Novel black soy peptides with antiobesity effects: activation of leptin-like signaling and AMP-activated protein kinase

Effects of the polypeptide from peanut meal mixed fermentation on lipid metabolism and intestinal flora of hyperlipidemic mice

BACKGROUND

Hyperlipidemia is one of the metabolic disorders posing great threat to human health. Our previous studies have shown that the nutritional properties of peanut meal after fermentation are markedly improved, and can effectively improve hyperlipidemia caused by high-fat diet in mice. In this study, in order to facilitate the further utilization of peanut meal, the effect of peanut polypeptide (PP) from peanut meal mixed fermentation on lipid metabolism in mice fed with high-fat diet (HFD) and its possible mechanism were investigated. Fifty male C57BL/6J mice were randomly divided into five groups: normal control group (N), high-fat model group (M), PP low-dose group (PL), PP high-dose group (PH), and atorvastatin positive control group (Y).

RESULTS

The results show that PP supplementation can effectively reduce the body weight of mice, decrease the serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and leptin levels (P < 0.05), increase the high-density lipoprotein cholesterol (HDL-C) levels (P < 0.05), up-regulate the expression levels of ileal tight junction proteins ZO-1 and occludin (P < 0.05), reduce the hepatocyte injury and lipid accumulation caused by high-fat diet and increase the species richness of intestinal flora.

CONCLUSION

PP can significantly improve hyperlipidemia and regulate intestinal flora disorders caused by hyperlipidemia. The possible mechanism may be related to the reduction of serum leptin levels and up-regulating the expression levels of the ileal tight junction proteins ZO-1 and occludin. This study provides evidence for its regulatory role in lipid metabolism and intestinal function, and provides a research basis for the potential nutritional benefits of underutilized food by-products. © 2023 Society of Chemical Industry.

Black and Yellow Soybean Consumption Prevents High-Fat Diet-Induced Obesity by Regulating Lipid Metabolism in C57BL/6 Mice

To evaluate the antiobesity effects of yellow and black soybean, C57BL/6 mice were provided with a normal diet, high-fat diet, HFD-containing yellow soybean powder (YS), and black soybean powder (BS) for six weeks. Compared with the HFD group, both YS and BS decreased body weight by 30.1% and 37.2% and fat in tissue by 33.3% and 55.8%, respectively. Simultaneously, both soybeans significantly reduced the serum triglyceride and total cholesterol levels and regulated the lipogenic mRNA expressions of Pparγ, Acc, and Fas genes in the liver, supporting reduced body adiposity. Furthermore, BS significantly increased Pgc-1α and Ucp1 mRNA expression levels in epididymal adipose tissue, indicating thermogenesis is the key mechanism of BS. Taken together, our findings suggest that both soybeans prevent high-fat diet-induced obesity in mice by regulating lipid metabolism, and BS, in particular, has a greater antiobesity potential than YS.

Canary Seed (Phalaris canariensis L.) Peptides Prevent Obesity and Glucose Intolerance in Mice Fed a Western Diet

Previous research showed that canary seed (Phalaris canariensis L.) peptides (CSP) possess robust in vitro antiobesity properties via inhibition of pancreatic lipase (PL). Nevertheless, no studies have yet explored their antiobesity properties in vivo. Consequently, we investigated the effects of CSP in C57BL/6J mice under a Western diet (WD). Mice were assigned into groups and fed a normal diet (ND) or a WD accompanied by an oral dose of CSP (250 or 500 mg/kg/day), orlistat (40 mg/kg/day), or distilled water. The results showed that consuming CSP can provide metabolic benefits, including preventing weight gain by up to 20%, increasing glucose tolerance, and reducing insulin, leptin, and LDL/VLDL levels in plasma. Conversely, total ghrelin was unaffected by CSP-500, but decreased by CSP-250, and amplified by orlistat. Surprisingly, CSP-250 was more effective in preventing weight gain and promoting satiety than CSP-500. Parallel to this, protein absorption in CSP-500 was decreased, supported by a rise in fecal crude protein (+3.5%). Similarly, fecal fat was increased by orlistat (38%) and was unaffected by CSP-250 (3.0%) and CSP (3.0%), comparatively to WD (2.5%). Despite this, both CSP treatments were equally effective in decreasing hepatic steatosis and avoiding hyperlipidemia. Furthermore, the enzymatic analysis showed that CSP-PL complexes dissociated faster (15 min) than orlistat-PL complexes (41 min). Lastly, CSP did not affect expression of hepatic lipid oxidation genes ACO and PPAR-α, but reduced the expression of the hydrolase gene LPL, and lipogenesis related genes FAS and ACC. Taken together, these results suggest that CSP antiobesity mechanism relies on lipid metabolism retardation to increase fat transit time and subsequently suppress hunger.

Food protein-derived bioactive peptides for the management of nutrition related chronic diseases

Dietary intervention via modifications of dietary pattern or supplementations of naturally derived bioactive compounds has been considered as an efficient approach in management of nutrition related chronic diseases. Food protein-derived bioactive peptide is representative of natural compounds which show the potential to prevent or mitigate nutrition related chronic diseases. In the past decades, substantial research has been conducted concentrating on the characterization, bioavailability, and activity assessment of bioactive peptides. Although various activities of bioactive peptides have been reported, the activity testes of most peptides were only conducted in cells and animal models. Some clinical trials of bioactive peptides were also reported but only limited to antihypertensive peptides, antidiabetic peptides and peptides modulating blood lipid profile. Hereby, clinical evidence of bioactive peptides in management of nutrition-related chronic diseases is summarized in this chapter, which aims at providing implications for the clinical studies of bioactive peptides in the future.

