Diamine Oxidase Activity Research Articles

Decarboxylation Pathways of Amino Acids in Some Mammal and Bird Tissues

The following data were obtained on the decarboxylation pathways of amino acids in some mammal and bird tissue homogenates: 1. PIG KIDNEY AND LIVER: Three preformed amine-like compounds were observed in the kidney and strong disappearance of added serotonin during anaerobic and aerobic incubation (strong conjugases? and monoamine oxidase activities). No significant disappearance of added histamine was found after anaerobic or aerobic incubation. In the liver serotonin disappeared only after aerobic incubation. Free glucose (reacting with the added amines) was present in the liver but not in the kidney. 2. Ox ADRENALS: Two preformed amine-like compounds were present which are not noradrenalin or dopa amine. Absence of conjugases or amine oxidases. 3. GUINEA PIG LIVER; Strong disappearance of added serotonin after anaerobic incubation. No significant disappearance of added histamine in both types of incubations, 4. Tarauco corythaix LIVER: Strong anaerobic and aerobic disappearance of added serotonin and very slight if any disappearance of histamine in both types of incubation. 5. Cathartes ama septentrionalis (TURKEY BUZZARD) LIVER: Absence of anaerobic metabolism of added serotonin or histamine (absence of conju­gases?) and strong aerobic disappearance of both amines after incubation with both amines, (strong mono and diamine oxidase activities). The Eollowing data were obtained on the decarboxylation pathways oE amino acids in some mammaI and bird tissue homogenates: 1 . P IG KIDNEY AND LIVER: Three preformed amine-like compounds were observed in the kidney and' strong disappearance oE added serotonin during anaerobic and aerobic incubation (strong conjugases? and monoamine oxidase activities). No signiEicant disappearance of added histamine was found after anaerobic or aerobic incubation. In the liver serotonin disappeared only after. aerobic incubation. Free glucose (reacting with the added amines) was present in the liver but not in the kidney. 2. Ox ADRENALS: Two preEormed amine-like compounds were present which are not noradrenalin or dopa amine. Absence oE conjugases or amine oxidases. 3. GUINEA PIe; UVER; Strong disappearance of added serotonin afterREVIs'rA DE InOLOGIA TROPICAt anaerobic incubation. No significant dis:lppearance of addcd histaminc in both typcs of incubations, 4. T arauco cOI'J'thclIx L1VER: Strong anaerobic and aerobic disappearance of added serotonin and very slight if any disappearance of histamine in both types of incubation. 5. CatiJartes ama Jeptentrionalu (TURKEY BUZZARD) UVER: Absence of anaerobic metabolism of added serotonin or histamine (absence of conju­ gases?) and strong aerobic disappearance of both amines after incubation with both amines, (strong mono and diamine oxidase activities).

Dietary supplementation of enzymatically treated Artemisia annua could alleviate the intestinal inflammatory response in heat-stressed broilers

The study was undertaken to evaluate the effects of enzymatically treated Artemisia annua (EA) on the intestinal inflammatory response of heat-stressed broilers. A total of 144 male Arbor Acres broilers aged 21 days were randomly divided into 3 groups with 6 replicates per group and 8 broilers in each replicate. The 3 treatment groups were as follows: the control group, in which broiler chickens were raised at 22 ± 1°C and fed basal diets, the heat stress (HS) and HS-EA groups, in which broiler chickens were raised at 34 ± 1°C for 8h (0900–1700h) and 22 ± 1°C for 16h, and fed basal diets supplemented with 0 or 1g/kg EA, respectively. From 22 to 41 days, the heat treatment lasted for 20 consecutive days. Compared with the control group, HS increased the activity of plasma diamine oxidase (P < 0.05) and the concentration of intestinal interleukin-1β, and up-regulated (P < 0.05) the mRNA expression of intestinal interleukin-1β, interleukin-6, interferon-γ, toll-like receptor 4 and heat shock protein 70, down-regulated (P < 0.05) jejunal zonula occludens-1 and ileal occluding mRNA abundances and intestinal interleukin-10 at both protein and transcriptional levels. However, EA treatment significantly decreased (P < 0.05) plasma diamine oxidase activity, the mRNA expression of heat shock protein 70, toll-like receptor 4, interleukin-6, interleukin-1β and interferon-γ in intestine of heat-stressed broilers, whereas upregulated (P < 0.05) the mRNA expression of ileal occluding, jejunal zonula occludens-1 and occluding. In addition, both protein and transcriptional levels of interleukin-10 in jejunum and ileum were increased (P < 0.05) by EA treatment in the HS group. In conclusion, dietary EA supplementation could alleviate the intestinal inflammatory response, and improve the intestinal barrier function in broilers during the heat stress period.

