Yinlai Decoction Protects Microstructure of Colon and Regulates Serum Level of D-Lactic Acid in Pneumonia Mice Fed with High-Calorie and High-Protein Diet.

OBJECTIVE: To investigate the effect of Yinlai Decoction (YD) on the microstructure of colon, and activity of D-lactic acid (DLA) and diamine oxidase (DAO) in serum of pneumonia mice model fed with high-calorie and high-protein diet (HCD). METHODS: Sixty male Kunming mice were randomly divided into 6 groups by the random number table method: normal control, pneumonia, HCD, HCD with pneumonia (HCD-P), YD (229.2 mg/mL), and dexamethasone (15.63 mg/mL) groups, with 10 in each group. HCD mice were fed with 52% milk solution by gavage. Pneumonia mice was modeled with lipopolysaccharide inhalation and was fed by gavage with either the corresponding therapeutic drugs or saline water, twice daily, for 3 days. After hematoxylin-eosin staining, the changes in the colon structure were observed under light microscopy and transmission electron microscope, respectively. Enzyme-linked immunosorbent assay was used to detect the protein levels of DLA and DAO in the serum of mice. RESULTS: The colonic mucosal structure and ultrastructure of mice in the normal control group were clear and intact. The colonic mucosal goblet cells in the pneumonia group tended to increase, and the size of the microvilli varied. In the HCD-P group, the mucosal goblet cells showed a marked increase in size with increased secretory activity. Loose mucosal epithelial connections were also observed, as shown by widened intercellular gaps with short sparse microvilli. These pathological changes of intestinal mucosa were significantly reduced in mouse models with YD treatment, while there was no significant improvement after dexamethasone treatment. The serum DLA level was significantly higher in the pneumonia, HCD, and HCD-P groups as compared with the normal control group (P<0.05). Serum DLA was significantly lower in the YD group than HCD-P group (P<0.05). Moreover, serum DLA level significantly increased in the dexamethasone group as compared with the YD group (P<0.01). There was no statistical significance in the serum level of DAO among groups (P>0.05). CONCLUSIONS: YD can protect function of intestinal mucosa by improving the tissue morphology of intestinal mucosa and maintaining integrity of cell connections and microvilli structure, thereby reducing permeability of intestinal mucosa to regulate the serum levels of DLA in mice.

Histamine intolerance.

Histamine intolerance (HIT) is a non-immunological disorder associated with an impaired ability to metabolize ingested histamine. Manifestation of HIT includes gastrointestinal and non-gastrointestinal symptoms. Clinical symptoms of HIT are non-specific and can imitate different diseases such as allergies, food intolerance, mastocytosis and other. The diagnosis of HIT is difficult. There are several candidate tests to detect DAO insufficiency, but their informative value is questionable. Currently, a positive clinical effect of a low-histamine diet is the most important for establishing the diagnosis. Equally in the treatment, a low-histamine diet is the most crucial approach. Other therapeutic options such as DAO supplementation treatment with antihistamines or probiotics are considered as complementary treatments. Our article provides a review on histamine intolerance, focusing on etiology and the diagnostic and treatment possibilities.

Enhanced Stability of Vegetal Diamine Oxidase with Trehalose and Sucrose as Cryoprotectants: Mechanistic Insights.

Enteric dysfunctions are common for various histamine-related intestinal disorders. Vegetal diamine oxidase (vDAO), an enzyme able to decompose histamine and thus alleviate histamine-related dysfunctions, was formulated in gastro-resistant tablet forms for oral administration as a food supplement and possible therapeutic agent. A major challenge for the use of proteins in the pharmaceutical field is their poor stability. In this study, vDAO was freeze-dried in the absence or in the presence of sucrose or trehalose as cryoprotectants and then formulated as tablets by direct compression. The stability of the obtained preparations was followed during storage at 4 °C and -20 °C for 18 months. In vitro dissolution tests with the vDAO powders formulated as tablets were performed in simulated gastric and in simulated intestinal fluids. The tablets obtained with the powder of the vDAO lyophilized with sucrose or trehalose cryoprotectants offered better protection for enzyme activity. Furthermore, the release of the vDAO lyophilized with the cryoprotectants was around 80% of the total loaded activity (enzyme units) compared to 20% for the control (vDAO powder prepared without cryoprotectants). This report revealed the potential of sucrose and trehalose as cryoprotectants to protect vDAO from freeze-drying stress and during storage, and also to markedly improve the vDAO release performance of tablets obtained with vDAO powders.

