In vitro and in vivo anti-allergic effects of 'benifuuki' green tea containing O-methylated catechin and ginger extract enhancement

Abstract

'Benifuuki', a tea (Camellia Sinensis L.) cultivar in Japan, is rich in anti-allergic epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3''Me). 'Benifuuki' green tea and simultaneous addition of ginger extract remarkably suppressed cytokine (TNF-alpha and MIP-1alpha) secretion from mouse bone marrow-derived mast cells after antigen stimulation and, as expected, suppressed delay-type allergy. After drinking 'benifuuki' green tea containing 43.5 mg of EGCG and 8.5 mg of EGCG3''Me, the AUC (area under the drug concentration time curve; min mug/ml) of EGCG was 6.72 +/- 2.87 and EGCG3''Me was 8.48 +/- 2.54 in healthy human volunteers. Though the dose of EGCG was 5.1 times the dose of EGCG3''Me, the AUC of EGCG3''Me was higher than that of EGCG. A double blind clinical study on subjects with Japanese cedar pollinosis was carried out. At the 11th week after starting the study, in the most severe cedar pollen scattering period, symptoms, i.e., blowing the nose and itching eyes, were significantly relieved in the 'benifuuki' intake group compared with the placebo group, and blowing the nose, itching eyes and nasal symptom score, and at the 11th and 13th weeks, stuffy nose, throat pain and the nasal symptom medication score were significantly relieved in the 'benifuuki' containing ginger extract group compared with the placebo group. These results suggested that over one consecutive month, drinking 'benifuuki' green tea was useful to reduce some of the symptoms from Japanese cedar pollinosis, and did not affect any normal immune response in subjects with seasonal rhinitis, and the ginger extract enhanced the effect of 'benifuuki' green tea.

Fig. 1

The effect of ‘benifuuki’ green tea and vegetable extract on TNF-α production after DNP antigen stimulation of BMMC. ‘Benifuuki’ green tea extract and vegetable extract were administered at 50 μg (equivalent to tannin content) and 50 μl per 1 × 10⁷ cells of BMMC, respectively

Fig. 2

The effect of ‘benifuuki’ green tea and vegetable extract on MIP-1α production after DNP antigen stimulation of BMMC. ‘Benifuuki’ green tea extract and vegetable extract was administered at 50 μg (equivalent to tannin content) and 50 μl per 1 × 10⁷ cells of BMMC, respectively

Fig. 3

Plasma unconjugated EGCG and EGCG3″Me concentration versus time profiles after oral administration of ‘benifuuki’ green tea beverage. Each point represents the average of six subjects, and the cross-vertical bars represent SD of the mean. All subjects drank ‘benifuuki’ green tea containing 43.5 mg of EGCG and 8.5 mg of EGCG3″Me within 3 min

Fig. 4

The effects of ‘benifuuki’ green tea and additive ginger extract on the symptom score of seasonal allergic rhinitis. All subjects drank 1.5 g of each tea powder, ‘benifuuki’ green tea, ‘benifuuki’ green tea containing 30 mg of ginger extract, and ‘yabukita’ green tea, with water twice a day for 13 weeks. Each point represents the average of nine subjects every 2 weeks and the cross-vertical bars represent SD of the mean. (a) blowing nose (0 (0 time)–4 (more than 21 times)), (b) itching eyes (0 (no)–4 (severe)), (c) nasal symptom medication score. *,**Significantly different from the placebo group (*p < 0.05, **p < 0.01)