Grosjacques Camille, Babiel Sabine, Hodes Jing, Bobier Anais, Cavagnino Andrea, Baraibar Martin
Henkel AG & Co. KGaA, Düsseldorf, Germany.
Oxiproteomics SAS, Créteil, France.
Int J Cosmet Sci. 2025 Aug;47(4):604-625. doi: 10.1111/ics.13052. Epub 2025 Feb 20.
The first objective of this study is to compare two molecular markers, cysteic acid and protein carbonylation, to track the level of chemical oxidation and photochemical (UV) oxidation of human hair. The second objective is to investigate how the protein carbonylation biomarker evolution is associated with physical characteristics of the fibre. The third objective is to understand the damage localization within the hair sub-structure.
For the chemical oxidation study European natural hair 6/0 (medium brown) is treated with non-pigmented commercial hair colour mixture and hair bleaching in increasing chemical oxidation conditions. For the photochemical study two European natural hair colours, 4/0 (dark brown) and 9/0 (extra light blond) are gradually photo irradiated. Molecular changes are investigated through cysteic acid measurement by NIR spectroscopy and protein carbonylation measurement; Biophysical changes by differential scanning calorimetry (DSC), and tensile strength measurements. Carbonyls are labelled with a specific fluorescent probe and measured in gel electrophoresis and in situ through image analysis and densitometric quantification after protein extraction respectively.
The two molecular markers, cysteic acid and protein carbonylation, increase similarly in both chemical and photochemical oxidation cases and show a good level of association across the oxidation levels. The fibre physical characteristics (DSC, Tensile Strength) decrease while the protein carbonylation and cysteic acid increase. The in situ visualization of the protein carbonylation shows a high impact on the hair cuticle and a gradual increase of photo-oxidation through the cortex, phenomenon which is more prominent for the extra light blonde hair in the case of photochemical oxidation.
The protein carbonylation biomarker is validated as another key molecular marker to monitor oxidative chemical changes in the hair chemical groups. It complements the cysteic acid, and appears more suitable in the case of photochemical oxidation, where it offers clear advantages over cysteic acid by being more sensitive and accurate, and by allowing in situ distinct damage visualization. Besides cysteic acid, amino acids such as proline, threonine, arginine, lysine, and peptide bonds are targets of oxidation. Under photochemical oxidation, the photoprotective effect of melanin is confirmed.
本研究的首要目的是比较两种分子标记物——半胱磺酸和蛋白质羰基化，以追踪人类头发的化学氧化和光化学（紫外线）氧化水平。第二个目的是研究蛋白质羰基化生物标志物的演变与纤维物理特性之间的关联。第三个目的是了解头发亚结构内的损伤定位。
对于化学氧化研究，将欧洲天然6/0号（中等棕色）头发用无色素商业染发剂处理，并在不断增加的化学氧化条件下进行漂发。对于光化学研究，对两种欧洲天然发色——4/0号（深棕色）和9/0号（极浅金色）头发进行逐步光照射。通过近红外光谱法测量半胱磺酸以及测量蛋白质羰基化来研究分子变化；通过差示扫描量热法（DSC）和拉伸强度测量来研究生物物理变化。羰基用特定荧光探针标记，分别在凝胶电泳中以及蛋白质提取后通过图像分析和密度定量原位测量。
在化学氧化和光化学氧化情况下，两种分子标记物——半胱磺酸和蛋白质羰基化的增加情况相似，并且在整个氧化水平上显示出良好的关联程度。纤维的物理特性（DSC、拉伸强度）下降，而蛋白质羰基化和半胱磺酸增加。蛋白质羰基化的原位可视化显示其对头发角质层有很大影响，并且在光化学氧化情况下，通过皮质的光氧化逐渐增加，这种现象在极浅金色头发中更为突出。
蛋白质羰基化生物标志物被确认为监测头发化学基团氧化化学变化的另一个关键分子标记物。它补充了半胱磺酸，并且在光化学氧化情况下似乎更合适，在这种情况下，它比半胱磺酸更敏感、更准确，并且能够实现原位清晰的损伤可视化，具有明显优势。除了半胱磺酸外，脯氨酸、苏氨酸、精氨酸、赖氨酸等氨基酸以及肽键也是氧化的目标。在光化学氧化下，黑色素的光保护作用得到证实。
