Anti-allergy effect of marc from silver vine Actinidia polygama prepared by supercritical fluid extraction

Anti-allergic effect of marc extract after supercritical fluid extraction SFE comparing the crude extract from silver vine was investigated to increase its potential for use as a new source of functional food that reduced non-favorable flavor. The results tested by thiazolyl blue tetrazolium bromide MTT assay indicated that the ethanol extract of silver vine ETOH and ethanol extract of SFE marc SFEM showed no cytotoxic effects on IgE-sensitized rat basophilic leukemia RBL-2H3 cells under the conditions. ETOH, as well as SFEM inhibited antigen-induced degranulation in RBL-2H3 mast cells dose dependently. The morphological change of the cells treated with compound 48/80 was prevented by the extracts. Production of tumor necrosis factor TNF-α on the activated RBL-2H3 cells was also reduced by ETOH and SFEM, similarly. Moreover, the total phenolic content of the extracts seems to correlate with the anti-allergic activity. In conclusion, the results suggest that the flavor-improved SFE marc extract suppressed the antigen-induced allergic reactions in RBL-2H3 mast cells.     

Inhibitory effects of water extracts of fermented rice bran on allergic response

In this study, the effects of water extracts of fermented rice bran (FRBE) on immediate-type allergic reactions in vitro (RBL-2H3 cell line) and in vivo [ovalbumin (OVA) sensitized mice model] were investigated. FRBE inhibited β-hexosaminidase release from RBL-2H3 cells activated by anti-dinitrophenyl (DNP) IgE while FRBE pretreatment profoundly inhibited the systemic allergic reaction induced by compound 48/80. Moreover, FRBE had a significant inhibitory effect on the mRNA expression of anti-DNP IgE-induced tumor necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-4, IL-6, and IL-10, all of which mediate inflammatory reactions triggered by allergic reaction. To determine the mRNA levels of cytokines in an OVA-sensitized mice model after FRBE treatment, spleen cells were harvested with several concentrations of FRBE. The FRBE-treated group showed decreased levels of TNF-α, IFN-γ, IL-6, and IL-10. These results suggest that FRBE suppressed allergic and inflammatory reactions through inhibition of degranulation, histamine release, and pro-inflammatory cytokine production from mast cells.     

Inhibitory effect of chlorophyll c2 from brown algae,Sargassum horneri,on degranulation of RBL-2H3 cells

The anti-allergic effect of alcohol extracts from edible seaweeds was evaluated by the degranulation of a rat basophilic leukemia cell line (RBL-2H3). Extracts prepared from the brown algae Sargassum horneri, Ecklonia cava and Ecklonia kurome, inhibited the degranulation of RBL-2H3 cells, whereas those from green algae and red algae did not. The active substance in S. horneri was purified and identified as chlorophyll c2, a major pigment in brown algae. The purified chlorophyll c2 preparation also suppressed the degranulation of RBL-2H3 cells. In contrast, chlorophyll a and b did not affect cell degranulation. Therefore, chlorophyll c2 from brown algae might be useful for the prevention or mitigation of allergic symptoms.     

Inhibitory effect of aqueous spinach extract on degranulation of RBL-2H3 cells

The inhibitory effect of an aqueous extract from spinach on degranulation of RBL-2H3 cells is herein reported. The extract significantly suppressed antigen-induced degranulation in a dose-dependent manner without affecting cell viability. Active substances in the extract were heat-stable and trypsin-resistant with molecular weights ranging from 500 Da to 14 kDa. The extract inhibited elevation of the intracellular Ca²⁺ concentration caused by stimulation by antigen, while not suppressing degranulation induced by a calcium ionophore A23187. Immunoblot analysis revealed that the inhibitory effect results from downregulation of phosphorylation of both Syk kinase and phosphatidylinositol 3-kinase in the signalling pathways involved in degranulation caused by the antigen–antibody interaction. Taken together, these findings suggest that aqueous spinach extract has an anti-allergic activity that controls degranulation.     

