Advanced hair damage model from ultra-violet radiation in the presence of copper.
OBJECTIVE
Damage to hair from UV exposure has been well reported in the literature and is known to be a highly complex process involving initiation via absorption of UV light followed by formation and propagation of reactive oxygen species (ROS). The objective of this work was to understand these mechanisms, explain the role of copper in accelerating the formation of ROS and identify strategies to reduce the hair damage caused by these reactive species.


METHODS
The location of copper in hair was measured by Transmission electron microscopy-(TEM) X-ray energy dispersive spectroscopy (XEDS) and levels measured by ICP-OES. Protein changes were measured as total protein loss via the Lowry assay, and MALDI ToF was used to identify the biomarker protein fragments. TBARS assay was used to measure lipid peroxide formation. Sensory methods and dry combing friction were used to measure hair damage due to copper and UV exposure and to demonstrate the efficacy of N,N' ethylenediamine disuccinic acid (EDDS) and histidine chelants to reduce this damage.


RESULTS
In this work, a biomarker protein fragment formed during UV exposure is identified using mass spectrometry. This fragment originates from the calcium-binding protein S100A3. Also shown is the accelerated formation of this peptide fragment in hair containing low levels of copper absorbed from hair during washing with tap water containing copper ions. Transmission electron microscopy (TEM) X-ray energy dispersive spectroscopy (XEDS) studies indicate copper is located in the sulphur-poor endo-cuticle region, a region where the S100A3 protein is concentrated. A mechanism for formation of this peptide fragment is proposed in addition to the possible role of lipids in UV oxidation. A shampoo and conditioner containing chelants (EDDS in shampoo and histidine in conditioner) is shown to reduce copper uptake from tap water and reduce protein loss and formation of S100A3 protein fragment. In addition, the long-term consequences of UV oxidation and additional damage induced by copper are illustrated in a four-month wear study where hair was treated with a consumer relevant protocol of hair colouring treatments, UV exposure and regular shampoo and conditioning.


CONCLUSIONS
The role of copper in accelerating UV damage to hair has been demonstrated as well as the ability of chelants such as EDDS and histidine in shampoo and conditioner products to reduce this damage.
The Procter and Gamble Company, Mason Business Center, 8700 Mason Montgomery Road, Mason, OH, 45040, U.S.A.
J M
JM
Marsh
The Procter and Gamble Company, Mason Business Center, 8700 Mason Montgomery Road, Mason, OH, 45040, U.S.A.
M G
MG
Davis
The Procter and Gamble Company, Mason Business Center, 8700 Mason Montgomery Road, Mason, OH, 45040, U.S.A.
M J
MJ
Flagler
The Procter and Gamble Company, Mason Business Center, 8700 Mason Montgomery Road, Mason, OH, 45040, U.S.A.
Y
Y
Sun
The Procter and Gamble Company, Mason Business Center, 8700 Mason Montgomery Road, Mason, OH, 45040, U.S.A.
T
T
Chaudhary
The Procter and Gamble Company, Mason Business Center, 8700 Mason Montgomery Road, Mason, OH, 45040, U.S.A.
M
M
Mamak
Center for Electron Microscopy and Analysis, The Ohio State University, 1305 Kinnear Road, Columbus, OH, 43212, U.S.A.
D W
DW
McComb
Center for Electron Microscopy and Analysis, The Ohio State University, 1305 Kinnear Road, Columbus, OH, 43212, U.S.A.
R E A
RE
Williams
Proteomics and Mass Spectrometry Laboratory, University of Cincinnati College of Medicine, 3125 Eden Ave., Cincinnati, OH, 45267, U.S.A.
K D
KD
Greis
IQAC-CSIC, C/Jordi Girona 18-26, 08034, Barcelona, Spain.
L
L
Rubio
IQAC-CSIC, C/Jordi Girona 18-26, 08034, Barcelona, Spain.
L
L
Coderch
D000595:Amino Acid Sequence; D003300:Copper / Q000378:metabolism*; D006197:Hair / Q000378:metabolism / Q000528:radiation effects*; D006801:Humans; D017348:Microscopy, Electron, Scanning Transmission; D008969:Molecular Sequence Data; D011506:Proteins / Q000737:chemistry; D053719:Tandem Mass Spectrometry; D014466:Ultraviolet Rays
D011506:Proteins; D003300:Copper
N,N' ethylenediamine disuccinic acid; UV; X-ray energy dispersive spectroscopy; chelants; copper; free radicals; hair; histidine; mass spectrometry; transmission electron microscopy