New approach for the diagnosis of histamine intolerance based on the determination of histamine and methylhistamine in urine

Histamine intolerance is a disorder in the homeostasis of histamine due to a reduced intestinal degradation of this amine, mainly caused by diamine oxidase (DAO) enzyme deficiency, which provokes its accumulation in plasma and the appearance of adverse health affects. A new approach for the diagnosis of this intolerance could be the determination of histamine and its metabolites in urine. The aim of this work was to develop and validate a rapid method to determine histamine and methylhistamine in human urine by Ultra High Performance Liquid Chromatography and Fluorimetric detection (UHPLC-FL). The proposed method is a consistent procedure to determine histamine and methylhistamine in less than 11min with adequate linearity and sensitivity. Relative standard deviation was always lower than 5.5%, ensuring method precision; and mean recovery was greater than 99% for both analytes. The structure of histamine and methylhistamine conjugated with OPA were confirmed by UHPLC-ITD-FTMS which enabled to unequivocally identify both analytes in standards and also in urine samples. The analysis of histamine and methylhistamine in urine samples could be a potential new approach for the routine diagnosis of histamine intolerance, more patient-friendly and with clear advantages in terms of equipment and personnel demand for sample collection in comparison with current plasmatic DAO activity determination.

Low serum diamine oxidase (DAO) activity levels in patients with migraine.

Histamine intolerance is a disorder in the homeostasis of histamine due to a reduced intestinal degradation of this amine, mainly caused by a deficiency in the enzyme diamine oxidase (DAO). Among the several multi-faced symptoms associated with histamine intolerance, headache is one of the most recognized and disabling consequences. The aim of this study was to determine the prevalence of DAO deficiency in patients with a confirmed migraine diagnosis according to the current International Headache Society (IHS) and in non-migraine subjects. DAO activity was assessed in a total of 198 volunteers recruited at the Headache Unit of the Hospital General de Catalunya, 137 in the migraine group and 61 as a control group. DAO enzyme activity in blood samples was determined by ELISA test. Values below 80 HDU/ml (Histamine Degrading Unit/ml) were considered as DAO deficient. Mean value of DAO activity from migraine population (64.5±33.5 HDU/ml) was significantly lower (p<0.0001) than that obtained from healthy volunteers (91.9±44.3 HDU/ml). DAO deficiency was more prevalent in migraine patients than in the control group. A high incidence rate of DAO deficiency (87%) was observed in the group of patients with migraine. On the other hand, 44% of non-migranous subjects had levels of DAO activity lower than 80 HDU/ml. Despite the multifactorial aetiology of migraine, these results seem to indicate that this enzymatic deficit could be related to the onset of migraine.

Dysbiosis of Intestinal Microbiota and Decreased Antimicrobial Peptide Level in Paneth Cells during Hypertriglyceridemia-Related Acute Necrotizing Pancreatitis in Rats.

