Protein Digests and Pure Peptides from Chia Seed Prevented Adipogenesis and Inflammation by Inhibiting PPARγ and NF-κB Pathways in 3T3L-1 Adipocytes.

The objective was to evaluate the mechanisms of digested total proteins (DTP), albumin, glutelin, and pure peptides from chia seed (Salvia hispanica L.) to prevent adipogenesis and its associated inflammation in 3T3-L1 adipocytes. Preadipocytes (3T3-L1) were treated during differentiation with either DTP or digested albumin or glutelin (1 mg/mL) or pure peptides NSPGPHDVALDQ and RMVLPEYELLYE (100 µM). Differentiated adipocytes also received DTP, digested albumin or glutelin (1 mg/mL), before (prevention) or after (inhibition) induced inflammation by addition of conditioned medium (CM) from inflamed macrophages. All treatments prevented adipogenesis, reducing more than 50% the expression of PPARγ and to a lesser extent lipoprotein lipase (LPL), fatty acid synthase (FAS), sterol regulatory element-binding protein 1 (SREBP1), lipase activity and triglycerides. Inflammation induced by CM was reduced mainly during prevention, while DTP decreased expression of NF-κB (-48.4%), inducible nitric oxide synthase (iNOS) (-46.2%) and COX-2 (-64.5%), p < 0.05. Secretions of nitric oxide, PGE2 and TNFα were reduced by all treatments, p < 0.05. DTP reduced expressions of iNOS (-52.1%) and COX-2 (-66.4%). Furthermore, digested samples and pure peptides prevented adipogenesis by modulating PPARγ and additionally, preventing and even inhibiting inflammation in adipocytes by inhibition of PPARγ and NF-κB expression. These results highlight the effectiveness of digested total proteins and peptides from chia seed against adipogenesis complications in vitro.

Investigation of the Effects of Glutens on Serum Interleukin-1 Beta and Tumor Necrosis Factor-Alpha Levels and the Immunohistochemical Distribution of CD3 and CD8 Receptors in the Small Intestine in Male Rats

Abstract While the role of cytokines in celiac disease has been investigated in detail, cytokine release in the event of the exposure of healthy subjects to glutens has only recently been studied. This study was aimed at determining the effects of corn and wheat glutens, incorporated as protein sources into the diet, on serum interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) levels and the immunohistochemical distribution of CD3 and CD8 receptors in the small intestine in male rats. The study material comprised 24 twenty-day-old male Wistar albino rats, which were randomly assigned in equal numbers to three groups (2 rats/replicate and 4 replicates/group). The feed rations provided to all three groups contained high levels of proteins, which were soybean meal, corn gluten and wheat gluten in the control, corn and wheat groups, respectively. The in Control, Corn and Wheat groups serum IL-1 beta and TNF-alpha levels respectively 55.83 - 46.37; 81.65 - 61.95 and 81.65-61.31 was determined but these differences were statistically insignificant. Furthermore, immunohistochemical examination demonstrated a mathematical increase to have occurred in the distribution of the CD3 and CD8 receptors in the duodenum, jejunum and ileum samples of the corn and wheat groups. In result, based on the findings obtained in this study, we suggest that the long-term feeding of rats on high levels of gluten causes systemic adverse effects.

Dietary Gluten as a Conditioning Factor of the Gut Microbiota in Celiac Disease.

The gut microbiota plays a relevant role in determining an individual's health status, and the diet is a major factor in modulating the composition and function of gut microbiota. Gluten constitutes an essential dietary component in Western societies and is the environmental trigger of celiac disease. The presence/absence of gluten in the diet can change the diversity and proportions of the microbial communities constituting the gut microbiota. There is an intimate relation between gluten metabolism and celiac disease pathophysiology and gut microbiota; their interrelation defines intestinal health and homeostasis. Environmental factors modify the intestinal microbiota and, in turn, its changes modulate the mucosal and immune responses. Current evidence from studies of young and adult patients with celiac disease increasingly supports that dysbiosis (i.e., compositional and functional alterations of the gut microbiome) is present in celiac disease, but to what extent this is a cause or consequence of the disease and whether the different intestinal diseases (celiac disease, ulcerative colitis, Crohn disease) have specific change patterns is not yet clear. The use of bacterial-origin enzymes that help completion of gluten digestion is of interest because of the potential application as coadjuvant in the current treatment of celiac disease. In this narrative review, we address the current knowledge on the complex interaction between gluten digestion and metabolism, celiac disease, and the intestinal microbiota.

Chia (Salvia hispanica L.) Seed Total Protein and Protein Fractions Digests Reduce Biomarkers of Inflammation and Atherosclerosis in Macrophages In Vitro.

