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Japanese catnip

Japanese catnip is an aromatic herb from the mint family, used for centuries in traditional East Asian medicine and rich in plant compounds such as flavonoids that interact with the body's immune signaling. Research has looked most at inflammation, where lab and animal studies found the extract lowered inflammatory signals such as TNF-alpha and IL-6 in immune cells. The evidence is very limited, though: nearly all of it comes from cells and animals, and no human trial results were reviewed here.

Sources: PMID 19051342; PMID 24650252

Best evidence
Grade D
Conditions studied
3
Outcomes
4
Graded outcomes
0004

Evidence by condition

  • Strong
  • Moderate
  • Limited
  • Very limited

3 conditions, plus general outcomes

General

General: outcomes studied for Japanese catnip
GradeOutcomeEffectSizeStudiesPeopleStudies list
Inflammation

In mouse peritoneal macrophages, S. tenuifolia extract inhibited TNF-alpha (48% reduction) and IL-6 (56% reduction) production, suppressed COX-2 and iNOS expression, and inhibited MAPK phosphorylation. A separate study confirmed anti-inflammatory activity via TLR4 signaling inhibition in LPS-stimulated macrophages. In a rat carrageenan-induced pleurisy model, volatile oils significantly reduced leukocytes, MPO, MDA, TNF-alpha, and IL-1beta. All evidence is preclinical.

Improves (the measure goes down)Moderate effect4 studies

Studies that measured inflammation

Allergic Diseases (General)

Allergic Diseases (General): outcomes studied for Japanese catnip
GradeOutcomeEffectSizeStudiesPeopleStudies list
Allergic Response

In IgE-stimulated RBL-2H3 mast cells, S. tenuifolia suppressed degranulation (beta-hexosaminidase release) and reduced IFN-gamma, TNF-alpha, IL-4, and IL-6 at 100 mcg/mL. In rats, the extract dose-dependently inhibited compound 48/80-induced systemic anaphylaxis and reduced plasma histamine levels. In a DNCB-induced atopic dermatitis mouse model, treatment suppressed serum IgE, TNF-alpha, and IL-6, and downregulated NF-kappaB and MAPK expression. No human data exists.

Improves (the measure goes down)Moderate effect3 studies

Studies that measured allergic response

Antioxidant Status

  • Antioxidant Status: improves
Antioxidant Status: outcomes studied for Japanese catnip
GradeOutcomeEffectSizeStudiesPeopleStudies list
Antioxidant Status

Aqueous extracts of S. tenuifolia demonstrated radical scavenging, reducing activity, and liposome protection in vitro, attributed to polyphenolic components including hesperidin, luteolin, and diosmetin. In UVB-irradiated hairless mice, ethanolic extract reduced wrinkle formation, collagen degradation, and AGE accumulation while upregulating hyaluronan synthases and hyaluronic acid levels, suggesting protection against oxidative skin damage. All evidence is preclinical.

Improves (the measure goes up)Small effect3 studies

Studies that measured antioxidant status

Cardiovascular Health

  • Platelet Aggregation: improves
Cardiovascular Health: outcomes studied for Japanese catnip
GradeOutcomeEffectSizeStudiesPeopleStudies list
Platelet Aggregation

In an in vitro study using collagen-stimulated human platelets, S. tenuifolia extract potently inhibited platelet aggregation, calcium mobilization, granule secretion, and fibrinogen binding to integrin alphaIIb-beta3 via suppression of MAPK and Akt signaling. No in vivo or human studies have been conducted.

Improves (the measure goes down)Small effect1 study

Studies that measured platelet aggregation

Key findings

  • InflammationImproves (the measure goes down)
  • Allergic ResponseAllergic Diseases (General)Improves (the measure goes down)
  • Antioxidant StatusAntioxidant StatusImproves (the measure goes up)

Shop Japanese catnip

Third-party tested Japanese catnip products. The evidence above is limited, so read it before you buy.

  • Grade D

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Studies cited

9 studies from PubMed

  1. Protective effect of Schizonepeta tenuifolia Briq. ethanolic extract against UVB-induced skin aging and photodamage in hairless miceFrontiers in Pharmacology, 2023 · PMID 37351505
  2. Spectrum-effect relationship between GC-QTOF-MS fingerprint and antioxidant, anti-inflammatory activities of Schizonepeta tenuifolia essential oilBiomedical Chromatography, 2021 · PMID 33638568
  3. Schizonepeta tenuifolia inhibits collagen stimulated platelet function via suppressing MAPK and Akt signalingJournal of Biomedical Research, 2019 · PMID 30783025
  4. Immunomodulation Effects of Schizonepeta tenuifolia Briq. on the IgE-Induced Allergic Model of RBL-2H3 CellsEvidence-Based Complementary and Alternative Medicine, 2018 · PMID 29849717
  5. Schizonepeta tenuifolia ethanol extract exerts anti-inflammatory activity through the inhibition of TLR4 signaling in lipopolysaccharide-stimulated macrophage cellsJournal of Medical Food, 2014 · PMID 24650252
  6. Schizonepeta tenuifolia inhibits the development of atopic dermatitis in micePhytotherapy Research, 2013 · PMID 22949410
  7. Antioxidant and anti-inflammatory activities of aqueous extracts of Schizonepeta tenuifolia BriqFood and Chemical Toxicology, 2012 · PMID 22198607
  8. Anti-inflammatory activity of Schizonepeta tenuifolia through the inhibition of MAPK phosphorylation in mouse peritoneal macrophagesAmerican Journal of Chinese Medicine, 2008 · PMID 19051342
  9. Effect of Schizonepeta tenuifolia extract on mast cell-mediated immediate-type hypersensitivity in ratsImmunopharmacology and Immunotoxicology, 1999 · PMID 10584206