Tier 2 — strong

Preventative effect of a flavonoid, enzymatically modified isoquercitrin on ocular symptoms of Japanese cedar pollinosis

Toru Hirano, Mari Kawai, Junsuke Arimitsu, Masako Ogawa, Yusuke Kuwahara, Keisuke Hagihara, Yoshihito Shima, Masashi Narazaki, Atsushi Ogata, Mihoko Koyanagi, Tomoko Kai, Ryosuke Shimizu, Masamitsu Moriwaki, Yukio Suzuki, Satoshi Ogino, Ichiro Kawase, Toshio Tanaka
Allergology international : official journal of the Japanese Society of Allergology 2009 58(3):373

Bibliography

PubMed
PMID 19454839
DOI
10.2332/allergolint.08-OA-0070
Funding
Funding was not specified in the indexed record or the disclosure metadata available for this entry.
Competing interests
A competing-interest declaration was not available in the indexed record or the disclosure metadata used for this entry.

Study snapshot

DesignDouble-blind placebo-controlled parallel-group allergy trial
ModelHuman intervention research
Sample24 adults with Japanese cedar pollinosis
InterventionEnzymatically modified isoquercitrin 100 mg/day or placebo
Duration8 weeks, beginning 4 weeks before pollen release
EndpointsSymptoms and quality of life

What the study showed, in plain terms

Published in 2009, this source examined allergies, histamine and mast cells. Design: Double-blind placebo-controlled parallel-group allergy trial. Sample/model: 24 adults with Japanese cedar pollinosis. The exposure or intervention was Enzymatically modified isoquercitrin 100 mg/day or placebo. Follow-up or treatment period: 8 weeks, beginning 4 weeks before pollen release.

Selected ocular symptom and medication scores improved; nasal symptoms and serum IgE did not differ significantly.

Small seasonal study of a modified glycoside. Results do not establish equivalence for ordinary quercetin or treatment of all allergic conditions.

Continue with Quercetin Data Center

For topic-level interpretation, read Quercetin for Allergies: Hay Fever Evidence and Limits. This is a related guide; the citation panel separately identifies articles that directly cite this paper.

Key findings

  • Selected ocular symptom and medication scores improved; nasal symptoms and serum IgE did not differ significantly.
  • The recorded outcome domains were Symptoms and quality of life.
  • The result applies to the tested exposure: Enzymatically modified isoquercitrin 100 mg/day or placebo; 8 weeks, beginning 4 weeks before pollen release.

What this study can and cannot tell us

  • Small seasonal study of a modified glycoside. Results do not establish equivalence for ordinary quercetin or treatment of all allergic conditions.
  • An individual controlled trial must be interpreted alongside its comparator, sample size, endpoint selection and independent replication. It does not validate a different commercial formulation or a general longevity claim.
  • Source basis: Source check: PubMed abstract and indexed metadata; full methods were not independently confirmed for this entry. Missing method details, funding information or participant denominators are not inferred.

Related papers in the corpus

Tier 2
Effect of enzymatically modified isoquercitrin, a flavonoid, on symptoms of Japanese cedar pollinosis: a randomized double-blind placebo-controlled trial
Mari Kawai et al. · International archives of allergy and immunology · 2009

Citation network

Articles citing this research paper

3 articles

Biohack Blueprint analyses that reference this study in their evidence base.

Editorial review

Reviewed by the Biohack Blueprint research team

Last verified

Dr. Khaled Mahmoud, MBBChCritical Care Medicine, Longevity Science & Editorial Direction Dr. Amr Yasser, PhDCardiometabolic, Musculoskeletal, Gut & Bioavailability Dr. Abdulla Mostafa, PhDCellular Senescence, Neurological, Mitochondrial & Brain-Ageing Biology