Hair Growth Promotion with Black Soybean Extracts: case series

Black soybean (BS) is widely thought to prevent or alleviate hair loss, which has been demonstrated by in vitro experiments. However, few clinical studies have directly assessed the effect of BS on hair growth. To assess the safety and efficacy of BS, we administered BS extract to 10 adult patients for 3 months without any other hair products and treatments. The number and diameter of hair lost from washing were examined every 4 weeks. In addition, the participants’ satisfaction with their hair condition was also measured using the VAS (1 to 10) before and after treatment. The mean number of lost hair was 140.7 (SD 59.4) at baseline and 38.8 (SD 54.4) after 12 weeks, and the diameter of lost hair was 72.4 µm (SD 11.9) at baseline and 80.4 µm (SD 8.8) after 12 weeks, which indicated a statistically significant improvement (p = 0.002, p = 0.022, paired t-test). The satisfaction score was significantly increased from 6.10 (SD 1.2) to 8.2 (SD 1.1) after 12 weeks. These results suggest that BS extract may promote hair growth and prevent hair loss.

A comprehensive review on the glucoregulatory properties of food-derived bioactive peptides

Diabetes mellitus, a group of metabolic disorders characterized by persistent hyperglycemia, affects millions of people worldwide and is on the rise. Dietary proteins, from a wide range of food sources, are rich in bioactive peptides with antidiabetic properties. Notable examples include AGFAGDDAPR, a black tea-derived peptide, VRIRLLQRFNKRS, a β-conglycinin-derived peptide, and milk-derived peptide VPP, which have shown antidiabetic effects in diabetic rodent models through variety of pathways including improving beta-cells function, suppression of alpha-cells proliferation, inhibiting food intake, increasing portal cholecystokinin concentration, enhancing insulin signaling and glucose uptake, and ameliorating adipose tissue inflammation. Despite the immense research on glucoregulatory properties of bioactive peptides, incorporation of these bioactive peptides in functional foods or nutraceuticals is widely limited due to the existence of several challenges in the field of peptide research and commercialization. Ongoing research in this field, however, is fundamental to pave the road for this purpose.

Bioactive Peptides: From Basic Research to Clinical Trials and Commercialization

Chronic diseases, including metabolic diseases, have become a worldwide public health issue. Research regarding the use of bioactive peptides or protein hydrolysates derived from food, as the diet-based strategies for the prevention and mitigation of chronic diseases, has increased exponentially in the past decades. Numerous in vitro and in vivo studies report the efficacy and safety of food-derived bioactive peptides and protein hydrolysates as antihypertensive, anti-inflammatory, antidiabetic, and antioxidant agents. However, despite promising preclinical results, an inadequate understanding of their mechanisms of action and pharmacokinetics restrict their clinical translation. Commercialization of bioactive peptides can be further hindered due to scarce information regarding their efficacy, safety, bitter taste, as well as the lack of a cost-effective method of production. This review provides an overview of the current clinical evidence and challenges to commercial applications of food-derived bioactive peptides and protein hydrolysates for the prevention and alleviation of chronic diseases.

Antidiabetic potential of soy protein/peptide: A therapeutic insight

Soybean (Glycine max) harbours high quality proteins which have been evident to exhibit therapeutic properties in alleviating many diseases including but not limited to diabetes and its related metabolic complications. Since diabetes is often manifested with hyperglycemia, impaired energy homeostasis and even low-grade chronic inflammation, plenty of information has raised the suggestion for soy protein supplementation in preventing and controlling these abnormalities. Moreover, clinical intervention studies have established a noteworthy correlation between soy protein intake and lower prevalence of diabetes. Besides soy protein, various soy-derived peptides also have been found to trigger antidiabetic response in different in vitro and in vivo models. Molecular mechanisms underlying the antidiabetic actions of soy protein and peptide have been predicted in many literatures. Results demonstrate that components of soy protein can act in diversified ways and modulate various cell signaling pathways to bring energy homeostasis and to regulate inflammatory parameters associated with diabetic pathophysiology. The main objective of the present review lies in a systemic understanding of antidiabetic role of soy protein and peptide in the context of impaired glucose and lipid metabolism, and inflammation.

The effect of soy products on circulating adiponectin and leptin concentration in adults: A systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Human clinical trials that have investigated the effect of soy product consumption on adipokines have reported inconsistent results. Our objective was to elucidate the role of soy product consumption on adiponectin and leptin in adults through a systematic review and meta-analysis of available randomised placebo-controlled trials (RCTs).

METHODS

The systematic search included PubMed, Scopus, Web of Science, EmBase, Google Scholar and Cochrane database from inception to July 2020. Human clinical trials that reported the effect of soy product consumption on leptin and adiponectin were included. The pooled weighted mean difference (WMD) was calculated by the random-effects model. Heterogeneity, sensitivity analysis, and publication bias were reported using standard methods. Quality assessment was performed using Cochrane risk of bias assessment tool.

