Preventive effects of black tea theaflavins against mouse type IV allergy
2010
Yoshino, Kyoji | Yamazaki, Katsuko | Sano, Mitsuaki
BACKGROUND: Tea (Camellia sinensis L.), one of the most popular beverages, contains various beneficial constituents. We investigated the preventive effects of black tea theaflavins, theaflavin-3-gallate (3-TF) and theaflavin-3,3′-digallate (TFDG), on oxazolone-induced type IV allergy in male ICR mice.RESULTS: Percutaneous administration of both 3-TF and TFDG at 0.2 mg ear⁻¹ showed significant preventive effects against mouse type IV allergy. Oral administration of these agents at 50 mg kg⁻¹ body weight also showed significant preventive effects against mouse type IV allergy. Oral administration of 3-TF and TFDG at a dose of 50 mg kg⁻¹ body weight prevented the increases in levels of some proinflammatory cytokines, interleukin-12 (IL-12), interferon-gamma (IFN-γ), and tumour necrosis factor-alpha (TNF-α), in the sera and/or ears of mice with type IV allergy. Lowering of serum antioxidant activity in mice with allergic symptoms was also prevented by oral administration of these theaflavins at a dose of 50 mg kg⁻¹ body weight. The anti-allergic mechanisms of action of theaflavins involve inhibition of the fluctuations of cytokines and maintenance of antioxidant status in allergic mice.CONCLUSION: These results suggest that the theaflavins as well as catechins contribute to the anti-allergic effects of black tea.
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