Flavonoids and related compounds as anti-allergic substances.
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.
Kawai
Mari
M
Department of Respiratory Medicine, Allergy and Rheumatic Diseases, Osaka University Medical School, Osaka, Japan.
Hirano
Toru
T
Higa
Shinji
S
Arimitsu
Junsuke
J
Maruta
Michiru
M
Kuwahara
Yusuke
Y
Ohkawara
Tomoharu
T
Hagihara
Keisuke
K
Yamadori
Tomoki
T
Shima
Yoshihito
Y
Ogata
Atsushi
A
Kawase
Ichiro
I
Tanaka
Toshio
T
D000818:Animals; D018926:Anti-Allergic Agents / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D001249:Asthma / Q000517:prevention & control; D001491:Basophils / Q000187:drug effects* / Q000378:metabolism; D023201:CD40 Ligand / Q000378:metabolism; D000529:Complementary Therapies; D003876:Dermatitis, Atopic / Q000276:immunology / Q000517:prevention & control; D004195:Disease Models, Animal; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D006636:Histamine Release / Q000187:drug effects; D006801:Humans; D006967:Hypersensitivity / Q000188:drug therapy* / Q000453:epidemiology / Q000276:immunology / Q000378:metabolism; D018793:Interleukin-13 / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D008407:Mast Cells / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D015394:Molecular Structure; D013329:Structure-Activity Relationship
D018926:Anti-Allergic Agents; D005419:Flavonoids; D018793:Interleukin-13; D023201:CD40 Ligand; D015847:Interleukin-4