Inhibitory effects of geranium essential oil and its major component, citronellol, on degranulation and cytokine production by mast cells.

We investigated the effects of geranium essential oil (GEO) on anaphylaxis. GEO can exert antioxidant and anti-inflammatory effects, but its roles in allergic reactions are incompletely understood. Here, we used mouse cells to show that GEO inhibited the degranulation of cultured mast cells (CMCs).

Suppression of allergic and inflammatory responses by essential oils derived from herbal plants and citrus fruits.

The aim of the present study was to investigate the biological activity of 20 essential oils (EOs) derived from herbal plants and citrus fruits. The in vitro anti-allergic and anti-inflammatory activities of these oils were investigated, and the EO which was found to have the strongest activity of the 20 EOs examined, was investigated further to identify its components and bioactive compounds. The in vitro anti-allergic activity was determined by measuring the release of β-hexosaminidase from rat basophilic leukemia (RBL-2H3) cells treated with the calcium ionophore, A23187.

Effects of essential oils from herbal plants and citrus fruits on DNA polymerase inhibitory, cancer cell growth inhibitory, antiallergic, and antioxidant activities.

In this study, the biological activity of 20 essential oils (EOs) from herbal plants and citrus fruits were investigated in terms of mammalian DNA polymerase (pol) inhibitory activity, cancer cell (human colon carcinoma, HCT116) growth inhibitory activity, antiallergic activity, as anti-β-hexosaminidase release activity in rat basophilic leukemia RBL-2H3 cells treated with calcium ionophore A23187, and antioxidant activity by a lipophilic-oxygen radical absorbance capacity method. These EOs showed patterns of inhibition of pol α, a DNA replicative pol, similar to their cancer cell growth inhibitory activity, and their inhibitory activity on pol λ, a DNA repair/recombination pol, by the EOs showed correlation with anti-β-hexosaminidase release activity. Among these EOs, chamomile (Matricaria chamomilla L.

Inhibitory effects of water-soluble low-molecular-weight β-(1,3-1,6) D-glucan isolated from Aureobasidium pullulans 1A1 strain black yeast on mast cell degranulation and passive cutaneous anaphylaxis.

We investigated the effects of water-soluble low-molecular-weight β-(1,3-1,6) D-glucan isolated from Aureobasidium pullulans 1A1 strain black yeast (LMW-β-glucan) on mast cell-mediated anaphylactic reactions. Although it is known that LMW-β-glucan has anti-tumor, anti-metastatic and anti-stress effects, the roles of LMW-β-glucan in immediate-type allergic reactions have not been fully investigated. We examined whether LMW-β-glucan could inhibit mast cell degranulation and passive cutaneous anaphylaxis (PCA).

Inhibitory effects of guarana seed extract on passive cutaneous anaphylaxis and mast cell degranulation.

This study investigated the effects of guarana seed extract (GSE) on an anti-allergic mechanism. GSE orally administered inhibited the anti-dinitrophenol IgE-induced passive cutaneous anaphylaxis reaction in mice. Furthermore, it inhibited the degranulation of rat basophilic leukemia RBL-2H3 cells.

Number of mast cells in the peritoneal cavity of mice: influence of microphthalmia transcription factor through transcription of newly found mast cell adhesion molecule, spermatogenic immunoglobulin superfamily.

The mi (microphthalmia) locus of mice encodes a transcription factor, MITF. B6-tg/tg mice that do not express any MITF have white coats and small eyes. Moreover, the number of mast cells decreased to one-third that of normal control (+/+) mice in the skin of B6-tg/tg mice.

Roles of MITF for development of mast cells in mice: effects on both precursors and tissue environments.

The mutant tg/tg mice, which do not express mi transcription factor (MITF), lack mast cells in most tissues. Since MITF is expressed in both mast cells and tissues where mast cells develop, there is a possibility that the tg/tg mice may show abnormalities in both mast cell precursors and tissue environments. We examined this possibility by bone marrow and skin transplantation.

Contribution of the SgIGSF adhesion molecule to survival of cultured mast cells in vivo.

