Intracerebroventricular administration of soy protein hydrolysates reduces body weight without affecting food intake in rats

Acute oral toxicity study on Wistar rats fed microalgal protein hydrolysates from Bellerochea malleus

Protein hydrolysates and bioactive peptides from various protein sources have demonstrated their effectiveness for the prevention of illness and the improvement of symptoms from several diseases. In particular, the use of microalgae to generate bioactive peptides has received a growing interest because of their potential to be cultivated on non-arable land and high nutritional value. However, scant research is available on the toxicity of peptide-based preparations. The present study aims to evaluate the toxicity of microalgal protein hydrolysates (MPH) from one marine species of microalgae (Bellerochea malleus) to determine the feasibility of their use for functional food applications. Results showed that the oral administration of MPH at three doses (D1, 100 mg kg^-1 BW; D2, 400 mg kg^-1 BW; and D3, 2000 mg kg^-1 BW) to male Wistar rats did not induce any adverse effects or mortality up to13 days of treatment. Data analysis of relative organ weights and biochemical and hematological parameters did not show any significant differences between control and treated groups at the three doses investigated. Data from histopathological observations did not reveal any signs of major toxicity at the doses D1 and D2. However, mild signs of inflammation and necrosis were observed in the kidney of rats fed MPH at D3. All together, these results reveal the overall safety of MPH and provide new evidence for advocating their use for functional food or nutraceutical applications.

Fish protein hydrolysate exhibits anti-obesity activity and reduces hypothalamic neuropeptide Y and agouti-related protein mRNA expressions in rats

Fish protein is a source of animal protein that is consumed worldwide. Although it has been reported that the intake of Alaska pollack protein (APP) reduces body fat accumulation and increases muscle weight in rats, the mechanisms underlying these effects are poorly understood. As a possibility, peptides released from APP in the gastrointestinal tract are important to the functions of APP. In the present study, we examined the effects of APP hydrolysate digested artificially with pepsin and pancreatin on white adipose tissue and skeletal muscle. We found that APP hydrolysate group shows significantly lower weight of white adipose tissue and higher weight of soleus muscle than the control group. We also found that APP hydrolysate group reduces food intake and mRNA expressions of neuropeptide Y and agouti-related protein in the hypothalamus compared with the control group. These results may imply that APP hydrolysate exhibits anti-obesity activity by the reduction of appetite and the enhancement of basal energy expenditure by skeletal muscle hypertrophy in rats. The downregulation of orexigenic gene by APP hydrolysate in the hypothalamus may contribute to the reduction of appetite. These results suggest that the effect of APP on anti-obesity and muscle hypertrophy may be induced by peptides released from APP in the gastrointestinal tract.

Pepsin Egg White Hydrolysate Ameliorates Obesity-Related Oxidative Stress, Inflammation and Steatosis in Zucker Fatty Rats

The aim of this work was to evaluate the effect of the administration of egg white hydrolysates on obesity-related disorders, with a focus on lipid metabolism, inflammation and oxidative stress, in Zucker fatty rats. Obese Zucker rats received water, pepsin egg white hydrolysate (750 mg/kg/day) or Rhizopus aminopeptidase egg white hydrolysate (750 mg/kg/day) for 12 weeks. Lean Zucker rats received water. Body weight, solid and liquid intakes were weekly measured. At the end of the study, urine, faeces, different organs and blood samples were collected. The consumption of egg white hydrolysed with pepsin significantly decreased the epididymal adipose tissue, improved hepatic steatosis, and lowered plasmatic concentration of free fatty acids in the obese animals. It also decreased plasma levels of tumor necrosis factor-alpha and reduced oxidative stress. Pepsin egg white hydrolysate could be used as a tool to improve obesity-related complications.