Inhibitory effects of flavonoid glycosides isolated from the peel of Japanese persimmon (Diospyros kaki Fuyu) on antigen-stimulated degranulation in rat basophilic leukaemia RBL-2H3 cells

We found that two distinct flavonoid glycosides isolated from the peel of Japanese persimmon (Diospyros kaki Fuyu), isoquercitrin (Isq) and hyperin (Hyp), are capable of inhibiting antigen-stimulated degranulation in rat basophilic leukaemia RBL-2H3 cells. In order to elucidate the underlying mechanisms, we examined effects of Isq and Hyp on cellular responses induced by antigen stimulation. Treatment with both Isq and Hyp markedly inhibited antigen-stimulated elevation of intracellular free Ca²⁺ concentration and reactive oxygen species (ROS). Isq and Hyp did not affect NADPH oxidase (NOX) activity, but they possessed DPPH radical-scavenging activity similar to that of epigallocatechin gallate, a potent anti-oxidant, Finally, Isq and Hyp showed little or no effects on Ag-stimulated Syk activation or phosphorylation of signalling molecules. These results indicate that inhibition of antigen-stimulated degranulation by Isq and Hyp is mainly due to suppression of intracellular Ca²⁺ elevation, which is caused by direct scavenging of ROS that are generated by NOX. Our findings suggest that Isq and Hyp, isolated from the peel of persimmon, would be beneficial for alleviating symptoms of type I allergy.     

Inhibitory effect of zinc on beta-hexosaminidase release from RBL-2H3 cells by synthetic chemicals

The effects of foods and chemicals related to food hygiene on degranulation were evaluated using a method for assaying the enzyme activity of beta-hexosaminidase as an index of chemical mediator release from RBL-2H3 cells in vitro. Using a previously developed assay system, we had found a large number of inhibitors and promoters of degranulation of RBL-2H3 cells. In the present study, we examined the inhibitory effect of zinc chloride on the degranulation (beta-hexosaminidase release) from RBL-2H3 cells with or without antigen in the presence of the degranulation-promotive chemicals, namely, 4 food additives, 7 pesticides and 2 veterinary drugs. These promotive chemicals were classified into two types on the basis of inhibitory profile by zinc chloride: 1) those which showed marked degranulation-inhibitory action when the cells were stimulated with antigen, such as butylhydroxyanisole, dibutylhydroxytoluene, EPN, cis- and trans-permethrin, prothiofos, pyridaben, terbufos, 2) those which showed marked degranulation-inhibitory action whether the cells were stimulated with antigen or not, such as butyl p-hydroxybenzoate, o-phenylphenol, bitertanol, salinomycin. In conclusion, zinc had a dramatic inhibitory effect on enhanced degranulation induced by synthetic chemicals in vitro.     

Inhibitory effects of blueberry root methanolic extract on degranulation in KU812F cells

The effect of blueberry (Vaccinium angustifolium) root methanolic extract (BRM) on the A23187 plus phorbol myristate acetate (PMA)-induced degranulation in human basophilic KU812F cells was investigated. The total phenolic content (TPC) was 170±1.9 mg gallic acid equivalents (GAE)/g BRM. BRM reduced levels of histamine and β-hexosaminidase released from stimulated KU812F cells. Intracellular calcium concentration ([Ca²⁺]i) were determined by spectrofluorometric analysis using Fura 2-AM was found to be reduced by BRM with dose-dependent manner. Moreover, Western blot analysis revealed that protein kinase C (PKC) translocation was inhibited by BRM with dose-dependent manner. These results indicated that BRM inhibited histamine and β-hexosaminidase through the suppression of Ca²⁺ influx and PKC translocation. Therefore, we suggest that BRM is potent inhibitor of degranulation in mast cells and basophils, and may be useful in preventing the allergic reactions.     