Recent advances in the application of microbial diamine oxidases and other histamine-oxidizing enzymes.

The consumption of foods fraught with histamine can lead to various allergy-like symptoms if the histamine is not sufficiently degraded in the human body. The degradation occurs primarily in the small intestine, naturally catalyzed by the human diamine oxidase (DAO). An inherent or acquired deficiency in human DAO function causes the accumulation of histamine and subsequent intrusion of histamine into the bloodstream. The histamine exerts its effects acting on different histamine receptors all over the body but also directly in the intestinal lumen. The inability to degrade sufficient amounts of dietary histamine is known as the 'histamine intolerance'. It would be preferable to solve this problem initially by the production of histamine-free or -reduced foods and by the oral supplementation of exogenous DAO supporting the human DAO in the small intestine. For the latter, DAOs from mammalian, herbal and microbial sources may be applicable. Microbial DAOs seem to be the most promising choice due to their possibility of an efficient biotechnological production in suitable microbial hosts. However, their biochemical properties, such as activity and stability under process conditions and substrate selectivity, play important roles for their successful application. This review deals with the advances and challenges of DAOs and other histamine-oxidizing enzymes for their potential application as processing aids for the production of histamine-reduced foods or as orally administered adjuvants to humans who have been eating food fraught with histamine.

Toward Oral Supplementation of Diamine Oxidase for the Treatment of Histamine Intolerance.

A new diamine oxidase (DAO-1) was discovered recently in the yeast Yarrowia lipolytica PO1f and investigated for its histamine degradation capability under simulated intestinal conditions. DAO-1 was formulated together with catalase as a sucrose-based tablet. The latter (9 × 7 mm; 400 mg) contained 690 nkat of DAO-1 activity, which was obtained from a bioreactor cultivation of a genetically modified Y. lipolytica with optimized downstream processing. The DAO-1 tablet was tested in a histamine bioconversion experiment under simulated intestinal conditions in the presence of food constituents, whereby about 30% of the histamine was degraded in 90 min. This amount might already be sufficient to help people with histamine intolerance. Furthermore, it was found that the stability of DAO-1 in a simulated intestinal fluid is influenced distinctively by the presence of a food matrix, indicating that the amount and type of food consumed affect the oral supplementation with DAO. This study showed for the first time that a microbial DAO could have the potential for the treatment of histamine intolerance by oral supplementation.

Basal Serum Diamine Oxidase Levels as a Biomarker of Histamine Intolerance: A Retrospective Cohort Study.

Background: Histamine Intolerance (HIT) is a multifaceted pseudoallergic disorder possibly due to defective histamine metabolism. Diamine oxidase (DAO) contributes to histamine degradation and can be measured in the serum. The role of DAO measurement in the diagnostic work-up of HIT still remains unclear, and conflicting results have been reported in the literature. Therefore, we aimed to evaluate the possible clinical usefulness and consistency of DAO value ranges as provided by the assay manufacturer and verify whether they could predict the response to treatment. Methods: We retrospectively analyzed 192 outpatients with HIT symptoms and measured serum DAO values at baseline. Patients were prescribed either with low-histamine diet and/or enzymatic supplementation according to symptom severity and re-evaluated six to eight months later. Patients were stratified into three groups according to DAO levels: <3 U/mL, 3−10 U/mL, and >10 U/mL. HIT severity was assessed on a scale of 1 to 5 before and after treatment. Results: A total of 146 patients completed the study. Gastrointestinal and cutaneous symptoms, often associated with headache, were more frequent in subjects with DAO < 10 U/mL. Symptom severity and DAO ranges were correlated. Patients with intermediate DAO levels (3−10 U/mL) showed a more complex clinical phenotype but also a more significant improvement in symptom severity (score reduction 50%, interquartile range (IQR) = 33−60%) when compared to patients with low DAO (40%, IQR = 20−60%; p = 0.045) or high DAO (33%, IQR = 0−50%; p < 0.001). Complex clinical phenotypes were also more frequent in patients with intermediate DAO levels. Conclusions: HIT is characterized by typical symptoms and low levels of DAO activity. Symptom severity was associated with the degree of DAO deficiency. Patients with DAO values between 3 and 10 U/mL show the best response to treatment (low-histamine diet and/or DAO supplementation). DAO value could arguably be considered as a predictor of clinical response to treatment. Prospective studies are needed to confirm these data.