Hypertriglyceridemia (HTG) aggravates the course of acute pancreatitis (AP). Intestinal barrier dysfunction is implicated in the pathogenesis of AP during which dysbiosis of intestinal microbiota contributes to the dysfunction in intestinal barrier. However, few studies focus on the changes in intestine during HTG-related acute necrotizing pancreatitis (ANP). Here, we investigated the changes in intestinal microbiota and Paneth cell antimicrobial peptides (AMPs) in HTG-related ANP (HANP) in rats. Rats fed a high-fat diet to induce HTG and ANP was induced by retrograde injection of 3.5% sodium taurocholate into biliopancreatic duct. Rats were sacrificed at 24 and 48 h, respectively. Pancreatic and ileal injuries were evaluated by histological scores. Intestinal barrier function was assessed by plasma diamine oxidase activity and D-lactate level. Systemic and intestinal inflammation was evaluated by tumor necrosis factor alpha (TNFα), interleukin (IL)-1β, and IL-17A expression. 16S rRNA high throughput sequencing was used to investigate changes in intestinal microbiota diversity and structure. AMPs (α-defensin5 and lysozyme) expression was measured by real-time polymerase chain reaction (PCR) and immunofluorescence. The results showed that compared with those of normal-lipid ANP (NANP) groups, the HANP groups had more severe histopathological injuries in pancreas and distal ileum, aggravated intestinal barrier dysfunction and increased TNFα, IL-1β, and IL-17A expression in plasma and distal ileum. Principal component analysis showed structural segregation between the HANP and NANP group. α-Diversity estimators in the HANP group revealed decreased microbiota diversity compared with that in NANP group. Taxonomic analysis showed dysbiosis of intestinal microbiota structure. In the HANP group, at phyla level, Candidatus_Saccharibacteria and Tenericutes decreased significantly, whereas Actinobacteria increased. At genus level, Allobaculum, Bifidobacterium, and Parasutterella increased significantly, while Alloprevotella, Anaerotruncus, Candidatus_Saccharimonas, Christensenellaceae_R-7_group, Rikenellaceae_RC9_gut_group, Ruminiclostridium_5, Ruminococcaceae_UCG-005, and Ruminococcaceae_UCG-014 decreased. Compared with those in the NANP rats, mRNA expression of lysozyme and α-defensin5 and protein expression of lysozyme decreased significantly in the HANP rats. Moreover, in the NANP rats and the HANP rats, Allobaculum abundance was inversely correlated with lysozyme expression, while Anaerotruncus abundance was positively correlated with it by Spearman test. In conclusion, intestinal microbiota dysbiosis and decreased AMPs of Paneth cells might participate in the pathogenesis of intestinal barrier dysfunction in HANP.

Dysbiosis of intestinal microbiota and decrease in paneth cell antimicrobial peptide level during acute necrotizing pancreatitis in rats.

ObjectivesIntestinal barrier dysfunction plays an important role in acute necrotizing pancreatitis (ANP) and intestinal microbiota dysbiosis was involved in intestinal barrier failure. Paneth cells protect intestinal barrier and are associated with intestinal microbiota. Here, we investigated changes in intestinal microbiota and antimicrobial peptides of Paneth cells in ileum during ANP.MethodsRats with ANP were established by retrograde injection of 3.5% sodium taurocholate into biliopancreatic duct and sacrificed at 24h and 48h, respectively. Injuries of pancreas and distal ileum were evaluated by histopathological score. Intestinal barrier function was assessed by plasma diamine oxidase activity (DAO) and D-lactate. Systemic and intestinal inflammation was evaluated by TNFα, IL-1β and IL-17A concentration by ELISA, respectively. 16S rRNA high throughput sequencing on fecal samples was used to investigate the changes in intestinal microbiota in the ANP group at 48h. Lysozyme and α-defensin5 were measured by real-time PCR, western blot and immunofluoresence.ResultsANP rats had more severe histopathological injuries in pancreas and distal ileum, injured intestinal barrier and increased expression of TNFα, IL-1β and IL-17A in plasma and distal ileum compared with those of the sham-operated (SO) group. Principal component analysis (PCA) showed structural segregation between the SO and ANP groups. Operational taxonomic unit (OTU) number and ACE index revealed decreased microbiota diversity in the ANP group. Taxonomic analysis showed dysbiosis of intestinal microbiota structure. At phyla level, Saccharibacteria and Tenericutes decreased significantly. At genus level, Escherichia-Shigella and Phascolarctobacterium increased significantly, while Candidatus_Saccharimonas, Prevotellaceae_UCG-001, Lachnospiraceae_UCG-001, Ruminiclostridium_5 and Ruminococcaceae_UCG-008 decreased significantly. Lysozyme and α-defensin5 mRNA expression levels decreased significantly in ANP group at 48h. Protein expression of lysozyme decreased in ANP groups at 24h and 48h. Meanwhile, the relative abundance of Escherichia-Shigella correlated inversely with the decrease in lysozyme.ConclusionThe disorder in intestinal microbiota and decreases of Paneth cell antimicrobial peptides might participate in the pathogenesis of intestinal barrier dysfunction during ANP.

