Immunomodulatory properties of water soluble arabinoxylans from extruded rice bran and wheat pentosan in an in vitro model of human monocytes and macrophages

Arabinoxylans (AXs) are major components of non-starch polysaccharides (NSPs). Recently, AXs have attracted a great deal of attention, because of their possible antitumor and immunomodulation activities. These activities have been suggested to be related to the content of low molecular weight (Mw) AXs, in particular those with a Mw below 32 kDa. Rice bran and wheat pentosan are rich sources of AXs. However, extraction of AXs is difficult and often gives low yield. Various methods have been used to increase the extraction yield of AXs with varying degrees of success, such as alkaline hydrolysis and enzymatic treatment. However, some of these treatments have been reported to be either expensive or produce hazardous wastes and non-environmentally friendly. Extrusion processing has been used to increase the solubility of cereal dietary fibre, however, these studies used alkaline or enzyme treatments with the extrusion to maximise the extraction yield. The use of extrusion alone as a pre-treatment method to increase the extraction yield and reduce the molecular weight (Mw) of AXs from rice bran or wheat endosperm pentosan has not been investigated. Hence, the current study aimed to determine if extrusion alone could change the extraction yield and Mw of the AXs. Wheat endosperm pentosan and rice bran were extruded with a twin-screw extruder at screw speeds of 80 and 160 revolutions per minute (rpm). It was found that the extraction yield of AXs increased with an increase in screw speed and was accompanied by a decrease in the Mw of the AXs. In vitro studies using immunoassays to measure proinflammatory markers showed that AXs from extruded rice bran and wheat pentosan significantly (P<0.05) increased nitric oxide (NO) and tumour necrosis factor α (TNFα) production from both U937 monocytes and macrophages in a concentration-dependent manner at (50, 500 and 1000 μg/ml), respectively. Moreover, the immunomodulatory activity of AXs was associated with the very low Mw of AXs. Moreover, inhibition of toll like receptor 4 (TLR4), which is known to be the receptor for bacterial lipopolysaccharides (LPS), significantly inhibited the AXs-induced increase in NO and TNFα production in both U937 monocytes and macrophages (P<0.05), suggesting the actions of AXs may be mediated at least in part through TLR4. The findings of this study indicate that AXs may compete with LPS for the same receptor TLR4, resulting in decreasing the inflammatory response that LPS produces during the infection. Thus AXs can produce a non-detrimental moderate increase in the inflammatory response

Modulate your immune response using cereals

Institute of Food Science and Technology (IFST) Young Scientist Competition (2018

Estrogen stimulates the clearance of wound bacteria by monocyte-derived macrophages via activation of estrogen-receptor alpha and actin cytoskeleton reorganization

Background: Chronic wounds in the elderly often become infected, leading to substantial morbidity and mortality. Age-related impaired healing is mediated by age-related changes in steroid hormones, particularly declining levels of estrogen with increasing age. Although the anti-inflammatory activity of estrogen has been defined, little is known about the effects of estrogen deprivation on bacterial clearance. The aim of this study was to determine the effect of ageing (estrogen deprivation) on the ability of human monocyte-derived macrophages to eliminate bacteria via phagocytosis. Materials/methods: Host-pathogen assays were used to measure macrophage-mediated phagocytosis of two major wound pathogens, methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, under in vitro and ex vivo conditions that model estrogen levels in the elderly, young adults and following estrogen supplementation. Fluorescence and scanning electron microscopy (SEM) were used to visualise host-pathogen interactions and protein mediators of phagocytosis were measured by immunoblotting. Results: Estrogen at concentrations typical of youth or supraphysiological levels significantly (P<0.05) increased the phagocytosis of MRSA and P. aeruginosa in a dose-dependent manner compared to estrogen deprivation with significantly enhanced clearance of bacteria by M1 macrophages compared to M2 macrophages. Epifluorescence, confocal and SEM confirmed estrogen increases co-localisation of fluorescent GFP-S. aureus or mCherry-P. aeruginosa within macrophages and promotes bacterial internalisation. Activation of estrogen receptor-alpha (ER-α) mirrored the stimulatory effect of estrogen on phagocytosis whilst ER-α antagonism significantly (P<0.01) blocked the phagocytic effect of estrogen. In contrast, activation of ER-beta (ER-β) had no significant effect on phagocytosis, confirming estrogen mediates bacterial clearance via ER-α. Immunoblotting analysis demonstrated that estrogen-enhanced phagocytosis is associated with altered levels of mediators involved in the actin cytoskeleton of phagocytes including increased levels of FAK, Rac1, Cdc42 and RhoG, but reduced levels of RhoA. Conclusion: Findings suggest estrogen may promote the resolution of wound infections during youth but this protection is lost as estrogen levels decline with increasing age, resulting in increased propensity and progression of age-related wound infections. Thus, novel wound dressings providing estrogen supplementation or selective activation of ER-α and/or specific targeting of downstream mediators of the actin cytoskeleton may provide effective treatment options for infected wounds in the elderly

