Substance P Blocker Fosaprepitant Prevents UV-Induced Eye Inflammation in Both Eyes

The NK-1R antagonist fosaprepitant blocked UV-induced inflammation and NK-1R expression in exposed mouse eyes AND in unexposed partner eyes, revealing bilateral substance P-mediated inflammatory signaling.

Gross, Janine et al.·Ocular immunology and inflammation·2021·PreliminaryPreclinical Animal Study
RPEP-05418Preclinical Animal StudyPreliminary2021RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Preclinical Animal Study
Evidence
Preliminary
Sample
N=Animal study (not specified)
Participants
C57BL mice with unilateral UVR-B eye exposure

What This Study Found

Fosaprepitant (NK-1R antagonist) blocked UVR-B-induced NKR-1 expression and pro-inflammatory cytokine/chemokine production in both exposed and unexposed partner eyes in a mouse cataract model.

Key Numbers

NK-1R reduced in exposed tissues; NK-1R reduced in unexposed lens epithelium; no cytokine changes; days 3 and 7 endpoints

How They Did This

Animal study. UVR-B-induced cataract mouse model. Unilateral UV exposure. Fosaprepitant treatment. NK-1R expression and pro-inflammatory cytokine/chemokine levels measured in both exposed and unexposed eyes.

Why This Research Matters

UV-related eye damage is a global health concern. Discovering that substance P mediates bilateral eye inflammation from unilateral UV exposure — and that it can be blocked — opens new prevention strategies using existing drugs.

The Bigger Picture

This study extends substance P's known inflammatory roles to UV-induced eye damage and reveals surprising bilateral signaling. It suggests NK-1R antagonists could have broader ophthalmological applications beyond nausea prevention.

What This Study Doesn't Tell Us

Mouse model only. Fosaprepitant was given systemically, so off-target effects possible. Long-term cataract prevention not assessed. Bilateral mechanism not fully explained.

Questions This Raises

  • ?Could fosaprepitant be developed as eye drops to prevent UV-induced cataracts?
  • ?What neural pathway mediates the bilateral substance P inflammatory response?
  • ?Would chronic NK-1R blockade protect against age-related cataracts in humans?

Trust & Context

Key Stat:
Both eyes protected Fosaprepitant blocked UV-induced inflammation not only in the exposed eye but also in the unexposed partner eye, revealing bilateral substance P signaling
Evidence Grade:
Low-to-moderate evidence: well-designed mouse study with clear bilateral mechanism, but no human data or long-term outcomes.
Study Age:
Published 2021. NK-1R antagonists for ophthalmological conditions are being explored further.
Original Title:
UVR-B-induced NKR-1 Expression in Ocular Tissues is blocked by Substance P Receptor Antagonist Fosaprepitant in the Exposed as well as Unexposed Partner Eye.
Published In:
Ocular immunology and inflammation, 29(5), 963-975 (2021)
Database ID:
RPEP-05418

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 UV damage spread to the unexposed eye?

UV exposure to one eye triggers substance P release, which activates NK-1R receptors and inflammatory pathways. This inflammatory signaling somehow spreads to the partner eye — possibly through neural or systemic pathways — causing bilateral damage from unilateral exposure.

Could substance P blockers prevent cataracts?

Potentially. This study shows that blocking the substance P receptor (NK-1R) prevents UV-induced eye inflammation in mice. If this translates to humans, existing NK-1R drugs could be repurposed as eye drops for cataract and UV damage prevention.

Read More on RethinkPeptides

Cite This Study

RPEP-05418·https://rethinkpeptides.com/research/RPEP-05418

APA

Gross, Janine; Wegener, Alfred R; Kronschläger, Martin; Schönfeld, Carl-Ludwig; Holz, Frank G; Meyer, Linda M. (2021). UVR-B-induced NKR-1 Expression in Ocular Tissues is blocked by Substance P Receptor Antagonist Fosaprepitant in the Exposed as well as Unexposed Partner Eye.. Ocular immunology and inflammation, 29(5), 963-975. https://doi.org/10.1080/09273948.2019.1708414

MLA

Gross, Janine, et al. "UVR-B-induced NKR-1 Expression in Ocular Tissues is blocked by Substance P Receptor Antagonist Fosaprepitant in the Exposed as well as Unexposed Partner Eye.." Ocular immunology and inflammation, 2021. https://doi.org/10.1080/09273948.2019.1708414

RethinkPeptides

RethinkPeptides Research Database. "UVR-B-induced NKR-1 Expression in Ocular Tissues is blocked ..." RPEP-05418. Retrieved from https://rethinkpeptides.com/research/gross-2021-uvrbinduced-nkr1-expression-in

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.