Impact of the clinically approved Petasites hybridus extract Ze 339 on intestinal mechanisms involved in the handling of histamine.

In patients with histamine intolerance accumulated or ingested histamine causes a broad range of undesirable symptoms. Food-derived histamine is degraded by intestinal diamine oxidase (DAO) and histamine-N-methyltransferase (HNMT), while the organic cation transporter 3 (OCT3) contributes to the transcellular flux of histamine. Anecdotal evidence from patients with HIT suggests an improvement of symptoms related to histamine intolerance after intake of Ze 339, a lipophilic CO2-extract prepared from the leaves of Petasites hybridus. Thus, it was the aim of this study to investigate the influence of Ze 339 on DAO, HNMT and OCT3 using Caco-2 and MDCKII cells. Even though Ze 339 reduced mRNA levels of HNMT and DAO, there was no change in protein expression. Ze 339 changed neither the basal release nor the enzymatic activity of DAO. Testing the interaction of Ze 339 with the transcellular histamine transport, we observed a significant increase in the basal to apical flux in presence of high Ze 339 concentrations at the early phases of the experiment. Testing the influence of Ze 339 on OCT3-mediated histamine uptake in overexpressing MDCKII cells revealed a dose-dependent inhibition with an estimated IC50 of 26.9 ug/mL for the extract. In conclusion, we report an effect of Ze 339 on transcellular histamine transport, where inhibition of OCT3 may contribute.

Acupuncture improves the symptoms, intestinal microbiota, and inflammation of patients with mild to moderate Crohn's disease: A randomized controlled trial.

BACKGROUND: The efficacy and mechanisms of acupuncture for Crohn's disease (CD) are not well understood. We investigated its effects on symptoms, intestinal microbiota, and circulating inflammatory markers in CD patients. METHODS: This 48-week, randomized, sham controlled, parallel-group clinical trial was performed at a tertiary outpatient clinic in China. From April 2015 to November 2019, 66 patients (mean age 40·4, 62·1% were male, all were Han Chinese) with mild to moderate active CD and unresponsive to drug treatment were enrolled and randomly assigned equally to an acupuncture group or a sham group. The treatment group received 3 sessions of acupuncture plus moxibustion per week for 12 weeks and a follow-up of 36 weeks. Clinicaltrials.gov: NCT02559037. FINDINGS: At week 12, the clinical remission rate (the primary outcome) and clinical response rate of acupuncture group were significantly higher than that of sham group, with a difference of 42·4% (95% CI: 20·1%-64·0%) and 45·5% (95% CI: 24·0%-66·9%), respectively, both of which maintained at week 48. The acupuncture group had significantly lower CD activity index and C-reactive protein level at week 12, which maintained at 36-week follow-up. The CD endoscopic index of severity, histopathological score, and recurrence rate at week 48 were significantly lower in acupuncture group. The number of operational taxonomic unit of intestinal microbiota and relative abundance of Faecalibacterium prausnitzii and Roseburia faecis were increased. Plasma diamine oxidase, lipopolysaccharide, and Th1/Th17 related cytokines were decreased in 12-week after acupuncture. INTERPRETATION: Acupuncture was effective in inducing and maintaining remission in patients with active CD, which was associated with increased abundance of intestinal anti-inflammatory bacteria, enhanced intestinal barrier, and regulation of circulating Th1/Th17-related cytokines. FUNDING: National Key Basic Research Program of China (2015CB554500 and 2009CB522900), Shanghai Rising-Star Program (19QA1408100).