Comments on “Probiotic Bifidobacterium strains and galactooligosaccharides improve intestinal barrier function in obese adults but show no synergism when used together as synbiotics”

A finite strain constitutive model to predict a complex elastoplastic deformation behaviour involves very high pressures and shockwaves in orthotropic materials is developed in this work. The important feature of the proposed hyperelastic-plastic constitutive model is a Mandel stress tensor combined with the new generalised orthotropic pressure. The formulation is developed in the isoclinic configuration and allows for a unique treatment for elastic and plastic orthotropy. The elastic orthotropy is taken into account through a stress tensor decomposition combined with the new pressure. A yield surface of Hill’s yield criterion aligned uniquely within the principal stress space is adopted to characterise plastic orthotropy by means of the evolving structural tensors. An isotropic hardening is adopted to define the evolution of plastic orthotropy. The formulation is further combined with a shock equation of state (EOS) and Grady spall failure model to predict shockwave propagation and spall failure in the materials, respectively. The proposed constitutive model is implemented as a new material model in the Lawrence Livermore National Laboratory (LLNL)-DYNA3D code of UTHM’s version. The ability of the newly constitutive model to describe finite strain deformation and shock propagation in orthotropic materials is first investigated against plate impact data of aluminium alloy in the longitudinal and transverse directions before a comparison against plate impact test data of carbon fibre reinforced epoxy composites along the through-thickness direction is finally conducted. A good agreement is obtained in each test

Induction of chronic subclinical systemic inflammation in sprague–dawley rats stimulated by intermittent bolus injection of lipopolysaccharide

Chronic subclinical systemic inflammation has a key role in stimulating several chronic conditions associated with cardiovascular diseases, cancer, rheumatoid arthritis, diabetes, and neurodegenerative diseases. Hence, developing in vivo models of chronic subclinical systemic inflammation are essential to the study of the pathophysiology and to measure the immunomodulatory agents involved. Male Sprague–Dawley rats were subjected to intraperitoneal, intermittent injection with saline, or lipopolysaccharide (LPS) (0.5, 1, 2 mg/kg) thrice a week for 30 days. Hematological, biochemical, and inflammatory mediators were measured at different timepoints and at the end of the study. The hearts, lungs, kidneys, and livers were harvested for histological evaluation. Significant elevation in peripheral blood leukocyte includes neutrophils, monocytes, and lymphocytes, as well as the neutrophils-to-lymphocyte ratio. The pro-inflammatory mediator levels [C-reactive protein, tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, and IL-8] along with the biochemical profile (alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transferase, creatine kinase, creatinine, and urea) were increased significantly (P < 0.05) and increased the expression of monocyte chemoattractant protein-1 and TNF-β. The histopathological changes of heart, lung, kidney, and liver tissues revealed degeneration, cellular infiltration of leukocyte in the inflammatory foci and interstitial space, edema, early signs of fibrosis, apoptosis, and necrosis. In conclusion, these results indicate that intermittent exposure to LPS produces chronic subclinical systemic inflammation in multiple organs leading to chronic conditions and supports this model to be a useful preclinical tool for developing immunotherapeutic agents that could prevent, or reduce, chronic inflammatory diseases associated with, or without, bacterial translocation

Stingless bee honey protects against lipopolysaccharide induced-chronic subclinical systemic inflammation and oxidative stress by modulating Nrf2, NF-κB and p38 MAPK

