Masamitsu Moriwaki

Preventative Effect of a Flavonoid, Enzymatically Modified Isoquercitrin on Ocular Symptoms of Japanese Cedar Pollinosis

BACKGROUND Flavonoids are nutrients that exert anti-allergic effects. We investigated the preventative effect of enzymatically modified isoquercitrin (EMIQ), a flavonoid, to relieve the symptoms of Japanese cedar pollinosis. METHODS In a parallel-group, double-blind placebo-controlled study design, 24 subjects with Japanese cedar pollinosis took 100mg EMIQ or a placebo for 8 weeks, starting 4 weeks prior to the onset of pollen release. Subjective symptoms, ADL scores and the usage of drugs were recorded daily, and the QOL score was obtained every 4 weeks. Blood sampling was performed before and after the study to measure serum levels of IgE and flavonoids. RESULTS During the entire study period, ocular symptom + medication score for the EMIQ group was significantly lower (p < 0.05) than that of the placebo group. When limited to the period, ocular symptom scores (p < 0.05, weeks 5-6), and ocular congestion scores (p < 0.05, weeks 5-6) for the EMIQ group was significantly lower than that for the placebo group while other scores for the EMIQ group, such as ocular itching scores (p = 0.09, weeks 4-5), lacrimation scores (p = 0.07, weeks 5-6), and ocular congestion scores (p = 0.06, weeks 4-5), all tended to be lower. However no significant differences were found in nasal symptoms between the two groups. Serum concentrations of IgE were not significantly downregulated but the serum concentrations of quercetin and its derivatives were elevated significantly by the intake of EMIQ. CONCLUSIONS Intake of the quercetin glycoside EMIQ proved to be effective for the relief of ocular symptoms caused by Japanese cedar pollinosis.

Effect of enzymatically modified isoquercitrin, a flavonoid, on symptoms of Japanese cedar pollinosis: a randomized double-blind placebo-controlled trial.

Background: Flavonoids exert antiallergic and antioxidant effects. We investigated the efficacy of enzymatically modified isoquercitrin (EMIQ), a flavonoid, to relieve symptoms of pollinosis. Methods: In a parallel-group, double-blind placebo-controlled study design, 20 subjects with Japanese cedar pollinosis took two capsules daily of 100 mg EMIQ or a placebo for 8 weeks during the pollen season. Subjective symptoms and activities of daily living (ADL) scores were recorded every day, and the quality of life (QOL) score was obtained every 4 weeks. Blood sampling was performed before and after the study to measure serum cytokines, chemokines, IgE, quercetin and oxidized biomarkers. Results: During the entire study period, total ocular score and ocular itching score for the EMIQ group were significantly lower (p < 0.05) than for the placebo group. When limited to the individual periods, total symptom score for the EMIQ group was significantly lower (p < 0.05, week 4–5) than that for the placebo group while other scores for the EMIQ group, such as total nasal score (p = 0.06, week 4–5), nasal obstruction score (p = 0.08, week 4–5), lacrimation score (p = 0.06, week 5–6), ocular congestion score (p = 0.08, week 4–7) and ADL score (p = 0.08, week 4–7), all tended to be lower. The levels of serum cytokines such as interleukin (IL)-4, IL-5, IL-12, IL-13, interferon-γ, and eotaxin and IgE were not significantly downregulated by the intake of EMIQ but the serum concentrations of oxidized low-density lipoprotein and thymus and activation-regulated chemokine were reduced. Conclusion: Intake of the quercetin glycoside EMIQ was safe and influenced ocular symptoms caused by pollinosis.

Enzymatic Production of Highly Soluble Myricitrin Glycosides Using β-Galactosidase

Myricitrin, a botanical flavonol glycoside, could be a useful ingredient of functional foods, cosmetics, and medicines because of its high anti-oxidative activity. However, due to its insolubility in water, it has a limited range of use. To improve this solubility, we glycosylated myricitrin by an enzymatic transglycosylate reaction. Myricitrin was galactosylated by β-galactosidase from Bacillus circulans using lactose as a sugar donor. The reaction product was 480 times more soluble than myricitrin. Four myricitrin galactosides were isolated from the reaction products by column chromatography, and their molecular structures were identified by using ESI-MS, 1H-NMR, 13C-NMR, 1H–1H COSY, 1H-13C HMQC and 1H-13C HMBC analysis. The solubility of these four myricitrin galactosides was more than 3.9×103 fold that of myricitrin, and each had similar anti-oxidative activity to that of myricitrin.