Prospective Randomized Trial of Early Postoperative Enteral and Total Parenteral Nutrition for Treating Esophageal Cancer.

BACKGROUND/AIM: Surgical stress significantly decreases serum diamine oxidase (DAO), a marker of intestinal mucosal maturation and integrity. This study aimed to determine the effects of postoperative enteral and total parenteral nutrition (EN and TPN, respectively) in patients with esophageal cancer. PATIENTS AND METHODS: This prospective randomized trial compared serum DAO activities, nutritional states, trace elements and complications between patients who underwent esophagectomy and received EN or TPN for seven days thereafter. RESULTS: Fifty-one patients were randomized to receive EN or TPN. The rates of change in serum DAO activity from the day before surgery were 0.79, 0.89 and 0.91 on postoperative days (POD) 1, 3 and 7, respectively, in the EN group, and 0.64, 0.76 and 1.06, respectively, in the TPN group, with no significant differences. Furthermore, the rates of changes in indicators of nutritional status, namely total protein, albumin, total cholesterol, trace element concentrations and infectious and non-infectious complications did not significantly differ between the groups. CONCLUSION: EN and/or TPN can be administered for early nutritional management until resumption of oral intake after esophagectomy according to the postoperative status of individual patients with esophageal cancer.

Guideline on management of suspected adverse reactions to ingested histamine: Guideline of the German Society for Allergology and Clinical Immunology (DGAKI), the Society for Pediatric Allergology and Environmental Medicine (GPA), the Medical Association of German Allergologists (AeDA) as well as the Swiss Society for Allergology and Immunology (SGAI) and the Austrian Society for Allergology and Immunology (ÖGAI).

Adverse reactions to food or food ingredients are more often perceived than objectively verifiable. However, reliable laboratory tests are often lacking. As a result, people with perceived adverse reactions to food often follow extensive elimination diets for years and unnecessarily restrict their diet, as in the case of the frequently suspected histamine intolerance. In this condition, laboratory parameters such as the determination of diamine oxidase in serum have been shown to be inconclusive. The lack of symptom reproducibility calls into question the clinical picture of adverse reactions to ingested histamine. In order to approach persons with perceived histamine intolerance and to support them in moving from blanket restrictions, which are often unnecessarily strict, to effective personalized therapeutic strategies, the present guideline of the Working Group on Food Allergy of the German Society of Allergology and Clinical Immunology (DGAKI) in cooperation with the Medical Association of German Allergists (AeDA), the Pediatric Allergology and Environmental Medicine (GPA) as well as the Swiss Society of Allergology and Immunology (SGAI) and the Austrian Society of Allergology and Immunology (ÖGAI) recommends a practicable diagnostic and therapeutic approach.

A Pilot Study Evaluating the Effectiveness and Safety of Daikenchuto (TJ-100) for the Treatment of Postoperative Abdominal Pain or Bloating in Patients Undergoing Hepatectomy: Study Protocol for a Randomized, Open, Controlled Trial.

This study is being performed to evaluate the effectiveness and safety of TJ-100 TSUMURA Daikenchuto (DKT) Extract Granules in preventing post-hepatectomy digestive symptoms, and to examine the effects of DKT on small intestinal mucosal atrophy using diamine oxidase (DAO) and glucagon-like peptide-2 (GLP-2) activities. This is a randomized, open, controlled trial using patients treated with usual care as the control group. Patients who meet the inclusion criteria are randomized to the study groups. Eligible patients are randomized to the DKT therapy group (DKT administration for 14 days postoperatively or until the day of discharge if a patient leaves the hospital less than 14 days after the surgery) or the usual care group (no administration of DKT (ratio 1:1). Using the NRS (numeric rating scale) as an indicator, we will attempt to show whether DKT is effective for abdominal pain and bloating after surgery by comparing both groups. We will also attempt to evaluate postoperative small intestinal mucosal atrophy using DAO and GLP-2 activities in the serum, and postoperative nutrient absorption using nutrient assessment indicators. This study is being conducted according to the CONSORT statement. A consent form was signed by all participants, and the study protocol has been approved by the Central Review Board and Local Ethics Committee (CRB7180001).