RESULTS

Overall, 13 RCTs with 824 participants were included in this meta-analysis. Our analysis showed that soy product consumption did not significantly affect leptin (WMD: 0.01 ng/mL; 95% CI, -0.16, 0.18; P = .88) and adiponectin (WMD: -0.09 ng/mL; 95% CI, -0.29, 0.12; P = .39) concentration in comparison with control. Furthermore, subgroup analysis indicated that the effect remained non-significant when analysed by study design, participant demographics and intervention characteristics. Based on the Cochrane Collaboration Risk of Bias tool, seven studies were considered good quality and six studies were fair.

CONCLUSION

The present systematic review and meta-analysis suggest that soy product consumption had no significant effect on leptin and adiponectin levels in adults. However, future larger and well-designed trials are still needed to further explore this research area and to address the heterogeneous study design used in the existing literature.

Plant-derived peptides improving lipid and glucose metabolism

Plant protein-derived peptides, focusing especially on soybean protein-derived peptides have considerable effects on metabolic regulation and modulation such as cholesterol lowering, triglyceride lowering, anti-obesity, inhibition of fatty acid synthase, and antidiabetic effects. The molecules targeted to study the metabolic regulatory functions of the peptides included the following: intestinal cholesterol micelle, cholesterol metabolism-related genes for cholesterol lowering, triglyceride metabolism-related genes for triglyceride lowering and anti-obesity, dipeptidyl peptidase-IV (DPP-IV), α-amylase, α-glucosidase, or glucose metabolism-related genes for lowering blood glucose levels. This review article outlines the physiological functions of plant protein-derived peptides for the improvement of lipid and glucose metabolism in vitro or in vivo.

Adiponectin and 8-epi-PGF2α as intermediate influencing factors in weight reduction after legume consumption: a 12-week randomised controlled trial

Legumes are rich sources of essential nutrients, and their potential health benefits were reported in many studies. Several studies showed a positive effect of legumes on obesity, but randomised clinical trials are limited in the Korean population. The present intervention study investigated the impact of legumes on body weight in obese Korean subjects. A total of 400 participants (BMI ≥ 25 kg/m²) were randomised into two groups. The legume-enriched diet (LD) group replaced one-third of their refined rice consumption with legumes three times per day as a carbohydrate source. In contrast, the usual diet (UD) group consumed their UD. The mean weight loss at 12 weeks was 2·87 (sem 0·21) kg and 0·17 (sem 0·11) kg in the LD and UD, respectively, which was significantly different between the groups (P < 0·001). HDL-cholesterol and adiponectin levels were increased, and levels of glucose, insulin, TAG, and 8-epi-PGF_2α and the homoeostasis model assessment of insulin resistance (IR) index value decreased at 12 weeks compared with baseline in the LD. The consumption of legumes may accelerate weight loss accompanied by regulation of adiponectin and 8-epi-PGF_2α in obese subjects. In particular, legumes seemed to induce significant changes in BMI by increasing adiponectin in females. Additionally, increases in plasma adiponectin due to greater substantial weight loss may be related to the improvement in IR.

Targeting STAT-3 signaling pathway in cancer for development of novel drugs: Advancements and challenges

Signal transducers and activators of transcription 3 (STAT-3) is a transcription factor that regulates the gene expression of several target genes. These factors are activated by the binding of cytokines and growth factors with STAT-3 specific receptors on cell membrane. Few years ago, STAT-3 was considered an acute phase response element having several cellular functions such as inflammation, cell survival, invasion, metastasis and proliferation, genetic alteration, and angiogenesis. STAT-3 is activated by several types of inflammatory cytokines, carcinogens, viruses, growth factors, and oncogenes. Thus, the STAT3 pathway is a potential target for cancer therapeutics. Abnormal STAT-3 activity in tumor development and cellular transformation can be targeted by several genomic and pharmacological methodologies. An extensive review of the literature has been conducted to emphasize the role of STAT-3 as a unique cancer drug target. This review article discusses in detail the wide range of STAT-3 inhibitors that show antitumor effects both in vitro and in vivo. Thus, targeting constitutive STAT-3 signaling is a remarkable therapeutic methodology for tumor progression. Finally, current limitations, trials and future perspectives of STAT-3 inhibitors are also critically discussed.

The potential of proteins, hydrolysates and peptides as growth factors forLactobacillusandBifidobacterium: current research and future perspectives

Probiotics are live microorganisms that provide health benefits to the host when consumed in adequate concentrations.

Functional properties and adipogenesis inhibitory activity of protein hydrolysates from quinoa (Chenopodium quinoa Willd.)

The functional properties and adipogenesis inhibitory activity of quinoa protein hydrolysates, prepared using papain, pepsin, and pancreatin for 0, 30, 60, 90, and 120 min, were studied. For these three kinds of proteases, the solubility of the hydrolysates significantly increased with the increasing DH in pH range of 3-8, while the EAI and ESI of these hydrolysates significantly decreased during hydrolysis. The anti-inflammatory activity of these protein hydrolysates was measured. All of these protein hydrolysates showed high anti-inflammatory activity. However, there was no significant difference in anti-inflammatory activity between protein hydrolysates and total protein from quinoa. These protein hydrolysates also inhibited lipid accumulation during differentiation within the range of concentrations of 0-1,600 μg/ml, which exerted no cytotoxicity toward 3T3-L1 cells. The protein hydrolysates from quinoa prepared using pepsin for 120 min (PEP-120) had the highest activity with an IC50 value of 786.58 μg/ml. Moreover, LC-MS/MS analysis of PEP-120 showed that five main bioactive peptides, which have been demonstrated to have ACE inhibitor, antioxidant, and antithrombotic activities, were present in PEP-120. In addition, gene expression and Western blot analysis revealed that PEP-120 suppressed the 3T3-L1 cell differentiation through the peroxisome proliferator-activated receptor γ (PPARγ) pathway.

