human mast cells

Nylidrin hydrochloride (Buphenine HCl) was an effective inhibitor of the IgG1-mediated release of histamine from passively sensitized guinea pig lung slices, and of the IgE-mediated release of histamine from passively sensitized rat peritoneal mast cells and human basophils.

Rupatadine (UR-12592) is a potent dual PAF H1 antagonist with Ki values of 0.55 μM in rabbit platelet membranes and 0.1 μM in guinea pig cerebellum membranes.

MK-571 sodium (L-660711 sodium salt) is a selective, orally active antagonist of the CysLT1 receptor. MK-571 sodium is a multidrug resistance protein-2 (ABCC2, Mrp2) inhibitor used to demonstrate the role of Mrp2 in the cellular efflux of drugs, xenobiotics, and their conjugates. MK-571 sodium can inhibit the synthesis of K-4′-O-GlcA (19.7 μM). MK571 dose-dependently inhibits the intracellular biosynthesis of all flavonol sulphates and glucuronides by Caco-2 cells. MK-571 sodium significantly inhibits phase-2 conjugation of kaempferol by cell-free extracts of Caco-2, and production of kaempferol-4′-O-glucuronide was competitively inhibited. In addition to inhibiting MRP2, MK571 is a potent inhibitor of enterocyte phase-2 conjugation.

14,15-Leukotriene D4 (14,15-LTD4) is a member of an alternate class of LTs synthesized by a pathway involving the dual actions of 15- and 12-lipoxygenases (15- and 12-LOs) on arachidonic acid via 15-HpETE and 14,15-LTA4 intermediates. 14,15-LTD4 is classified as an eoxin (EXD4), because it is formed mostly by eosinophils. However, mast cells and nasal polyps can synthesize 14,15-LTD4 as well. Little is known about the physiological actions of 14,15-LTD4. It has weak contractile activity on both guinea pig ileum and pulmonary parenchyma in contrast to the effects of 5-LO-derived LTs. However, in an in vitro permeability assay, 14,15-LTD4 can increase vascular permeability of human endothelial cell monolayers, with similar potency to that of 5-LO-derived LTs, resulting in plasma leakage, a hallmark of inflammation.

Produced by neutrophils, macrophages, mast cells, and by transcellular metabolism in platelets, leukotriene C4 (LTC4) is the parent cysteinyl leukotriene formed by the LTC4 synthase-catalyzed conjugation of glutathione to LTA4. It is one of the constituents of slow-reacting substance of anaphylaxis (SRS-A) and exhibits potent smooth muscle contracting activity. LTC4, however, is rapidly metabolized to LTD4 and LTE4, which makes the characterization of LTC4 pharmacology difficult. N-methyl Leukotriene C4 (N-methyl LTC4) is a synthetic analog of LTC4 that is not readily metabolized to LTD4 and LTE4.It acts as a potent and selective CysLT2 receptor agonist exhibiting EC50 values of 122 and > 2,000 nM at the human CysLT2 and CysLT1 receptors, respectively. It has essentially the same potency as LTC4 at both the human and murine receptors CysLT2 receptors. N-methyl LTC4 is potent and active in vivo, causing vascular leak in mice overexpressing the human CysLT2 receptor but not in CysLT2 receptor knockout mice.

Confluentin has antimicrobial activity against the gram-positive bacteria.Confluentin significantly inhibits compound 48/80-induced histamine release from rat peritoneal mast cells. Confluentin also shows weak cytotoxicity against four human tumor cell li

Bufrolin, an analog of Cromoglycate (histamine release inhibitor) and a potent agonist of GPR35, enhances the interaction between β-arrestin-2 and both human GPR35a and rat GPR35. It stabilizes mast cells, exhibiting antiallergic properties, and inhibits anti-inflammatory responses triggered by internalization peptides. Furthermore, Bufrolin is researched for its anti-inflammatory properties in pharmaceutic applications associated with internalization peptides [1] [2] [3].

