (stearic, oleic) were effective towards blood neutrophils. The C18 fatty acids up-regulated (P < 0·05) the gene expression of u-PA, u-PA receptor, intercellular adhesion molecule 1 and inducible NO synthase (in monocytes) but not that of cyclo-oxygenase-2, integrin α X and plasminogen activator inhibitor types 1 and 2 by ovine phagocytes. SPH blocked completely or partially all C18 fatty acid-induced changes in the expression of various pro-inflammatory genes. In conclusion, fatty acids selectively ‘activate’ ovine phagocytes, suggesting that these cells ‘sense’ metabolic signals derived from adipocytes. Soya protein peptides inhibit all changes in gene expression induced by fatty acids in ovine phagocytes in vitro. This constitutes a novel mechanism of action.

Attenuating effect of casein glycomacropeptide on proliferation, differentiation, and lipid accumulation of in vitro Sprague-Dawley rat preadipocytes

Food components with the ability to suppress preadipocyte proliferation and intracellular lipid accumulation may be helpful in the prevention of obesity, which is a worldwide health concern. Casein glycomacropeptide (GMP), which has pronounced gastric inhibitory activity, could potentially possess fat synthesis inhibition properties and an obesity-alleviating capacity. The objective of the present study was to investigate the effect of GMP on the proliferation and differentiation of preadipocytes as well as triglyceride accumulation and glycerol-3-phosphate dehydrogenase activity in preadipocytes isolated from Sprague-Dawley rats. Different dosages (0, 0.31, 0.625, 1.25, 2.5, and 5.0 mg/mL) of GMP were co-incubated with preadipocytes. The proliferation activity of preadipocytes significantly decreased in the GMP-treated group compared with that of the control group without GMP supplementation. The GMP exhibited an inhibitory effect against preadipocyte proliferation in a dose-dependent manner; the maximal antiproliferative effect was obtained with 2.5 mg/mL. The GMP also attenuated differentiation, as revealed by decreased lipid content, and the effect was more pronounced when cells were treated with GMP before or at the beginning of differentiation induction than at later stages of cell differentiation. Cultured preadipocytes treated with GMP accumulated fewer triglycerides and had lower glycerol-3-phosphate dehydrogenase activity than did the control cells without GMP supplementation. In conclusion, GMP can inhibit the proliferation, differentiation, and lipid accumulation of preadipocytes in vitro.

Common bean (Phaseolus vulgaris L.) hydrolysates inhibit inflammation in LPS-induced macrophages through suppression of NF-κB pathways

The objectives of this study were to evaluate the antioxidant capacity of protein hydrolysates of the common bean (Phaseolus vulgaris L.) varieties Negro 8025 and Pinto Durango and determine their effect on the markers of inflammation in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. Cell viability was determined and the percentage of viable cells was calculated and concentrations that allowed >80% cell viability were used to determine the markers of inflammation. Alcalase hydrolysates and pepsin-pancreatin hydrolysates showed the highest antioxidant capacity after 80 and 120min of hydrolysis, respectively. Alcalase hydrolysates of the common bean Pinto Durango at 120min inhibited inflammation, with IC50 values of 34.9±0.3, 13.9±0.3, 5.0±0.1 and 3.7±0.2μM, while var. Negro needed 43.6±0.2, 61.3±0.3, 14.2±0.3 and 48.2±0.1μM for the inhibition of cyclooxygenase-2 expression, prostaglandin E2 production, inducible nitric oxide synthase expression and nitric oxide production, respectively. Also, hydrolysates significantly inhibited the transactivation of NF-κB and the nuclear translocation of the NF-κB p65 subunit. In conclusion, hydrolysates from the common bean can be used to combat inflammatory and oxidative-associated diseases.

Soy and the exercise-induced inflammatory response in postmenopausal women

Aging is associated with increasing inflammation and oxidative stress in the body, both of which can have negative health effects. Successful attenuation of such processes with dietary countermeasures has major public health implications. Soy foods, as a source of high-quality protein and isoflavones, may improve such indices, although the effects in healthy postmenopausal women are not well delineated. A single-blind, randomized controlled trial was conducted in 31 postmenopausal women who were assigned to consume 3 servings of soy (n = 16) or dairy (n = 15) milk per day for 4 weeks. Parameters of systemic inflammation (tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6)) and the oxidative defense system (superoxide dismutase (SOD), glutathione peroxidase, cyclooxygenase-2) were measured post supplementation, before and after an eccentric exercise bout performed to elicit an inflammatory response. A significant group-by-time effect for plasma TNF-α was observed (p = 0.02), with values in the dairy group increased post supplementation and then decreasing into the postexercise period. Additionally, significant time effects were observed for plasma SOD (p < 0.0001) and IL-6 (p < 0.0001) in the postexercise period. Overall results from our study do not support the notion that 4 weeks of daily soy milk ingestion can attenuate systemic elevations in markers of inflammation or oxidative defense. However, data do suggest that the downhill-running protocol utilized in this study can be effective in altering systemic markers of inflammation and oxidative defense enzyme activity, and that the ingestion of soy may help prevent fluctuations in plasma TNF-α.