Tyrosol Suppresses Allergic Inflammation by Inhibiting the Activation of Phosphoinositide 3-Kinase in Mast Cells

Methiothepin downregulates SNAP-23 and inhibits degranulation of rat basophilic leukemia cells and mouse bone marrow-derived mast cells

In the present study, we found that methiothepin (a nonselective 5-hydroxytryptamine [5-HT] receptor antagonist) inhibited antigen-induced degranulation in rat basophilic leukemia cells and mouse bone marrow-derived mast cells. Although antigen stimulation induces release of histamine and serotonin (5-HT) by exocytosis and mast cells express several types of 5-HT receptor, the detailed role of these receptors remains unclear. Here, pretreatment of cells with methiothepin attenuated increased intracellular Ca2+ concentration, phosphorylated critical upstream signaling components (Src family tyrosine kinases, Syk, and PLCγ1), and suppressed TNF-α secretion via inhibition of Akt (a Ser/Thr kinase activated by PI3K)and ERK phosphorylation. Furthermore, it inhibited PMA/ionomycin-induced degranulation; this finding suggested that methiothepin affected downstream signaling. IκB kinase β phosphorylates synaptosomal associated protein 23, which regulates the fusion events of the secretory granule/plasma membrane after mast cell activation, resulting in degranulation. We showed that methiothepin blocked PMA/ionomycin-induced phosphorylation of synaptosomal associated protein 23 by inhibiting its interaction with IκB kinase β. Together with the results of selective 5-HT antagonists, it is suggested that methiothepin inhibits mast cell degranulation by downregulating upstream signaling pathways and exocytotic fusion machinery through mainly 5-HT1A receptor. Our findings provide that 5-HT antagonists may be used to relieve allergic reactions.

Metabolite Chemical Composition of the Bletilla striata (Thunb.) Reichb. f. Endophyte Penicillium oxalicum

Penicillium oxalicum strain can be isolated from the Bletilla striata (Thunb.) Reichb. f. tubers. Its solid-state fermentation products are concentrated by percolation extraction. Separation and purification have been conducted to the ethyl acetate extracts by preparative HPLC. Based on the use of spectrometry, we have determined 17 known compounds, 12,13-dihydroxy-fumitremorgin C (1), pseurotin A (2), tyrosol (3), cyclo-(L-Pro-L-Val) (4), cis-4-hydroxy-8-O-methylmellein (5), uracil (6), cyclo-(L-Pro-L-Ala) (7), 1,2,3,4-tetrahydro-4-hydroxy-4-quinolin carboxylic acid (8), cyclo-(Gly-L-Pro) (9), 2'-deoxyuridine (10), 1-(β-D-ribofuranosyl)thymine (11), cyclo-(L-Val-Gly) (12), 2'-deoxythymidine (13), cyclo-(Gly-D-Phe) (14), cyclo-L-(4-hydroxyprolinyl)-D-leucine (15), cyclo-(L)-4-hydroxy-Pro-(L)-Phe (16), uridine (17). Here, we report compounds 1-3, 5, 7-8, 11-12, 14-17 are first found and isolated from this endophyte.

Oleanolic Acid Acetate Inhibits Mast Cell Activation in Ovalbumin-Induced Allergic Airway Inflammation

PURPOSE

Asthma is a complex, heterogeneous chronic inflammatory airway disease with multiple phenotypes. There has been a great progress in managing asthma, but there are still unmet needs for developing uncontrolled asthma treatments. The present study aimed to determine the effectiveness of oleanolic acid acetate (OAA) from Vigna angularis against allergic airway inflammation and the underlying mechanism of action with a focus on mast cells.

METHODS

To investigate the effect of OAA in allergic airway inflammation, we used the ovalbumin (OVA)-sensitized and challenged mice. To examine allergic airway inflammation associated with immune responses of mast cell activation in vitro, various types of mast cells were used. Systemic and cutaneous anaphylaxis models were used for mast cell-mediated hyper-responsiveness in vivo.

RESULTS

OAA reduced OVA-induced airway inflammatory responses such as bronchospasm, increase of immune cell infiltration and serum immunoglobulin E and G₁ levels. Especially, OAA decreased the mast cell infiltration, and β-hexosaminidase release as a mast cell activation marker in the bronchoalveolar lavage fluid. OAA inhibited mast cell degranulation in mast cell line (RBL-2H3) and primary cells (rat peritoneal mast cell and mouse bone marrow-derived mast cell). Mechanistically, OAA suppressed intracellular signaling pathways including the phosphorylation of phospholipase Cγ and nuclear factor-κB, resulting from the suppression of intracellular calcium influx and pro-inflammatory cytokine expression. Further, oral administration of OAA attenuated mast cell-mediated systemic and cutaneous anaphylaxis.

CONCLUSIONS

Our study showed that OAA can inhibit mast cell-mediated allergic reaction. Consequently, the application of OAA to mast cells for the allergic airway inflammation facilitate a new direction of treating allergic asthma.