Thapsigargicin (Thapsigargicine) acts as an activator for mast cells and leukocytes, prompting histamine release from rat peritoneal mast cells and human basophil leukocytes. Additionally, it elevates cytoplasmic free calcium levels in human blood platelets [1].

Spiraeoside (Quercetin 4′-O-glucoside) is a compound that can be extracted from red onion skins. It exhibits antioxidant, anti-allergy, anti-inflammatory, and anti-tumor activities. It protects human myocardial cells from high glucose-induced damage, oxidative stress, and apoptosis by activating the PI3K Akt Nrf2 pathway. It also inhibits mast cell activation and IgE-mediated allergic reactions by suppressing phospholipase C-γ-mediated signaling.

Interleukin-2-inducible T cell kinase (ITK) is a non-receptor tyrosine kinase expressed in T cells, NKT cells and mast cells which plays a crucial role in regulating the T cell receptor (TCR), CD28, CD2, chemokine receptor CXCR4, and FcepsilonR-mediated signaling pathways. ITK inhibitors can be used for the treatment of inflammation and immune-mediated disorders. ITK inhibitor (N-[5-[[3-[(4-Acetylpiperazin-1-yl)carbonyl]-4-methyl-6-methoxy-phenyl]thio]thiazol-2-yl]-4-(N-1,2-dimethylpropylaminomethyl)benzamide) is the analogue of BMS-509744, which can potently and selectively inhibit Itk kinase activity. In vitro: BMS-509744 could reduce TCR-induced functions including PLCγ1 tyrosine phosphorylation, calcium mobilization, IL-2 secretion, and T-cell proliferation in vitro in both human and mouse cells [1]. In vivo: BMS-509744 suppressed the production of IL-2 induced by anti-TCR antibody administered to mice. BMS-509744 also significantly diminishes lung inflammation in a mouse model of ovalbumin-induced allergy/asthma [1]. Clinical trial: Up to now, both BMS-509744 and ITK inhibitor is still in the preclinical development stage.

Leukotriene C4 (14,15-LTC4) is an inflammatory mediator synthesized from arachidonic acid through the actions of 15- and 12-lipoxygenases (LOs), involving intermediates such as 15-HpETE and 14,15-LTA4. Unlike the majority of leukotrienes formed via the 5-LO pathway, 14,15-LTC4 is an eoxin predominantly produced by eosinophils, although mast cells and nasal polyps can also synthesize it. While its physiological roles are not well understood, 14,15-LTC4 exhibits limited contractile activity on guinea pig ileum and pulmonary parenchyma. However, it can increase vascular permeability in human endothelial cell monolayers in vitro with potency comparable to 5-LO-derived leukotrienes, contributing to plasma leakage characteristic of inflammation.

9(S),12(S),13(S)-TriHOME is a linoleic acid-derived oxylipin that has diverse biological activities.1,2,3,4It has been found in various plants and is produced in human eosinophils in a 15-lipoxygenase-dependent, soluble epoxide hydrolase-independent manner.1,59(S),12(S)13(S)-TriHOME inhibits antigen-induced β-hexosaminidase release from RBL-2H3 mast cells (IC50= 28.7 μg ml).2It inhibits LPS-induced nitric oxide (NO) production in BV-2 microglia (IC50= 40.95 μM).3In vivo, 9(S),12(S),13(S)-TriHOME (1 g animal) enhances the antiviral IgA and IgG antibody responses induced by a nasal influenza hemagglutinin (HA) vaccine by 5.2- and 2-fold, respectively, in mice.4 1.Hamberg, M., and Hamberg, G.Peroxygenase-catalyzed fatty acid epoxidation in cereal seeds: Sequential oxidation of linoleic acid into 9(S),12(S),13(S)-trihydroxy-10(E)-octadecenoic acidPlant Physiol.110(3)807-815(1996) 2.Hong, S.S., and Oh, J.S.Inhibitors of antigen-induced degranulation of RBL-2H3 cells isolated from wheat branJ. Korean Soc. Appl. Biol. Chem.5569-74(2012) 3.Kim, C.S., Kwon, O.W., Kim, S.Y., et al.Five new oxylipins from Chaenomeles sinensisLipids49(11)1151-1159(2014) 4.Shirahata, T., Sunazuka, T., Yoshida, K., et al.Total synthesis, elucidation of absolute stereochemistry, and adjuvant activity of trihydroxy fatty acidsTetrahedron62(40)9483-9496(2006) 5.Fuchs, D., Tang, X., Johnsson, A.-K., et al.Eosinophils synthesize trihydroxyoctadecenoic acids (TriHOMEs) via a 15-lipoxygenase dependent processBiochim. Biophys. Acta Mol. Cell Biol. Lipids1865(4)158611(2020)