SCOPE: The objectives are to evaluate the anti-inflammatory and anti-atherosclerotic effects of digested total protein and digested protein fractions from chia seed in macrophages in vitro. METHODS AND RESULTS: Total protein and protein fractions (albumin, globulin, glutelin, and prolamin) are isolated from chia seed and digested using simulated gastrointestinal conditions, resulting in digested total protein (DTP) and digested protein fractions (DPF). DTP and DPF are applied (1.0 mg mL-1 ) in RAW 264.4 macrophages stimulated with LPS (1 µg mL-1 ) for inflammation or ox-LDL (80 µg mL-1 ) for atherosclerosis. In the inflammatory process, DTP and DPF reduce p-NF-κB, iNOS, p-JNK, and AP-1. Digested glutelin reduces the secretion of nitric oxide (65.1%), reactive oxygen species (19.7%), prostaglandins (34.6%), TNF-α (24.1%), MCP-1 (18.9%), IL-6 (39.6%), and IL-10 (68.7%). DTP and DPF reduce the NF-κB translocation to nuclei. DTP and digested glutelin reduce iCAM expression (86.4%, 80.8%), LOX-1 (37.3%, 35.7%), iNOS (67.0%, 42.2%), and NF-κB (57.5%, 71.1%). DTP is effective in reducing secretion of nitric oxide (43.4%), lipid accumulation (41.9%), prostaglandins (41.9%), TNF-α (43.3%), MCP-1 (47.6%), and IL-6 (50.5%). Peptides from chia DTP and DPF are also characterized. CONCLUSION: DTP and digested glutelin from chia seed reduce expression and secretion of markers related to inflammation and atherosclerosis pathways.

The Effect of Gluten-Free Diet on Health and the Gut Microbiota Cannot Be Extrapolated from One Population to Others.

Gluten-related disorders (GRD) affect millions of people worldwide and have been related to the composition and metabolism of the gut microbiota. These disorders present differently in each patient and the only treatment available is a strict life-long gluten-free diet (GFD). Several studies have investigated the effect of a GFD on the gut microbiota of patients afflicted with GRD as well as healthy people. The purpose of this review is to persuade the biomedical community to think that, while useful, the results from the effect of GFD on health and the gut microbiota cannot be extrapolated from one population to others. This argument is primarily based on the highly individualized pattern of gut microbial composition and metabolic activity in each person, the variability of the gut microbiota over time and the plethora of factors associated with this variation. In addition, there is wide variation in the composition, economic viability, and possible deleterious effects to health among different GFD, both within and among countries. Overall, this paper encourages the conception of more collaborative efforts to study local populations in an effort to reach biologically and medically useful conclusions that truly contribute to improve health in patients afflicted with GRD.

Growth-dependent effects of dietary protein concentration and quality on the biomechanical properties of the diaphyseal rat femur.

OBJECTIVES: This study compares the effects of feeding growing rats with increasing concentrations of casein (C) and wheat gluten (G), proteins that show different biological qualities, on the morphometrical and biomechanical properties of the femoral diaphysis. MATERIALS AND METHODS: Female rats were fed with one of ten diets containing different concentrations (5-30%) of C and G between the 30th and 90th days of life (Control=C-20%). Biomechanical structural properties of the right femur middiaphysis were estimated using a 3-point bending mechanical test with calculation of some indicators of bone material properties. RESULTS: Body weight and length were affected by treatments, values being highest in rats fed the C-20% diet. G diets affected negatively both parameters. Changes in cross-sectional geometry (mid-diaphyseal cross-sectional and cortical areas, femoral volume, and rectangular moment of inertia) were positively related to the C content of the diet, while they were severely and negatively affected by G diets. Similar behaviors were observed in the bone structural properties (fracture load, yielding load, diaphyseal stiffness and elastic energy absorption). When values of strength and stiffness were normalized for body weight, the differences disappeared. The bone material quality indicators (elastic modulus, yielding stress, elastic energy absorption/volume) did not differ significantly among all studied groups. Femoral calcium concentration in ashes was not significantly different among groups. CONCLUSION: The clear differences in strength and stiffness of bone beams induced by dietary protein concentration and quality seemed to be the result of an induced subnormal gain in bone structural properties as a consequence of a correlative subnormal gain in bone growth and mass, yet not in bone material properties.

Tryptic amaranth glutelin digests induce endothelial nitric oxide production through inhibition of ACE: antihypertensive role of amaranth peptides.

