Role of Histamine in Modulating the Immune Response and Inflammation

Leveraging thiol-functionalized biomucoadhesive hybrid nanoliposome for local therapy of ulcerative colitis

Directly administering medication to inflamed intestinal sites for treating ulcerative colitis (UC), poses significant challenges like retention time, absorption variability, side effects, drug stability, and non-specific delivery. Recent advancements in therapy to treat colitis aim to improve local drug availability that is enema therapy at the site of inflammation, thereby reducing systemic adverse effects. Nevertheless, a key limitation lies in enemas' inability to sustain medication in the colon due to rapid peristaltic movement, diarrhea, and poor local adherence. Therefore, in this work, we have developed site-specific thiolated mucoadhesive anionic nanoliposomes to overcome the limitations of conventional enema therapy. The thiolated delivery system allows prolonged residence of the delivery system at the inflamed site in the colon, confirmed by the adhesion potential of thiolated nanoliposomes using in-vitro and in-vivo models. To further provide therapeutic efficacy thiolated nanoliposomes were loaded with gallic acid (GA), a natural compound known for its antibacterial, antioxidant, and potent anti-inflammatory properties. Consequently, Gallic Acid-loaded Thiolated 2,6 DALP DMPG (GATh@APDL) demonstrates the potential for targeted adhesion to the inflamed colon, facilitated by their small size 100 nm and anionic nature. Therapeutic studies indicate that this formulation offers protective effects by mitigating colonic inflammation, downregulating the expression of NF-κB, HIF-1α, and MMP-9, and demonstrating superior efficacy compared to the free GA enema. The encapsulated GA inhibits the NF-κB expression, leading to enhanced expression of MUC2 protein, thereby promoting mucosal healing in the colon. Furthermore, GATh@APDL effectively reduces neutrophil infiltration and regulates immune cell quantification in colonic lamina propria. Our findings suggest that GATh@APDL holds promise for alleviating UC and addressing the limitations of conventional enema therapy.

Colorimetric detection of diamine using diamine oxidase and horseradish peroxidase co-incorporated hybrid microsphere as biomimetic cascade enzymes

Dual-enzyme co-embedded materials have shown high potential for achieving efficient detection due to the convenience of two-enzyme cascade reactions. Herein, we developed a dual-enzyme hybrid microsphere (HM) based biosensor to detect diamines (histamine was included for ease of description) in aquatic products. The HM was made from diamine oxidase, horseradish peroxidase, and copper phosphate through the biomineralization method. Under optimal conditions, the system displayed linear color response to histamine of different concentrations ranging from 0 to 200 μg/mL. The detection limit of histamine was 0.15 μg/mL, showing higher sensitivity than the two-step free enzyme assay. Moreover, the detection system exhibited good specificity to diamines. The method was used to detect diamines in commercial samples, and the results were compared with those measured by the high-performance liquid chromatography method. Overall, the proposed assay exhibited high potential in diamine quantification and was readily extended to other cascade enzymatic reaction-based detection strategies.

Polysaccharides of Floccularia luteovirens regulate intestinal immune response, and oxidative stress activity through MAPK/Nrf2/Keap1 signaling pathway in immunosuppressive mice

This study explores the novel immunomodulatory effects of polysaccharides from the rare Floccularia luteovirens, a fungus with significant potential yet unexplored bioactive components, traditionally used in Tibetan medicine. This study employs a wide array of analytical techniques, including HPGPC, HPLC, western blotting, ELISA, and 16S rRNA gene sequencing, to comprehensively investigate FLP1's effects. The main structure of FLP1 was characterized by IF-TR and NMR spectrometry. The structural backbone of FLP1 was →3,6)-β-D-Glcp-(1 → and →2,3)-α-D-Manp-(1→. After immunosuppressed mice treated with FLP1, the findings demonstrated that FLP1 stimulated the production of secretory sIgA and secretion of cytokines (IL-4, TNF-α, and IFN-γ) in the intestine of Cy-treated mice, resulting in the activation of the MAPK pathway. Additionally, FLP1 protected oxidative stress by triggering Nrf2/Keap1 pathways and antioxidation enzymes (SOD, MDA, T-AOC, CAT, and GSH-Px). It also enhanced the intestinal barrier function by regulating the villous height ratio and expression of tight-junction protein. Furthermore, FLP1 remarkably reversed the gut microbiota dysbiosis in immunosuppressed mice by increasing the abundance of Oscilliospiraceae, and Lachnospiraceae, and altered the fecal metabolites by increasing LysoPE (0:0/18:0); 0:0/16:0; 18:1(11Z)/0:0, LysoPG (16:0/0:0), LysoPG 18:1 (2n) PE (14:0/20:1), echinenone, 2-(2-Nitroimidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl) acetamide, and suberic acid which is closely related to the immunity function. These results suggested that FLP1 may regulate the intestinal immune response by modulating the gut microbiota and fecal metabolites in immunosuppressed mice thereby activating the immune system.

Effect of a Phytochemical-Rich Olive-Derived Extract on Anthropometric, Hematological, and Metabolic Parameters

BACKGROUND

Extra virgin olive oil is a fundamental component of the Mediterranean diet. It contains several molecules that sustain human well-being by modulating cellular metabolism and exerting antioxidant, anti-inflammatory, and anti-ageing effects to protect normal tissues, and it can exert anti-angiogenic and pro-apoptotic effects on cancer cells. Metabolites found in different parts of the olive tree, including leaves, also possess properties that might help in cancer prevention and promote wellness in aging. Olive mill wastewater (OMWW), a liquid residue produced during olive oil extraction, represents an environmental issue. However, it is rich in phytochemicals with potential beneficial properties. Dietary supplements based on OMWW can be produced for nutritional supplementation with advantages to the ecology.

PURPOSE

This work aims to measure hematochemical, anthropometric, and metabolomic parameters in volunteers taking an OMWW dietary supplement, Oliphenolia® (OMWW-OL).

METHODS

The supplementation of OMWW-OL 25 mL twice daily for 30 days was tested on a pilot cohort of volunteers with characteristics close to metabolic syndrome. Hematochemical, anthropometric, serum biomarkers and serum metabolomic parameters were analyzed before the intervention, at 30 days, and 30 days after stopping consumption.

RESULTS

A total of 29 volunteers were enrolled, and 23 completed the study. The participants' parameters at baseline were measured, and then twice daily at 30 days of treatment and 30 days after assumption discontinuation. Although treatment was with an olive derivative, their weight did not increase. Their body mass index, instead of augmenting, slightly decreased, particularly in the women. Also, hydration increased, especially in the women, while blood pressure, glycemia, and insulin decreased. Cholesterol, high-density lipoproteins, and triglycerides were stable, and LDL levels decreased, while vitamin D levels, alongside calcium, perceptibly increased. Albumin also increased. All the values were in support of an equilibrium, with no damaging effects. By mass spectrometry analysis, we also found favorable changes in the vitamin D/histamine and homocysteine/methionine ratios, an increase in a new metabolite of unknown formula, and the vitamin D/unknown metabolite ratio.

CONCLUSIONS

Supplementation of OMWW-OL has no detrimental effects and might imply the beneficial modulation of several biological parameters. Although this is a small pilot study, with limited potency, it preliminarily suggests that the OMWW extract use could be potentially valuable for people at risk of metabolic syndrome. Some of these parameters could also be relevant in supporting healthy ageing and in cancer prevention.

Independent factors for the development of vasoplegic syndrome in patients undergoing coronary artery bypass surgery

Objective

Vasoplegic syndrome remains a common complication of cardiac surgery. It has serious implications for the healthcare system and individual patients, as it leads to rising healthcare costs and higher mortality. A better understanding of factors triggering vasoplegic syndrome is essential for the development of effective prevention strategies. We aimed to identify clinical characteristics and intraoperative parameters associated with the development of vasoplegic syndrome in coronary artery bypass graft surgery and the influence of vasoplegia on outcome.

Methods

We retrospectively analyzed the data of all patients who underwent isolated coronary artery bypass graft surgery or coronary artery bypass graft surgery combined with atrial appendage occlusion, using the heart-lung machine at our institution from 04/2019 to 12/2020. Vasoplegic syndrome was defined as MAP ≤60 mmHg and norepinephrine equivalence dosage of ≥0.2 μg/kg/min with a central venous saturation ≥60% within 2 days from surgery.

Results

Of 647 patients included in this study, 72 (11.1%) developed vasoplegic syndrome. Patients experiencing vasoplegia had longer stay in ICU, more frequently underwent tracheostomy and suffered more often from pneumonia. The duration of extracorporeal circulation, intraoperative application of platelet concentrates and usage of cold crystalloid cardioplegia (Bretschneider) independently predicted development of vasoplegic syndrome.

Conclusions

Even in relatively low-risk cardiac surgery, vasoplegic syndrome is a common complication and was associated with serious adverse effects. The use of warm blood cardioplegia (Calafiore) seems to be safer than cold crystalloid cardioplegia (Bretschneider) and might be preferable in patients that are vulnerable to the consequences of vasoplegic syndrome.