Rosiptor is a potent and selective SHIP1 activator. AQX-1125 inhibits Akt phosphorylation in SHIP1-proficient but not in SHIP1-deficient cells, reduces cytokine production in splenocytes, inhibits the activation of mast cells and inhibits human leukocyte

HR1, a mastoid protease, enhances the permeability of human erythrocyte membranes and can induce cytoplasmic membrane permeation in bacteria and mast cells [1].

SFNGGP-NH2 is a biologically active peptide that interacts with Protease-Activated Receptor 3 (PAR-3), a high-affinity thrombin receptor. Human cutaneous mast cells express PAR-3 mRNA, implicating a role in itch mechanotransduction, with both histamine-dependent and independent pathways reported. While PAR-3 alone does not induce itch, it may potentiate itch when co-expressed with PAR-4, enhancing thrombin's action. This suggests that PAR-3's primary function is not as a signal transmitter across the membrane, but rather as a cofactor necessary for PAR-4 activation.

NBI-42902 is a potent inhibitor of peptide radioligand binding to the human GnRH receptor (K(i) = 0.56 nm). Tritiated NBI-42902 binds with high affinity (K(d) = 0.19 nm) to a single class of binding sites and can be displaced by a range of peptide and nonpeptide GnRH receptor ligands. In vitro experiments demonstrate that NBI-42902 is a potent functional, competitive antagonist of GnRH stimulated IP accumulation, Ca(2+) flux, and ERK1 2 activation. It did not stimulate histamine release from rat peritoneal mast cells. Finally, it is effective in lowering serum LH in castrated male macaques after oral administration. Overall, these data provide a benchmark of pharmacological characteristics required for a nonpeptide GnRH antagonist to effectively suppress gonadotropins in humans and suggest that NBI-42902 may have clinical utility as an oral agent for suppression of the hypothalamic-pituitary-gonadal axis. (source: Endocrinology. 2007 Feb;148(2):857-67. Epub 2006 Nov 9.)

APC-366 is a selective inhibitor of the mast cell tryptase that inhibits tryptase-induced histamine release from human tonsil and lung cells.

8 Hydroxy PIPAT oxalate is a selective 5-HT1A receptor agonist that enhances the spontaneous release of histamine by promoting the degranulation of mast cells in guinea pig and human intestinal preparations. By activating the serotonin signaling pathway, this compound demonstrates potential in regulating gastrointestinal functions and offers insight into the management and suppression of functional gastrointestinal disorders such as irritable bowel syndrome. Its effects in increasing histamine release could play a crucial role in gastrointestinal regulation.

1. Acetylshikonin exhibits weak cytotoxicity against human umbilical vein endothelial cells (HUVECs) with IC5 of over 2 microM, exhibits the antiangiogenic and antitumorigenic effects by suppressing proliferation and angiogenic factors. 2. Acetylshikonin inhibits the generation of NADPH oxidase complex in the activation of respiratory burst of PMNs, but does not directly inhibit the activity of NADPH oxidase already generated. 3. Certain shikonin derivatives(such as Acetylshikonin) act as modulators of the Nur77-mediated apoptotic pathway and identify a new shikonin-based lead that targets Nur77 for apoptosis induction. 4. Acetylshikonin, shikonin, and alkannin have accelerative effect on the proliferation of granulation tissue in rats. 5. Acetylshikonin has inhibitory effect on the edematous response is due neither to the release of steroid hormones from the adrenal gland nor to the glucocorticoid activity, but probably partly to the suppression of mast cell degranulation and partly to protection of the vasculature from mediator challenge. 6. Acetylshikonin induces apoptosis of hepatitis B virus X protein-expressing human hepatocellular carcinoma cells via endoplasmic reticulum stress.