Peptides and Peptidomimetics as Potential Antiobesity Agents: Overview of Current Status

There is a high occurrence of obesity worldwide without many new medications being approved for its treatment. Therefore, there is an urgent need to introduce new approaches for treating obesity. Bioactive peptides have been used to treat metabolic disorders- such as type-2 diabetes and obesity; while also possessing anti-oxidant, anti-inflammatory, anti-microbial, and anti-viral properties. However, the development of these peptides has taken backstage due to their size, reduced stability, poor delivery and bioavailability, fast rate of degradation etc. But with the emergence of newer techniques for multifunctional peptides, mimetics, peptide analogs, and aptamers, there is a sudden revival in this therapeutic field. An increased attention is required for development of the natural peptides from food and marine sources which can mimic the function of mediators involved in weight management to avoid obesity. Herein, the search for the structures of anti-obesity peptides was carried out in order to establish their potential for drug development in future. An extensive search for the current status of endogenous, food and marine peptides, with reference to novel and interesting experimental approaches based on peptidomimetics for controlling obesity, was performed. Apolipoprotein A-I (apoA-I), melanocortin-4 receptor (MC4R)-specific agonist, GLP-1 dual and triple agonists, neuropeptides and prolactin-releasing peptide mimetics were specifically examined for their anti-obesity role. Novel peptides, mimetics, and synthesis interventions are transpiring and might offer safer alternatives for otherwise scarcely available safe antiobesity drug. A deeper understanding of peptides and their chemistry through the use of peptide engineering can be useful to overcome the disadvantages and select best mimetics and analogs for treatment in future.

Molecular targets and mechanisms of bioactive peptides against metabolic syndromes

Bioactive peptides are present in all living organisms and have critical roles ranging from protection against infection as the key element of innate immunity, regulating blood pressure and glucose levels, to reducing signs of ageing by killing senescent cells. Bioactive peptides are also encrypted within food protein sequences that can be released during proteolysis or food processing. These specific food protein fragments are reported to have potential for improving human health and preventing metabolic diseases through their impact on inflammation, blood pressure, obesity, and type-2 diabetes. This review mainly focuses on the molecular targets and the underlying mechanisms of bioactive peptides against various metabolic syndromes including inflammation, high blood pressure, obesity, and type-2 diabetes, to provide new insights and perspectives on the potential of bioactive peptides for management of metabolic syndromes.

Black soybean extract improves lipid profiles in fenofibrate-treated type 2 diabetics with postprandial hyperlipidemia

Black soybeans (Glycine max (L.) Merr.) are known to be rich in polyphenols, including anthocyanins, and they have been consumed since ancient times for their beneficial effects on health. In addition, it has been reported that black soybean (BS) seed coat may ameliorate obesity and insulin resistance. In the present study, we administered BS extract to type 2 diabetics for 2 months to investigate the effects of BS on glycemic control and lipid metabolism parameters. In addition, we administered BS and antihyperlipidemic agent, fenofibrate, to patients with type 2 diabetes complicated by postprandial hyperlipidemia for 2 months and assessed the combined effects of fenofibrate and BS on serum lipid profile. The results showed that administration of the BS alone had no effect on the blood glucose or lipid levels, but that administration of fenofibrate alone and fenofibrate in combination with the BS significantly lowered their serum triglyceride (TG) level at fasting state, and the percent decrease in the serum TG level after combined administration was significantly higher than in the subjects who received fenofibrate alone. Furthermore, the serum LDL cholesterol concentration, which did not decrease when fenofibrate was administered alone, decreased significantly when the BS and fenofibrate were administered in combination. These results suggest that combined administration of the BS with fenofibrate enhanced the antihyperlipidemic action of fenofibrate, and the results of this study demonstrated the usefulness of the BS in clinical practice.

Heavy metal complexation of thiol-containing peptides from soy glycinin hydrolysates

Many thiol-containing molecules show heavy metal complexation ability and are used as antidotes. In this study, the potential function associated with thiol-containing peptides (TCPs) from soy protein hydrolysates as natural detoxicants for heavy metals is reported. TCPs enriched by Thiopropyl-Sepharose 6B covalent chromatography had different molecular weight distributions as well as different numbers of proton dissociable groups, depending on the proteases and degree of hydrolysis. The major contribution of sulfhydryl groups was confirmed by the largest pH decrease between 8.0 and 8.5 of the pH titration curves. The complexation of TCPs with heavy metalswas evaluated by stability constants (β_n) of TCP-metal complexes whose stoichiometry was found to be 1:1 (ML) and 1:2 (ML₂). TCPs from degree of hydrolysis of 25% hydrolysates gave high affinities towards Hg²⁺, Cd²⁺, and Pb²⁺ (giving similar or even bigger lgβ values than that of glutathione). A significantly positive correlation was found between the logarithm of stability constants for ML₂ (lgβ₂) and the sulfhydryl group content. Molecular weight distribution of TCPs affected the complexation with Pb²⁺ notably more than Hg²⁺ and Cd²⁺. These results suggest that soy TCPs have the potential to be used in the formulation of functional foods to counteract heavy metal accumulation in humans.