Pathophysiological role of histamine signaling and its implications in glioblastoma

Glioblastoma (GBM), an extremely aggressive and prevalent malignant brain tumor, remains a challenge to treat. Despite a multimodality treatment approach, GBM recurrence remains inevitable, particularly with the emergence of temozolomide (TMZ) resistance and limited treatment options. Surprisingly, previous studies show that a history of allergies, atopy, or asthma is inversely associated with GBM risk. Further, the electronic medical record at the University Hospital of Lausanne showed that the GBM patients taking antihistamine during treatment had better survival. Histamine is an essential neurotransmitter in the brain and plays a significant role in regulating sleep, hormonal balance, and cognitive functions. Elevated levels of histamine and increased histamine receptor expression have been found in different tumors and their microenvironments, including GBM. High histamine 1 receptor (HRH1) expression is inversely related to overall and progression-free survival in GBM patients, further emphasizing the role of histamine in disease progression. This review aims to provide insights into the challenges of GBM treatment, the role of histamine in GBM progression, and the rationale for considering antihistamines as targeted therapy. The review concludes by encouraging further investigation into antihistamine mechanisms and their impact on the tumor microenvironment.

Metabolomic analysis revealed the inflammatory and oxidative stress regulation in response to Vibrio infection in Plectropomus leopardus

Frequent outbreaks of infectious diseases in aquaculture have led to significant economic losses. The leopard coral grouper (Plectropomus leopardus) often suffers from vibriosis. Improving host immunity presents a superior strategy for disease control, with minimal side effects compared to the use of antibiotics, highlighting the necessity of exploring the mechanisms underlying the fish's response to pathogen infections. Here, we conducted a comparative metabolomic analysis on the livers of the P. leopardus infected with Vibrio harveyi. A total of 1124 differential metabolites (DMs) were identified, with 190, 218, 359, and 353 DMs being identified at 6, 12, 24, and 48 h post-infection (hpi), respectively. Then, based on the time series analysis, we found that the lipid metabolism pathways were modulated in response to the Vibrio infection, with an increase in the quantity of eicosanoids and gycerophospholipids (GPLs), as well as a decrease in the quantity of bile acids (BAs), vitamin D, and sex hormones. Furthermore, 13 enriched pathways involving 31 DMs were identified through KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analyses. We identified histamine, 15(S)-HpETE, and anandamide in the transient receptor potential (TRP) channels pathway, as well as (7S,8S)-DiHODE, 5S,8R-DiHODE, and 13(S)-HpODE in the linoleic acid (LA) metabolism pathway. The DM levels increased, which may be attributed to inflammation. The DMs in the thyroid hormone synthesis pathway were identified, and the contents of nicotinamide adenine dinucleotide phosphate (NADPH) and glutathione (GSH) decreased, which may be crucial in antioxidants. Our findings highlighted the dynamic adjustments in lipid metabolism and the response to inflammation and oxidative stress during the infection of V. harveyi in P. leopardus. This study not only deepens our understanding of the metabolic underpinnings of fish immune responses but also lays the groundwork for research into functional metabolomics and mechanisms of disease resistance.

Biochemical implication of acetylcholine, histamine, IL-18, and interferon-alpha as diagnostic biomarkers in hepatitis C virus, coronavirus disease 2019, and dual hepatitis C virus-coronavirus disease 2019 patients

Globally, hepatitis C virus (HCV) and coronavirus disease 2019 (COVID-19) are the most common causes of death due to the lack of early predictive and diagnostic tools. Therefore, research for a new biomarker is crucial. Inflammatory biomarkers are critical central players in the pathogenesis of viral infections. IL-18, produced by macrophages in early viral infections, triggers inflammatory biomarkers and interferon production, crucial for viral host defense. Finding out IL-18 function can help understand COVID-19 pathophysiology and predict disease prognosis. Histamine and its receptors regulate allergic lung responses, with H1 receptor inhibition potentially reducing inflammation in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. angiotensin-converting enzyme 2 (ACE-2) receptors on cholangiocytes suggest liver involvement in SARS-CoV-2 infection. The current study presents the potential impact of circulating acetylcholine, histamine, IL-18, and interferon-Alpha as diagnostic tools in HCV, COVID-19, and dual HCV-COVID-19 pathogenesis. The current study was a prospective cross-section conducted on 188 participants classified into the following four groups: Group 1 COVID-19 (n = 47), Group 2 HCV (n = 47), and Group 3 HCV-COVID-19 patients (n = 47), besides the healthy control Group 4 (n = 47). The levels of acetylcholine, histamine, IL-18, and interferon-alpha were assayed using the ELISA method. Liver and kidney functions within all groups showed a marked alteration compared to the healthy control group. Our statistical analysis found that individuals with dual infection with HCV-COVID-19 had high ferritin levels compared to other biomarkers while those with COVID-19 infection had high levels of D-Dimer. The histamine, acetylcholine, and IL-18 biomarkers in both COVID-19 and dual HCV-COVID-19 groups have shown discriminatory power, making them potential diagnostic tests for infection. These three biomarkers showed satisfactory performance in identifying HCV infection. The IFN-Alpha test performed well in the HCV-COVID-19 group and was fair in the COVID-19 group, but it had little discriminative value in the HCV group. Moreover, our findings highlighted the pivotal role of acetylcholine, histamine, IL-18, and interferon-Alpha in HCV, COVID-19, and dual HCV-COVID-19 infection. Circulating levels of acetylcholine, histamine, IL-18, and interferon-Alpha can be potential early indicators for HCV, COVID-19, and dual HCV-COVID-19 infection. We acknowledge that further large multicenter experimental studies are needed to further investigate the role biomarkers play in influencing the likelihood of infection to confirm and extend our observations and to better understand and ultimately prevent or treat these diseases.

C-ter100 peptide derived from Vibrio vEP-45 protease acts as a pathogen-associated molecular pattern to induce inflammation and innate immunity

The bacterium Vibrio vulnificus causes fatal septicemia in humans. Previously, we reported that an extracellular metalloprotease, vEP-45, secreted by V. vulnificus, undergoes self-proteolysis to generate a 34 kDa protease (vEP-34) by losing its C-terminal domain to produce the C-ter100 peptide. Moreover, we revealed that vEP-45 and vEP-34 proteases induce blood coagulation and activate the kallikrein/kinin system. However, the role of the C-ter100 peptide fragment released from vEP-45 in inducing inflammation is still unclear. Here, we elucidate, for the first time, the effects of C-ter100 on inducing inflammation and activating host innate immunity. Our results showed that C-ter100 could activate NF-κB by binding to the receptor TLR4, thereby promoting the secretion of inflammatory cytokines and molecules, such as TNF-α and nitric oxide (NO). Furthermore, C-ter100 could prime and activate the NLRP3 inflammasome (NLRP3, ASC, and caspase 1), causing IL-1β secretion. In mice, C-ter100 induced the recruitment of immune cells, such as neutrophils and monocytes, along with histamine release into the plasma. Furthermore, the inflammatory response induced by C-ter100 could be effectively neutralized by an anti-C-ter100 monoclonal antibody (C-ter100Mab). These results demonstrate that C-ter100 can be a pathogen-associated molecular pattern (PAMP) that activates an innate immune response during Vibrio infection and could be a target for the development of antibiotics.

Histamine promotes mouse decidualization through stimulating epithelial amphiregulin release

Accumulating evidence shows that inflammation is essential for embryo implantation and decidualization. Histamine, a proinflammatory factor that is present in almost all mammalian tissues, is synthesized through decarboxylating histidine by histidine decarboxylase (HDC). Although histamine is known to be essential for decidualization, the underlying mechanism remains undefined. In the present study, histamine had no obvious direct effects on in vitro decidualization in mice. However, the obvious differences in HDC protein levels between day 4 of pregnancy and day 4 of pseudopregnancy, as well as between delayed and activated implantation, suggested that the blastocyst may be involved in regulating HDC expression. Furthermore, blastocyst-derived tumor necrosis factor α (TNFα) significantly increased HDC levels in the luminal epithelium. Histamine increased the levels of amphiregulin (AREG) and disintegrin and metalloproteinase domain-containing protein 17 (ADAM17) proteins, which was abrogated by treatment with famotidine, a specific histamine type 2 receptor (H2R) inhibitor, or by TPAI-1 (a specific inhibitor of ADAM17). Intraluminal injection of urocanic acid (HDC inhibitor) on day 4 of pregnancy significantly reduced the number of implantation sites on day 5 of pregnancy. TNFα-stimulated increases in HDC, AREG and ADAM17 protein levels was abrogated by urocanic acid, a specific inhibitor of HDC. Additionally, AREG treatment significantly promoted in vitro decidualization. Collectively, our data suggests that blastocyst-derived TNFα induces luminal epithelial histamine secretion, and histamine increases mouse decidualization through ADAM17-mediated AREG release.

