Preserving fibre health: reducing oxidative stress throughout the life of the hair fibre

Abstract

Hair health is an important attribute to women globally -specifically attributes such as shine, healthy tips, frizz-free and strength. However, many women will claim to have at least moderate hair damage caused by habits and practices such as washing, combing and brushing, use of heated implements and regular use of chemical treatments. The objective of this work was to investigate two mechanisms of damage -hair colouring and UV exposure -where oxidative processes are involved. The role of copper in these oxidative processes was then investigated: its presence in hair and its consequent impact on hair damage via free radical formation. Finally, the role of chelants N,N'-ethylene diamine disuccinic acid (EDDS) and histidine in preventing free radical formation was investigated and shown to improve hair health. R esum eLa sant e des leurs cheveux est un sujet important pour les femmes dans le monde entier -en particulier les attributs sp ecifiques de brillance, absence de frisottis et pointes en bonne sant e. Cependant, beaucoup de femmes affirment avoir au moins quelques probl emes de cheveux caus es par leurs habitudes et leurs pratiques de lavage, peignage, brossage, utilisation d'outils chauffants et de traitements chimiques. L'objectif de ce travail etait d' etudier deux m ecanismes d'agression -la coloration des cheveux et l'exposition aux UVdans lesquels des processus d'oxydation sont impliqu es. Le rôle du cuivre dans ces processus oxydatifs a ensuite et e etudi e; sa pr esence dans les cheveux et son incidence sur les dommages des cheveux par la formation de radicaux libres. Enfin, le rôle des agents ch elateurs comme l'acide N-ethyl ene diamine di-succinique et l'histidine a pr evenir la formation de radicaux libres a et e etudi e et leur efficacit e a am eliorer la sante des cheveux a et e d emontr ee.

A comment on the science of hair aging

“…The value of the special ingredients shampoos cannot be underscored as additional elements to enhance the action of the pharmaceutical agents, either topical or systemic, by cleansing the scalp and contributing to a healthy scalp microbiome. The use of appropriate surfactants, combined with ingredients such as zinc pyrithione, ciclopirox, salicylic acid,[83848586] copper chelating agents, such as N, N'-ethylene diamine disuccinic acid and histidine,[87] and others, contribute to maintain Malassezia spp. and oxidative stress under control.…”

Transepidermal UV radiation of scalp skin ex vivo induces hair follicle damage that is alleviated by the topical treatment with caffeine

“…20 mJ/cm 2 (low) and 50 mJ/cm 2 (high) UVB doses correspond, respectively, to 22–30 min and 56–73.5 min of sunlight in July in Germany. Considering that hair themselves absorb UV radiation , the impact of UVA and UVB on the scalp skin is usually reduced. However, this is not the case in patients suffering from skin barrier defects , lipid production deregulation , or alopecia, where the scalp skin surface is totally exposed to sunlight and to sunburn .…”

A review of developments in industrial hair colorant actives for oxidative dyes

“…While the necessity of combatting the latter's ability to destabilise oxidant solutions prior to use has long been known, 16 the presence of redox‐active metals within the hair shaft is believed to contribute to catalytic decomposition of peroxide into species, which, fortunately, accelerate the coloration process relative to reaction in aqueous solution outside of the hair fibre 10 . A downside to the presence of such metals, in particular that of copper, is the adverse effect of catalysing the formation of destructive radicals which damage hair 190,191 . EDDS suppresses their formation and resultant cuticle damage during coloration more effectively than the traditional chelant EDTA.…”