Black soybean extract reduces fatty acid contents in subcutaneous, but not in visceral adipose triglyceride in high-fat fed rats

It is known that black soybean (BS) extract, rich in polyphenols, has beneficial effects against obesity, inflammation and insulin resistance. However, detailed effects of BS on lipid metabolism have not been documented well. In the present study, we compared fatty acid composition in visceral and subcutaneous adipose tissues of high-fat fed (HFF) rats and BS administered HFF rats. Black soybean administration for 6 weeks influenced neither body nor adipose tissue weights, blood glucose, plasma insulin levels, or insulin sensitivity. However, BS reduced several saturated (C14:0 and C16:0), monounsaturated (C14:1n-5 and C18:1n-9) and n-6 polyunsaturated (C18:2n-6, C20:3n-6, C20:4n-6 and C22:4n-6) fatty acid contents in subcutaneous fat without any change in n-3 polyunsaturated fatty acid contents. No such effect was observed in fatty acid composition in visceral fat. Long-chain fatty acids are involved in regulation of inflammation. Therefore, those reduced fatty acids may be linked to the effects on suppressing inflammation.

Functional significance of bioactive peptides derived from soybean

Biologically active peptides play an important role in metabolic regulation and modulation. Several studies have shown that during gastrointestinal digestion, food processing and microbial proteolysis of various animals and plant proteins, small peptides can be released which possess biofunctional properties. These peptides are to prove potential health-enhancing nutraceutical for food and pharmaceutical applications. The beneficial health effects of bioactive peptides may be several like antihypertensive, antioxidative, antiobesity, immunomodulatory, antidiabetic, hypocholesterolemic and anticancer. Soybeans, one of the most abundant plant sources of dietary protein, contain 36-56% of protein. Recent studies showed that soy milk, an aqueous extract of soybean, and its fermented product have great biological properties and are a good source of bioactive peptides. This review focuses on bioactive peptides derived from soybean; we illustrate their production and biofunctional attributes.

Targeting the STAT3 signaling pathway in cancer: role of synthetic and natural inhibitors

Signal transducers and activators of transcription (STATs) comprise a family of cytoplasmic transcription factors that mediate intracellular signaling that is usually generated at cell surface receptors and thereby transmit it to the nucleus. Numerous studies have demonstrated constitutive activation of STAT3 in a wide variety of human tumors, including hematological malignancies (leukemias, lymphomas, and multiple myeloma) as well as diverse solid tumors (such as head and neck, breast, lung, gastric, hepatocellular, colorectal and prostate cancers). There is strong evidence to suggest that aberrant STAT3 signaling promotes initiation and progression of human cancers by either inhibiting apoptosis or inducing cell proliferation, angiogenesis, invasion, and metastasis. Suppression of STAT3 activation results in the induction of apoptosis in tumor cells, and accordingly its pharmacological modulation by tyrosine kinase inhibitors, antisense oligonucleotides, decoy nucleotides, dominant negative proteins, RNA interference and chemopreventive agents have been employed to suppress the proliferation of various human cancer cells in culture and tumorigenicity in vivo. However, the identification and development of novel drugs that can target deregulated STAT3 activation effectively remains an important scientific and clinical challenge. This review presents the evidence for critical roles of STAT3 in oncogenesis and discusses the potential for development of novel cancer therapies based on mechanistic understanding of STAT3 signaling cascade.

Obesity-related metabolomic analysis of human subjects in black soybean peptide intervention study by ultraperformance liquid chromatography and quadrupole-time-of-flight mass spectrometry

The present study aimed to identify key metabolites related to weight reduction in humans by studying the metabolic profiles of sera obtained from 34 participants who underwent dietary intervention with black soybean peptides (BSP) for 12 weeks. This research is a sequel to our previous work in which the effects of BSP on BMI and blood composition of lipid were investigated. Sera of the study were subjected to ultra performance liquid chromatography and quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS), and the data were analyzed using partial least-squares discriminate analysis (PLS-DA) score plots. Body mass index and percent body fat of the test group were reduced. Levels of betaine, benzoic acid, pyroglutamic acid, pipecolic acid, N-phenylacetamide, uric acid, l-aspartyl-l-phenylalanine, and lysophosphatidyl cholines (lysoPCs) (C18:1, C18:2, C20:1, and C20:4) showed significant increases. Levels of l-proline, valine, l-leucine/isoleucine, hypoxanthine, glutamine, l-methionine, phenylpyruvic acid, several carnitine derivatives, and lysoPCs (C14:0, PC16:0, C15:0, C16:0, C17:1, C18:0, and C22:0) were significantly decreased. In particular, lysoPC 16:0 with a VIP value of 12.02 is esteemed to be the most important metabolite for evaluating the differences between the 2 serum samples. Our result confirmed weight-lowering effects of BSP, accompanied by favorable changes in metabolites in the subjects' blood. Therefore, this research enables us to better understand obesity and increases the predictability of the obesity-related risk by studying metabolites present in the blood.