Tyrosol inhibits NF-κB pathway in the treatment of enterotoxigenic Escherichia coli-induced diarrhea in mice

Tyrosol is one of the main polyphenol compounds in white wine and extra virgin olive oil (EVOO), which plays an antioxidant and anti-inflammatory role in vitro. In the present study, we investigated the possible anti-inflammatory mechanism of tyrosol in Escherichia coli (ETEC)-induced diarrhea in mice. ICR mice were randomly divided into control group, ETEC group, and ETEC + Tyrosol group with 10 mice in each group. In addition to the control group, a bacterial diarrhea model was induced in mice by continuous administration of 0.2 ml × 10⁹ CFU/ml ETEC. After 7 days, the ETEC + Tyrosol group was given tyrosol (20 mg/kg) once a day by gavage, during which the body weight of mice and the degree of diarrhea were measured daily. On the 15th day, all animals in this experiment were sacrificed, colon tissue was collected, and colon length was recorded. Our results indicate that tyrosol significantly attenuated the extent of ETEC-induced diarrhea, including inhibition of pro-inflammatory cytokine, repair of the intestinal epithelial mechanical barrier, and significant inhibition of NF-κB activation. This finding is helpful for the development and further application of tyrosol in the treatment of diarrhea.

Efficacy and safety of three species of Rhodiola L. in patients with chronic obstructive pulmonary disease: A systematic review and meta-analysis

Background: Chronic obstructive pulmonary disease (COPD) is characterized by chronic hypoxia, inflammation, oxidative stress, and irreversible airflow limitations. Rhodiola L. is a genus of botanical drugs used in traditional medicine that may influence COPD. Objective: A systematic review of the safety and efficacy of Rhodiola L. in patients with COPD. Material and methods: We searched the PubMed, Embase, Cochrane Library, Web of Science, Scopus, China National Knowledge Infrastructure (CNKI), Chongqing VIP, Wanfang, and SinoMed databases. The search strategy used terms including "COPD" and "Rhodiola." Two independent reviewers conducted the literature screening, data extraction, and risk of bias assessment, with a third reviewer involved to resolve disagreements. Statistical analysis was conducted in Review Manager (version 5.4.1), following the Cochrane Handbook. Results: This review included nine studies, of which two focused on Rhodiola crenulata (Hook.f. and Thomson) H. Ohba (R. crenulata) and two on Rhodiola kirilowii (Regel) Maxim (R. kirilowii); the remaining five focused on Rhodiola wallichiana (Hook.) S.H.Fu (R. wallichiana). Compared with the placebo, patients who received Rhodiola L. presented no more adverse events (p = 0.65) but showed significant improvement in the percentage of forced expiratory volume in 1 s at prediction (FEV1%pred), forced expiratory volume in 1 s (FEV1), the ratio of forced expiratory volume in 1 s on forced vital capacity (FEV1/FVC), saturation of oxygen in arterial blood, partial pressure of oxygen in arterial blood (PaO₂), partial pressure of carbon dioxide in arterial blood (PaCO₂), systolic pulmonary arterial pressure, diastolic pulmonary arterial pressure, COPD assessment test, efficient rate, C-reactive protein, and N-terminal pro-B-type natriuretic peptide (all p < 0.01). Compared with ambroxol, R. kirilowii provided additional benefits to patients with COPD in FEV1%pred, FEV1, FEV1/FVC, PaO2, PaCO2, 8-iso-prostaglandin F2α, superoxide dismutase, glutathione, malondialdehyde, and total antioxidant capacity (all p < 0.01). Conclusion: Among the Rhodiola L. genus, this review included R. wallichiana, R. crenulata, and R. kirilowii, which might be safe and effective in COPD. Although this study has several limitations, further RCTs are needed. Systematic Review Registration: [https://www.crd.york.ac.uk/PROSPERO/ display_record.php?RecordID=302881], identifier [CRD42022361890].

In silico approach to target PI3K/Akt/mTOR axis by selected Olea europaea phenols in PIK3CA mutant colorectal cancer

Worldwide disease burden of colorectal cancer (CRC) increasing alarmingly, but a suitable therapeutic strategy is not available yet. Abnormal activation of the PI3K/Akt/mTOR signalling because of mutation in the PIK3CA gene is a driving force behind CRC development. Therefore, this study aimed to comprehensively characterise the potential of phenolic compounds from Olea europaea against the PI3K/Akt/mTOR axis by using in silico methodologies. Molecular docking was utilised to study key interactions between phenolic compounds of O. europaea and target proteins PI3K, Akt, mTOR with reference to known inhibitor of target. Drug likeness and ADME/T properties of selected phenols were explored by online tools. Dynamic properties and binding free energy of target-ligand interactions were studied by molecular dynamic simulation and MM-PBSA method respectively. Molecular docking revealed apigenin, luteolin, pinoresinol, oleuropein, and oleuropein aglycone as the top five phenolic compounds which showed comparable/better binding affinity than the known inhibitor of the respective target protein. Drug likeness and ADME/T properties were employed to select the top three phenols namely, apigenin, luteolin, and pinoresinol which shown to bind stably to the catalytic cleft of target proteins as confirmed by molecular dynamics simulations. Therefore, Apigenin, luteolin, and pinoresinol have the potential to be used as the non-toxic alternative to synthetic chemical inhibitors generally used in CRC treatment as they can target PI3K/Akt/mTOR axis. Particularly, pinoresinol showed great potential as dual PI3K/mTOR inhibitor. However, this study needs to be complemented with future in vitro and in vivo studies to provide an alternative way of CRC treatment. Communicated by Ramaswamy H. Sarma.