Picropodophyllotoxin (AXL 1717) is a cyclolignan alkaloid found in the mayapple plant family (Podophyllum peltatum), and a small molecule inhibitor of the insulin-like growth factor 1 receptor (IGF1R) with potential antineoplastic activity. Picropodophyllotoxin (AXL 1717) specifically inhibits the activity and downregulates the cellular expression of IGF1R without interfering with activities of other growth factor receptors, such as receptors for insulin, epidermal growth factor, platelet-derived growth factor, fibroblast growth factor and mast stem cell growth factor (KIT). This agent shows potent activity in the suppression o f tumor cell proliferation and the induction of tumor cell apoptosis. IGF1R, a receptor tyrosine kinase overexpressed in a variety of human cancers, plays a critical role in the growth and survival of many types of cancer cells.

11-trans Leukotriene C4 (11-trans LTC4) is a C-11 double bond isomer of LTC4. LTC4 undergoes slow temperature-dependent isomerization to 11-trans LTC4 during storage. 11-trans LTC4 is produced in smaller amounts relative to LTC4 in ionophore-stimulated HMC-1 cells (a human mast cell line) and equine eosinophils, but not in human neutrophils or RBL-1 cells. It is nearly equipotent with LTC4 for contraction of guinea pig parenchymal and ileum. In a radioligand binding assay using guinea pig ileum as a cysteinyl leukotriene receptor preparation, the pKis for LTC4 and 11-trans LTC4 were determined to be 6.42 and 6.58, respectively.

β-Defensin-3 is a peptide with antimicrobial properties that protects the skin and mucosal membranes of the respiratory, genitourinary, and gastrointestinal tracts. It inhibits the growth of the periodontopathogenic and cariogenic bacteria F. nucleatum, S. mutans, S. sobrinus, S. salivarius, and L. casei (MICs = 12.5-100 mg/l). It also inhibits the growth of S. aureus, S. pyogenes, P. aeruginosa, E. coli, and C. albicans. β-Defensin-3 stimulates gene expression and production of IL-6, IL-10, CXCL10, CCL2, MIP-3α, and RANTES by keratinocytes when used at a concentration of 30 μg/ml. It also stimulates calcium mobilization, migration, and proliferation of keratinocytes when used at concentrations of 30, 5, and 20 μg/ml, respectively. β-Defensin-3 induces IL-31 production by human peripheral blood-derived mast cells in vitro when used at a concentration of 10 μg/ml and by rat mast cells in vivo following a 500 ng intradermal dose.

BTL-MK (Compound 19) is an orally active antiallergic agent that inhibits degranulation of mast cells with an IC50 of 6.7 μM by binding to the inhibitory receptor FcγRIIB. BTL-MK improves metabolic stability in human liver microsomes and ameliorates the allergic response in an Ovalbumin-induced food allergy mice model. It exhibits good pharmacokinetic characteristics with metabolic stability [1].

Leukotrienes (LTs) are a group of acute inflammatory mediators derived from arachidonic acid in leukocytes. The majority of these metabolites are formed through the 5-lipoxygenase (5-LO) pathway. 14,15-LTE4 is a metabolite of 14,15-LTC4 and 14,15-LTD4, an alternate class of LTs synthesized by a pathway involving the dual actions of 15- and 12-LOs on arachidonic acid via 15-HpETE and 14,15-LTA4 intermediates. These metabolites are classified as eoxins because they are formed mostly by eosinophils. Mast cells and nasal polyps can synthesize 14,15-LTC4 as well, however metabolism to 14,15-LTE4 in these cells and tissue has not been documented. 14,15-LTE4 increases vascular permeability of human endothelial cell monolayers with about 10-fold less potency than LTC4, but approximately 100-fold greater potency than histamine.