Histochemical and immunohistochemical investigation of the number and localization of mast cells in the feline tongue

This is the first study to describe the subtypes, number and distribution of mast cells (MC) in cat tongue by histochemical and immunohistochemical methods. Six male adult felines' tongue tissue samples consist of the study's material. Samples were fixed in 10% formaldehyde. MC number and distribution in the feline tongue were assessed using toluidine blue. Also, sections taken from blocks were stained in alcian blue/safranin O (AB/SO) combined dyes to determine the MC subtypes. The Streptavidin biotin complex method using anti-chymase and anti-tryptase primary antibodies was used for immunohistochemistry. Metachromatic MCs were mainly observed in the lamina propria close to the multilayered keratinized stratified squamous epithelium. The high number of MCs in this region may be because the dorsal surface of the tongue plays an essential role in the defence system of tongue tissue and, thus, of the body as a whole. Additionally, the number of MCs stained with AB (+) (1.7 ± 0.08) in the feline tongue was statistically higher than those with SO (+) (0.18 ± 0.02). This might be interpreted as an indication that MC heterogeneity may be due not only to their staining properties but also to their localization. It is also conceivable that the high histamine content may be a factor in this. Tryptase-positive MCs were found in the loose connective tissue around blood vessels, between the glands, as solitary cells, or in groups of several cells. Chymase-positive MCs were observed more individually rather than in groups. Moreover, chymase-positive MCs were detected to be located in the filiform papillae subepithelial and in the blood vessels' immediate vicinity. Animals often lick themselves to clean themselves and promote healing. For this reason, it is very important to protect the tongue, which is in direct contact with the external environment, against foreign agents. Considering both the functional and protective properties of the tongue, we concluded that MCs may play a role in oral cavity immunity and protective effect.

Salivary Histamine Levels in Patients with Oral Lichen Planus Lesions

Background and Objectives: An oral lichen planus (OLP) chronic lesion refers to a group of oral potentially malignant disorders (OPMDs) that still lack a proper understanding from the point of view of relevant biomarkers for diagnostics and prognosis. The aim of the study was to assess the salivary histamine levels in patients with oral lichen planus lesions. Materials and Methods: The study included a group of 76 patients with oral lichen planus. General diseases and medication taken, smoking habits, severity of pain assessed using a visual analogue scale (VAS), oral hygiene status, and duration of OLP were evaluated. ELISA diagnostics for histamines in saliva levels were assessed. Results: The histamine levels in the OLP group were higher (0.468) in comparison with the control group (0.056), without a statistically significant value p = 0.090 (Mann-Whitney U Test). The median age of 76 OLP patients was 63 years (min 22.0-max. 81), with the biological sex being 80.3% females and 15 19.7% males. The average duration of OLP lesion presence was 29.4 months (SD 37.1) and the median value was 14.5 months. The median of the VAS was 3.0. OLP assessment in accordance with the Malhotra methodology showed the highest frequency-30.3% for only two of the point areas involved and 17.1% for three points. Clinical assessment of the different OLP grades, severity, and oral site involvement and the VAS in correlation with histamine salivary levels showed a lack of statistical significance in the investigated population. Conclusions: Undertaking further research could provide further possibilities for searching for general factors in OLP development.

The role of the gut microbiome in disorders of gut-brain interaction

Disorders of Gut-Brain Interaction (DGBI) are widely prevalent and commonly encountered in gastroenterology practice. While several peripheral and central mechanisms have been implicated in the pathogenesis of DGBI, a recent body of work suggests an important role for the gut microbiome. In this review, we highlight how gut microbiota and their metabolites affect physiologic changes underlying symptoms in DGBI, with a particular focus on their mechanistic influence on GI transit, visceral sensitivity, intestinal barrier function and secretion, and CNS processing. This review emphasizes the complexity of local and distant effects of microbial metabolites on physiological function, influenced by factors such as metabolite concentration, duration of metabolite exposure, receptor location, host genetics, and underlying disease state. Large-scale in vitro work has elucidated interactions between host receptors and the microbial metabolome but there is a need for future research to integrate such preclinical findings with clinical studies. The development of novel, targeted therapeutic strategies for DGBI hinges on a deeper understanding of these metabolite-host interactions, offering exciting possibilities for the future of treatment of DGBI.

Histamine-related genes participate in the establishment of an immunosuppressive microenvironment and impact the immunotherapy response in hepatocellular carcinoma

Chronic inflammation is pivotal in the pathogenesis of hepatocellular carcinoma (HCC). Histamine is a biologically active substance that amplifies the inflammatory and immune response and serves as a neurotransmitter. However, knowledge of histamine's role in HCC and its effects on immunotherapy remains lacking. We focused on histamine-related genes to investigate their potential role in HCC. The RNA-seq data and clinical information regarding HCC were obtained from The Cancer Genome Atlas (TCGA). After identifying the differentially expressed genes, we constructed a signature using the univariate Cox proportional hazard regression and least absolute shrinkage and selection operator (LASSO) analyses. The signature's predictive performance was evaluated using a receiver operating characteristic curve (ROC) analysis. Furthermore, drug sensitivity, immunotherapy effects, and enrichment analyses were conducted. Histamine-related gene expression in HCC was confirmed using quantitative real-time polymerase chain reaction (qRT-PCR). A histamine-related gene prognostic signature (HRGPS) was developed in TCGA. Time-dependent ROC and Kaplan-Meier survival analyses demonstrated the signature's strong predictive power. Importantly, patients in high-risk groups exhibited a higher frequency of TP53 mutations, elevated immune checkpoint-related gene expression, and increased infiltration of immunosuppressive cells-indicating a potentially favorable response to immunotherapy. In addition, drug sensitivity analysis revealed that the signature could effectively predict chemotherapy efficacy and sensitivity. qRT-PCR results validated histamine-related gene overexpression in HCC. Our findings demonstrate that inhibiting histamine-related genes and signaling pathways can impact the therapeutic effect of anti-PD-1/PD-L1. The precise predictive ability of our signature in determining the response to different therapeutic options highlights its potential clinical significance.

Metabolome analyses of skin dialysate: Insights into skin interstitial fluid biomarkers

BACKGROUND

Metabolites in biofluids can serve as biomarkers for diagnosing diseases and monitoring body conditions. Among the available biofluids, interstitial fluid (ISF) in the skin has garnered considerable attention owing to its advantages, which include inability to clot, easy access to the skin, and possibility of incorporating wearable devices. However, the scientific understanding of skin ISF composition is limited.

OBJECTIVE

In this study, we aimed to compare metabolites between skin dialysate containing metabolites from the skin ISF and venous blood (plasma) samples, both collected under resting states.

METHODS

We collected forearm skin dialysate using intradermal microdialysis alongside venous blood (plasma) samples from 12 healthy young adults. We analyzed these samples using capillary electrophoresis-fourier transform mass spectrometry-based metabolomics (CE-FTMS).

RESULTS

Significant positive correlations were observed in 39 metabolites between the skin dialysate and plasma, including creatine (a mitochondrial disease biomarker), 1-methyladenosine (an early detection of cancer biomarker), and trimethylamine N-oxide (a posterior predictor of heart failure biomarker). Based on the Human Metabolome Technologies database, we identified 12 metabolites unique to forearm skin dialysate including nucleic acids, benzoate acids, fatty acids, amino acids, ascorbic acid, 3-methoxy-4-hydroxyphenylethyleneglycol (an Alzheimer's disease biomarker), and cysteic acid (an acute myocardial infarction biomarker).

CONCLUSION

We show that some venous blood biomarkers may be predicted from skin dialysate or skin ISF, and that these fluids may serve as diagnostic and monitoring tools for health and clinical conditions.

Anti-inflammatory and/or immunomodulatory activities of Uncaria tomentosa (cat's claw) extracts: A systematic review and meta-analysis of in vivo studies

Background

Uncaria tomentosa (Willd. ex Schult.) DC. (Rubiaceae) is traditionally used by Amazonian indigenous groups to treat inflammatory diseases. To date, there are no systematic reviews and meta-analyses on the use of U. tomentosa for inflammation control in animals supporting the traditional knowledge about this species. This study was conducted to evaluate the effect of U. tomentosa extracts in modulating inflammatory mediators and to determine which types of inflammatory diseases can be treated by this species.

Methods

We conducted a systematic review and meta-analysis of preclinical studies published before 26 July 2023, identified in PubMed, Embase, and Scopus. Four independent reviewers extracted the data and assessed the risks of bias. The effects of U. tomentosa on inflammatory diseases and the inflammatory mediators involved were extracted from the studies. Standardized mean differences (SMD) and 95% confidence intervals (95%CI) of the outcomes were estimated. The meta-analyses were conducted using RevMan 5.4 (Cochrane Collaboration). This protocol was registered in PROSPERO (CRD42023450869).

