Photodamage determination of human hair

Sunlight on human hair causes photo-degradation. This results in bleaching due to melanin oxidation through free radicals, and induces keratin impairment. Protein degradation, tryptophan degradation, lipidic peroxidation and electron paramagnetic resonance can be used to evaluate proteic and lipidic photodecomposition and free radical formation in hair fibres subjected to antioxidant action and different UV intensities. All these methodologies have been optimised to determine protein, lipid and melanin degradation in hair subjected to different UV intensities.

► We optimise four methodologies to study integrity of human hair.
► We determine changes of irradiated hair and these procedures are also performing with non-irradiated hair as a control.
► UV radiation shows an increase protein degradation, lipidic peroxidation, tryptophan degradation and free radicals formation.
► The efficacy of formulations with antioxidant active agents could be evaluated following these optimised methodologies.