Metabolome and lipidome derangements during a severe mast cell activation event in a patient with indolent systemic mastocytosis.

BACKGROUND: The number of mast cells in various organs is elevated manifold in individuals with systemic mastocytosis. Degranulation can lead to life-threatening symptomatology. No data about the alterations of the metabolome and lipidome during an attack have been published. OBJECTIVE: Our aim was to analyze changes in metabolomics and lipidomics during the acute phase of a severe mast cell activation event. METHODS: A total of 43 metabolites and 11 lipid classes comprising 200 subvariants from multiple plasma samples in duplicate, covering 72 hours of a severe mast cell activation attack with nausea and vomiting, were compared with 2 baseline samples by using quantitative liquid chromatography-mass spectrometry. RESULTS: A strong enterocyte dysfunction reflected in an almost 20-fold reduction in the functional small bowel length was extrapolated from strongly reduced ornithine and citrulline concentrations and was very likely secondary to severe endothelial cell dysfunction with hypoperfusion and extensive vascular leakage. Highly increased histamine and lactate concentrations accompanied the peak in clinical symptoms. Elevated asymmetric and symmetric dimethylarginine levels combined with reduced arginine levels compromised endothelial nitric oxide synthase activity and nitric oxide signaling. Specific and extensive depletion of many lysophosphatidylcholine variants indicates localized autotaxin activation and lysophosphatidic acid release. A strong correlation of clinical parameters with histamine concentrations and symptom reduction after 100-fold elevated plasma diamine oxidase concentrations implies that histamine is the key driver of the acute phase. CONCLUSIONS: Rapid elimination of elevated histamine concentrations through use of recombinant human diamine oxidase, supplementation of lysophosphatidylcholine for immunomodulation, inhibition of autotaxin activity, and/or blockade of lysophosphatidic acid receptors might represent new treatment options for life-threatening mast cell activation events.

Histamine Intolerance Originates in the Gut.

Histamine intolerance (HIT) is assumed to be due to a deficiency of the gastrointestinal (GI) enzyme diamine oxidase (DAO) and, therefore, the food component histamine not being degraded and/or absorbed properly within the GI tract. Involvement of the GI mucosa in various disorders and diseases, several with unknown origin, and the effects of some medications seem to reduce gastrointestinal DAO activity. HIT causes variable, functional, nonspecific, non-allergic GI and extra-intestinal complaints. Usually, evaluation for HIT is not included in differential diagnoses of patients with unexplained, functional GI complaints or in the here-listed disorders and diseases. The clinical diagnosis of HIT is challenging, and the thorough anamnesis of all HIT-linked complaints, using a standardized questionnaire, is the mainstay of HIT diagnosis. So far, DAO values in serum have not been established to correlate with DAO activity in the gut, but the diagnosis of HIT may be supported with determination of a low serum DAO value. A targeted dietary intervention, consisting of a histamine-reduced diet and/or supplementation with oral DAO capsules, is helpful to reduce HIT-related symptoms. This manuscript will present why histamine should also be taken into account in the differential diagnoses of patients with various diseases and disorders of unknown origin, but with association to functional gastrointestinal complaints. In this review, we discuss currently increasing evidence that HIT is primarily a gastrointestinal disorder and that it originates in the gut.

Astrocytes Control Sensory Acuity via Tonic Inhibition in the Thalamus.