Zymographic approach to determine the intrinsic enzyme specific activity of diamine oxidase in presence of interfering enzymes

The purpose of this investigation was to elaborate a fast zymographic assay of oxidase enzymes in the presence of interfering enzymes as catalase (which disturbs current dosages based on H2O2 detection). This method also allows the determination of intrinsic specific activity (ISA) of oxidases, such as diamine oxidase (DAO) or glucose oxidase (GOD). The SDS-PAGE gels with entrapped peroxidase have been obtained by polymerization of acrylamide and bis-acrylamide in the presence of horse-radish peroxidase. The entrapped peroxidase was uniformly distributed in the PolyacrylAmide (PAA) material and did not migrate during electrophoresis. The obtained PAA gels allow the electrophoretic separation of various oxidases from contaminating proteins. As an example, to reveal DAO, the resulting PAA-gel should be incubated after the electrophoretic run in the developing solution containing putrescine (a DAO substrate) and o-phenylenediamine (a HRP substrate) to give coloured bands on the gel in the presence of DAO-generated H2O2. The results showed that is possible to determine the DAO in the presence of interfering catalase because they migrate differently. Thus, the H2O2 released in situ by DAO is no more decomposed by catalase because of its different mobility. It was also found that the same electrophoretic gel, after zymography, can be restained by Coomassie Blue for quantitation of proteins corresponding to the zymographic bands. With the obtained enzyme units and protein concentration it is also possible to calculate the intrinsic specific activity of DAO directly from the intensities of enzyme bands in zymography and from those of protein bands (Coomassie Blue staining), quantified by densitometry.

The Variation Tendency of Polyamines Forms and Components of Polyamine Metabolism in Zoysiagrass (Zoysia japonica Steud.) to Salt Stress with Exogenous Spermidine Application.

To understand dynamic changes in polyamines (PAs) forms and components of polyamine metabolism in zoysiagrass (Zoysia japonica Steud.) response to salt stress with exogenous spermidine (Spd) application, two Chinese zoysia cultivars, z081 and z057, were exposed to sodium chloride stress for 2, 4, 6, and 8 days. The z057 cultivar possesses higher salinity tolerance than the z081 cultivar. Salt stress decreased the zoysiagrass fresh weight (FW) and increased free Spd and spermine (Spm) levels and soluble and insoluble putrescine (Put), Spd and Spm levels in both cultivars. Moreover, salt stress enhanced the activities of arginine decarboxylase (ADC), ornithine decarboxylase (ODC), S-adenosylmethionine decarboxylase (SAMDC), and diamine oxidase (DAO). Exogenous Spd increased PA metabolism and ADC, SAMDC, and DAO activities and decreased free Put levels under salt stress conditions in both cultivars. In addition, structural equation modeling (SEM) showed that ODC, SAMDC, and DAO contributed to PA metabolism, and endogenous Spd levels also contributed to endogenous Spm levels. Free PAs may be the primary factor influencing the variation of other PA forms. SEM also indicated that ADC and polyamine oxidase (PAO) play a limited role in enhancing zoysia salt tolerance via PA metabolism under salt stress.

γ-Aminobutyric Acid (GABA) Accumulation in Tea (Camellia sinensis L.) through the GABA Shunt and Polyamine Degradation Pathways under Anoxia.