Background: Epidemiological and experimental studies have extensively indicated that chronic subclinical systemic inflammation (CSSI) and oxidative stress are risk factors for several chronic diseases, including cancer, arthritis, type 2 diabetes, and cardiovascular and neurodegenerative diseases. This study examined the protective effect of stingless bee honey (SBH) supplementation against lipopolysaccharide (LPS)-induced CSSI, pointing to the possible involvement of NF-κB, p38 MAPK and Nrf2 signaling. Methods: CSSI was induced in male Sprague Dawley rats by intraperitoneal injection of LPS three times per week for 28 days, and SBH (4.6 and 9.3 g/kg/day) was supplemented for 30 days. Results: LPS-induced rats showed significant leukocytosis, and elevated serum levels of CRP, TNF-α, IL-1β, IL-6, IL-8, MCP-1, malondialdehyde (MDA) and 8-hydroxy-2′-deoxyguanosine (8-OHdG), accompanied with diminished antioxidants. Treatment with SBH significantly ameliorated inflammatory markers, MDA and 8-OHdG, and enhanced antioxidants in LPS-induced rats. In addition, SBH decreased NF-κB p65 and p38 MAPK, and increased Nrf2 expression in the liver, kidney, heart and lung of LPS-induced rats. Furthermore, SBH prevented LPS-induced histological and functional alterations in the liver, kidney, heart and lung of rats. Conclusion: SBH has a substantial protective role against LPS-induced CSSI in rats mediated via amelioration of inflammation, oxidative stress and NF-κB, p38 MAPK and Nrf2 signaling

Health-related effects and improving extractability of cereal arabinoxylans

Arabinoxylans (AXs) are major dietary fibers. They are composed of backbone chains of -(1–4)- linked xylose residues to which -l-arabinose are linked in the second and/or third carbon positions. Recently, AXs have attracted a great deal of attention because of their biological activities such as their immunomodulatory potential. Extraction of AXs has some difficulties; therefore, various methods have beenusedto increase the extractability ofAXs withvaryingdegrees of success, suchas alkaline, enzymatic, mechanical extraction. However, some of these treatments have been reported to be either expensive, such as enzymatic treatments, or produce hazardous wastes and are non-environmentally friendly, such as alkaline treatments. On the other hand, mechanical assisted extraction, especially extrusion cooking, is an innovative pre-treatment that has been used to increase the solubility of AXs. The aim of the current review article is to point out the health-related effects and to discuss the current research on the extraction methods of AXs

Estrogen Enhances Host-Pathogen Interactions in an in vitro Model of Age-Related Impaired Healing.

Chronic wounds are difficult to treat and often become colonised by bacteria, leading to substantial morbidity and mortality in the elderly. Impaired healing in the elderly is mediated changes in steroid hormones, particularly declining levels of estrogen with increasing age. The aim of this study was to determine the effect of aging (estrogen deprivation) on the ability of inflammatory cells to eliminate bacteria via phagocytosis. An in vitro host-pathogen assay was developed to determine the ability of U937 macrophages to internalise methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa under conditions that model endogenous levels of estrogen found in the elderly (estrogen deprivation; 1x10-9M estradiol or an absolute absence of estrogen), during youth (1x10-8M estradiol) and following estrogen supplementation (suprabasal levels; 1x10-7M estradiol). To confirm phagocytosis was taking place, co-localisation of fluorescence from GFP-labelled S. aureus SH1000 and mCherry-labelled P. aeruginosa PAO1 with macrophages was measured on a fluorescent cell counter and host-pathogen interactions were visualised by confocal microscopy, epifluorescence microscopy and scanning electron microscopy (SEM). Findings indicated estrogen (1x10-8M and 1x10-7M) significantly (P<0.05) increased the amount of phagocytosis (i.e. decreased bacterial recovery) in a concentration-dependent manner compared to estrogen deprivation. Co-localisation of fluorescent signal from GFP-labelled S. aureus and mCherry-labelled P. aeruginosa with macrophages was significantly (P<0.05) enhanced by estrogen (1x10-8M and 1x10-7M) compared with estrogen deprivation. Host-pathogen interactions, visualised by microscopy, confirmed estrogen-mediated internalisation of bacteria by macrophages. In conclusion, elevated levels of estrogen found in youth or following estrogen supplementation result in increased phagocytosis of both gram-positive S. aureus and gram-negative P. aeruginosa by U937 macrophages. The findings suggest estrogen may promote the resolution of wound infections during youth but this protection may decline with increasing age as estrogen levels decline, resulting in increased propensity and progression of wound infections in the elderly

sj-docx-1-nah-10.1177_02601060221127853 - Supplemental material for The effects of consuming a Mediterranean style diet on associated COVID-19 severity biomarkers in obese/overweight adults: A systematic review

Supplemental material, sj-docx-1-nah-10.1177_02601060221127853 for The effects of consuming a Mediterranean style diet on associated COVID-19 severity biomarkers in obese/overweight adults: A systematic review by Ella Moore, Abdulmannan Fadel and Katie E. Lane in Nutrition and Health</p