Therapeutic perspectives of epigenetically active nutrients

Many nutrients are known for a wide range of activities in prevention and alleviation of various diseases. Recently, their potential role in regulating human health through effects on epigenetics has become evident, although specific mechanisms are still unclear. Thus, nutriepigenetics/nutriepigenomics has emerged as a new and promising field in current epigenetics research in the past few years. In particular, polyphenols, as part of the central dynamic interaction between the genome and the environment with specificity at physiological concentrations, are well known to affect mechanisms underlying human health. This review summarizes the effects of dietary compounds on epigenetic mechanisms in the regulation of gene expression including expression of enzymes and other molecules responsible for drug absorption, distribution, metabolism and excretion in cancer, metabolic syndrome, neurodegenerative disorders and hormonal dysfunction.

The effects of soy bean flour enriched bread intake on anthropometric indices and blood pressure in type 2 diabetic women: a crossover randomized controlled clinical trial

Previous studies showed that soy bean has the potential to improve many aspects of diabetes state and provide metabolic benefits that aid in weight management. We aimed to determine the effects of soy bean flour enriched bread on anthropometric indices and blood pressure among type 2 diabetic patients. This randomized, crossover, clinical trial was performed in 30 type 2 diabetic women. There were two trial periods for 6 weeks and a wash-out period for 4 weeks. In the soy bread diet period, 120 g of soy bean flour enriched bread was consumed each day instead of the same amount of their usual bread or other cereal products. After a 4-week wash-out period, participants were crossed over for another 6 weeks. Mean (±SD) age of study participants was 45.7 ± 3.8 years. The results of our study showed no significant effects of soy bean flour enriched bread on anthropometric indices and blood pressure among diabetic patients. Despite the slight reduction in BMI, waist circumference, and percent of body fat, there were no significant differences in changes of these values between two groups. No significant changes in waist to hip ratio and blood pressure were seen.

Peptides in pepsin-pancreatin hydrolysates from commercially available soy products that inhibit lipopolysaccharide-induced inflammation in macrophages

The potential of pepsin-pancreatin hydrolysates, from different foods, to inhibit inflammation using lipopolysaccharide (LPS)-induced RAW 264.7 macrophages as an in vitro model was evaluated. Eight different products were digested sequentially with pepsin and pancreatin and were evaluated for their anti-inflammatory properties. Hydrolysates from strawberry-banana soymilk (SBH), mixed berry soymilk (MXH) and vanilla soymilk (SVMH) inhibited the production of nitric oxide (27.9%, 16.4% and 28.6%, respectively), interleukin-1β (26.3%, 39.5% and 21.6%, respectively) and tumour necrosis factor-α (50.2%, 47.5% and 33.3%, respectively). In addition, SBH, MXH and SVMH inhibited the expression of pro-inflammatory enzymes: inducible nitric oxide synthase (66.7%, 65.1% and 88.0%, respectively) and cyclooxygenase-2 (62.0%, 69.9% and 40.6%, respectively). Bioactive peptides (RQRK and VIK) were generated. In conclusion, soymilk products can potentially be used to maintain health under inflammatory stress.

A six-month randomized controlled trial of whole soy and isoflavones daidzein on body composition in equol-producing postmenopausal women with prehypertension

OBJECTIVES

This paper reported the effects of commonly used whole soy foods (soy flour) and purified daidzein (one of the major isoflavones and the precursor of equol) on changes in anthropometric measurements and body composition in a 6-month double-blind, randomized, placebo-controlled trial among prehypertensive postmenopausal women who are also equol producers.

METHODS

270 eligible women were randomized to either one of the three treatments: 40 g soy flour (whole soy group), 40 g low-fat milk powder + 63 mg daidzein (daidzein group), or 40 g low-fat milk powder (placebo group) daily each for 6 months. Anthropometric indicators and body composition were measured before and after intervention.

RESULTS

253 subjects completed the study with good compliance. Urinary isoflavones levels suggested good compliance of subjects with supplementation. Whole soy and purified daidzein had no significant effect on body weight, body mass index (BMI), waist and hip circumferences, waist to hip ratio (WHR), body fat percentage, fat mass, and free fat mass.