Sensory discrimination is essential for survival. However, how sensory information is finely controlled in the brain is not well defined. Here, we show that astrocytes control tactile acuity via tonic inhibition in the thalamus. Mechanistically, diamine oxidase (DAO) and the subsequent aldehyde dehydrogenase 1a1 (Aldh1a1) convert putrescine into GABA, which is released via Best1. The GABA from astrocytes inhibits synaptically evoked firing at the lemniscal synapses to fine-tune the dynamic range of the stimulation-response relationship, the precision of spike timing, and tactile discrimination. Our findings reveal a novel role of astrocytes in the control of sensory acuity through tonic GABA release.

[Effect of electroacupuncture on intestinal epithelial mucosal barrier function in rats with diarrhea-predominant irritable bowel syndrome].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on intestinal epithelial mucosal barrier function in diarrhea-predominant irritable bowel syndrome(IBS-D) rats, so as to explore its mechanisms underlying improvement of IBS-D. METHODS: Forty SD rats (half male and half female) were randomly divided into control, model, EA and medication (Pinaverium Bromide, PB) groups, with 10 rats in each group. The IBS-D model was established by chronic unpredictable mild stress combined with gavage of Senna-leaf solution. EA (2 Hz/15 Hz，0.1-1 mA) was applied to unilateral "Zusanli"(ST36),"Tianshu" (ST25), "Sanyinjiao"(SP6) and "Taichong"(LR3) alternatively for 15 min, once daily for 14 days. Rats of the medication group was treated by gavage of PB (10 mL·kg-1·d-1) for 14 days. The visceral sensitivity (pain) was assessed by using the pressure threshold which the inserted rectal balloon catheter air-inflation (connected to a blood pressure gauge) induced stronger abdominal muscular contraction to force the rat's abdomen to lift the experimental stand surface. The diarrhea index was used to evaluate loose stool grade. The expression of Claudin-1 and Occludin (intestinal epithelial tight junction proteins) of colon tissue was detected by immunohistochemistry. The activity of plasma diamine oxidase (DAO) was assayed by using spectrophotometry. RESULTS: Compared with the control group, the diarrhea index and plasma DAO activity in the model group were significantly increased (P<0.01), while the visceral pain threshold, expression of Claudin-1 and Occludin in the model group were significantly decreased (P<0.01). After the treatment, the diarrhea index and plasma DAO activity were significantly lower in both EA and medication groups than that in the model group (P<0.01), and the visceral pain threshold and expression levels of Claudin-1 and Occludin were obviously increased (P<0.05, P<0.01). No significant differences were found between the EA and medication groups in all the above-mentioned indexes (P>0.05). CONCLUSION: Electroacupuncture can significantly improve abdominal pain and diarrhea in IBS-D model rats, which may be closely associated with its effects in up-regulating the expression of intestinal epithelial tight junction proteins Claudin-1 and Occludin to restore the function of intestinal epithelial mucosal barrier.

Evaluation of porcine diamine oxidase for the conversion of histamine in food-relevant amounts.

Histamine exists in a multitude of foods and displays an emerging role within food intolerances. Our aim was to identify the activity of porcine diamine oxidase (DAO) required for the in vitro degradation of histamine amounts that are found in typical meals containing histamine (75 mg, equaled 150 mg/L). Furthermore, we investigated an actual dietary supplement that is commercially available for histamine intolerant individuals for its histamine reduction capability. Kinetic investigations of porcine DAO showed a substrate inhibition by histamine concentrations greater than 56 mg/L (0.5 mM). The stability of free porcine DAO was tested in a fed state simulated intestinal fluid and exhibited a half-life period of around 19 min. A total of 50 nanokatal (nkat) free porcine DAO, which equaled the amount of enzyme isolated from around 100 g pig kidney, were necessary for the in vitro reduction of around 90% of the histamine. The dietary supplement that contains a pig kidney extract did not show DAO activity. Instead, the used histamine (0.75 mg) was apparently reduced due to the adsorption of histamine onto a capsule component by 18.9 ± 2.3% within 5 hr. Although the capsule preparation retained its overall structure and shape for at least 90 min in simulated gastric fluid, the apparent histamine reduction was significantly reduced to 12.1 ± 2.3% (P ≤ 0.05). In conclusion, an alternative to the pig kidney DAO or an improved capsule preparation is needed to ensure an adequate supplementation for histamine-intolerant humans. PRACTICAL APPLICATION: Histamine intolerance is an emerging issue in our society and the intolerance-related physiological symptoms are currently not reliably treatable due to a lack of scientific investigation. A commercially available dietary supplement for histamine intolerance does not fulfil the requirements for a satisfactory histamine reduction in intolerant humans. The activity of the histamine degrading enzyme diamine oxidase, required for a satisfactory histamine degradation, is by far higher than the theoretical amount apparently given in the dietary supplement. With this knowledge, it is obvious that improved food supplements must be developed to help histamine intolerant humans.