Amaranth seed proteins have a better balance of essential amino acids than cereals and legumes. In addition, the tryptic hydrolysis of amaranth proteins generates, among other peptides, angiotensin converting enzyme (ACE) inhibitory (ACEi) peptides. ACE converts angiotensin I (Ang I) into Ang II, but is also responsible for the degradation of bradykinin (BK). In contrast to Ang II, BK stimulates vasodilation modulated through endothelial nitric oxide (NO) production. The aim of the present study was to characterize the ACEi activity of amaranth trypsin-digested glutelins (TDGs) and their ability to induce endothelial NO production. An IC(50) value of 200microgml(-1) was measured for TDG inhibition of ACE. TDGs stimulated endothelial NO production in coronary endothelial cells (CEC) by 52% compared to control. The effects of TDGs were comparable to those of BK and Captopril, both used as positive controls of NO production. Consistent with these effects, TDGs induced, in a dose-dependent manner, endothelial NO-dependent vasodilation in isolated rat aortic rings. These results suggest that TDGs induce endothelial NO production and consequent vasodilation through their ACEi activity. Amaranth TDGs have a high potential as a nutraceutical food in prevention of cardiovascular diseases. Further molecular, cellular and physiological studies are currently under way and the results may contribute to a better understanding and control of cardiovascular disorders.

Time course of nitric oxide synthase generation after gluten exposure in the rectal mucosa of gluten-sensitive patients.

BACKGROUND: Nitric oxide is thought to play an important role in modulating chronic inflammatory responses as well as in immune-mediated inflammation. We reproduced a gluten-mediated mucosal response in the rectum of celiac and control subjects in order to determine the role of inducible and constitutive nitric oxide synthases in the pathogenesis of this process. MATERIAL: Nine patients with confirmed celiac disease and five healthy controls underwent a long-term rectal gluten challenge (48 h) after an enema of 6 g of crude gluten, and constitutive and inducible nitric oxide synthase activity were determined in rectal biopsies. The histological localization of inducible nitric oxide synthase was determined by immunohistochemistry. RESULTS: Activity of both isoforms of nitric oxide synthase in control subjects did not change significantly after gluten instillation. In celiac patients, constitutive nitric oxide synthase on rectal mucosa also showed no significant changes after challenge with gluten. Inducible nitric oxide synthase isoform exhibited a modest increase 4 h after gluten instillation in celiac patients (mean increase 35% compared with baseline levels) but, 8 h after challenge, generation of iNO synthase was significantly higher: 54% more than pre-challenge production (P < 0.05) and higher than control values (P < 0.05). Inducible nitric oxide synthase staining was mostly localized in mononuclear cells of the epithelium and the lamina propria. After gluten instillation, the enhanced staining was mainly localized in subepithelial areas of the lamina propria. CONCLUSION: Our data suggest a role for nitric oxide, generated by inducible nitric oxide synthase, in the process of rectal mucosa injury by local gluten instillation in sensitized patients. We could not, however, determine if the role of nitric oxide in the ensuing injury of this gluten-induced immune inflammation model is a protective one, or merely a by-product generated by the activation of the inflammatory cells.

Gluten sensitivity in patients with primary biliary cirrhosis.

OBJECTIVE: Whereas celiac disease and primary biliary cirrhosis have been reported to coexist in the same patient, the frequency of this relationship has not been clarified. Nowadays, the concept of celiac disease has been extended from that of a severe enteropathy to a broader concept of gluten-driven intestinal immunological response. In this study we assessed features of gluten sensitivity in a cohort of patients with primary biliary cirrhosis. METHODS: Ten patients with primary biliary cirrhosis were evaluated a mean of 2 yr after diagnosis. The following features of gluten sensitivity were assessed: serum antigliadin and endomysial antibodies, small bowel histology (degree of atrophy and quantitative histological parameters), the presence of the typical celiac HLA genotype (DQ2), and intraepithelial lymphocyte response in the rectal mucosa after local gluten instillation (rectal gluten challenge). RESULTS: Overall, three patients presented evidence of gluten sensitivity. All three had abnormal titers of antigliadin antibody type IgA and one was positive for endomysial antibody. Two patients had partial villous atrophy. The rectal gluten challenge showed a celiac-like response, evidenced by an increase in intraepithelial lymphocyte infiltration after gluten exposure, in the three patients. The characteristic celiac HLA genotypes (DQA1 0501 and DQB1 0201) were identified in three patients. One of them also exhibited other features of gluten sensitivity. However, despite evidence of gluten intolerance, patients had minimal or no symptoms characteristic of celiac disease. CONCLUSION: We detected features of gluten sensitivity in a high proportion of patients with primary biliary cirrhosis. Further studies should be performed to elucidate the clinical significance of this association.