Results

Twenty-four of 523 studies were included. U. tomentosa extracts decreased the cytokines interleukin (IL)-6 (SMD: -0.72, 95%CI: -1.15, -0.29, p = 0.001) and transcription factor nuclear factor kappa-B (NF-κB) (SMD: -1.19, 95%CI: -1.89, -0.48, p = 0.001). However, the extracts did not significantly alter IL-1 (SMD: -0.16, 95%CI: -0.87, +0.56, p = 0.67), IL-10 (SMD: -0.05, 95%CI:-0.35, 0.45, p = 0.80), or tumor necrosis factor-alpha (TNF-α) levels (SMD: 0.18, 95%CI: -0.25, 0.62, p = 0.41).

Conclusion

Many extracts of stem bark, roots, and leaves of U. tomentosa, mostly aqueous and hydroethanolic, exhibited anti-inflammatory and/or immunomodulatory activities and low toxicity. The extracts decreased NF-κB and IL-6. These findings suggest that this species has the potential to treat inflammatory diseases in which these markers are increased, according to the ethnopharmacological use. These activities are not related to a specific class of compounds.

Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=450869, Identifier CRD42023450869.

Roles of blood metabolites in mediating the relationship between vitiligo and autoimmune diseases: Evidence from a Mendelian randomization study

OBJECTIVE

This study employed Mendelian Randomization (MR) to investigate the causal relationship between genetic susceptibility to vitiligo and the risk of various autoimmune diseases, along with the mediating role of blood metabolites.

METHODS

We performed two-sample MR analyses using aggregated genome-wide association studies (GWAS) data on 486 blood metabolites, vitiligo, and nine autoimmune diseases to investigate blood metabolites' causal effects on the susceptibility of vitiligo and the associations of vitiligo with nine autoimmune comorbidities. We also applied multivariable MR to unravel metabolites by which vitiligo influences the pathogenesis of autoimmune diseases.

RESULTS

Our findings indicate that vitiligo amplified the risk of several autoimmune diseases, including rheumatoid arthritis (OR 1.17; 95 % CI 1.08-1.27), psoriasis (OR 1.10; 95 % CI 1.04-1.17), type 1 diabetes (OR 1.41; 95 % CI 1.23-1.63), pernicious anemia (OR 1.23; 95 % CI 1.12-1.36), autoimmune hypothyroidism (OR 1.19; 95 % CI 1.11-1.26), alopecia areata (OR 1.22; 95 % CI 1.10-1.35), and autoimmune Addison's disease (OR 1.22; 95 % CI 1.12-1.33). Additionally, our analysis identified correlations with vitiligo for 14 known (nine risk, five protective) and seven uncharacterized serum metabolites. After adjusting for genetically predicted levels of histidine and pyruvate, the associations between vitiligo and these diseases were attenuated.

CONCLUSIONS

We substantiated vitiligo's influence on susceptibility to seven autoimmune diseases and conducted a thorough investigation of serum metabolites correlated with vitiligo. Histidine and pyruvate are potential mediators of vitiligo associated with autoimmune diseases.By combining metabolomics with genomics, we provide new perspectives on the etiology of vitiligo and its immune comorbidities.

Therapeutic potential of LINS01 histamine H3 receptor antagonists as antineoplastic agents for triple negative breast cancer

The aims of this work were to evaluate the expression of histamine H3 receptor (H3R) in triple negative breast cancer (TNBC) samples and to investigate the antitumoral efficacy and safety of the LINS01 series of H3R antagonists, through in silico, in vitro, and in vivo approaches. Antitumor activity of LINS01009, LINS01010, LINS01022, LINS01023 was assayed in vitro in 4T1 and MDA-MB-231 TNBC cells (0.01-100 μM), and in vivo in 4T1 tumors orthotopically established in BALB/c mice (1 or 20 mg/kg). Additionally, H3R expression was assessed in 50 human TNBC samples. We have described a higher H3R mRNA expression in basal-like/TNBC tumors vs. matched normal tissue using TCGA Pan-Cancer Atlas data, and a higher H3R expression in human tumor samples vs. peritumoral tissue evidenced by immunohistochemistry associated with poorer survival. Furthermore, while all the essayed compounds showed antitumoral properties, LINS01022 and LINS01023 exhibited the most potent antiproliferative effects by: i) inducing cell apoptosis and suppressing cell migration in 4T1 and MDA-MB-231 TNBC cells, and ii) inhibiting cell growth in paclitaxel-resistant 4T1 cells (potentiating the paclitaxel antiproliferative effect). Moreover, 20 mg/kg LINS01022 reduced tumor size in 4T1 tumor-bearing mice, exhibiting a safe toxicological profile and potential for druggability estimated by ADME calculations. We conclude that the H3R is involved in the regulation of TNBC progression, offering promising therapeutic potential for the novel LINS01 series of H3R antagonists.

Promising probiotic-fermented soymilk for alleviating acute diarrhea: insights into the microbiome and metabolomics

Fermented soymilk (FSM4) has attracted much attention due to its nutritional and health characteristics. Exploring FSM4 products to alleviate diarrhea can ensure their effectiveness as a therapeutic food for alleviating gastrointestinal disorders. However, the relationship between gut microbiota and gut metabolite production remains unknown during diarrheal episodes. Therefore, the diarrhea-alleviating role and mechanisms of FSM4 in diarrhea rats were investigated via biochemical, gut microbiota, and serum metabolite analyses. The findings showed that consuming FSM4 improved diarrhea symptoms and reduced systemic inflammation better than non-fermented soymilk (NFSM). It is worth noting that FSM4 promoted the diversity, richness, structure, and composition of gut microbiota. It increased the ability to reduce inflammation associated with harmful bacteria (Anaerofilum, Flavonifractor, Bilophila, Anaerostipes, [Ruminococcus]_torques_group, Clostridium_sensu_stricto_1, Turicibacter, Ruminococcus_1, Ruminiclostridium_6, Prevotellaceae_NK3B31_group and Fusicatenibacter), while stimulating the growth of healthy species (Lactobacillus, Ruminococcaceae_UCG-014, Oscillibacter, [Eubacterium]_coprostanoligenes_group, Negativibacillus, and Erysipelotrichaceae_UCG-003). Moreover, metabolomics analysis showed that lipid metabolites such as lysophosphatidylethanolamine (LysoPE) and sphingolipids were upregulated in the NG group, closely related to pro-inflammatory cytokines (IL-6, IL-1β, TNF-α, and IFN-γ) and the aforementioned pathogenic bacteria. Notably, in treatment groups, especially FSM4, the accumulation of L-ornithine, aspartic acid, ursocholic acid, 18-oxooleate, and cyclopentanethiol was increased, which was robustly associated with the anti-inflammatory factor IL-10 and beneficial bacteria mentioned above. Therefore, it can be inferred that the amino acids, bile acid, 18-oxooleate, and cyclopentanethiol produced in the FSM4 group can serve as metabolic biomarkers, which synergistically act with the gut microbiota to help alleviate inflammation for diarrhea remission. Overall, FSM4 may provide a new alternative, as an anti-inflammatory diet, to alleviate diarrhea.

Local regulation of striatal dopamine: A diversity of circuit mechanisms for a diversity of behavioral functions?

Striatal dopamine governs a wide range of behavioral functions, yet local dopamine concentrations can be dissociated from somatic activity. Here, we discuss how dopamine's diverse roles in behavior may be driven by local circuit mechanisms shaping dopamine release. We first look at historical and recent work demonstrating that striatal circuits interact with dopaminergic terminals to either initiate the release of dopamine or modulate the release of dopamine initiated by spiking in midbrain dopamine neurons, with particular attention to GABAergic and cholinergic local circuit mechanisms. Then we discuss some of the first in vivo studies of acetylcholine-dopamine interactions in striatum and broadly discuss necessary future work in understanding the roles of midbrain versus striatal dopamine regulation.

Spatially Resolved Molecular Analysis of Host Response to Medical Device Implantation Using the 3D OrbiSIMS Highlights a Critical Role for Lipids

A key goal for implanted medical devices is that they do not elicit a detrimental immune response. Macrophages play critical roles in the modulation of the host immune response and are the cells responsible for persistent inflammatory reactions to implanted biomaterials. Two novel immune-instructive polymers that stimulate pro- or anti-inflammatory responses from macrophages in vitro are investigated. These also modulate in vivo foreign body responses (FBR) when implanted subcutaneously in mice. Immunofluorescent staining of tissue abutting the polymer reveals responses consistent with pro- or anti-inflammatory responses previously described for these polymers. Three Dimensional OrbiTrap Secondary Ion Mass Spectrometry (3D OrbiSIMS) analysis to spatially characterize the metabolites in the tissue surrounding the implant, providing molecular histology insight into the metabolite response in the host is applied. For the pro-inflammatory polymer, monoacylglycerols (MG) and diacylglycerols (DG) are observed at increased intensity, while for the anti-inflammatory coating, the number of phospholipid species detected decreased, and pyridine and pyrimidine levels are elevated. Small molecule signatures from single-cell studies of M2 macrophages in vitro correlate with the in vivo observations, suggesting potential for prediction. Metabolite characterization by the 3D OrbiSIMS is shown to provide insight into the mechanism of bio-instructive materials as medical devices and to inform on the FBR to biomaterials.