Food ingredients as anti-obesity agents: a review

Overweight and obesity have a major impact on global health; their prevalence has rapidly increased in all industrialized countries in the past few decades and diabetes and hypertension are their direct consequences. Pharmacotherapy provides reinforcement for obesity treatment, but should be an adjunctive support to diet, exercise, and lifestyle modification. At present, only orlistat and sibutramine have been approved by the US Food and Drug Administration for long-term use, but sibutramine was withdrawn for sale by the European Medicines Agency. The development of functional foods for the prevention and/or treatment of obesity suppose an opportunity for the food market and involve the knowledge of the mechanisms of appetite and energy expenditure as well as the metabolic sensation of satiety. Strategies for weight control management affect gut hormones as potential targets for the appetite metabolic regulation, stimulation of energy expenditure (thermogenesis), and modifications in the metabolic activity of the gut microbiota. Functional foods for obesity may also include bioactive fatty acids, phenolic compounds, soybean, plant sterols, dietary calcium, and dietary fiber. This review intends to offer an overview of the present situation of the anti-obesity agents currently used in dietary therapy as well as some functional food ingredients with potentially anti-obesity effects.

AMP-activated protein kinase and ATP-citrate lyase are two distinct molecular targets for ETC-1002, a novel small molecule regulator of lipid and carbohydrate metabolism

ETC-1002 (8-hydroxy-2,2,14,14-tetramethylpentadecanedioic acid) is a novel investigational drug being developed for the treatment of dyslipidemia and other cardio-metabolic risk factors. The hypolipidemic, anti-atherosclerotic, anti-obesity, and glucose-lowering properties of ETC-1002, characterized in preclinical disease models, are believed to be due to dual inhibition of sterol and fatty acid synthesis and enhanced mitochondrial long-chain fatty acid β-oxidation. However, the molecular mechanism(s) mediating these activities remained undefined. Studies described here show that ETC-1002 free acid activates AMP-activated protein kinase in a Ca(2+)/calmodulin-dependent kinase β-independent and liver kinase β 1-dependent manner, without detectable changes in adenylate energy charge. Furthermore, ETC-1002 is shown to rapidly form a CoA thioester in liver, which directly inhibits ATP-citrate lyase. These distinct molecular mechanisms are complementary in their beneficial effects on lipid and carbohydrate metabolism in vitro and in vivo. Consistent with these mechanisms, ETC-1002 treatment reduced circulating proatherogenic lipoproteins, hepatic lipids, and body weight in a hamster model of hyperlipidemia, and it reduced body weight and improved glycemic control in a mouse model of diet-induced obesity. ETC-1002 offers promise as a novel therapeutic approach to improve multiple risk factors associated with metabolic syndrome and benefit patients with cardiovascular disease.

Weight reduction effects of a black soy peptide supplement in overweight and obese subjects: double blind, randomized, controlled study

The present study determined the effect of black soy peptide supplementation on body weight and body fat in overweight/obese subjects. In a double-blind controlled trial, participants (n = 80) were randomized to either soy peptide supplementation (the test group) or to a placebo (the placebo group). Sixty-four people completed the study, and anthropometric parameters, serum inflammatory markers, and leptin and lipid profiles were measured. After 6 weeks, the test group (n = 35) had significant reductions in body weight (p = 0.003) and body mass index (BMI) (p = 0.004), body fat mass (p = 0.038). After 12 weeks, they also had significant reductions in body weight (p < 0.001), BMI (p < 0.001), body fat percentage (p = 0.002), and body fat mass (p = 0.001). However, these significances were not observed in the placebo group (n = 29). In addition, net changes in body weight and body fat mass in the test group were significantly bigger than those in the placebo group after 12 weeks. Leptin levels were significantly reduced in the test groups (p = 0.047), but were not observed in the placebo group (p = 0.323). Interestingly, the subjects with weight reductions ≥1kg in the test group had greater reductions in circulating leptin levels (p = 0.002). Additionally, fasting insulin levels were significantly reduced in the test groups. The conclusion is that black soy peptide supplementation may be beneficial for body weight control in overweight/obese subjects.

Critical role of peroxisome proliferator activated receptor-δ on body fat reduction in C57BL/6J and human apolipoprotein E2 transgenic mice fed delipidated soybean

The consumption of soy protein and fiber reduces body fat accumulation; however, the mechanism of this effect has not been clearly understood. We investigated the antiobesogenic effect of soy protein and fiber in two different mouse models. Normolipidemic nonobese C57BL/6J and hyperlipidemic obese human apolipoprotein E2 transgenic mice were fed either delipidated soybean (DLSB) containing soy protein and fiber or a control diet. The DLSB-fed mice showed a significant reduction in body weight gain and adiposity compared with controls, in both C57BL/6J and apoE2 mice. All metabolic parameters were significantly improved in the DLSB group compared with controls: total cholesterol, low-density lipoprotein cholesterol, insulin, and leptin levels were significantly reduced. Adiponectin concentrations were significantly elevated, and glucose tolerance was improved. In both types of DLSB-fed mice, the specific induction of PPAR-δ protein expression was evident in muscle and adipose tissues. The expression of PPAR-δ target genes in the DLSB-fed mice was also significantly altered. Acetyl-CoA carboxylase-1 and fatty acid synthase levels in adipose tissue were downregulated, and uncoupling protein-2 in muscle was upregulated. Intestinal expression of fatty acid transport protein-4, cluster of differentiation-36, and acyl-CoA synthetase were significantly downregulated. We propose that marked activation of PPAR-δ is the primary mechanism mediating the antiobesogenic effect of soybean and that PPAR-δ has multiple actions: induction of thermogenesis in muscle, reduction of fatty acid synthesis in adipose tissue, and reduction of fatty acid uptake in intestinal tissue.

