Attenuation of allergic responses following treatment with resveratrol in anaphylactic models and IgE-mediated mast cells.

Resveratrol exists widely in plant species and has a variety of anti-oxidant, anti-inflammatory, and immunomodulatory properties. However, there have been few reports regarding its anti-food allergic activity. In this study, we demonstrated that resveratrol (isolated from Abies georgei) could decrease the release of ß-hexosaminidase and histamine in rat basophilic leukemia-2H3 cells. Resveratrol was not only found to suppress the development of diarrhea, up-regulate the rectal temperature of ovalbumin-allergic mice, and decrease the serum level of specific immunoglobulin E, mouse mast cell protease-1 and histamine, but also found to decrease the population of dendritic cells, B cells and mast cells of ovalbumin -allergic mice in the spleen or mesenteric lymph node. Furthermore, resveratrol inhibited the release of ß-hexosaminidase and histamine in bone marrow-derived cells and alleviated mast cell-mediated passive cutaneous anaphylaxis reactions. These findings indicated that resveratrol isolated from Abies georgei might have the potential to alleviate food hypersensitivity or allergic disease.

Cirsium maritimum Makino Inhibits the Antigen/Immunoglobulin-E-Mediated Allergic Response In Vitro and In Vivo.

We investigated whether Cirsium maritimum Makino can inhibit immunoglobulin-E-mediated allergic response in rat basophilic leukemia (RBL-2H3) cells and passive cutaneous anaphylaxis (PCA) in BALB/c mice. In vitro, the ethyl acetate extract of C. maritimum Makino (ECMM) significantly inhibited ß-hexosaminidase release and decreased intracellular Ca2+ levels in RBL-2H3 cells. Moreover, ECMM leaves more strongly suppressed the release of ß-hexosaminidase than ECMM flowers. ECMM leaves also significantly suppressed the PCA reaction in the murine model. High-performance liquid chromatography and 1H and 13C nuclear magnetic resonance indicated that cirsimaritin, a flavonoid, was concentrated in active fractions of the extract. Our findings suggest that ECMM leaves have a potential regulatory effect on allergic reactions that may be mediated by mast cells. Furthermore, cirsimaritin may be the active anti-allergic component in C. maritimum Makino.

Anti-Allergic Activities of Smilax glabra Rhizome Extracts and Its Isolated Compounds.

BACKGROUND: The rhizomes of Smilax glabra (SG) has long been used in Traditional Chinese and Thai herbal medicine to treat a variety of infectious diseases and immunological disorders. OBJECTIVE: To investigate the in vitro anti-allergic activities of crude extracts andpure isolated flavonoid compounds from SG by determination of inhibitory effect on antigen-induced release of ß-hexosaminidasefrom RBL-2H3 cells. MATERIAL AND METHOD: The in vitro inhibitory effects ofcrude aqueous and organic extracts on ß-hexosaminidase release in RBL-2H3 cells were evaluated as an in vitro indication ofpossible anti-allergic activity. Bioassay-guided fractionation of extracts was used to isolate flavonoid compounds from the ethanolic extracts. RESULTS: The 95% and 50% ethanolic extracts of SG showed remarkably high anti-allergic activity, with IC50 values of 5.74 ± 2.44 and 23.54 ± 4.75 µg/ml, much higher activity than that for Ketotifen (IC50 58.90 µM). The water extract had negligible activity (IC50 > 100 µg/ml). The two isolated flavonols, Engeletin and Astilbin, showed weak anti-allergic activity, IC50 values 97.46 ± 2.04 and >100 µg/ml, respectively. CONCLUSION: The 95% and 50% ethanolic extracts of SG showed strong anti-allergic activity, but two flavonol constituents did not show any significant anti-allergic activity. These findings suggest that a combination of effects of various phytochemicals in crude extracts used in traditional medicine, are responsible for the purported anti-allergic activity of SG herbal preparations. The plethora of constituents in crude extracts, as yet unidentified, are likely to be acting synergistically to account for the strong observed anti-allergic in vitro activity.

Anti-allergic action of aged black garlic extract in RBL-2H3 cells and passive cutaneous anaphylaxis reaction in mice.

Garlic (Allium sativum) has been used as a food as well as a component of traditional medicine. Aged black garlic (ABG) is known to have various bioactivities. However, the effect of ABG on allergic response is almost unknown. In the present study, we investigated whether ABG can inhibit immunoglobulin E-mediated allergic response in RBL-2H3 cells as well as in vivo passive cutaneous anaphylaxis (PCA). In in vitro tests, ethyl acetate extract (EBG) of ABG significantly inhibited the release of ß-hexosaminidase (IC50, 1.53 mg/mL) and TNF-α (IC50, 0.98 mg/mL). Moreover, BG10, an active fraction of EBG, dramatically suppressed the release of ß-hexosaminidase (IC50, 53.60 µg/mL) and TNF-α (IC50, 27.80 µg/mL). In addition, BG10 completely blocked the formation of prostaglandin E2 and leukotriene B4 at ≥25 µg/mL. When the effect of BG10 on FcɛRI receptor cascade was investigated, BG10 significantly inhibited the phosphorylation of Syk, but not Lyn. Furthermore, BG10 dose dependently decreased the phosphorylation of cytosolic phospholipase A2 (cPLA2) and 5-lipoxygenase (5-LO) as well as the expression of cyclooxygenase-2 (COX-2). Consistent with what has been mentioned earlier, BG10 also significantly inhibited the PCA reaction in mice. In conclusion, these results indicate that ABG suppresses the allergic response, and the mechanism for its anti-allergic action may involve suppressions of Syk, cPLA2, 5-LO, and COX-2. The anti-allergic actions of ABG, EBG, or BG10 suggest that they may be useful as functional foods for allergic diseases.

Effect of Sophora flavescens Aiton extract on degranulation of mast cells and contact dermatitis induced by dinitrofluorobenzene in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: The dried root of Sophora flavescens Aiton (Sophorae radix, SR) has long been used in traditional medicine for the treatment of fever and swelling in eastern countries. MATERIALS AND METHODS: The present study investigated the anti-allergic and anti-inflammatory effects of SR using 1-fluoro-2,4-dinitrofluorobenzene (DNFB)-induced contact dermatitis mouse model and in vitro using RBL-2H3 cells. RESULTS: In mice, the topical application of 10 mg/mL of SR effectively inhibited enlargement of ear thickness and weight induced by repeated painting with DNFB. Topical application of SR also inhibited hyperplasia, edema, spongiosis and infiltration of mononuclear cells in ear tissue. In addition, production levels of interferon-gamma and tumor necrosis factor-alpha were decreased by SR in vivo. Finally, the release of histamine and ß-hexosaminidase, and migration were inhibited by treatment with SR. CONCLUSIONS: These data indicate the potential of SR in treating patients with allergic skin diseases and also suggest that related mechanisms are involved in anti-inflammatory action on the Th 1 skewing reaction and inhibition against recruitment and degranulation of mast cells.