Tyrosol improves ovalbumin (OVA)-induced asthma in rat model through prevention of airway inflammation

Asthma is an inflammatory disease that affects many people around the world, especially persons at paediatric age group. The effectiveness of tyrosol, a natural phenolic compound, was examined in the asthma model induced by ovalbumin (OVA). For this purpose, four groups, each consisting of eight rats, were arranged. For 21 days, physiological saline solution was treated to the control group and OVA was treated to the groups of OVA, OVA + dexamethasone (Dexa) and OVA + tyrosol groups, intraperitoneally and through inhalation. Additionally, 0.25 mg/kg Dexa was treated to the OVA + Dexa group and 20 mg/kg tyrosol to the OVA + tyrosol group by oral gavage. Serum, blood, bronchoalveolar lavage fluid (BALF) and lung tissues of the rats were examined. It was observed that MDA level decreased, GSH level and GPx activity increased, and there was no change in CAT activity in lung tissues of the tyrosol treatment groups. It was also observed that NF-κB, TNF-α, IL-4, IL-5, IL-13, IFN-γ and IgE levels decreased compared to the OVA group in lung tissue and serum samples except for serum NF-κB and IL-4. However, no effect on IL-1 β level was observed. In addition, it was determined that tyrosol treatment increased the IL-10 level on both tissue samples. The results of the histopathological investigation of lung tissue showed that tyrosol significantly ameliorated OVA-induced histopathological lesions. Additionally, PAS staining showed that mucus hypersecretion was significantly reduced with the use of tyrosol. In addition, it was determined that the number of eosinophils decreased significantly in blood and BALF samples. The obtained results showed that tyrosol possessed antioxidant and anti-inflammatory features on OVA-induced rats and preserved tissue architecture.

Tyrosol as a Neuroprotector: Strong Effects of a "Weak" Antioxidant

The use of neuroprotective agents for stroke is pathogenetically justified, but the translation of the results of preclinical studies of neuroprotectors into clinical practice has been a noticeable failure. One of the leading reasons for these failures is the one-target mechanism of their activity. p-Tyrosol (Tyr), a biophenol, is present in a variety of natural sources, mainly in foods, such as olive oil and wine. Tyr has a wide spectrum of biological activity: antioxidant, stress-protective, anti-inflammatory, anticancer, cardioprotective, neuroprotective and many others. This review analyzes data on the neuroprotective, antioxidant, anti-inflammatory, anti-apoptotic and other kinds of Tyr activity as well as data on the pharmacokinetics of the substance. The data presented in the review substantiate the acceptability of tyr as the basis for the development of a new neuroprotective drug with multitarget activity for the treatment of ischemic stroke. Tyr is a promising molecule for the development of an effective neuroprotective agent for use in ischemic stroke.

Upregulation of Sirt1 by tyrosol suppresses apoptosis and inflammation and modulates extracellular matrix remodeling in interleukin-1β-stimulated human nucleus pulposus cells through activation of PI3K/Akt pathway

Intervertebral disc degeneration (IDD) is the major pathogenesis of lower back pain. Tyrosol is a polyphenolic compound that exhibits anti-oxidant, anti-apoptotic, and anti-inflammatory effects. Herein, we explored the effects and mechanisms of tyrosol on IDD progression in interleukin (IL)-1β-stimulated human nucleus pulposus cells (HNPCs). Cell viability and apoptosis were detected by CCK-8 and flow cytometry analysis, respectively. The production of tumor necrosis factor-α (TNF-α), IL-6, nitric oxide (NO), and prostaglandin E2 (PGE2) was examined to evaluate inflammation. The mRNA expression of matrix metalloproteinases (MMPs) (MMP-3/9/13), collagen type II, SRY-related high mobility group box 9 (SOX-9), and aggrecan was measured by qRT-PCR. Protein levels of silent information regulator 2 homolog 1 (Sirt1), phosphorylated protein kinase B (p-Akt), Akt, collagen type II, SOX-9, and aggrecan were determined by western blot. Results showed that tyrosol attenuated IL-1β-induced viability reduction, apoptosis, and caspase-3/7 activity in HNPCs. The increase in the production of TNF-α, IL-6, NO, and PGE2 in IL-1β-treated HNPCs was abolished by tyrosol treatment. Tyrosol treatment reversed IL-1β-induced upregulation of MMP-3, MMP-9, and MMP-13, and downregulation of collagen II, SOX-9, and aggrecan in HNPCs. Additionally, tyrosol treatment activated the phosphatidylinositol 3-kinase (PI3K)/Akt pathway in IL-1β-stimulated HNPCs. Sirt1 was upregulated by tyrosol, and Sirt1 silencing inhibited Akt phosphorylation in HNPCs. Sirt1 knockdown attenuated the effects of tyrosol on IL-1β-induced apoptosis, inflammation, and ECM remodeling in HNPCs. In summary, upregulation of Sirt1 by tyrosol suppressed apoptosis and inflammation and regulated ECM remodeling in IL-1β-stimulated HNPCs through activation of PI3K/Akt pathway.