γ-Aminobutyric acid (GABA) is an important bioactive component of tea (Camellia sinensis) providing various health benefits. We studied GABA accumulation via the GABA shunt and polyamine degradation pathways under anoxia in tea leaves. Anoxia caused a ∼20-fold increment in GABA concentration, relative to fresh tea leaves. This increment was due to the increase of glutamate decarboxylase and diamine oxidase activities. Genes involved in GABA formation, such as CsGAD1 and CsGAD2, were significantly up-regulated by anoxia. The concentrations of putrescine and spermine, two substrates for GABA production, were also increased by anoxia. Treating tea leaves with aminoguanidine completely inhibited diamine oxidase activity during anoxia, but the concentration of GABA decreased by only ∼25%. We infer that about one-fourth of GABA formed in tea leaves under anoxia comes from the polyamine degradation pathway, opening the possibility of producing GABA tea based through the regulation of metabolism.

Screening of Some Dioxaboreninopyridine and Aniline Derivatives for Carcinogenic Properties Using a Model Cell-Free System of Regenerating Rat Liver

We studied the effects of some aniline and dioxaborininopyridine derivatives on the rate of oxidative deamination of putrescine and polyamines in a tissue with high mitotic index. These effects were evaluated quantitatively by measuring diamine oxidase and polyamine oxidase activities in a model cell-free test system of regenerating rat liver tissue. Aniline derivatives exhibited mainly antiproliferative effects and promoted oxidative degradation of putrescine, spermidine, and spermine. Dioxaborininopyridine derivatives inhibited this process, thus exhibiting carcinogenic properties.

Effect of dietary fatty acid and micronutrient intake/energy ratio on serum diamine oxidase activity in healthy women.

Serum diamine oxidase (DAO) activity varies to a greater extent in women than in men. DAO activity during the luteal phase was higher than that during the follicular phase in healthy women. Recent reports have indicated that duodenal lipid infusion increased DAO activity in the intestinal lymph in rats. The aim of this study was to elucidate the effect of dietary nutrient intake on serum DAO activity in healthy women. Thirty-four healthy Japanese women were recruited. Food surveys were performed using dietary records for 3d during both the follicular and luteal phases. Nutrient intake was calculated and expressed as the energy intake ratio. The correlation between DAO activity and nutrient intake was analyzed. Serum DAO activity in both phases was positively correlated with intake of long-chain fatty acids, saturated fatty acids, and monounsaturated fatty acids (P<0.05). Intake of phosphorus, calcium, zinc, magnesium, iron, and vitamin B12 during the luteal phase was positively correlated with serum DAO activity (P<0.05). In healthy women, serum DAO activity was influenced by dietary fatty acid and micronutrient intake.

Effects of hydrogen on expression of ROCK1 and mDia1 in intestinal tissues of septic mice

Objective To evaluate the effects of hydrogen on the expression of Rho-associated protein kinase 1(ROCK1)and mammalian diaphanous-related formin 1(mDia1)in intestinal tissues of septic mice. Methods Ninety male C57BL/6 mice, weighing 20-25 g, aged 6 weeks, were divided into 3 groups(n=30 each)using a random number table: control group(group C), sepsis group(group S)and sepsis plus hydrogen group(group SH). Sepsis was produced by cecal ligation and puncture(CLP). Group SH inhaled 2% hydrogen for 1 h starting from 1 and 6 h after CLP.Twenty mice in each group were selected and observed for 7-day survival rate.Ten mice in each group were sacrificed at 24 h after CLP, and blood samples were obtained from hearts to measure the activity of serum diamine oxidase(DAO)and to count the colony-forming units after bacterial culture.The small intestinal samples were obtained for microscopic examination of pathological changes and for determination of ROCK1 and mDia1 positive cell rates(using immunohistochemical staining)and expression of intestinal epithelial junctional protein E-cadherin(by immunofluorescent staining). Intestinal damage was assessed and scored.The ratio of ROCK1 to mDia1 positive cell rates(ROCK1/mDia1 ratio)was calculated. Results Compared with group C, the survival rate was significantly decreased, the serum DAO activity, colony counts and intestinal damage scores were increased, ROCK1 and mDia1 positive cell rates were increased, and the expression of E-cadherin was down-regulated in S and SH groups, ROCK1/mDia1 ratio was increased in group S(P 0.05). Compared with group S, the survival rate was significantly increased, the serum DAO activity, colony counts and intestinal damage scores were decreased, the ROCK1 positive cell rate was decreased, the mDia1 positive cell rate was increased, ROCK1/mDia1 ratio was decreased, and the expression of E-cadherin was up-regulated in group SH(P<0.05). Conclusion The mechanism by which hydrogen improves intestinal barrier function may be related to down-regulation of ROCK1 expression, up-regulation of mDia1 expression and correction of the imbalance in ROCK1/mDia1 ratio in intestinal tissues of septic mice. Key words: Hydrogen; Sepsis; rho-associated kinases; rhoA GTP-binding protein; Intestinal mucosa

