Protection of hair from damage induced by ultraviolet irradiation using tea (Camellia sinensis) extracts

Background Damage to hair by UV is relevant to most people, and for many, it is a major source of hair damage. Prevention of UV damage is of high interest to cosmetic companies. Objectives Describe UV damage mechanisms and link these mechanisms to measurable changes in hair protein composition and color changes resulting from breakdown of yellow-colored kynurenines. Test the power of botanical antioxidants, specifically Camellia sinensis (tea) extracts to prevent this protein damage and color change. Link specific phytochemistry of extract samples to hair performance. Methods Camellia sinensis (tea) extracts were analyzed by LC-MS to identify the key composition chemistries. ORAC (Oxygen Radical Antioxidant Capacity) was used to measure ability of the extract to react with a peroxyl radical via a hydrogen abstraction mechanism. Hair protein structural damage was measured by quantification of a biomarker peptide that is specific to UV-induced damage and hair color changes were measured with a spectrophotometer. Results Levels of key phytochemistry in the extracts, specifically the catechins, correlated with prevention of UV-induced protein damage and prevention of color changes due to kynurenine breakdown. Extracts with higher phytochemistry levels also had higher ORAC scores indicating that they were more effective antioxidants. Conclusions Camellia sinensis (tea) extracts can be used as effective protective treatments for hair protection but this efficacy is linked to extract concentrations of key chemistries (catechins).