ABSTRACT

Allergies are disorders of the immune system. In healthy individuals, the immune system is poised between maximizing protection from unwelcome invasion or internal imbalance, and minimizing harmful overreaction to external or internal events. In allergic diseases, this delicate balance is disturbed with consequent adverse effects on morbidity and mortality. Most of us are familiar with the consequences of allergic diseases. Allergic diseases, such as asthma, rhinitis, eczema, and food allergies, are reaching epidemic proportions in both the developed and developing world (Holgate, 1999). e

12.1 Introduction 233 12.2 IgE Production Inhibitor in Green Tea 234 12.3 Degranulation Inhibitors in Green Tea 237

12.3.1 EGCG and ECG 237 12.3.2 Methylated Catechins 239 12.3.3 A Cell Surface EGCG Receptor 240 12.3.4 Antidegranulation Action of Catechins through the

EGCG Receptor 241 12.4 Suppressors for the High-Affinity IgE Receptor FcεRI Expression 243 12.5 Antiallergic Effect of Green Tea in Human Studies 245 12.6 Conclusions 246 References 247

costs to public health and its reflection on economy are massive and growing, and a major research effort has been underway for many years to understand these diseases. Seasonal allergic rhinitis (SAR) is a very common disease in developed countries, and its occurrence has been increasing in recent years. e prevalence of Japanese cedar pollinosis, the most common SAR in Japan, is estimated to be approximately 16.2% of the population (Okuda, 2003).