Protective effects of dimethyl sulfoxide on zymosan-insulted gut barrier impairment

To explore the effect of dimethyl sulfoxide(DMSO) on suppressing the release of gut inflammatory cytokine and re-store of the barrier impairment following zymosan-insulted systemic inflammatory response syndrome (SIRS). S D rats were randomly divided into four groups:sham with administration of normal saline (SS group); sham with administration of DMSO (DS group); zymosan with administration of normal saline (ZS group); and zymosan with administration of DMSO (ZD group), each group includes two subgroups at 4 h and 24 h after surgery. At 4 h and 24 h after intraperitoneal injection of zymosan (750 mg/kg), the levels of intestinal inflammatory cytokines (tumor necrosis factor-αand interleukin-10) and the activity of diamine oxidase in plasma were examined. Intestinal injury was evaluated by using an intestinal histological score. DMSO suppressed the release of tumor necrosis factor-αand increased interleukin-10 levels in the intestine compared with the ZS group at the corresponding time points. DMSO decreased the level of diamine oxidase in plasma compared with the ZS group. DMSO restored the injury of intestinal villi and the gut injury score was significantly lower than that in the ZS group. DMSO can suppress the release of intestinal inflammatory cytokines and restore zymosan-insulted gut barrier impairment.

N-Acetylcysteine improves intestinal function in lipopolysaccharides-challenged piglets through multiple signaling pathways.

This study determined whether N-acetylcysteine (NAC) could improve intestinal function through phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR), epithelial growth factor receptor (EGFR), toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB), adenosine 5'-monophosphate-activated protein kinase (AMPK), and type I interferon (IFN) signaling pathways in a piglet model of lipopolysaccharides (LPS) challenge. Thirty-two piglets (24-day-old) were randomly allocated to one of four treatments, with eight replicates per treatment and one piglet per replicate. The experiment consisted of four treatments in a 2×2 factorial arrangement with two diets (supplemented with 0 or 500mg NAC/kg diet) and saline or LPS administration. On day 20 of the trial, piglets in the LPS and LPS+NAC groups were intraperitoneally injected with 0 (saline) or 100μg LPS/kg BW. Blood samples were obtained at 3h and intestinal mucosae were collected at 6h post LPS or saline injection. The growth performance was not affected by dietary NAC. LPS induced intestinal dysfunction, as indicated by: (1) reductions in the small-intestinal glutathione concentrations and plasma D-xylose levels; (2) elevations in plasma diamine oxidase activity, mucosal MMP3 mRNA levels and caspase-3 protein abundance; (3) reduced the activities of the small-intestinal mucosal maltase, sucrase and lactase. The adverse effects of LPS on porcine intestinal function and redox status were mitigated by NAC supplementation through the activation of multiple signaling pathways involving PI3K/Akt/mTOR, EGFR, TLR4/NF-κB, AMPK, and type I IFN. Our findings provide novel mechanisms for beneficial effects of NAC in protecting the intestine from inflammation in animals.