Effect of electroacupuncture on intestinal epithelial mucosal barrier function in rats with diarrhea-predominant irritable bowel syndrome / 针刺研究

OBJECTIVE: To observe the effect of electroacupuncture (EA) on intestinal epithelial mucosal barrier function in diarrhea-predominant irritable bowel syndrome(IBS-D) rats, so as to explore its mechanisms underlying improvement of IBS-D. METHODS: Forty SD rats (half male and half female) were randomly divided into control, model, EA and medication (Pinaverium Bromide, PB) groups, with 10 rats in each group. The IBS-D model was established by chronic unpredictable mild stress combined with gavage of Senna-leaf solution. EA (2 Hz/15 Hz，0.1-1 mA) was applied to unilateral "Zusanli"(ST36),"Tianshu" (ST25), "Sanyinjiao"(SP6) and "Taichong"(LR3) alternatively for 15 min, once daily for 14 days. Rats of the medication group was treated by gavage of PB (10 mL·kg-1·d-1) for 14 days. The visceral sensitivity (pain) was assessed by using the pressure threshold which the inserted rectal balloon catheter air-inflation (connected to a blood pressure gauge) induced stronger abdominal muscular contraction to force the rat's abdomen to lift the experimental stand surface. The diarrhea index was used to evaluate loose stool grade. The expression of Claudin-1 and Occludin (intestinal epithelial tight junction proteins) of colon tissue was detected by immunohistochemistry. The activity of plasma diamine oxidase (DAO) was assayed by using spectrophotometry. RESULTS: Compared with the control group, the diarrhea index and plasma DAO activity in the model group were significantly increased (P0.05). CONCLUSION: Electroacupuncture can significantly improve abdominal pain and diarrhea in IBS-D model rats, which may be closely associated with its effects in up-regulating the expression of intestinal epithelial tight junction proteins Claudin-1 and Occludin to restore the function of intestinal epithelial mucosal barrier.

A comparative study on antidiarrheal effects of Mongolian medicines Holarrhena antidysenterica, Forsythia suspensa and Cynanchum thesioides / 中草药