Black soybean extract can attenuate thrombosis through inhibition of collagen-induced platelet activation

Many clinical trials have demonstrated the beneficial effects of soybean (Glycine max) on general cardiovascular health. Among a variety of soybeans, black soybean is known to display diverse biological activities superior to those of yellow and green soybeans, such as in antioxidant, anti-inflammatory and anticancer activities. However, few studies have been directed on the effect of black soybean on cardiovascular function. In this study, we aimed to investigate the effect of black soybean extract (BB) on platelet activation, a key contributor to thrombotic diseases. In freshly isolated human platelets, BB has shown potent inhibitory activity on collagen-induced platelet aggregation, while yellow soybean extract had marginal activity only. BB also attenuated serotonin secretion and P-selectin expression, which are important factors for the platelet-tissue interaction along with thromboxane A(2) formation. These in vitro results were further confirmed in an ex vivo platelet aggregation measurement and in vivo venous thrombosis model where oral administration of BB reduced collagen-induced platelet aggregation and FeCl(3)-induced thrombus formation significantly. A potential active ingredient for antiplatelet effects of BB was isolated and identified to be adenosine through bioassay-directed fractionation and NMR and ESI-MS analyses. These results indicate that black soybean can be a novel dietary supplement for the prevention of cardiovascular risks and the improvement of blood circulation.

Oxytocin-messages via the cerebrospinal fluid: behavioral effects; a review

The cerebrospinal fluid (CSF) usually is considered as a protective 'nutrient and waste control' system for the brain. Recent findings suggest, however, that the composition of CSF is actively controlled and may play an influential role in the changes in brain activity, underlying different behavioral states. In the present review, we present an overview of available data concerning the release of oxytocin into the CSF, the location of the oxytocin-receptive brain areas and the behavioral effects of intracerebroventricular oxytocin. About 80% of the oxytocin-receptive areas are located close to the ventricular or subarachnoid CSF, including the hypothalamic 'Behavior Control Column' (L.W.Swanson, 2003). As a conclusion we suggest that 'CSF-oxytocin' contributes considerably to the non-synaptic communication processes involved in hypothalamic-, brainstem- and olfactory brain areas and behavioral states and that the flowing CSF is used as a 'broadcasting system' to send coordinated messages to a wide variety of nearby and distant brain areas.

Thermostable Kunitz trypsin inhibitor with cytokine inducing, antitumor and HIV-1 reverse transcriptase inhibitory activities from Korean large black soybeans

A large number of trypsin inhibitors belonging to various types have been purified from different kinds of legumes. In this study, by using liquid chromatography, a Kunitz type trypsin inhibitor (KBTI) with a molecular weight of 20107.645 Da was purified from Korean large black soybeans. KBTI reduced the proteolytic activities of trypsin and alpha-chymotrypsin with the activity of approximately 8520 BAEE units/mg and approximately 24 BTEE units/mg, respectively. It showed high thermal stability (0-100 degrees C) as well as stability over a large range of pH values (pH 3-11). Furthermore, KBTI inhibited HIV-1 reverse transcriptase activity with an IC(50) value of 0.71 microM and induced the release of pro-inflammatory cytokines such as TNF-alpha, IL-1beta, IL-2 and interferon-gamma at the mRNA level. KBTI exerted weak antiproliferative activity toward CNE-2 and HNE-2 nasopharyngeal cancer cells, MCF-7 breast cancer cells, and Hep G2 hepatoma cells. KBTI was destitute of mitogenic, ribonuclease and antifungal activities.

In vivo and in vitro application of black soybean peptides in the amelioration of endoplasmic reticulum stress and improvement of insulin resistance

AIMS

Hepatic endoplasmic reticulum (ER) stress plays a key role in the development of obesity-induced insulin resistance. This study evaluated the effects of peptides from black soybean (BSP) on ER stress and insulin signaling in vitro and in vivo.

MAIN METHODS

Using C2C12 myotubes or HepG2 cells, we evaluated the effects of BSP on the expression of proteins involved in insulin signaling and in the ER stress response in insulin-sensitive or insulin-resistant cells. BSP was given orally to db/db mice for 5weeks to investigate its antidiabetic effects in vivo and the underlying mechanisms.

KEY FINDINGS

BSP increased GLUT4 translocation and glucose transport in myotubes and stimulated Akt-mediated glycogen synthase kinase-3beta (GSK-3beta) and Foxo1 phosphorylation in HepG2 cells. BSP significantly restored the suppression of insulin-mediated Akt phosphorylation in insulin-resistant cells. BSP significantly inhibited the activation of ER stress-responsive proteins by thapsigargin. BSP also significantly reduced blood glucose and improved glucose tolerance in db/db mice. The serum lipid profile (triglyceride and high-density lipoprotein concentrations) improved concomitantly with the BSP-induced downregulation of hepatic fatty acid synthase expression in db/db mice. Consistent with the results observed in HepG2 cells, BSP downregulated the elevated hepatic ER stress response in diabetic mice concomitantly with an increased expression of phospho-Foxo1.