Modulation of Antioxidant Defense System and Polyamine Catabolism in Rice Leaves under Two Planting Conditions

Aerobic rice offers an attractive alternative approach over transplanting system as it consumes less water with low labour expenses. Flag leaf of six rice cultivars, viz. PR 120, PR 115, PR 116, Feng Ai Zan, PAU 201 and Punjab Mehak 1 was analysed for antioxidant defence mechanism and polyamine catabolism under the aerobic and the transplanting conditions. Ascorbate peroxidase (APX), guaiacol peroxidase (GPX), catalase (CAT), superoxide dismutase (SOD), diamine oxidase (DAO) and polyamine oxidase (PAO) activities increased gradually from tillering to anthesis stage and then declined towards maturity stage under both planting conditions. Apparently, contents of ascorbic acid, α-tocopherol, proline and polyamines (PAs) also revealed similar trend. The aerobic condition elevated activities of PAO, SOD as well as contents of PAs, lipid peroxide and H2O2 whereas the transplanting condition had higher levels of APX, GPX, CAT and total antioxidant activities and contents of ascorbate, α-tocopherol and proline. Cultivars Feng Ai Zan, PR 115 and PR 120 exhibited superior tolerance over other cultivars by accumulating higher contents of PAs with increasing levels of PAO and SOD activities under the aerobic condition. However, under the transplanting condition PR 116 and PAU 201 showed higher activities of antioxidative enzymes with decreasing contents of lipid peroxide and H2O2. We infer that under the aerobic condition, enhancement of PAs and PAO activity enabled rice cultivars to tolerate oxidative stress, while under the transplanting condition, antioxidative defence system with decreasing of lipid peroxide content was closely associated with the protection of flag leaf by maintaining membrane integrity. In crux, results indicated that H2O2 metabolic machinery was strongly up-regulated especially at the anthesis stage.

Effect of curcumin on intestinal mucosal mechanical barrier in rats with non-alcoholic fatty liver disease

Objective: To investigate the effect of curcumin on intestinal mucosal mechanical barrier in rats with non-alcoholic fatty liver disease. Methods: A total of 30 male Sprague-Dawley rats were equally divided into normal control group, model group, and curcumin intervention group. The rats in the model group and the curcumin intervention group were given high-fat feed for 16 weeks, and those in the curcumin intervention group were given curcumin 200 mg/kg/day by gavage once a day after 8 weeks of high-fat feeding. The rats were sacrificed at the end of week 16. A light microscope was used to observe pathological changes in the liver, an electron microscope was used to observe the tight junction of the intestinal mucosa, an automatic biochemical analyzer was used to measure the serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), chromogenic substrate Limulus amebocyte lysate assay was used to measure plasma lipopolysaccharide (LPS) level, spectrophotometric method was used to measure the activity of serum diamine oxidase, ELISA was used to measure the serum level of tumor necrosis factor-α (TNFα), and immunohistochemistry was used to measure the expression of the tight junction protein occludin. One-way ANOVA test and SNK-q test were used for statistical analysis. Results: Under the light microscope, the control group had no hepatocyte steatosis, the model group had significant hepatocyte steatosis and inflammatory cell infiltration, and the curcumin intervention group had reduced hepatocyte steatosis and inflammatory cell infiltration. Under the electron microscope, the control group had a clear and complete structure of the tight junction of the intestinal mucosa and normal structures of mitochondria and endoplasmic reticulum; in the model group, the structure of the tight junction of the intestinal mucosa was destroyed, the intercellular space was widened, the desmosomes had a loose structure, there was edema in some mitochondria, and the endoplasmic reticulum was dilated; the curcumin intervention group had improvements in the structure of tight junction of the intestinal mucosa, intercellular space, edema in the mitochondria, and dilation of the endoplasmic reticulum. Compared with the control group, the model group had significant increases in the serum levels of AST, ALT, DAO, TNFα, and LPS (q = -15.918, -14.402, -33.700, -8.944, and -10.832, P < 0.05); compared with the model group, the curcumin intervention group had significant reductions in the serum levels of AST, ALT, DAO, TNFα, and LPS (q = 10.457, 7.752, 18.802, 5.202, and 4.279, P < 0.05). In the control group, occludin showed a linear distribution along the top of small intestinal mucosal epithelial cells. The model group had a significant reduction in positive staining compared with the control group, and the curcumin intervention group had a significant increase in positive staining compared with the model group. The relative expression of occludin was 0.29±0.03 in the control group, 0.12±0.02 in the model group, and 0.21±0.02 in the curcumin intervention group (P < 0.05). Conclusion: Intestinal mucosal mechanical barrier is impaired in rats with NAFLD. Curcumin can reduce such damage, and its mechanism of action may be related to up-regulating the expression of occludin in the intestinal mucosa and reducing the levels of TNFα and LPS.