Umbilical therapy for promoting transdermal delivery of topical formulations: Enhanced effect and underlying mechanism

Umbilical paste therapy is a promising method to promote transdermal drug delivery of topical formulations. This work investigated the effect and mechanism of transdermal drug delivery through the umbilical skin. The transdermal permeation studies showed the phenomenon of higher cumulative penetration and faster penetration rates for drug through the umbilical skin compared with non-umbilical skin, namely umbilical pro-permeability. This special transdermal permeability of drugs is influenced by their molecular weight, logP value, ability to form hydrogen bonds, and molecular volume. The underlying mechanism of umbilical pro-permeability was elucidated from unique structure and regulation the effect of drugs on microcirculation in the umbilical skin. Mechanistic studies revealed that this phenomenon was not only associated with the structural and physiological properties of the skin but also to the interactions between drugs and different skin layers. The umbilical pro-permeation is attributed to the thinner stratum corneum layer, differences in stratum corneum lipid composition and keratin structure, and lower levels of intercellular tight junction proteins in the viable epidermis and dermis layer of the skin. Our research indicated that umbilical paste therapy enhanced the transdermal delivery and absorption of drugs by stimulating local blood flow through mast cell activation. Surprisingly, skin temperature modulation and calcitonin gene-related peptide and substance P levels did not appear to significantly affect this process. In conclusion, umbilical drug administration, as a straightforward and non-invasive approach to enhance transdermal drug delivery, presents novel concepts for continued investigation and practical implementation of transdermal drug delivery systems.

Exopolysaccharide secreted by Lactiplantibacillus plantarum Y12 showed inhibitory effect on the pathogenicity of Shigella flexneri in vitro and in vivo

Shigella flexneri is a prevalent foodborne and waterborne pathogen that threatens human health. Our previous research indicated that the Lactiplantibacillus plantarum Y12 exopolysaccharide (L-EPS) potentially inhibited the pathogenicity of S. flexneri. The in vitro results of this study demonstrated that L-EPS effectively mitigated the symptoms induced by S. flexneri in HT-29 cells, including inhibited gene expression levels of IL-1β, IL-6, IL-8, TNF-α, TLR 2/4, and NOD1/2; decreased apoptosis ratio; and alleviated damage degree of intestinal barrier function (Zona occludens 1, Occludin, and Claudin-1). The in vivo results demonstrated that S. flexneri treated with L-EPS elicited mild adverse physiological manifestations, an inflammatory response, and tissue damage. The infection of S. flexneri caused significant alterations in the abundance of phylum (Firmicutes, Bacteroidota, Actinobacteriota, and Proteobacteria), family (Lachnospiraceae, Muribaculaceae, Rikenellaceae, Prevotellaceaea, Ruminococcaceae, and Lactobaillaceae), and genus (Escherichia Shigella and Lachnospirillaceae NK4A136 group) within the cecal microbiota. These changes were accompanied by perturbations in taurine and hypotaurine metabolism, tricarboxylic acid (TCA) cycle activity, arginine biosynthesis, and histidine metabolic pathways. However, intervention with L-EPS attenuated the dysbiosis of cecal microbiota and metabolic disturbances. In summary, our research suggested a potential application of L-EPS as a functional food additive for mitigating S. flexneri infection.

The impact of skin color and tone on histamine iontophoresis and Doppler flowmetry measurements as a pharmacodynamic biomarker

The phenotypical manifestations of asthma among children are diverse and exhibit varying responses to therapeutic interventions. There is a need to develop objective biomarkers to improve the characterization of allergic and inflammatory responses relevant to asthma to predict therapeutic treatment responses. We have previously investigated histamine iontophoresis with laser Doppler flowmetry (HILD) as a potential surrogate biomarker that characterizes histamine response and may be utilized to guide the treatment of allergic and inflammatory disease. We have identified intra-individual variability of HILD response type among children and adults with asthma and that HILD response type varied in association with racial classification. As laser Doppler flowimetry may be impacted by skin color, we aimed to further validate the HILD method by determining if skin color or tone is associated with observed HILD response type differences. We conducted an observational study utilizing quantification of skin color and tone obtained from photographs of the skin among participants during HILD assessments via the RGB color model. We compared RGB values across racial, ethnic, and HILD response type via the Kruskal-Wallis test and calculated Kendall rank correlation coefficient to evaluate the relationship between RGB composite scores and HILD pharmacodynamic measures. We observed that RGB scores differed among racial groups and histamine response phenotypes (p < 0.05). However, there was a lack of correlation between the RGB composite score and HILD pharmacodynamic measures (r values 0.1, p > 0.05). These findings suggest that skin color may not impact HILD response variations, necessitating further research to understand previously observed differences across identified racial groups.

Advances in clinical application of H1 antihistamines in the treatment of skin diseases

Histamine receptors are classified into 4 types: H1, H2, H3, and H4, each mediating distinct physiological effects and possessing its corresponding antagonistshat that can be used for the prevention and treatment of various diseases. Among them, H1 antihistamines are the fundamental medications in dermatology and are widely used in many diseases such as urticaria and atopic dermatitis. In recent years, with the emergence of novel antihistamines and the discovery of new potential indications for traditional H1 antihistamines, the clinical application of antihistamines is facing new challenges. Further investigation of the novel mechanism for H1 antihistamines, the use of multiple doses of common drugs and potential indications will furnish vital insights for practical clinical application.

Novel insights on the probable mechanism associated with histamine oral model-inducing neuropathological and behavioral toxicity in rats

Histamine (HIS) is an important chemical mediator that causes vasodilation and contributes to anaphylactic reactions. Recently, HIS is an understudied neurotransmitter in the central nervous system, and its potential role in neuroinflammation and neurodegeneration is a critical area of research. So, the study's goal is to investigate the consequences of repeated oral intake of HIS on the rat's brain and explore the mechanistic way of its neurotoxicity. Thirty male rats were divided into three groups (n = 10). The following treatments were administered orally to all rats every day for 14 days. Group (1) was given distilled water, whereas groups (2 & 3) were given HIS at dosage levels 250 and 500 mg/kg body weight (BWT), respectively. Brain tissue samples were collected at 7- and 14-days from the beginning of the experiment. Our results revealed that continuous oral administration of HIS at both doses for 14 days significantly reduced the BWT and induced severe neurobehavioral changes, including depression, dullness, lethargy, tremors, abnormal walking, and loss of spatial learning and memory in rats. In all HIS receiving groups, HPLC data showed a considerable raise in the HIS contents of the brain. Additionally, the daily consumption of HIS causes oxidative stress that is dose- and time-dependent which is characterized by elevation of malondialdehyde levels along with reduction of catalase activity and reduced glutathione levels. The neuropathological lesions were commonly observed in the cerebrum, striatum, and cerebellum and confirmed by the immunohistochemistry staining that demonstrating moderate to strong caspase-3 and inducible nitric oxide synthase expressions in all HIS receiving groups, mainly those receiving 500 mg/kg HIS. NF-κB, TNF-α, and IL-1β gene levels were also upregulated at 7- and 14-days in all HIS groups, particularly in those getting 500 mg/kg. We concluded that ROS-induced apoptosis and inflammation was the essential mechanism involved in HIS-mediated neurobehavioral toxicity and histopathology.

Exploring the Relationship between Diamine Oxidase and Psychotropic Medications in Fibromyalgia Treatment, Finding No Reduction in Diamine Oxidase Levels and Activity except with Citalopram

Background: Histamine intolerance manifests when there is an imbalance between the production of histamine and the body's capacity to metabolise it. Within the gastrointestinal tract, diamine oxidase (DAO) plays a pivotal role in breaking down ingested histamine. Insufficient levels of DAO have been linked to various diseases affecting the respiratory, cardiovascular, nervous, muscular, and digestive systems; some of these symptoms are evidenced in fibromyalgia syndrome. This underscores the crucial role of DAO in maintaining the histamine balance and highlights its association with diverse physiological systems and health conditions. The management of fibromyalgia commonly involves the use of psychotropic medications; however, their potential interactions with DAO remain not fully elucidated. Methods: This study delved into the influence of various psychotropic medications on DAO activity through in vitro experiments. Additionally, we explored their impact on the human intestinal cell line Caco-2, examining alterations in DAO expression at both the mRNA and protein levels along with DAO activity. Results: Notably, the examined drugs-sertraline, pregabalin, paroxetine, alprazolam, and lorazepam-did not exhibit inhibitory effects on DAO activity or lead to reductions in DAO levels. In contrast, citalopram demonstrated a decrease in DAO activity in in vitro assays without influencing DAO levels and activity in human enterocytes. Conclusions: These findings imply that a collaborative approach involving psychotropic medications and DAO enzyme supplementation for individuals with fibromyalgia and a DAO deficiency could offer potential benefits for healthcare professionals in their routine clinical practice.