Prunus serrulata var. spontanea inhibits mast cell activation and mast cell-mediated anaphylaxis

ETHNOPHARMACOLOGICAL RELEVANCE

A promising approach to treat a variety of diseases are considered as complementary and alternative herbal medicines. Prunus serrulata var. spontanea L. (Rosaceae) is used as herbal medicine to treat allergic diseases according to the Donguibogam, a tradition medical book of the Joseon Dynasty in Korea.

AIM OF THE STUDY

We prepared the aqueous extract of the bark of P. serrulata (AEBPS) and aimed to investigate the effects in mouse anaphylaxis models and various types of mast cells, including RBL-2H3, primary cultured peritoneal and bone marrow-derived mast cells.

MATERIALS AND METHODS

We used ovalbumin (OVA)-induced active systemic anaphylaxis (ASA) and immunoglobulin (Ig) E-mediated passive cutaneous anaphylaxis (PCA) models, in vivo. The control drug dexamethasone (10 mg/kg) was used to compare the effectiveness of AEBPS (1-100 mg/kg). In vitro, IgE-stimulated mast cells were used to confirm the role of AEBPS (1-100 μg/mL). For statistical analyses, p values less than 0.05 were considered to be significant.

RESULTS

In ASA model, oral administration of AEBPS suppressed the hypothermia and increased level of serum histamine in a dose-dependent manner. AEBPS attenuated the serum IgE, OVA-specific IgE, and interleukin (IL)-4. Oral administration of AEBPS also blocked mast cell-dependent PCA. AEBPS suppressed degranulation of mast cells by reducing intracellular calcium level in mast cells. AEBPS inhibited tumor necrosis factor-α and IL-4 expression and secretion in a concentration-dependent manner through the reduction of nuclear factor-κB.

CONCLUSIONS

On the basis of these findings, AEBPS could serve as a potential therapeutic target for the management of mast cell-mediated allergic inflammation and as a regulator of mast cell activation.

Protective Effects of Tyrosol Against DSS-Induced Ulcerative Colitis in Rats

In this study, the effects of tyrosol were investigated in DSS-induced experimental ulcerative colitis model. For this purpose, rats were divided into five groups of seven rats in each: control group, colitis group (DSS-4%), tyrosol group (tyrosol 20 mg/kg), sulfasalazine (sulfasalazine+DSS 100 mg/kg), and treatment group (tyrosol+DSS 20 mg/kg). In the study, the active substances were administered to all animals for a period of 21 days. At the end of the study, malondialdehyde (MDA) levels increased (p < 0.001); GSH level (p < 0.05) along with GSH.Px (p < 0.01) and CAT (p < 0.001) activities decreased in the DSS-induced colitis group. However, with the administration of tyrosol, MDA and GSH levels along with GSH.Px and CAT activities came to the same levels as the control group. In the colitis group, an increase occurred in IL-6, COX-2, and NF-κB parameters, which created a significant difference compared to the control group (p < 0.001). Similarly, TNF-α levels also significantly increased with the administration of DSS (p < 0.05) which created a significant difference compared to the control group, while there was no difference among the other groups. As for the Nrf-2 data, it decreased with the administration of DSS which created a significant difference compared to the control group (p < 0.05), while there was no difference in other groups. In the colitis-induced group, IL-6, COX-2, and NF-κB gene expression levels also similarly increased but returned to the normal levels with the administration of tyrosol. In the histopathological scoring, the negativity that increased with the administration of DSS returned to the normal levels with the administration of tyrosol+DSS. In conclusion, according to the data obtained, tyrosol fixed the destruction picture in the DSS-induced colitis model, giving rise to thought that it has a protective effect.

SG-SP1 Suppresses Mast Cell-Mediated Allergic Inflammation via Inhibition of FcεRI Signaling

Background: As the number of allergic disease increases, studies to identify new treatments take on new urgency. Epigallocatechin gallate (EGCG), a major component of green tea, has been shown to possess a wide range of pharmacological properties, including anti-inflammation and anti-viral infection. In previous study, gallic acid (GA), a part of EGCG, has shown anti-allergic inflammatory effect. To improve on preliminary evidence that GA has allergy mitigating effect, we designed SG-SP1 based on GA, and aimed to assess the effects of SG-SP1 on mast cell-mediated allergic inflammation using various animal and in vitro models.