Anthocyanins,but not Anthocyanidins,from Bilberry (Vaccinium myrtillus L.) Alleviate Pruritus via Inhibition of Mast Cell Degranulation

Abstract: We have previously reported that bilberry anthocyanins exhibit an anti‐pruritic effect in a mouse model of allergic contact dermatitis. It has been reported that anthocyanins are particularly sensitive to thermal treatment and are easily hydrolyzed to anthocyanidins when exposed to high temperatures. The objective of this study was to compare the anti‐pruritic effect of anthocyanin‐rich quality‐controlled bilberry extract and anthocyanidin‐rich degraded extract using a mouse model of allergic contact dermatitis. BALB/c mice with allergic contact dermatitis induced by 4 weeks of repeated application of 2,4,6‐trinitro‐1‐chlorobenzene (TNCB) were administered Bilberon‐25 orally for 4 weeks after sensitization with TNCB. The effect of Bilberon‐25 on pruritus was evaluated by measurement of scratching behavior. RBL‐2H3 mast cells were used to investigate the effect of Bilberon‐25 on degranulation in 48/80‐stimulated mast cells. Compared with nonheated Bilberon‐25, the proportion of anthocyanins in heated Bilberon‐25 decreased, and the proportion of anthocyanidins was increased in heated‐time dependent manner. Treatment with non‐heated Bilberon‐25 significantly attenuated the TNCB‐induced increase in scratching behavior, whereas treatment with 2 h‐heated Bilberon‐25 did not. Moreover, 300 μg/mL nonheated Bilberon‐25 showed significant inhibition of degranulation in RBL‐2H3 mast cells, whereas 2 h‐heated Bilberon‐25 had no effect at any concentration studied. It is assumed that the inhibitory effect of bilberry anthocyanins on pruritus might be mediated, at least in part, by its inhibitory effect on mast cell degranulation. In conclusion, the anthocyanin‐rich but not anthocyanidin‐rich bilberry extract may be a useful dietary supplement for skin diseases involving pruritic symptoms, such as chronic allergic contact dermatitis, atopic dermatitis, and rhinitis.     

基于RBL-2H3模型分析过敏反应效应细胞激活的差异基因

构建IgE介导的大鼠嗜碱性粒细胞（rat basophilic leukemia，RBL）-2H3作为过敏反应细胞模型，并利用转录组测序分析比较RBL-2H3细胞激活前后的转录组基因差异，富集相关信号通路。IgE介导的RBL-2H3细胞激活后，过敏介质和细胞因子分泌显著提高；转录组测序得到RBL-2H3细胞激活前后的232 个差异表达基因，其中有127 个（54.74%）可进行基因功能注释；RBL-2H3细胞激活主要影响肿瘤坏死因子、丝裂原活化蛋白激酶、Janus激酶-信号转导与转录激活子、Toll样受体等信号通路，涉及的转录因子有MAP3K8、Nfkbia、Junb、Jun、Fos等。本研究建立了IgE介导的过敏反应体外细胞模型，并且通过对效应细胞转录组信息的全面分析和潜在靶点及信号通路的富集为过敏性疾病的防控治疗提供参考。     

Effect of the structure and potential allergenicity of glycated tropomyosin,the shrimp allergen

The aim is to elucidate whether the structural changes of shrimp tropomyosin (TM) following ribose treatment affected its potential allergenicity. The structural changes of glycated TM were analysed by fluorescence, ultraviolet spectrum (UV), circular dichroism (CD) and liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the changes in allergenicity were investigated by enzyme-linked immunosorbent assay (ELISA) and RBL-2H3 cell model. The result indicated that ribose could cause the conformational structural changes of TM. Moreover, the phenylalanine, isoleucine and DL-methionine residues were altered by ribose by LC-MS/MS analysis. These modified amino acids also appeared in the shrimp allergic epitopes region. Furthermore, the glycated TM (4000 mmol L⁻¹ ribose) could significantly decrease the IgE-binding capacity and inhibit the release of cytokines and mediators from RBL-2H3 cells. These findings suggest that ribose-induced glycation could damage the allergic epitope of TM, decreasing the potential allergenicity and could be considered for alleviating TM-induced food allergy.     