Objective: To compare the antidiarrheal effects of Mongolian medicine, Holarrhena antidysenterica, Forsythia suspensa and Cynanchum thesioides on diarrhea model rats and investigate its effects on serum DAO (diamine oxidase), cAMP (cyclic adenosine phosphate), TNF-α (tumor necrosis factor-α), ATPase and calcium ions. Methods: The normal control group, model group, H. antidysenterica low-dose and high-dose groups, F. suspensa low dose and high-dose groups, C. thesioides low dose and high dose groups were set. Except the normal control group, the other groups were ig administrated water decoction of Cassia angustifolia to establish diarrhea model; After the success of the model, the rats in treatment groups were administrated by gastric drug for 7 d, the type mental state, diarrhea and body weight changes were observed. the abdominal aortic blood was obtained at the last day of fasting 12 h after the administration. DAO, cAMP, TNF-α, ATP enzyme, OD value of the calcium ions in serum were determined by using ELISA (enzyme-linked immune detection reagent) kits. Results: General status: except for the normal group, the mental state of the rats in the other groups was depressed after modeling, the fur color of them was significantly decreased and the body weight was decreased. The diarrhea rate was 100% on the 4th day after modeling. Compared with the model group, there were significant differences in the number of loose stools, grade of loose stools and diarrhea index (P < 0.05, 0.01) in each administration group. The serum DAO, TNF-α, ATPase, cAMP and calcium ion OD values were compared: the serum concentrations of DAO in H. antidysenterica low dose group, C. thesioides low dose group and F. suspensa high and low dose groups of rats were significantly lower than model group with significant differences (P < 0.05), and were significantly higher than normal group. The serum concentration of TNF-α in C. thesioides high and low dose groups were lower compared with model group (P < 0.05). The serum ATPase in C. thesioides high and low dose groups had significant difference (P < 0.05) compared with model group. The serum concentration of cAMP in H. antidysenterica high-dose group and F. suspensa low-dose group was significantly lower compared with model group with significant differences (P < 0.05). Serum Ca2+ concentration in the drug administration groups was significantly different from that in the model group (P < 0.05). Conclusion: The antidiarrheal effect of C. thesioides is better than that of H. antidysenterica and F. suspensa.

In vitro determination of diamine oxidase activity in food matrices by an enzymatic assay coupled to UHPLC-FL.

Intestinal diamine oxidase (DAO) acts as a protective barrier against exogenous histamine. A deficit of DAO activity can lead to the appearance of histamine intolerance, a clinical condition that may be treated by a low-histamine diet and oral DAO supplementation to enhance intestinal histamine degradation. As sources of DAO, porcine kidneys and certain legume seedlings are suitable components for the formulation of a DAO supplement. The aim of this work was to develop a rapid and reliable methodology for the in vitro determination of DAO activity in food matrices based on an enzymatic assay coupled to UHPLC-FL. The proposed method showed a satisfactory linearity and sensitivity and provided a relative standard deviation lower than 3%, guaranteeing method precision, and a mean recovery greater than 99% both for lyophilized pea sprouts and porcine kidney protein extracts. A high specificity is a key attribute of this method due to the use of histamine as the reaction substrate and the direct quantification of its degradation. Moreover, the lack of interference of catalase and hydrogen peroxide is another advantage in comparison with previously published methods. Lyophilized pea sprouts showed the greatest histamine-degrading activity (0.40 ± 0.01 mU/mg), followed by porcine kidney protein extracts (0.23 ± 0.01 mU/mg) and commercial DAO supplements (0.09 ± 0.06 mU/mg). This technique could be used as a tool to validate the DAO activity of food matrices of potential interest for the treatment of histamine intolerance.

Pyrrolizidine Alkaloids: Biosynthesis, Biological Activities and Occurrence in Crop Plants.

Pyrrolizidine alkaloids (PAs) are heterocyclic secondary metabolites with a typical pyrrolizidine motif predominantly produced by plants as defense chemicals against herbivores. They display a wide structural diversity and occur in a vast number of species with novel structures and occurrences continuously being discovered. These alkaloids exhibit strong hepatotoxic, genotoxic, cytotoxic, tumorigenic, and neurotoxic activities, and thereby pose a serious threat to the health of humans since they are known contaminants of foods including grain, milk, honey, and eggs, as well as plant derived pharmaceuticals and food supplements. Livestock and fodder can be affected due to PA-containing plants on pastures and fields. Despite their importance as toxic contaminants of agricultural products, there is limited knowledge about their biosynthesis. While the intermediates were well defined by feeding experiments, only one enzyme involved in PA biosynthesis has been characterized so far, the homospermidine synthase catalyzing the first committed step in PA biosynthesis. This review gives an overview about structural diversity of PAs, biosynthetic pathways of necine base, and necic acid formation and how PA accumulation is regulated. Furthermore, we discuss their role in plant ecology and their modes of toxicity towards humans and animals. Finally, several examples of PA-producing crop plants are discussed.