Methods: For in vitro experiments, various types of IgE-stimulated mast cells (RBL-2H3: mast cell-like basophilic leukemia cells, and primary cultured peritoneal and bone marrow-derived mast cells) were used to determine the role of SG-SP1 (0.1–1 nM). Immunoglobulin (Ig) E-induced passive cutaneous anaphylaxis and ovalbumin-induced systemic anaphylaxis, standard animal models for immediate-type hypersensitivity were also used.

Results: For in vitro, SG-SP1 reduced degranulation of mast cells by down-regulating intracellular calcium levels in a concentration-dependent manner. SG-SP1 decreased expression and secretion of inflammatory cytokines in activated mast cells. This suppressive effect was associated with inhibition of the phosphorylation of Lyn, Syk and Akt, and the nuclear translocation of nuclear factor-κB. Due to the strong inhibitory effect of SG-SP1 on Lyn, the known upstream signaling to FcεRI-dependent pathway, we confirmed the direct binding of SG-SP1 to FcεRI, a high affinity IgE receptor by surface plasmon resonance experiment. Oral administration of SG-SP1 hindered allergic symptoms of both anaphylaxis models evidenced by reduction of hypothermia, serum IgE, ear thickness, and tissue pigmentation. This inhibition was mediated by the reductions in serum histamine and interleukin-4.

Conclusions: We determined that SG-SP1 directly interacts with FcεRI and propose SG-SP1 as a therapeutic candidate for mast cell-mediated allergic inflammatory disorders via inhibition of FcεRI signaling.

Anti-inflammatory effects of Rhodiola rosea L.: A review

Rhodiola rosea L., a worldwide botanical adaptogen, has been confirmed to possess protective effects of inflammatory injury for many diseases, including cardiovascular diseases, neurodegenerative diseases, diabetes, sepsis, and cancer. This paper is to review the recent clinical and experimental researches about the anti-inflammatory effects and the related mechanisms of Rhodiola rosea L. extracts, preparations, and the active compounds. From the collected information reviewed, this paper will provide the theoretical basis for its clinical application, and provide the evidences or guidance for future studies and medicinal exploitations of Rhodiola rosea L.

Phenotype-Specific Therapeutic Effect of Rhodiola wallichiana var. cholaensis Combined with Dexamethasone on Experimental Murine Asthma and Its Comprehensive Pharmacological Mechanism

The heterogeneity of asthma involves complex pathogenesis leading to confusion regarding the choice of therapeutic strategy. In the clinic, asthma is commonly classified as having either eosinophilic asthma (EA) or non-eosinophilic asthma (NEA) phenotypes. Microbiota colonizing in airways has been demonstrated to induce distinct phenotypes of asthma and the resistance to steroids. Rhodiola wallichiana var. cholaensis (RWC) has the potential to alleviate asthmatic inflammation according to recent studies, but its pharmacological mechanisms remain unclarified. In our study, murine asthmatic phenotypes were established and treated with RWC and/or dexamethasone (DEX). Combined treatment with RWC and DEX could improve spirometry and airway hyperresponsiveness (AHR) in asthmatic phenotypes, alleviate steroid resistance in NEA, and reduce the inflammatory infiltration of the both phenotypes. The combined treatment increased Th1, regulated the imbalance of Th2/Th1, and decreased the related cytokines in EA. As for NEA, the combined treatment reduced Th17 and promoted the accumulation of regulatory T cells (Tregs) in lung. A microbiome study based on 16S rDNA sequencing technique revealed the significantly changed structure of the lower airway microbiota after combined treatment in NEA, with 4 distinct genera and 2 species identified. OPLS-DA models of metabolomics analysis based on UPLC-Q/TOF-MS technique identified 34 differentiated metabolites and 8 perturbed metabolic pathways. A joint multiomics study predicted that the colonized microbiota in airways might be associated with susceptibility of asthma and steroid resistance, which involved systematic and pulmonary metabolic perturbation. In summary, the pharmacological network of RWC included the complicated interaction mechanisms of immune regulation, microbiota change, and metabolic perturbation.

Synthesis of Lipophilic Esters of Tyrosol, Homovanillyl Alcohol and Hydroxytyrosol

Low-molecular weight phenols such as tyrosol, homovanillyl alcohol and hydroxytyrosol are valuable compounds that exhibit a high number of health-promoting effects such as antioxidant, anti-inflammatory and anticancer activity. Despite these remarkable properties, their applications such as dietary supplements and stabilizers of foods and cosmetics in non-aqueous media are limited for the hydrophilic character. With the aim to overcome this limitation, the paper describes a simple and low-cost procedure for the synthesis of lipophilic esters of tyrosol, homovanillyl alcohol and hydroxytyrosol. The reactions were carried out under mild and green chemistry conditions, at room temperature, solubilizing the phenolic compounds in dimethyl carbonate, an eco-friendly solvent, and adding a little excess of the appropriate C2-C18 acyl chloride. The final products were isolated in good yields. Finally, according to the "circular economy" strategy, the procedure was applied to hydroxytyrosol-enriched extracts obtained by Olea europaea by-products to prepare a panel of lipophilic extracts that are useful for applications where solubility in lipid media is required.