Countermeasures against Pulmonary Threat Agents

Inhaled toxicants are used for diverse purposes, ranging from industrial applications such as agriculture, sanitation, and fumigation to crowd control and chemical warfare, and acute exposure can induce lasting respiratory complications. The intentional release of chemical warfare agents (CWAs) during World War I caused life-long damage for survivors, and CWA use is outlawed by international treaties. However, in the past two decades, chemical warfare use has surged in the Middle East and Eastern Europe, with a shift toward lung toxicants. The potential use of industrial and agricultural chemicals in rogue activities is a major concern as they are often stored and transported near populated areas, where intentional or accidental release can cause severe injuries and fatalities. Despite laws and regulatory agencies that regulate use, storage, transport, emissions, and disposal, inhalational exposures continue to cause lasting lung injury. Industrial irritants (e.g., ammonia) aggravate the upper respiratory tract, causing pneumonitis, bronchoconstriction, and dyspnea. Irritant gases (e.g., acrolein, chloropicrin) affect epithelial barrier integrity and cause tissue damage through reactive intermediates or by direct adduction of cysteine-rich proteins. Symptoms of CWAs (e.g., chlorine gas, phosgene, sulfur mustard) progress from airway obstruction and pulmonary edema to acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), which results in respiratory depression days later. Emergency treatment is limited to supportive care using bronchodilators to control airway constriction and rescue with mechanical ventilation to improve gas exchange. Complications from acute exposure can promote obstructive lung disease and/or pulmonary fibrosis, which require long-term clinical care. SIGNIFICANCE STATEMENT: Inhaled chemical threats are of growing concern in both civilian and military settings, and there is an increased need to reduce acute lung injury and delayed clinical complications from exposures. This minireview highlights our current understanding of acute toxicity and pathophysiology of a select number of chemicals of concern. It discusses potential early-stage therapeutic development as well as challenges in developing countermeasures applicable for administration in mass casualty situations.

Molluscum Contagiosum Virus: Biology and Immune Response

Molluscum contagiosum virus is a poxvirus belonging to the Poxviridae family, which includes Orthopoxvirus, Parapoxvirus, Yantapoxvirus, Molluscipoxvirus, Smallpox virus, Cowpox virus and Monkeypox virus. MCV belongs to the genus Molluscipoxvirus and has a tropism for skin tissue. MCV infects keratinocytes and, after an incubation period of 2 weeks to 6 weeks, causes a breakdown of the skin barrier with the development of papules of variable size depending on the proper functioning of the immune response (both adaptive and acquired). MCV only infects humans and does not cause viraemia. MCV encodes for several inhibitory proteins responsible to circumvent the immune response through different signalling pathways. Individuals who can be infected with MCV are children, immunocompromised individuals such as organ transplant recipients and Human Immunodeficiency Virus (HIV)-infected individuals. Current treatments to manage MCV-induced lesions are different and include the use of immunomodulators, which, however, do not provide an effective response.

Diamine Oxidase Interactions with Anti-Inflammatory and Anti-Migraine Medicines in the Treatment of Migraine

Histamine intolerance arises when there is a disparity between the production of histamine and the body's ability to break it down. In the gastrointestinal tract, the primary enzyme responsible for metabolizing ingested histamine is diamine oxidase (DAO), and a shortage of this enzyme has been associated with some diseases related to the respiratory, cardiovascular, nervous, muscular, and digestive systems, in addition to migraines. The treatment of migraines typically revolves around the utilization of both anti-migraine and anti-inflammatory drugs, but their interaction with DAO is not thoroughly understood. In this study, we examined the impact of nonsteroidal anti-inflammatory drugs (NSAIDs) and anti-migraine medications on DAO activity through in vitro experiments. We also investigated their effects on the human intestinal cell line Caco-2, assessing changes in DAO expression (both at the mRNA and protein levels) as well as DAO activity. The tested drugs, including ibuprofen, acetylsalicylic acid, paracetamol, a combination of acetylsalicylic acid with paracetamol and caffeine, zolmitriptan, and sumatriptan, did not inhibit DAO activity or reduce their levels. However, naproxen reduced DAO protein levels in human enterocyte cultures while not affecting DAO activity. These results suggest that combining anti-inflammatory and anti-migraine drugs with DAO enzyme supplementation for migraine patients with DAO deficiency could be beneficial for healthcare professionals in their daily practice.

Histamine excretion in common indoor and hematophagous arthropods

Histamine is a biogenic amine that regulates multiple physiological functions in diverse organisms, specifically playing a central role in the mammalian immune response. The common bed bug, Cimex lectularius L. (Hemiptera: Cimicidae), excretes histamine in large amounts in its feces as a component of its aggregation pheromone, which contaminates homes. The potential health risks associated with the presence of indoor histamine are unclear, but to predict future exposure risks, it is critical that we understand if other arthropods excrete histamine in any discernible phylogenetic pattern. In the present study, we evaluated histamine excretion by various arthropods; specifically those commonly found in large numbers indoors, other hematophagous species, and other species in the order Hemiptera. To evaluate arthropods for histamine excretion, rearing containers for each arthropod were swabbed and/or the harborage substrates were collected. Samples were then analyzed for the presence of histamine using gas chromatography-mass spectrometry. For those arthropods where histamine was present above the method detection limit, total histamine excretion was quantified over a period of 2 wk. Our results indicate that histamine excretion is limited to hematophagous hemipterans (bed bugs, bat bugs, tropical bed bugs, and kissing bugs), suggesting that indoor histamine contamination in the United States can be primarily linked to bed bugs.

Pathogenetic mechanisms and treatment targets in cerebral malaria

Malaria, the most prevalent mosquito-borne infectious disease worldwide, has accompanied humanity for millennia and remains an important public health issue despite advances in its prevention and treatment. Most infections are asymptomatic, but a small percentage of individuals with a heavy parasite burden develop severe malaria, a group of clinical syndromes attributable to organ dysfunction. Cerebral malaria is an infrequent but life-threatening complication of severe malaria that presents as an acute cerebrovascular encephalopathy characterized by unarousable coma. Despite effective antiparasite drug treatment, 20% of patients with cerebral malaria die from this disease, and many survivors of cerebral malaria have neurocognitive impairment. Thus, an important unmet clinical need is to rapidly identify people with malaria who are at risk of developing cerebral malaria and to develop preventive, adjunctive and neuroprotective treatments for cerebral malaria. This Review describes important advances in the understanding of cerebral malaria over the past two decades and discusses how these mechanistic insights could be translated into new therapies.

Eucalyptus torquata L. flowers: a comprehensive study reporting their metabolites profiling and anti-gouty arthritis potential

Gouty arthritis is one of the most common metabolic disorders affecting people. Plant based drugs can lower the risk of this health disorder. The anti-gouty potential of Eucalyptus torquata flowers methanol extract (ETME) was evaluated in vitro via measuring the inhibitory effects of five pro-inflammatory enzymes; xanthine oxidase (XO), hyaluronidase, lipoxygenase (5-LOX), cyclooxygenases COX-1, and COX-2, in addition to evaluating the inhibition of histamine release, albumin denaturation, membrane stabilization, tyrosinase, and protease inhibitory activities. Also, its antioxidant potential was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging assays and ferric reducing power assay (FRAP). HPLC-PDA-MS/MS was used to identify the metabolites in the tested extract. The latter exhibited substantial anti-arthritic properties in all assays with comparable potential to the corresponding reference drugs. HPLC-MS/MS analysis of this bioactive extract tentatively annotated 46 metabolites including phloroglucinols, gallic and ellagic acids derivatives, terpenes, flavonoids, fatty acids, and miscellaneous metabolites. Our study highlights the medicinal importance of E. torquata as an anti-gouty candidate and opens new avenues of gouty management.

Neuropsychiatric Manifestations of Mast Cell Activation Syndrome and Response to Mast-Cell-Directed Treatment: A Case Series

Mast cell activation syndrome (MCAS) is an immune disease with an estimated prevalence of 17%. Mast cell chemical mediators lead to heterogeneous multisystemic inflammatory and allergic manifestations. This syndrome is associated with various neurologic and psychiatric disorders, including headache, dysautonomia, depression, generalized anxiety disorder, and many others. Although MCAS is common, it is rarely recognized, and thus, patients can suffer for decades. The syndrome is caused by aberrant mast cell reactivity due to the mutation of the controller gene. A case series is presented herein including eight patients with significant neuropsychiatric disorders that were often refractory to standard medical therapeutics. Five patients had depression, five had generalized anxiety disorder, and four had panic disorder. Other psychiatric disorders included attention-deficit hyperactivity disorder, obsessive compulsive disorder, phobias, and bipolar disorder. All eight patients were subsequently diagnosed with mast cell activation syndrome; six had comorbid autonomic disorders, the most common being postural orthostatic tachycardia syndrome; and four had hypermobile Ehlers-Danlos syndrome. All patients experienced significant improvements regarding neuropsychiatric and multisystemic symptoms after mast-cell-directed therapy. In neuropsychiatric patients who have systemic symptoms and syndromes, it is important to consider the presence of an underlying or comorbid MCAS.

