Photo-oxidative evaluation of dyed hair fiber treated with bioactive sunscreen hair conditioner

Abstract

Products for coloring the hair fibers are widely distributed and used worldwide. There are three types of hair dyes: permanent, semi-permanent and temporary. The molecules in the permanent dye, in principle, should not let the hair fiber, but by different mechanisms, such as washing procedures and exposure to ultraviolet radiation, the hair fiber changes its color characteristics. The solar ultraviolet radiation is responsible for the color change, reduction of gloss and protein content of the hair fiber, especially that submitted to the coloring process. Additionally, it promotes the oxidation of dye molecules and thus has been proposed the incorporation of antioxidants in hair care products in order to minimize its harmful effects and promote the maintenance of their physiological characteristics. Currently, sunscreens act by mechanism of film formation and there are few chemical structures available for this action. The flavonoids rutin and quercetin have been studied for its antioxidant properties, but also to promote photoprotection, especially if associated with chemical filters. In this project, these polyphenols will be incorporated into conditioners formulations to be applied to tresses of hair dyed, in the form of a fluid emulsion, and these will be exposed to artificial ultraviolet radiation and subjected or not to washing procedures. All tresses will be assessed for the parameters color, brightness, tensile rupture and protein loss albumin equivalent.