MicroRNA 27b-3p Modulates SYK in Pediatric Asthma Induced by Dust Mites

The PI3K-AKT pathway is known to regulate cytokines in dust mite-induced pediatric asthma. However, the underlying molecular steps involved are not clear. In order to clarify further the molecular steps, this study investigated the expression of certain genes and the involvement of miRNAs in the PI3K-AKT pathway, which might affect the resultant cytokine-secretion. in-vivo and in-vitro ELISA, qRT-PCR and microarrays analyses were used in this study. A down-expression of miRNA-27b-3p in dust mite induced asthma group (group D) was found by microarray analysis. This was confirmed by qRT-PCR that found the miRNA-27b-3p transcripts that regulated the expression of SYK and EGFR were also significantly decreased (p < 0.01) in group D. The transcript levels of the SYK and PI3K genes were higher, while those of EGFR were lower in the former group. Meanwhile, we found significant differences in plasma concentrations of some cytokines between the dust mite-induced asthma subjects and the healthy controls. On the other hand, this correlated with the finding that the transcripts of SYK and its downstream PI3K were decreased in HBE transfected with miRNA-27b-3p, but were increased in HBE transfected with the inhibitor in vitro. Our results indicate that the differential expression of the miRNAs in dust mite-induced pediatric asthma may regulate their target gene SYK and may have an impact on the PI3K-AKT pathway associated with the production of cytokines. These findings should add new insight into the pathogenesis of pediatric asthma.

Tyrosol attenuates pro-inflammatory cytokines from cultured astrocytes and NF-κB activation in in vitro oxygen glucose deprivation

Subsequent inflammation in stroke plays an important role in the damage of neurons in the perilesional area. Therapeutic intervention targeting inflammation may be a promising complementary strategy to current treatments of stroke. Here, we explored the possible beneficial effects of tyrosol, a derivative of phenethyl alcohol and natural antioxidant, playing an anti-inflammatory role in astrocyte culture and in vitro oxygen glucose deprivation (OGD) model. MTT, western blot, ELISA and EMSA assays were carried out to investigate cell viability, protein expression level, cytokine expression and NF-κB activity. We found tyrosol protected cultured astrocytes against OGD-induced cell viability loss in MTT test. Meanwhile, tyrosol attenuated the released TNF-α and IL-6 level from astrocyte via regulating Janus N-terminal kinase (JNK). The reduction of cytokines from astrocyte might be due to its inhibition of astrocyte activation and regulation of STAT3 signaling pathway since tyrosol attenuated the expression level of GFAP (glial fibrillary acidic protein) and the phosphorylation of STAT3. Additionally, we demonstrated that tyrosol prevented the degradation of IκBα and the increase of IκBα phosphorylation in astrocytes exposed to OGD, which led to the suppression of NF-κB function during ischemia. Collectively, our results showed that tyrosol may be a promising complementary treatment compound for stroke via modulating the inflammatory response in astrocytes during ischemia.

Correlation between mast cell-mediated allergic inflammation and length of perfluorinated compounds

Perfluorinated compounds (PFC) have widely been used in numerous applications including clothing, food packaging, and nonstick coating. With the widespread use of PFC, concerns regarding potential adverse health effects in humans and wildlife have increased. In spite of the known PFC-mediated immunotoxiciy, correlation with PFC and allergic inflammation still requires elucidation. The aim of this study was to examine the effect of four types of PFC (perfluoroheptanoic acid [PFHpA], perfluorononanoic acid [PFNA], perfluorodecanoic acid [PFDA], and perfluoroundecanoic acid [PFUnA]) on mast cell-mediated allergic inflammation in the presence of high-affinity immunoglobulin (Ig) E receptor (FcεRI) cross-linking. Among PFC family, long-chain PFDA and PFUnA increased release of histamine and β-hexosaminidase by up-regulation of intracellular calcium levels in IgE-stimulated mast cells. In addition, PFDA and PFUnA enhanced gene expression of pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-8 by activation of nuclear factor-κB in IgE-stimulated mast cells. In ovalbumin (OVA)-induced model of systemic anaphylaxis in the presence of hypothermia, PFNA, PFDA, and PFUnA exacerbated allergic symptoms accompanied by elevation in serum histamine, TNF-α, IgE, and IgG₁. Our data indicate that some PFC aggravated high-affinity IgE receptor (FcεRI)-mediated mast cell degranulation and allergic symptoms. Consequently, the results demonstrated that carbon-chain length of PFC may serve as a factor in allergic inflammation.

