Hair color change by dye application is a common procedure among women. Hair dyes are classified, according to color resistance, into temporary, semipermanent, demipermanent and permanent. The first two are based on molecules which are already colored. Temporary dyes act through dye deposition on cuticles, but semipermanent may penetrate a little into the cortex and so the color resists up to six washes. Demipermanent and permanent dyes are based on color precursors, called oxidation dyes, and the final shade is developed by their interactions with an oxidizing agent, but they differ from the alkalizing agent used. In oxidation systems, there is an intense diffusion of the molecules into the cortex, what promotes a longer color resistance. Dyes and color precursors present differences related to chromophore groups, hair fiber affinity, water solubility, and photo stability. The aim of this review is to discuss the differences among hair dye products available in the market and their action mechanisms, molecular structures, application methods, and some aspects of formulations.

Azadirachta indica (Neem) is a large tree that is native to India and is traditionally used due to its several properties, mainly to treat skin diseases, as well as its “herbicidal” activity. Its bark, leaves, seeds, fruits and flowers are widely used in medicinal treatment due to the presence of active secondary metabolites with biological effects, mainly limonoids and tetranortriterpenoids, such as azadirachtin. Thus, A. indica was studied in a variety of conditions, such as anticancer, antiseptic, anti-inflammatory and chemopreventive agents, as well as a biopesticide. Furthermore, differentiated cell tissue in A. indica cultivation was reported to produce active metabolites for different purposes. However, only a few studies have been developed regarding its potential use in cosmetics. For instance, most studies explained the antimicrobial properties in health conditions, such as acne, dandruff and personal health care. Here, we summarized not only the most common cosmetic claims to treat acne but also mitigating other skin disorders related to inflammatory and oxidant processes in recent in vivo studies and patents to aid researchers and industrialists to select A. indica derivatives as novel cosmetic ingredients.

Sustainable ingredients in cosmetics have been discussed for the past decade, and the COVID-19 pandemic has increased awareness of this significant topic. Consumers are informed and vigilant about clean labels, driving the necessity for sustainability throughout the cosmetic production chain. Moreover, nanotechnology and green chemistry approaches have emerged as innovative perspectives to develop sustainable and eco-friendly cosmetic ingredients. In this sense, in this review, we present examples and applications of sustainable ingredients derived from several types of sources (i.e., plants, animals, microorganisms, cell cultures, and recycled materials/biomaterials). The benefits and drawbacks of all classes of compounds were organized and discussed in relation to novel formulations/products. Finally, we addressed perspectives on cosmetic ingredients that prioritize sustainability and safety, with an emphasis on exploring sustainable ingredients, compounds, or molecules as promising areas for research and development.

A radiação ultravioleta pode provocar danos ao DNA, imunossupressão, alterações químicas e histológicas na epiderme, envelhecimento precoce, cataratas e carcinogênese, dentre outras deteriorações. A fotoproteção previne estes e outros efeitos danosos da radiação ultravioleta. Protetores solares, vestimentas, acessórios adequados e exposição segura ao sol são ferramentas essenciais da fotoproteção. Neste artigo, são apresentadas e discutidas as principais formas de fotoproteção, incluindo os protetores solares com filtros inorgânicos e orgânicos, a avaliação da eficácia dos mesmos e atualizações envolvendo o tema