Traditional Chinese Herb Coptis Blocks the LL-37 Pathway Driving Rosacea Inflammation

Coptis chinensis extract reduced rosacea-related inflammation by inhibiting KLK5 enzyme activity and blocking the conversion of inactive cathelicidin into the inflammatory LL-37 peptide.

Roh, Kyung-Baeg et al.·Molecules (Basel·2020·Preliminary Evidencein-vitro
RPEP-05097In VitroPreliminary Evidence2020RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
in-vitro
Evidence
Preliminary Evidence
Sample
N=in vitro
Participants
Human epidermal keratinocytes and microvascular endothelial cells

What This Study Found

Coptis chinensis downregulated KLK5 and cathelicidin expression, inhibited KLK5 protease activity (reducing LL-37 processing), decreased pro-inflammatory cytokines, blocked TLR2/chitin signaling, and inhibited LL-37-induced endothelial cell proliferation.

Key Numbers

Reduced KLK5 expression and activity; reduced cathelicidin and LL-37 processing; blocked TLR2 from Demodex chitin; inhibited endothelial proliferation

How They Did This

In vitro study using human epidermal keratinocytes and microvascular endothelial cells. Tested CC effects on KLK5/cathelicidin expression and activity, LL-37 processing, inflammatory cytokine production, TLR2 signaling (chitin stimulation), and endothelial proliferation.

Why This Research Matters

Rosacea affects millions and current treatments are limited. Understanding how a traditional remedy targets the specific LL-37/KLK5 pathway behind rosacea could lead to more effective, mechanism-based treatments.

The Bigger Picture

This study provides molecular evidence for a traditional medicine's efficacy in rosacea, connecting it to the now well-established cathelicidin/LL-37 overexpression pathway that drives rosacea pathogenesis.

What This Study Doesn't Tell Us

In vitro only — no clinical trial data. Herb extract composition may vary; active compounds not isolated. Bioavailability after topical application unknown. Single keratinocyte cell line used.

Questions This Raises

  • ?Which specific compounds in Coptis chinensis are responsible for KLK5/LL-37 inhibition?
  • ?Would a topical Coptis formulation show clinical improvement in rosacea patients?
  • ?Does Coptis over-suppress LL-37 to levels that would impair skin antimicrobial defense?

Trust & Context

Key Stat:
Multi-target rosacea action Coptis chinensis inhibits KLK5 activity, LL-37 processing, TLR2 signaling, and angiogenesis — all key rosacea drivers
Evidence Grade:
Preliminary — in vitro mechanistic evidence supporting traditional use, but no clinical validation in rosacea patients.
Study Age:
Published in 2020; the LL-37/KLK5 pathway remains a central target in rosacea research and drug development.
Original Title:
Coptis chinensis Franch Directly Inhibits Proteolytic Activation of Kallikrein 5 and Cathelicidin Associated with Rosacea in Epidermal Keratinocytes.
Published In:
Molecules (Basel, Switzerland), 25(23) (2020)
Database ID:
RPEP-05097

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study
What do these levels mean? →

Frequently Asked Questions

How does LL-37 cause rosacea if it is supposed to be a defense peptide?

LL-37 normally protects skin from infection, but in rosacea, it is overproduced and over-processed by the enzyme KLK5. Excess LL-37 triggers inflammation, promotes blood vessel growth (causing redness), and activates immune responses — all hallmarks of rosacea.

Is Coptis chinensis safe for rosacea treatment?

Coptis chinensis (goldthread) has a long history of use in traditional Chinese medicine for inflammatory skin conditions. While this study provides a scientific mechanism, clinical trials are needed to confirm safety and efficacy specifically for rosacea.

Read More on RethinkPeptides

Cite This Study

RPEP-05097·https://rethinkpeptides.com/research/RPEP-05097

APA

Roh, Kyung-Baeg; Ryu, De-Hun; Cho, Eunae; Weon, Jin Bae; Park, Deokhoon; Kweon, Dae-Hyuk; Jung, Eunsun. (2020). Coptis chinensis Franch Directly Inhibits Proteolytic Activation of Kallikrein 5 and Cathelicidin Associated with Rosacea in Epidermal Keratinocytes.. Molecules (Basel, Switzerland), 25(23). https://doi.org/10.3390/molecules25235556

MLA

Roh, Kyung-Baeg, et al. "Coptis chinensis Franch Directly Inhibits Proteolytic Activation of Kallikrein 5 and Cathelicidin Associated with Rosacea in Epidermal Keratinocytes.." Molecules (Basel, 2020. https://doi.org/10.3390/molecules25235556

RethinkPeptides

RethinkPeptides Research Database. "Coptis chinensis Franch Directly Inhibits Proteolytic Activa..." RPEP-05097. Retrieved from https://rethinkpeptides.com/research/roh-2020-coptis-chinensis-franch-directly

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.