Diospyros kaki calyx inhibits immediate-type hypersensitivity via the reduction of mast cell activation

CONTEXT

Diospyros kaki L. (Ebenaceae) fruit is widely distributed in Asia and is known to exert anti-inflammatory and antithrombotic effects.

OBJECTIVE

We evaluated the inhibitory effect of aqueous extract of D. kaki calyx (AEDKC) on mast cell-mediated immediate-type hypersensitivity and underlying mechanism of action.

MATERIALS AND METHODS

For in vivo, ovalbumin (OVA)-induced active systemic anaphylaxis (ASA) and immunoglobulin (Ig) E-mediated passive cutaneous anaphylaxis (PCA) models were used. In the ASA, AEDKC (1-100 mg/kg) was orally administered 3 times during 14 days. In the PCA, AEDKC was orally treated 1 h before the antigen challenge. The control drug dexamethasone was used to compare the effectiveness of AEDKC. For in vitro, IgE-stimulated RBL-2H3 cells and primary cultured peritoneal mast cells were used to determine the role of AEDKC (0.01-1 mg/mL).

RESULTS

Oral administration of AEDKC dose dependently suppressed rectal temperature decrease and increases in serum histamine, total IgE, OVA-specific IgE, and interleukin (IL)-4 in the ASA. In the PCA, AEDKC reduced Evans blue pigmentation. Compared to dexamethasone (10 mg/kg), AEDKC (100 mg/kg) showed similar inhibitory effects in vivo. AEDKC concentration dependently suppressed the release of histamine and β-hexosaminidase through the reduction of intracellular calcium in mast cells. In addition, AEDKC decreased the expression and secretion of tumour necrosis factor-α and IL-4 by the reduction of nuclear factor-κB. The inhibitory potential of AEDKC (1 mg/mL) was similar with dexamethasone (10 μM) in vitro.

CONCLUSIONS

We suggest that AEDKC may be a potential candidate for the treatment of mast cell-mediated allergic diseases.

Formononetin ameliorates mast cell-mediated allergic inflammation via inhibition of histamine release and production of pro-inflammatory cytokines

Various allergic diseases cause allergic inflammation, which is mediated by mast cells. The current study investigated the anti-allergic inflammatory effects of formononetin and its mechanism of action in vitro using mast cells. Levels of histamine and pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6, were measured to assess the effects of formononetin on allergic inflammation. The activation of intracellular calcium and nuclear factor (NF)-κB, as well as the activity of caspase-1, were assessed to determine the mechanism of action. It was determined that difference concentrations of formononetin (0.1, 1 and 10 µM) suppressed histamine release and secretion of TNF-α, IL-1β and IL-6. Further investigations indicated that the effects of formononetin were associated with a reduction of intracellular calcium, suppression of NF-κB activation and upstream IκKα phosphorylation and inhibition of caspase-1 activity. Therefore, the results of the current study demonstrated that formononetin ameliorated mast cell-mediated allergic inflammation.

Coumarins from the roots of Angelica dahurica cause anti-allergic inflammation

Allergic inflammation is induced by allergens and leads to various allergic diseases, including rhinitis, asthma and conjunctivitis. Histamine is important in the pathogenesis of an immunoglobulin E-dependent allergic reaction and results in the secretion of cytokines associated with inflammation. Angelica dahurica (A. dahurica) is a medicinal plant widely used in China for the treatment of symptoms related to allergic inflammation. The present study investigated the chemical constituents from A. dahurica and evaluated their reductive effect on allergic inflammation. As a result, 15 compounds including 13 coumarins have been identified as isoimperatorin (1), imperatorin (2), oxypeucedanin (3), oxypeucedanin hydrate (4), bergapten (5), byakangelicin (6), phellopterin (7), byakangelicol (8), isopimpinellin (9), xanthotoxol (10), xanthotoxin (11), pimpinellin (12), scopoletin (13), β-sitosterol (14) and daucosterol (15). Compounds 1-13 were able to reduce the release of histamine, with compounds 4-6 exhibiting the most potent activity. Furthermore, compounds 1-12 were able to inhibit the secretion of tumor necrosis factor-α, interleukin (IL)-1β and IL-4, with compounds 5 and 7 exhibiting the strongest inhibitory effects. These compounds implemented the inhibitory effects on the expression of inflammatory cytokine genes through the inhibition of nuclear factor-κB activation. Virtual screening by a docking program indicated that compound 3 is a potent histamine H₁ receptor antagonist. Additionally, the calculated physicochemical properties of these compounds support most furanocoumarins to be delivered to binding sites and permeate the cell membrane. The present findings contribute to understanding how A. dahurica attenuates allergic inflammation.

