Flavonoids and Related Compounds as Anti-Allergic Substances

Abstract

The prevalence of allergic diseases has increased all over the world during the last two decades. Dietary change is considered to be one of the environmental factors that cause this increase and worsen allergic symptoms. If this is the case, an appropriate intake of foods or beverages with anti-allergic activities is expected to prevent the onset of allergic diseases and ameliorate allergic symptoms. Flavonoids, ubiquitously present in vegetables, fruits or teas possess anti-allergic activities. Flavonoids inhibit histamine release, synthesis of IL-4 and IL-13 and CD40 ligand expression by basophils. Analyses of structure-activity relationships of 45 flavones, flavonols and their related compounds showed that luteolin, ayanin, apigenin and fisetin were the strongest inhibitors of IL-4 production with an IC(50) value of 2-5 microM and determined a fundamental structure for the inhibitory activity. The inhibitory activity of flavonoids on IL-4 and CD40 ligand expression was possibly mediated through their inhibitory action on activation of nuclear factors of activated T cells and AP-1. Administration of flavonoids into atopic dermatitis-prone mice showed a preventative and ameliorative effect. Recent epidemiological studies reported that a low incidence of asthma was significantly observed in a population with a high intake of flavonoids. Thus, this evidence will be helpful for the development of low molecular compounds for allergic diseases and it is expected that a dietary menu including an appropriate intake of flavonoids may provide a form of complementary and alternative medicine and a preventative strategy for allergic diseases. Clinical studies to verify these points are now in progress.

Flavonoid glucuronides isolated from spinach inhibit IgE-mediated degranulation in basophilic leukemia RBL-2H3 cells and passive cutaneous anaphylaxis reaction in mice

“…In addition, it is necessary to have a series of evidence to support both in vitro and in vivo effectiveness of these promising materials. Several flavonoids including quercetin, luteolin, kaempferol and myricetin are known to inhibit histamine release from human basophils and rat basophilic leukemia cells [12,14]. It has been also reported that some flavonoid glucosides or glucuronides exhibit the inhibitory effect on IgE-mediated degranulation [1,2,[14][15][16][17].…”

“…The antioxidant effect of spinach is reported to be mainly due to the flavonoid compounds such as spinacetin glucoside, patuletin glucoside and dioxol flavonoid [5,7,10]. On the other hand, some flavonoid compounds isolated from other plants, including quercetin, kaempherol and so on have been shown to inhibit histamine release from rat basophilic leukemia cells [2,[12][13][14][15][16][17][18]. However, it is unknown that spinach has an inhibitory component on both IgE-mediated degranulation from the cells and in vivo allergic reactions.…”

Evaluation of the Effects of Tetrapleura tetraptera Extract and Clomiphene Citrate to Determine Influence of Reproductive Hormones and Estrous Cycle on Leukocyte Counts: Novel Evidence for a Potential Developmental Link Between Luteinizing Hormone and MID Cells

“…Therefore, alteration in secretion of these colony stimulating factors impair proliferation and differentiation of leukocytes. Because studies have shown that flavonoids inhibit IL-1β-stimulated granulocyte-colony stimulating factor expression and subsequent neutrophil differentiation as well as suppressing the expression of granulocyte/monocytecolony stimulating factor [23,24] could suggest that Tetrapleura tetraptera pod extract inhibited proliferation and differentiation processes required to necessitate neutrophil production resulting in the reduction in the peripheral neutrophil count. Besides inhibition of granulocyte-colony stimulating factor and granulocyte/monocyte-colony stimulating factor, apigenin and chalcones have been shown to inhibit interleukins-6and blocked tumor necrosis factor-α [25,26].…”

Flavonoids as complementary medicine for allergic diseases: current evidence and future prospects

“…They exert several biological benefits for humans, such as antioxidant, anti-inflammatory, antibacterial, anti-viral, anti-angionic, anti-allergic and immune-modulating effects. An appropriate intake of flavonoids may therefore be expected to prevent chronic diseases including allergic diseases 7,[14][15][16] . Third, the inhibitory effect of flavonoids on activation of high-affinity IgE receptor (FcRI)-expressing cells, such as mast cells and basophils is well known, and was found to also inhibit histamine release and synthesis of leukotriene or other chemical mediators 7,19 .…”