Dai-Huang-Fu-Zi-Tang Alleviates Intestinal Injury Associated with Severe Acute Pancreatitis by Regulating Mitochondrial Permeability Transition Pore of Intestinal Mucosa Epithelial Cells.

Objective The aim of the present study was to examine whether Dai-Huang-Fu-Zi-Tang (DHFZT) could regulate mitochondrial permeability transition pore (MPTP) of intestinal mucosa epithelial cells for alleviating intestinal injury associated with severe acute pancreatitis (SAP). Methods A total of 72 Sprague-Dawley rats were randomly divided into 3 groups (sham group, SAP group, and DHFZT group, n = 24 per group). The rats in each group were divided into 4 subgroups (n = 6 per subgroup) accordingly at 1, 3, 6, and 12 h after the operation. The contents of serum amylase, D-lactic acid, diamine oxidase activity, and degree of MPTP were measured by dry chemical method and enzyme-linked immunosorbent assay. The change of mitochondria of intestinal epithelial cells was observed by transmission electron microscopy. Results The present study showed that DHFZT inhibited the openness of MPTP at 3, 6, and 12 h after the operation. Meanwhile, it reduced the contents of serum D-lactic acid and activity of diamine oxidase activity and also drastically relieved histopathological manifestations and epithelial cells injury of intestine. Conclusion DHFZT alleviates intestinal injury associated SAP via reducing the openness of MPTP. In addition, DHFZT could also decrease the content of serum diamine oxidase activity and D-lactic acid after SAP.

In vivo inhibition of polyamine oxidase by a spermine analogue, MDL-72527, in tomato exposed to sublethal and lethal salt stress

The spermine analogue N1,N4-bis-(2,3-butadienyl)-1,4-butanediamine (MDL-72527), an effective inhibitor of polyamine oxidases (PAOs), triggers a systemic response in tomato (Solanum lycopersicum L.) exposed to sublethal (100mM) and lethal (250mM) NaCl concentrations. The accumulation of free polyamines (PAs), the terminal oxidation of PAs by diamine oxidases (DAOs) and PAOs, and the production of H2O2 by PA oxidases depends on the intensity of salt stress. Spermidine and spermine content increased significantly under sublethal salt concentrations, but remained low under lethal salt stress. Along with increased expression of the selected SlDAO1 and SlPAO1 genes in the leaves and roots, respectively, DAO and PAO activities and their product, H2O2, increased and initiated cell death by irreversible loss of electrolytes at 250mM NaCl. MDL-72527 significantly increased spermine, spermidine and/or putrescine contents as a result of reduced activity of PA oxidases; furthermore, it inhibited H2O2 and NO production during salt treatment. These results indicate that PAO contributed to H2O2 and NO production under salt stress, and the terminal activities of DAO and PAO play a role in cell death induction at 250mM NaCl. However, the inhibition of PAO by MDL-72527 does not increase the salt tolerance of plants, since electrolyte leakage increased significantly in the presence of the inhibitor.

The colorimetric assay of diamine oxidase activity with high sensitivity based on calixarene derivative-capped gold nanoparticles

Diamine oxidase (DAO) is involved in regulating ingested or endogenous histamine, several types of human cancer, and the cell mass during embryonic development.

Cиндром непереносимості гістаміну у дітей

In recent years there has been a significant increase in allergic conditions. The clinic is dominated by IgE-independent mechanisms of allergic pathology, which are based on a violation of histamine metabolism in the body. Increased levels of extracellular histamine on the background of decreasing the activity of the enzyme diamine oxidase (DAO) leads Histamineintolerance syndrome (HIT). This state is characterized by a wide variety of clinical manifestations. The most informative method of diagnosis HIT is skin prick test with histamine (Test Histamine-50), which allows you to confirm the low activity of DAO in the body and the need for replacement therapy.Key words: allergic syndroms, histamine, diamine oxidase (DAO), HIT syndrome, scin prick test (SPT), Test Histamine-50.