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The effects of ultraviolet (UV) radiation on the skin, arising from sun exposure, have been explored since the previous century. Sunlight consists mainly of infrared (IR), visible, and UV radiation. UV region is divided into three subcategories, that is, UVC, UVB, and UVA. UVC (200-280 nm) is absorbed by the ozone layer in the stratosphere, while UVB and UVA (290-320 and 320-400 nm, respectively) reach the Earth's surface and influence human life and ecosystems. Consequently, human health may be affected under UV exposition. 1,2 In fact, UV exposure leads to health benefits such as production of cholecalciferol (vitamin D3), that is involved in functions

Summary Background Hair‐straightening treatments may involve the use of thermal devices, which potentially cause damages in the cuticle and cortex of the hair fibers. Particularly, the heat causes denaturation of the α‐keratin and the degradation of the components of the hair cortex. Objectives The aim of this study was to evaluate the effect of heating on the cuticle and cortex of the Caucasian and Asian virgin hair by using heat iron flat. Methods The effects of the heating in the tresses of Caucasian and Asian virgin hair were analyzed by thermogravimetry/differential scanning calorimetry‐Fourier transform infrared/mass spectrometry (TG/DSC‐MS/FTIR), protein loss analysis (PLA), Fourier transform infrared (FTIR‐ATR), and scanning electron microscope (SEM). Results TG/DSC‐MS/FTIR results were: formation of the H2O between 25‐170°C and CO2, SCO and H2S from 200°C. Denaturation temperature = 237°C. Protein loss: Asian hair>Caucasian hair. Data presented statistically significant alterations, α = 5, P ≤ 0.05, n = 3. FTIR‐ATR: changes in the secondary structural conformation of the protein of hair cuticle. SEM: heat caused damage to hair cuticle. Conclusions The results evidenced the importance of the control of temperature in the procedures involving heat. The damage caused by thermal devices showed be dependent of the ethnicity analyzed (Caucasian and Asian hair).

Vitamins are part of the antioxidant system of human skin, and are detectable in different layers, so the topical application can be an alternative to maintain the functionality of the system. The capacity of the antioxidant gradient of keratinocytes is associated with attenuation of the action of related free radicals in both esthetics and health. These problems arise from extrinsic aging and are related to the risk of cancer. Vitamin E has been proven to have antioxidant and moisturizing properties in the skin and can protect against the damage of UVB radiation, with emphasis on the reduction of acute erythema and photoaging. The choice for the use of topical vitamin E, compared to the oral is given by the safety as mild irritation and it has potential for multifunctional topical formulations. The purpose of the chapter is to review the topical use of formulations with vitamin E, addressing the development, safe use and evaluation of effectiveness.

The Ginoide Hydrolipodystrophy (GHLD), commonly known as cellulite, occurs in 80-90% of the female population after the puberty period and comes from a metabolic modification in the cutaneous adipose tissue. Caffeine has been used in topical formulations due to its lipolytic action. We studied a nanoemulsion (F3) containing caffeine with two surfactants (oleth-3 and oleth-20) by emulsification method by phase inversion temperature inversion (PIT). The polydispersion indices (PDI) showed the reduced deviation of 0.1. The mean droplet size was ~ 40 nm. The evaluated constant of Ostwald, in the refrigerator condition was the most favorable during the stability test. In the In Raman spectroscopy assay, the caffeine bands found in F3 were compatible with those found in the caffeine solution (1337, 652.5 and 558.2 cm-1). There was no interaction of caffeine anhydrous with other ingredients in nanoemulsion. In the in vitro safety assay the result of 1.4 ranked the F3 as slightly irritating. In the natural membrane, cutaneous permeation test (human skin) permeate concentrations did not exceed the saturation concentration of the PBS buffer (48.96 μg/3 mL). The caffeine solution and F3 permeated statistically equal, but the nanoemulsion visually and sensorially improved the caffeine precipitation.

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.

Ao meu namorado Lucas Ferreira Borge pelo companherismo e apoio, À Sueli Pereira Fabbri e Reynaldo Fabbri por incentivarem meu ingresso no mestrado, Aos meus amigos e parentes mais próximos, À minha orientadora Prof a. Assoc. a Maria Valéria Robles Velasco por sempre ter acreditado em meu potencial. vi AGRADECIMENTOS À minha orientadora Prof. a Assoc. a Maria Valéria Robles Velasco.

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