SIGNIFICANCE

A peptide mixture, BSP, showed beneficial effects through multiple mechanisms involving the suppression of hepatic ER stress and restoration of insulin resistance, suggesting that it has potential as an antidiabetic agent.

Signal transducer and activator of transcription-3, inflammation, and cancer: how intimate is the relationship?

Signal transducer and activator of transcription-3 (STAT-3) is one of six members of a family of transcription factors. It was discovered almost 15 years ago as an acute-phase response factor. This factor has now been associated with inflammation, cellular transformation, survival, proliferation, invasion, angiogenesis, and metastasis of cancer. Various types of carcinogens, radiation, viruses, growth factors, oncogenes, and inflammatory cytokines have been found to activate STAT-3. STAT-3 is constitutively active in most tumor cells but not in normal cells. Phosphorylation of STAT-3 at tyrosine 705 leads to its dimerization, nuclear translocation, DNA binding, and gene transcription. The phosphorylation of STAT-3 at serine 727 may regulate its activity negatively or positively. STAT-3 regulates the expression of genes that mediate survival (survivin, bcl-xl, mcl-1, cellular FLICE-like inhibitory protein), proliferation (c-fos, c-myc, cyclin D1), invasion (matrix metalloproteinase-2), and angiogenesis (vascular endothelial growth factor). STAT-3 activation has also been associated with both chemoresistance and radioresistance. STAT-3 mediates these effects through its collaboration with various other transcription factors, including nuclear factor-kappaB, hypoxia-inducible factor-1, and peroxisome proliferator activated receptor-gamma. Because of its critical role in tumorigenesis, inhibitors of this factor's activation are being sought for both prevention and therapy of cancer. This has led to identification of small peptides, oligonucleotides, and small molecules as potential STAT-3 inhibitors. Several of these small molecules are chemopreventive agents derived from plants. This review discusses the intimate relationship between STAT-3, inflammation, and cancer in more detail.

Signal transducer and activator of transcription-3, inflammation, and cancer: how intimate is the relationship?

Signal transducer and activator of transcription-3 (STAT-3) is one of six members of a family of transcription factors. It was discovered almost 15 years ago as an acute-phase response factor. This factor has now been associated with inflammation, cellular transformation, survival, proliferation, invasion, angiogenesis, and metastasis of cancer. Various types of carcinogens, radiation, viruses, growth factors, oncogenes, and inflammatory cytokines have been found to activate STAT-3. STAT-3 is constitutively active in most tumor cells but not in normal cells. Phosphorylation of STAT-3 at tyrosine 705 leads to its dimerization, nuclear translocation, DNA binding, and gene transcription. The phosphorylation of STAT-3 at serine 727 may regulate its activity negatively or positively. STAT-3 regulates the expression of genes that mediate survival (survivin, bcl-xl, mcl-1, cellular FLICE-like inhibitory protein), proliferation (c-fos, c-myc, cyclin D1), invasion (matrix metalloproteinase-2), and angiogenesis (vascular endothelial growth factor). STAT-3 activation has also been associated with both chemoresistance and radioresistance. STAT-3 mediates these effects through its collaboration with various other transcription factors, including nuclear factor-kappaB, hypoxia-inducible factor-1, and peroxisome proliferator activated receptor-gamma. Because of its critical role in tumorigenesis, inhibitors of this factor's activation are being sought for both prevention and therapy of cancer. This has led to identification of small peptides, oligonucleotides, and small molecules as potential STAT-3 inhibitors. Several of these small molecules are chemopreventive agents derived from plants. This review discusses the intimate relationship between STAT-3, inflammation, and cancer in more detail.

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

Obesity is a worldwide health concern and a well recognized predictor of premature mortality associated with a state of chronic inflammation. The objective was to evaluate the effect of soy protein hydrolysates (SPH) produced from different soybean genotypes by alcalase (SAH) or simulated gastrointestinal digestion (SGIH) on lipid accumulation in 3T3-L1 adipocytes. The anti-inflammatory effect of SPH produced by alcalase on LPS-induced macrophage RAW 264.7 cell line was also investigated. SAH (100 microM) derived from soybean enriched in beta-conglycinin (BC) (up to 47% total protein) decreased lipid accumulation (33-37% inhibition) through downregulation of gene expression of lipoprotein lipase (LPL) and fatty acid synthase (FAS). SGIH (100 microM) inhibited lipid accumulation to a lesser extent (8-14% inhibition) through inhibition of LPL gene expression. SAH (5 microM) decreased the production of nitric oxide (NO) (18-35%) and prostaglandin E(2) (PGE(2)) (47-71%) and the expression of inducible nitric oxide synthase (iNOS) (31-53%) and cycloxygenase-2 (COX-2) (30-52%). This is the first investigation showing that soy hydrolysates inhibit LPS-induced iNOS/NO and COX-2/PGE(2 )pathways in macrophages. Soybeans enriched in BCs can provide hydrolysates that limit fat accumulation in fat cells and inflammatory pathways in vitro and therefore warrant further studies as a healthful food.