Linking Migraine to Gut Dysbiosis and Chronic Non-Communicable Diseases

In the world, migraine is one of the most common causes of disability in adults. To date, there is no a single cause for this disorder, but rather a set of physio-pathogenic triggers in combination with a genetic predisposition. Among the factors related to migraine onset, a crucial role seems to be played by gut dysbiosis. In fact, it has been demonstrated how the intestine is able to modulate the central nervous system activities, through the gut-brain axis, and how gut dysbiosis can influence neurological pathologies, including migraine attacks. In this context, in addition to conventional pharmacological treatments for migraine, attention has been paid to an adjuvant therapeutic strategy based on different nutritional approaches and lifestyle changes able to positively modulate the gut microbiota composition. In fact, the restoration of the balance between the different gut bacterial species, the reconstruction of the gut barrier integrity, and the control of the release of gut-derived inflammatory neuropeptides, obtained through specific nutritional patterns and lifestyle changes, represent a possible beneficial additive therapy for many migraine subtypes. Herein, this review explores the bi-directional correlation between migraine and the main chronic non-communicable diseases, such as diabetes mellitus, arterial hypertension, obesity, cancer, and chronic kidney diseases, whose link is represented by gut dysbiosis.

COVID-19 as a polymorphic inflammatory spectrum of diseases: a review with focus on the brain

There appear to be huge variations and aberrations in the reported data in COVID-19 2 years now into the pandemic. Conflicting data exist at almost every level and also in the reported epidemiological statistics across different regions. It is becoming clear that COVID-19 is a polymorphic inflammatory spectrum of diseases, and there is a wide range of inflammation-related pathology and symptoms in those infected with the virus. The host's inflammatory response to COVID-19 appears to be determined by genetics, age, immune status, health status and stage of disease. The interplay of these factors may decide the magnitude, duration, types of pathology, symptoms and prognosis in the spectrum of COVID-19 disorders, and whether neuropsychiatric disorders continue to be significant. Early and successful management of inflammation reduces morbidity and mortality in all stages of COVID-19.

Multi-omics approach to socioeconomic disparity in metabolic syndrome reveals roles of diet and microbiome

The epidemy of metabolic syndrome (MetS) is typically preceded by adoption of a "risky" lifestyle (e.g., dietary habit) among populations. Evidence shows that those with low socioeconomic status (SES) are at an increased risk for MetS. To investigate this, we recruited 123 obese subjects (body mass index [BMI] ≥ 30) from Chicago. Multi-omic data were collected to interrogate fecal microbiota, systemic markers of inflammation and immune activation, plasma metabolites, and plasma glycans. Intestinal permeability was measured using the sugar permeability testing. Our results suggest a heterogenous metabolic dysregulation among obese populations who are at risk of MetS. Systemic inflammation, linked to poor diet, intestinal microbiome dysbiosis, and gut barrier dysfunction may explain the development of MetS in these individuals. Our analysis revealed 37 key features associated with increased numbers of MetS features. These features were used to construct a composite metabolic-inflammatory (MI) score that was able to predict progression of MetS among at-risk individuals. The MI score was correlated with several markers of poor diet quality as well as lower levels of gut microbial diversity and abnormalities in several species of bacteria. This study reveals novel targets to reduce the burden of MetS and suggests access to healthy food options as a practical intervention.

Targeting inflammatory pathways for treatment of the major depressive disorder

Current treatments modalities for major depressive disorder (MDD) mainly target the monoaminergic neurotransmission. However, the therapeutic inadequacy and adverse effects confine the use of these conventional antidepressants to a limited subset of MDD patients. The classical antidepressants are increasingly proving unsatisfactory in tackling the treatment-resistant depression (TRD). Hence, the focus of treatment is shifting to alternative pathogenic pathways involved in depression. Preclinical and clinical evidences accumulated across the last decades have unequivocally affirmed the causative role of immuno-inflammatory pathways in the progression of depression. There is an upsurge in the clinical evaluations of the drugs having anti-inflammatory effects as antidepressants. This review highlights the molecular mechanisms connecting the inflammatory pathways to the MDD and current clinical status of inflammation modulating drugs in the treatment of MDD.

Targeted Metabolomics Analysis of Individuals Carrying the ANGPTL8 R59W Variant

ANGPTL8 is recognized as a regulator of lipid metabolism through its role in inhibiting lipoprotein lipase activity. ANGPTL8 gene variants, particularly rs2278426 leading to the R59W variant in the protein, have been associated with lipid traits in various ethnicities. We aimed to use metabolomics to understand the impact of the ANGPTL8 R59W variant on metabolites in humans. We used the Biocrates-p400 kit to quantify 408 plasma metabolites in 60 adult male Arab individuals from Kuwait and identify differences in metabolite levels between individuals carrying reference genotypes and those with carrier genotypes at ANGPTL8 rs2278426. Individuals with carrier genotypes (CT+TT) compared to those carrying the reference genotype (CC) showed statistically significant differences in the following metabolites: acylcarnitine (perturbs metabolic pathways), phosphatidylcholine (supports liver function and cholesterol levels), cholesteryl ester (brings chronic inflammatory response to lipoprotein depositions in arteries), α-aminoadipic acid (modulates glucose homeostasis), histamine (regulates glucose/lipid metabolism), sarcosine (links amino acid and lipid metabolism), diacylglycerol 42:1 (regulates homeostasis of cellular lipid stores), and lysophosphatidylcholine (regulates oxidative stress and inflammatory response). Functional aspects attributed to these metabolites indicate that the ANGPTL8 R59W variant influences the concentrations of lipid- and inflammation-related metabolites. This observation further highlights the role of ANGPTL8 in lipid metabolism.

Is Histamine and Not Acetylcholine the Missing Link between ADHD and Allergies? Speer Allergic Tension Fatigue Syndrome Re-Visited

Speer allergic tension-fatigue syndrome (SATFS) is a classic allergy syndrome characterized by allergy-like symptoms, muscle tension, headaches, chronic fatigue, and other particular behaviors that were initially described in the fifties. The particular behaviors displayed include symptoms such as hyperkinesis, hyperesthesia (i.e., insomnia), restlessness, and distractibility, among others. Interestingly, these symptoms are very similar to descriptions of attention deficit hyperactivity disorder (ADHD), the most prevalent neurodevelopmental disorder worldwide, which is characterized by inattention, hyperactivity, and impulsivity. The clinical description of SATFS precedes the nomination of ADHD in 1960 by Stella Chess. In this conceptual paper, we stress that there is a gap in the research on the relationship between ADHD and allergic pathologies. The hypotheses of this conceptual paper are (1) SATFS is probably one of the first and best historical descriptions of ADHD alongside a common comorbidity (allergy) displayed by these patients; (2) SATFS (ADHD) is a systemic disease that includes both somatic and behavioral manifestations that may influence each other in a bidirectional manner; (3) The role of neuroinflammation and histamine is key for understanding the pathophysiology of ADHD and its frequent somatic comorbidities; (4) The deficiency of the diamine oxidase (DAO) enzyme, which metabolizes histamine extracellularly, may play a role in the pathophysiology of ADHD. Decreased DAO activity may lead to an accumulation of histamine, which could contribute to core ADHD symptoms and comorbid disorders. Further empirical studies are needed to confirm our hypotheses.

Mast cell-mediated immune regulation in health and disease

Mast cells are important components of the immune system, and they perform pro-inflammatory as well as anti-inflammatory roles in the complex process of immune regulation in health and disease. Because of their strategic perivascular localization, sensitivity and adaptability to the microenvironment, and ability to release a variety of preformed and newly synthesized effector molecules, mast cells perform unique functions in almost all organs. Additionally, Mast cells express a wide range of surface and cytoplasmic receptors which enable them to respond to a variety of cytokines, chemicals, and pathogens. The mast cell's role as a cellular interface between external and internal environments as well as between vasculature and tissues is critical for protection and repair. Mast cell interactions with different immune and nonimmune cells through secreted inflammatory mediators may also turn in favor of disease promoting agents. First and forefront, mast cells are well recognized for their multifaceted functions in allergic diseases. Reciprocal communication between mast cells and endothelial cells in the presence of bacterial toxins in chronic/sub-clinical infections induce persistent vascular inflammation. We have shown that mast cell proteases and histamine induce endothelial inflammatory responses that are synergistically amplified by bacterial toxins. Mast cells have been shown to exacerbate vascular changes in normal states as well as in chronic or subclinical infections, particularly among cigarette smokers. Furthermore, a potential role of mast cells in SARS-CoV-2-induced dysfunction of the capillary-alveolar interface adds to the growing understanding of mast cells in viral infections. The interaction between mast cells and microglial cells in the brain further highlights their significance in neuroinflammation. This review highlights the significant role of mast cells as the interface that acts as sensor and early responder through interactions with cells in systemic organs and the nervous system.

