Evidence map›Paper›PMID 42123554›Full record

ArticleInternational journal of molecular sciences2026

Unraveling UVA1-Induced Photomodifications of Eumelanin and Pheomelanin in Human Skin: Insights into Pigment Darkening.

Shosuke Ito, Juliette Sok, Yukiko Nakanishi, Kazumasa Wakamatsu, Sandra Del Bino

Abstract read
In one paragraph

Article in International journal of molecular sciences, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0cells of the map it votes in
0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors.

Shosuke ItoInstitute for Melanin Chemistry, Fujita Health University, Toyoake 470-1192, Japan.ORCID 0000-0001-9182-5144
Juliette SokL'Oreal Research and Innovation, 93601 Aulnay-sous-Bois, France.ORCID 0009-0001-2538-5483
Yukiko NakanishiInstitute for Melanin Chemistry, Fujita Health University, Toyoake 470-1192, Japan.
Kazumasa WakamatsuInstitute for Melanin Chemistry, Fujita Health University, Toyoake 470-1192, Japan.ORCID 0000-0003-1748-9001
Sandra Del BinoL'Oreal Research and Innovation, 93601 Aulnay-sous-Bois, France.ORCID 0000-0002-8488-1890

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

UVA exposure elicits immediate and persistent pigment darkening of the skin, which is thought to result from the oxidation and polymerization of existing melanin and/or precursors. Melanocytes produce eumelanin and pheomelanin. Eumelanin consists of 5,6-dihydroxyindole (DHI) and 5,6-dihydroxyindole-2-carboxylic acid (DHICA), while pheomelanin consists of benzothiazine and benzothiazole units. Melanins can be analyzed by quantifying specific degradation products using HPLC. Specifically, eumelanin can be analyzed as pyrrole-2,3,5-tricarboxylic acid (PTCA) and pyrrole-2,3-dicarboxylic acid (PDCA), specific degradation products of DHICA and DHI, respectively. Benzothiazole pheomelanin can be analyzed as thiazole-2,4,5-tricarboxylic acid (TTCA), whereas benzothiazine pheomelanin is analyzed as 4-amino-3-hydroxyphenylalanine (4-AHP) and 3-amino-4-hydroxyphenylalanine (3-AHP). Upon UVA exposure, melanins undergo structural modifications. Eumelanin undergoes oxidative cleavage to free pyrrole-2,3,5-tricarboxylic acid (Free PTCA) and undergoes cross-linking to form pyrrole-2,3,4,5-tetracarboxylic acid (PTeCA). UVA exposure of pheomelanin induces oxidative conversion from the benzothiazine to the benzothiazole. Nevertheless, these structural modifications have never been previously characterized in human skin. In this study, we exposed ex vivo skin to increasing UVA1 doses (60, 90 and 120 J/cm

Indexed as

MelaninsSkinSkin PigmentationUltraviolet RaysChromatography, High Pressure LiquidHumansMelanocyteseumelaninMelaninspheomelanineumelaninmelaninspheomelaninphotodegradationphotooxidationpigment darkeningUVA1

Identifiers

PMID42123554
PMCPMC13163989

What Socratic holds

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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.