Background Essential oils have great interest among the increasing demand for herbal cosmetics in the market. They are natural sources of biologically active ingredients due to the wide application of such compounds as well as their particular chemical composition. Several researches have evaluated the effectiveness of these bioactive ingredients for use in cosmeceuticals, mainly in both hair scalp and shaft hair damage repair. Thus, the amounts and their associations define the properties of these compositions with interest for hair cosmetic use, such as antioxidant, inflammatory, and antimicrobial activities. Because they are complex compounds, their actions on the skin, hair scalp, and shaft are not yet fully understood. Aims The purpose of this review is to highlight the relevant researches and findings on essential oils in hair care. Methods In order to achieve this objective, the present work comprises an updated bibliographic review related to essential oils used in hair care. Results It was possible to observe that cosmeceuticals containing essential oils applied to the scalp are preferable for topical activity. Also, it was noticed that there are few reports regarding their use in hair shaft. However, it was found that some oils are used to intensify the brightness and fix the hair color. Conclusions This work demonstrated that the use of essential oils in both cosmetic products (industrial application) and those associated with oils carriers (as individual protocols) may lead to satisfactory results in the treatment of some scalp dysfunctions.

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

The skin is constantly exposed to various environmental stresses, in particular to the damage caused by pollution and ultraviolet radiation (UV), and as a consequence, the horny extract can be negatively impacted by the harmful influence of some of its surface components. The mechanisms involved in the degradation processes promoted by UV radiation are driven by the direct absorption of radiation via cellular chromophores, the formation of excited states and the consequent chemical reactions, or even by the photosensitization mechanisms, in which UV light is absorbed by the sensitizers that are excited and their reactions promote the formation of reactive oxygen species (ROS). The mechanisms of polluting agents are not yet fully understood, however, they indicate that one of the main mechanisms involved is oxidative stress by lipid peroxidation, with the ability to promote damage to the composition of sebum, the quality of the stratum corneum and also, promote aging skin. Recent studies demonstrate the potential of antioxidant agents, with an emphasis on products of natural origin, which try to promote the maintenance of the physiological balance of the skin.

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.

No abstract