CONCLUSION

Six-month consumption of whole soy and purified daidzein at provided dosage had no improvement on body weight and composition compared with isocaloric milk placebo among prehypertensive equol-producing postmenopausal women. This trial is registered with ClinicalTrials.gov NCT01270737.

Mitigation of obesity-promoted diseases by Nigella sativa and thymoquinone

Obesity is closely associated with increased incidence of cardiovascular diseases, cancer, insulin resistance, and immune dysfunction, and thus obesity-mitigation strategies should take into account these secondary pathologies in addition to promoting weight loss. Recent studies indicate that black cumin (Nigella sativa) has cardio-protective, anti-cancer, anti-diabetic, antioxidant, and immune-modulatory properties. While black cumin and/or its major bioactive constituent, thymoquinone have demonstrated bioactivity in a variety of disease models, the mechanisms of action are largely unknown. Given the growing interest in and the use of functional foods and nutraceuticals, as well as the increase in obesity and chronic diseases worldwide, further research into the therapeutic/preventive effects of black cumin may be beneficial.

Antioxidant capacity of alcalase hydrolysates and protein profiles of two conventional and seven low glycinin soybean cultivars

Soy protein hydrolysates are considered a potential dietary source of natural antioxidants with important biological activities. This study was conducted to compare the effect of two conventional and seven low glycinin soybean cultivars on the antioxidant capacity (AC) of soy hydrolysates. Nine cultivars were grown in Bloomington, IL, Findlay, OH and Huxley, IA. The hydrolysates were produced enzymatically using alcalase and analyzed for AC using oxygen radical absorbance capacity (ORAC) assay and soluble protein. Statistical differences were observed in the protein profiles and AC among the different cultivars tested (P < 0.05). The hydrolysate from low glycinin cultivar 3 enriched in β-conglycinin, grown in Bloomington, exhibited the highest AC, compared to the other cultivars across all locations. On average, soy cultivars rich in BC and purified BC hydrolysates (36.2 and 31.8 μM Trolox equivalents (TE)/μg soluble protein, respectively) (P > 0.05) had higher AC than purified glycinin (GL) hydrolysate (28.5 μM TE/μg soluble protein) (P < 0.05). It was possible to select a soybean cultivar that produced a higher antioxidant capacity upon alcalase hydrolysis.

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.

Bowman-Birk inhibitor and genistein among soy compounds that synergistically inhibit nitric oxide and prostaglandin E2 pathways in lipopolysaccharide-induced macrophages

Inflammation has an important role in the development of chronic diseases. In this study, we evaluated the anti-inflammatory properties of eight soybean bioactive compounds using lipopolysaccharide-induced RAW 264.7 macrophages. Genistein, daidzein, a mix of isoflavone glucosides, saponin A group glycosides (saponin A), saponin B group glycosides (saponin B), sapogenol B, Bowman-Birk inhibitor (BBI), lunasin, and pepsin-pancreatin glycinin hydrolysates were tested by measuring their ability to inhibit cyclooxygenase-2/prostaglandin E(2) (PGE(2)) and inducible nitric oxide synthase (iNOS)/nitric oxide (NO) inflammatory pathways. Of the eight soy bioactive compounds (SBCs) tested, BBI and sapogenol B resulted in the highest inhibition of pro-inflammatory responses at a concentration 10 times lower than the one used for the other compounds. Also, sapogenol B and genistein (molar ratio 1:1) synergistically inhibited NO and additively inhibited PGE(2). Saponin A group glycosides showed inhibition of the iNOS/NO pathway only, while pepsin-pancreatin glycinin hydrolysates enhanced induction and production of the four inflammatory responses. For the first time, synergistic interactions were observed between BBI and genistein inhibiting NO (92.7%) and PGE(2) (95.6%) production. An antagonistic interaction was observed between the saponin B group glycosides and sapogenol B. All interactions were further confirmed by isobolographic analysis. These findings demonstrated that some SBCs possess anti-inflammatory properties and therefore are important in modulating mammalian inflammation pathways which may lead to inhibition of some types of chronic disease. Furthermore, through their interaction they can modulate the inflammatory process.