Suppression of thymic stromal lymphopoietin production by rutin in mast cells

Thymic stromal lymphopoietin (TSLP) is a key player in allergic diseases such as asthma and atopic dermatitis. Rutin (RU), a non-nutritive component of many foods, possesses anti-inflammatory, hepatoprotective, and anti-tumour effects. We investigated how RU inhibits the production of TSLP in human mast cell line (HMC-1) cells. RU inhibited the production and mRNA expression of TSLP in HMC-1 cells. The maximal inhibition rate of TSLP production by RU (50 μM) was 56.25 ± 2.81%. Nuclear factor-κB luciferase activity induced by phorbol myristate acetate plus A23187 was inhibited by RU. In the activated HMC-1 cells, the activation of caspase-1 was increased, whereas the activation of caspase-1 was decreased by pre-treatment with RU. Finally, RU inhibited the numbers of TSLP-positive mast cells in lesions of PMA-induced ear oedema model. These results suggest that RU would be helpful for the treatment of inflammatory and atopic diseases through the inhibition of TSLP.     

Purification of novel anti-inflammatory peptides from enzymatic hydrolysate of the edible microalgal Spirulina maxima

Natural bioactive peptides have been known as ingredients in nutraceuticals and pharmaceuticals. In this study, the potential anti-inflammatory peptides were purified from enzymatic hydrolysate of the edible microalgae Spirulina maxima using gastrointestinal endopeptidases (trypsin, α-chymotrypsin, and pepsin). Purification of the hydrolysate resulted in two peptides with amino acid sequences of LDAVNR (P1, 686 Da) and MMLDF (P2, 655 Da). It was found that peptides P1 and P2 exhibited significant inhibition on the release and production of histamine from antigen-stimulated RBL-2H3 mast cells. Moreover, the suppressive effect of P1 and P2 on production as well as expression of interleukin-8 in histamine-stimulated EA.hy926 endothelial cells was determined. Notably, the production of intracellular reactive oxygen species from mast cells and endothelial cells was decreased in the presence of P1 or P2. Collectively, the peptides P1 and P2 from S. maxima could be used as functional ingredients with potent anti-inflammatory benefits.     

Effects of veterinary drugs on beta-hexosaminidase release from rat basophilic leukemia cells (RBL-2H3)

Little is known about the effects of residual veterinary drugs on the allergic reaction, except for the antigenicity of antibiotics and synthetic antimicrobials. Therefore, 59 kinds of veterinary drugs were investigated for their effects on the IgE receptor-mediated beta-hexosaminidase release from RBL-2H3 cells as an index of immediate allergic reaction. We found that the antibiotics chlorotetracycline, doxycycline, monensin, the synthetic antimicrobial pyrimethamine and the steroid hormone testosterone inhibited beta-hexosaminidase release. Most of the veterinary drugs showed no action, though the ionophores lasalocid, salinomycin and the steroid hormone hexestrol promoted beta-hexosaminidase release from injured cells. Based on the residual levels of these drugs and the frequencies of detection in actual food samples, it seems unlikely that these drugs have any immediate allergic effect in practice.     

葡萄柚籽提取物及其纳米乳对大肠杆菌和金黄色葡萄球菌生物菌膜的抑制作用

目的：研究葡萄柚籽提取物(grapefruitseedextract,GSE)及其纳米乳(grapefruitseedextract nanoemulsion,GNE)对大肠杆菌和金黄色葡萄球菌生物菌膜的抑制作用。方法：分析菌膜黏附菌数变化、胞外聚合物(extracellular polymeric substances,EPS)含量并进行微观结构观察,比较GSE和GNE对两菌菌膜(单种菌膜和混合菌膜)形成的抑制作用和已形成菌膜的清除效果。结果：与对照组相比,1/2最小抑菌浓度(minimum inhibitory concentration,MIC)GSE和GNE可以抑制两菌单种菌膜形成时黏附菌和EPS产生,且对金黄色葡萄球菌的抑制作用更强。扫描电子显微镜(scanning electron microcopy,SEM)和共聚焦激光扫描显微镜(confocal laser scanning microscope,CLSM)所观察到的微观结构变化也显示出GSE和GNE对两菌菌膜形成具有抑制作用。GSE和GNE对已形成菌膜也有良好清除效果,且对金黄色葡萄球菌菌膜的清除作用更强,但混合菌膜...     

