The Efficacy of Early Treatment of Seasonal Allergic Rhinitis with Benifuuki Green Tea Containing O-methylated Catechin before Pollen Exposure: An Open Randomized Study

Abstract

Background: We previously reported that 'benifuuki' green tea containing O-methylated catechin significantly relieved the symptoms of perennial or seasonal rhinitis compared with a placebo green tea that did not contain O-methylated catechin in randomized double-blind clinical trials. In this study we assessed the effects of 'benifuuki' green tea on clinical symptoms of seasonal allergic rhinitis. Methods: An open-label, single-dose, randomized, parallel-group study was performed on 38 subjects with Japanese cedar pollinosis. The subjects were randomly assigned to long-term (December 27, 2006 – April 8, 2007, 1.5 months before pollen exposure) or short-term (February 15, 2007: after cedar pollen dispersal – April 8, 2007) drinking of a 'benifuuki' tea drink containing 34 mg O-methylated catechin per day. Each subject recorded their daily symptom scores in a diary. The primary efficacy variable was the mean weekly nasal symptom medication score during the study period. Results: The nasal symptom medication score in the long-term intake group was significantly lower than that of the short-term intake group at the peak of pollen dispersal. The symptom scores for throat pain, nose-blowing, tears, and hindrance to activities of daily living were significantly better in the long-term group than the short-term group. In particular, the differences in the symptom scores for throat pain and nose-blowing between the 2 groups were marked. Conclusions: We conclude that drinking 'benifuuki' tea for 1.5 months prior to the cedar pollen season is effective in reducing symptom scores for Japanese cedar pollinosis.

Keywords

• 'benifuuki' green tea
• epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG3"Me)
• Japanese cedar pollinosis
• long-term pre-seasonal
• O-methylated catechin