Spermatogenic immunoglobulin superfamily (SgIGSF) is a recently identified adhesion molecule, and the microphthalmia transcription factor (MITF) was essential for its expression in mast cells. Since the tg mutant allele is practically a null mutation of the MITF gene, cultured mast cells (CMCs) derived from (WBxC57BL/6)F(1) (F(1))-tg/tg mice did not express SgIGSF whereas CMCs from F(1)-wild-type (+/+) mice expressed it abundantly. When cocultured with NIH/3T3 fibroblasts, F(1)-tg/tg CMCs showed poor adhesion to NIH/3T3 fibroblasts.

Effect of anatomical distribution of mast cells on their defense function against bacterial infections: demonstration using partially mast cell-deficient tg/tg mice.

Mast cells were depleted in the peritoneal cavity of WBB6F1-tg/tg mice that did not express a transcription factor, MITF. When acute bacterial peritonitis was induced in WBB6F1-+/+, WBB6F1-W/Wv, and WBB6F1-tg/tg mice, the proportion of surviving WBB6F1-+/+ mice was significantly higher than that of surviving WBB6F1-W/Wv or WBB6F1-tg/tg mice. The poor survival of WBB6F1-W/Wv and WBB6F1-tg/tg mice was attributed to the deficient influx of neutrophils into the peritoneal cavity.

SgIGSF: a new mast-cell adhesion molecule used for attachment to fibroblasts and transcriptionally regulated by MITF.

Microphthalmia transcription factor (MITF) is a basic-helix-loop-helix-leucine zipper-type transcription factor. The mutant mi and Mi(wh) alleles encode MITFs with deletion and alteration of a single amino acid, respectively, whereas the tg is a null mutation. In coculture with NIH/3T3 fibroblasts, the numbers of cultured mast cells (CMCs) derived from C57BL/6 (B6)(mi/mi), B6(Miwh/Miwh), and B6(tg/tg) mice that adhered to NIH/3T3 fibroblasts were one third as large as the number of B6(+/+) CMCs that adhered to NIH/3T3 fibroblasts.

Additive effect of mouse genetic background and mutation of MITF gene on decrease of skin mast cells.

The mi transcription factor (MITF) is a basic-helix-loop-helix leucine zipper transcription factor and is encoded by mi locus. The mi/mi mutant mice showed a significant decrease of skin mast cells in C57BL/6 (B6) genetic background but not in WB genetic background. Kit ligand (KitL) is the most important growth factor for development of mast cells, and the decrease of skin mast cells in B6-mi/mi mice was attributable to the reduced expression of c-kit receptor tyrosine kinase (KIT) that is a receptor for KitL.

Dual abnormal effects of mutant MITF encoded by Mi(wh) allele on mouse mast cells: decreased but recognizable transactivation and inhibition of transactivation.

MITF is a basic helix-loop-helix leucine zipper-type transcription factor and is important for development of mast cells. MITF encoded by Mi(wh) allele (Mi(wh)-MITF) was mutated at a single amino acid of basic domain, and possessed a deficient but apparent DNA-binding ability. Here, we characterized the unique effects of Mi(wh)-MITF on the expression of mast cell-related genes.

Effect of MITF on mast cell differentiation.

The mi transcription factor (MITF) is a basic helix-loop-helix leucine zipper (bHLH-Zip) transcription factor and encoded by the mi locus of mice. Double gene dose of mutant allele at the mi locus results the decrease of mast cells and phenotypic abnormalities of mast cells. Various mutations have been reported at the mi locus.

Regulation of mast cell phenotype by MITF.

The development of mast cells is controlled through the cooperative effects of growth factors and nuclear transcription factors. The signals generated by the binding of stem cell factor (SCF) to c-kit receptor tyrosine kinase (KIT) are essential for their development and survival. A double gene dose of mutant alleles at either the SCF or KIT locus results in a decrease of mast cells.

Isoforms of mi transcription factor preferentially expressed in cultured mast cells of mice.

MITF is a basic helix-loop-helix leucine zipper transcription factor, which is important for normal phenotypic expression of mast cells. Three isoforms of MITF have been known in mice, MITF-A, -H, and -M. Since cultured mast cells (CMCs) are useful for studying the function of MITF, we examined isoforms of MITF expressed in CMCs using 5'-RACE, and found a new isoform of MITF, MITF-E.