2-Hydroxy-3-methoxybenzoic acid attenuates mast cell-mediated allergic reaction in mice via modulation of the FcεRI signaling pathway

Mast cells are important effector cells in immunoglobulin (Ig) E-mediated allergic reactions such as asthma, atopic dermatitis and rhinitis. Vanillic acid, a natural product, has shown anti-oxidant and anti-inflammatory activities. In the present study, we investigated the anti-allergic inflammatory effects of ortho-vanillic acid (2-hydroxy-3-methoxybenzoic acid, o-VA) that was a derivative of vanillic acid isolated from Amomum xanthioides. In mouse anaphylaxis models, oral administration of o-VA (2, 10, 50 mg/kg) dose-dependently attenuated ovalbumin-induced active systemic anaphylaxis and IgE-mediated cutaneous allergic reactions such as hypothermia, histamine release, IgE production and vasodilation; administration of o-VA also suppressed the mast cell degranulator compound 48/80-induced anaphylaxis. In cultured mast cell line RBL-2H3 and isolated rat peritoneal mast cells in vitro, pretreatment with o-VA (1-100 μmol/L) dose-dependently inhibited DNP-HSA-induced degranulation of mast cells by decreasing the intracellular free calcium level, and suppressed the expression of pro-inflammatory cytokines TNF-α and IL-4. Pretreatment of RBL-2H3 cells with o-VA suppressed DNP-HSA-induced phosphorylation of Lyn, Syk, Akt, and the nuclear translocation of nuclear factor-κB. In conclusion, o-VA suppresses the mast cell-mediated allergic inflammatory response by blocking the signaling pathways downstream of high affinity IgE receptor (FcεRI) on the surface of mast cells.

Furan, phenolic, and heptelidic acid derivatives produced by Aspergillus oryzae

Eleven compounds, including a new sesquiterpene, were isolated from the culture medium of Aspergillus oryzae incubated with capsaicin. The structure of the new compound was determined to be 1,3,5a,6,7,8,9,9a-octahydro-9-hydroxy-9-(hydroxymethyl)-6-isopropyl-1-oxobenzo[c]oxepine-4- carboxylic acid, a heptelidic acid derivative. In addition, 10 known compounds were identified, namely 5-(hydroxymethyl)-3-furancarboxylic acid (flufuran), 3-hydroxypropanoic acid, 5-(hydroxymethyl)-2- furancarboxylic acid, 2-(4-hydroxyphenyl)-ethanol, 4-hydroxybenzoic acid, vanillic acid, 3,4-dihydroxybenzoic acid, 2-furanol, hydroheptelidic acid, and trichoderonic acid A, using spectroscopic data from nuclear magnetic resonance and electrospray ionization-mass spectroscopy.

Developing criteria for evaluation of geroprotectors as a key stage toward translation to the clinic

In the coming decades, a massive shift in the aging segment of the population will have major social and economic consequences around the world. One way to offset this increase is to expedite the development of geroprotectors, substances that slow aging, repair age‐associated damage and extend healthy lifespan, or healthspan. While over 200 geroprotectors are now reported in model organisms and some are in human use for specific disease indications, the path toward determining whether they affect aging in humans remains obscure. Translation to the clinic is hampered by multiple issues including absence of a common set of criteria to define, select, and classify these substances, given the complexity of the aging process and their enormous diversity in mechanism of action. Translational research efforts would benefit from the formation of a scientific consensus on the following: the definition of ‘geroprotector’, the selection criteria for geroprotectors, a comprehensive classification system, and an analytical model. Here, we review current approaches to selection and put forth our own suggested selection criteria. Standardizing selection of geroprotectors will streamline discovery and analysis of new candidates, saving time and cost involved in translation to clinic.

Ethanol Extract of Sanguisorbae Radix Inhibits Mast Cell Degranulation and Suppresses 2,4-Dinitrochlorobenzene-Induced Atopic Dermatitis-Like Skin Lesions

Sanguisorbae Radix (SR) is well known as herbal medicine named “Zi-Yu” in Korea, which is the dried roots of Sanguisorba officinalis L. (Rosacease). We investigated the underlying mechanism on the inhibition of atopic dermatitis (AD) of an ethanol extract of SR (ESR) using 2,4-dinitrochlorobenzene- (DNCB-) induced AD mice model. Oral administration of ESR significantly suppressed DNCB-induced AD-like symptoms such as scratching behavior, ear thickness, epidermal thickness, and IgE levels. To investigate the effects of ESR treatment on degranulation of IgE/Ag-activated mouse bone marrow-derived mast cells (BMMCs), we measured the release of β-hexosaminidase (β-HEX, degranulation marker). ESR decreased the infiltration of eosinophils and mast cells into the AD skin lesions. Furthermore, ESR significantly inhibited degranulation of IgE/Ag-activated BMMCs. We have demonstrated that ESR decreased AD symptoms in mice and inhibits degranulation of IgE/Ag-activated mast cells. Our study suggests that ESR may serve as a potential therapeutic candidate for the treatment of AD symptoms.

Powering tyrosol antioxidant capacity and osteogenic activity by biocatalytic polymerization

Oxidative polymerization of tyrosol afforded a mixture of oligomers (OligoTyr) which proved to be more active than tyrosol as antioxidant and as stimulator of alkaline phosphatase (ALP) activity when loaded into polylactic acid (PLA) scaffolds.