Bioactive dietary polyphenols inhibit heme iron absorption in a dose-dependent manner in human intestinal Caco-2 cells

Abstract: Although heme iron is an important form of dietary iron, its intestinal absorption mechanism remains elusive. Our previous study revealed that (‐)‐epigallocatechin‐3‐gallate (EGCG) and grape seed extract (GSE) markedly inhibited intestinal heme iron absorption by reducing the basolateral iron export in Caco‐2 cells. The aim of this study was to examine whether small amounts of EGCG, GSE, and green tea extract (GT) could inhibit heme iron absorption, and to test whether the inhibitory action of polyphenols could be offset by ascorbic acid. A heme‐⁵⁵Fe absorption study was conducted by adding various concentrations of EGCG, GSE, and GT to Caco‐2 cells in the absence and presence of ascorbic acid. Polyphenolic compounds significantly inhibited heme‐⁵⁵Fe absorption in a dose‐dependent manner. The addition of ascorbic acid did not modulate the inhibitory effect of dietary polyphenols on heme iron absorption when the cells were treated with polyphenols at a concentration of 46 mg/L. However, ascorbic acid was able to offset or reverse the inhibitory effects of polyphenolic compounds when lower concentrations of polyphenols were added (≤ 4.6 mg/L). Ascorbic acid modulated the heme iron absorption without changing the apical heme uptake, the expression of the proteins involved in heme metabolism and basolateral iron transport, and heme oxygenase activity, indicating that ascorbic acid may enhance heme iron absorption by modulating the intracellular distribution of ⁵⁵Fe. These results imply that the regular consumption of dietary ascorbic acid can easily counteract the inhibitory effects of low concentrations of dietary polyphenols on heme iron absorption but cannot counteract the inhibitory actions of high concentrations of polyphenols. Practical Application: Bioactive dietary polyphenols inhibit heme iron absorption in a dose‐dependent manner. The small amounts of polyphenolic compounds present in foods are capable of reducing heme iron transport across the intestinal enterocyte. However, the inhibitory effects of dietary polyphenolic compounds on heme iron absorption can be offset by ascorbic acid and can possibly be avoided by decreasing the consumption of polyphenols while simultaneously taking ascorbic acid.     

Anti-allergic effect of strawberry extract

We examined the anti-allergic effect of strawberry extract on human peripheral blood mononuclear cells (PBMCs) and atopic dermatitis model mice NC/NgaTndCrlj. The addition of strawberry extract suppressed total IgE production in the cedar pollen antigen Cry j 1-stimulated PBMCs. Flow cytometric analysis showed that strawberry extract decreased the rate of CD3⁺CD4⁺ helper T cells by 17.3% and increased the rate of CD3⁺CD8⁺ cytotoxic T cells by 19.7% in PBMCs. Moreover, the extract inhibited the expression level of GATA3 that is the master regulator of type 2 helper T cells (Th2) in human primary pan T cells isolated from PBMCs. Oral administration of strawberry extract lowered dermatitis scores and serum IgE levels in mice. In addition, it also decreased the GATA3 expression level in mouse blood cells. These results revealed that strawberry extract suppressed the severity of atopic dermatitis through the down-regulation of serum IgE by inhibition of Th2 differentiation.     

I型超敏反应中肥大细胞脱颗粒活性物质及其 信号通路研究进展

Ig E介导的I型超敏反应是最受关注的变态反应类型,肥大细胞是其中主要应答细胞。Ig E致敏的肥大细胞被激活后,通过释放和分泌介质发挥生物学作用,参与炎症反应。释放的介质主要有组胺、肝素、类蛋白酶、花生四稀酸的代谢产物、细胞因子等。肥大细胞脱颗粒的信号通路是个复杂的网络体系,涉及到多种蛋白分子的参与,不同信号的逐级放大和众多细胞因子的合成、分泌。近年来食物过敏反应信号通路的主要分子机制已深入研究,各信号通路之间的网络调控研究进展有待综述。本文重点介绍了I型超敏反应中肥大细胞脱颗粒依赖的酪氨酸激酶Lyn和Fyn介导的信号通路,为人们更好地理解食物过敏机制提供参考。