Mast Cells and Basophils in IgE-Independent Anaphylaxis

Anaphylaxis is a life-threatening or even fatal systemic hypersensitivity reaction. The incidence of anaphylaxis has risen at an alarming rate in the past decades in the majority of countries. Generally, the most common causes of severe or fatal anaphylaxis are medication, foods and Hymenoptera venoms. Anaphylactic reactions are characterized by the activation of mast cells and basophils and the release of mediators. These cells express a variety of receptors that enable them to respond to a wide range of stimulants. Most studies of anaphylaxis focus on IgE-dependent reactions. The mast cell has long been regarded as the main effector cell involved in IgE-mediated anaphylaxis. This paper reviews IgE-independent anaphylaxis, with special emphasis on mast cells, basophils, anaphylactic mediators, risk factors, triggers, and management.

Immunometabolic coevolution defines unique microenvironmental niches in ccRCC

Tumor cell phenotypes and anti-tumor immune responses are shaped by local metabolite availability, but intratumoral metabolite heterogeneity (IMH) and its phenotypic consequences remain poorly understood. To study IMH, we profiled tumor/normal regions from clear cell renal cell carcinoma (ccRCC) patients. A common pattern of IMH transcended all patients, characterized by correlated fluctuations in the abundance of metabolites and processes associated with ferroptosis. Analysis of intratumoral metabolite-RNA covariation revealed that the immune composition of the microenvironment, especially the abundance of myeloid cells, drove intratumoral metabolite variation. Motivated by the strength of RNA-metabolite covariation and the clinical significance of RNA biomarkers in ccRCC, we inferred metabolomic profiles from the RNA sequencing data of ccRCC patients enrolled in 7 clinical trials, and we ultimately identifyied metabolite biomarkers associated with response to anti-angiogenic agents. Local metabolic phenotypes, therefore, emerge in tandem with the immune microenvironment, influence ongoing tumor evolution, and are associated with therapeutic sensitivity.

Interaction of Diamine Oxidase with Psychostimulant Drugs for ADHD Management

Histamine intolerance occurs when there is an imbalance between histamine production and the capacity for histamine degradation. Diamine oxidase (DAO) is the main enzyme for the catabolism of ingested histamine degradation in the gastrointestinal tract and its deficiency has been linked to allergy-like symptoms. Psychostimulant drugs are commonly used to treat Attention Deficit Hyperactivity Disorder (ADHD), but their interaction with DAO is not well characterized. In this work, we evaluated the effects of psychostimulant drugs (methylphenidate and lisdexamfetamine) on in vitro DAO activity and in the human cell line of enterocytes (Caco-2), evaluating DAO expression (mRNA and protein) and DAO activity. Methylphenidate and lisdexamfetamine did not repress the in vitro DAO activity. In addition, in Caco-2 cells, lisdexamfetamine promoted a strong upregulation of DAO mRNA levels, whereas methylphenidate tended to induce DAO activity. To sum up, methylphenidate and lisdexamfetamine treatments do not reduce DAO activity. These findings could be useful for physicians prescribing these two drugs to ADHD patients affected by DAO deficiency.

Spatial distribution of histamine in bed bug-infested homes

Histamine is a component of the bed bug aggregation pheromone. It was recently identified as an environmental contaminant in homes with active bed bug infestations, posing a potential health risk to humans via skin contact or inhalation. It remains unclear how histamine is distributed in homes and if histamine can become airborne. In the present study, histamine levels in household dust were quantified from multiple locations within bed bug infested and uninfested apartments. Bed bug population levels were quantified using both traps and visual counts. The amount of histamine detected varied significantly with respect to sampling location, with the highest concentration of histamine quantified from bedding material. Infestation severity did not have a significant effect on histamine quantified at any location. Our results indicate that the bedroom should be the primary focus of histamine mitigation efforts, although histamine can be found throughout the home. Histamine quantified from homes without active bed bug infestations suggests that histamine from previous infestations can persist following pest eradication. These findings highlight the importance of histamine as a potential insect allergen and will be important for the development of targeted mitigation strategies of bed bug histamine.

Renal histaminergic system and acute effects of histamine receptor 2 blockade on renal damage in the Dahl salt-sensitive rat

Histamine is involved in the regulation of immune response, vasodilation, neurotransmission, and gastric acid secretion. Although elevated histamine levels and increased expression of histamine metabolizing enzymes have been reported in renal disease, there is a gap in knowledge regarding the mechanisms of histamine-related pathways in the kidney. We report here that all four histamine receptors as well as enzymes responsible for the metabolism of histamine are expressed in human and rat kidney tissues. In this study, we hypothesized that the histaminergic system plays a role in salt-induced kidney damage in the Dahl salt-sensitive (DSS) rat, a model characterized with inflammation-driven renal lesions. To induce renal damage related to salt sensitivity, DSS rats were challenged with 21 days of a high-salt diet (4% NaCl); normal-salt diet (0.4% NaCl)-fed rats were used as a control. We observed lower histamine decarboxylase and higher histamine N-methyltransferase levels in high-salt diet-fed rats, indicative of a shift in histaminergic tone; metabolomics showed higher histamine and histidine levels in the kidneys of high-salt diet-fed rats, whereas plasma levels for both compounds were lower. Acute systemic inhibition of histamine receptor 2 in the DSS rat revealed that it lowered vasopressin receptor 2 in the kidney. In summary, we established here the existence of the local histaminergic system, revealed a shift in the renal histamine balance during salt-induced kidney damage, and provided evidence that blockage of histamine receptor 2 in the DSS rat affects water balance and urine concentrating mechanisms.NEW & NOTEWORTHY Histamine is a nitrogenous compound crucial for the inflammatory response. The knowledge regarding the renal effects of histamine is very limited. We showed that renal epithelia exhibit expression of the components of the histaminergic system. Furthermore, we revealed that there was a shift in the histaminergic tone in salt-sensitive rats when they were challenged with a high-salt diet. These data support the notion that histamine plays a role in renal epithelial physiological and pathophysiological functions.

Histamine-producing bacteria and their role in gastrointestinal disorders

INTRODUCTION

Gut microbiota produces thousands of metabolites, which have a huge impact on the host health. Specific microbial strains are able to synthesize histamine, a molecule with a crucial role in many physiologic and pathologic mechanisms of the host. This function is mediated by the histidine decarboxylase enzyme (HDC) that converts the amino acid histidine to histamine.

AREAS COVERED

This review summarizes the emerging data on histamine production by gut microbiota, and the effect of bacterial-derived histamine in different clinical contexts, including cancer, irritable bowel syndrome, and other gastrointestinal and extraintestinal pathologies. This review will also outline the impact of histamine on the immune system and the effect of probiotics that can secrete histamine. Search methodology: we searched the literature on PubMed up to February 2023.

EXPERT OPINION

The potential of modulating gut microbiota to influence histamine production is a promising area of research, and although our knowledge of histamine-secreting bacteria is still limited, recent advances are exploring their diagnostic and therapeutical potential. Diet, probiotics, and pharmacological treatments directed to the modulation of histamine-secreting bacteria may in the future potentially be employed in the prevention and management of several gastrointestinal and extraintestinal disorders.

Inflammatory Bowel Disease: Crosstalk between Histamine, Immunity, and Disease

Inflammatory bowel disease (IBD) is increasingly recognized as a serious, worldwide public health concern. It is generally acknowledged that a variety of factors play a role in the pathogenesis of this group of chronic inflammatory diseases. The diversity of molecular actors involved in IBD does not allow us to fully assess the causal relationships existing in such interactions. Given the high immunomodulatory activity of histamine and the complex immune-mediated nature of inflammatory bowel disease, the role of histamine and its receptors in the gut may be significant. This paper has been prepared to provide a schematic of the most important and possible molecular signaling pathways related to histamine and its receptors and to assess their relevance for the development of therapeutic approaches.

IRF3 Activation in Mast Cells Promotes FcεRI-Mediated Allergic Inflammation

(1) Background: This study aims to elucidate a novel non-transcriptional action of IRF3 in addition to its role as a transcription factor in mast cell activation and associated allergic inflammation; (2) Methods: For in vitro experiments, mouse bone-marrow-derived mast cells (mBMMCs) and a rat basophilic leukemia cell line (RBL-2H3) were used for investigating the underlying mechanism of IRF3 in mast-cell-mediated allergic inflammation. For in vivo experiments, wild-type and Irf3 knockout mice were used for evaluating IgE-mediated local and systemic anaphylaxis; (3) Results: Passive cutaneous anaphylaxis (PCA)-induced tissues showed highly increased IRF3 activity. In addition, the activation of IRF3 was observed in DNP-HSA-treated mast cells. Phosphorylated IRF3 by DNP-HSA was spatially co-localized with tryptase according to the mast cell activation process, and FcεRI-mediated signaling pathways directly regulated that activity. The alteration of IRF3 affected the production of granule contents in the mast cells and the anaphylaxis responses, including PCA- and ovalbumin-induced active systemic anaphylaxis. Furthermore, IRF3 influenced the post-translational processing of histidine decarboxylase (HDC), which is required for granule maturation; and (4) Conclusion: Through this study, we demonstrated the novel function of IRF3 as an important factor inducing mast cell activation and as an upstream molecule for HDC activity.