Abstract: Organisms produce free radicals which are essential for various metabolic processes (enzymatic oxidation, cellular respiration, signaling). Antioxidants are important chemical compounds that specifically prevent the oxidation of substances by scavenging radicals, especially reactive oxygen species (ROS). Made up of one or two unpaired electrons, ROS are free radicals that are highly reactive and can attack other metabolites. By using electron paramagnetic resonance (EPR) spectroscopy, it is possible to measure paramagnetic substances such as free radicals. Therefore the dermal antioxidant activity can be determined by applying semi-stable radicals onto the skin and measuring the antioxidant-induced radical scavenging activity in the skin. In recent years, EPR has been developed as a spectroscopic method for determining the antioxidant status in vivo. Several studies have shown that an additional uptake of dietary supplements, such as carotenoids or vitamin C in physiological concentrations, provide a protective effect against free radicals. Using the EPR technique it could be demonstrated that the radical production in stress situations, such as irradiation with infrared and visible light, was reduced with time. However, not only the oral uptake of antioxidants, but also the topical application of antioxidants, e.g., a hyperforin-rich cream, is very useful against the development of oxidative stress. Regular application of a hyperforin-rich cream reduced radical formation. The skin lipids, which are very important for the barrier function of the skin, were also stabilized.
Abstract: Portable Energy Dispersive X-ray Fluorescence is a viable, cost and time effective analytical technique for qualitative and quantitative evaluation of a wide range of samples. The objective of this study is to present a methodology for quantification of nail polishes, eye shadows, lipsticks and lip gloss using thin film geometry. The samples were applied over thin films, simulating its use on face and nails. It was possible to quantify S, K, Ca, Ti, Mn, Fe, Cu, Zn, Br, Rb, Sr, Ba and Bi. The methodology is viable and could be useful to forensic science, quality control on industry of raw materials or final products and supervision by regulatory agencies.
Abstract: The consumer demand for natural ingredients in cosmetic products is increasing. Phenolic compounds are among the most studied natural antioxidant compounds, they also present antimicrobial, anti-inflammatory or antiaging actions and can permeate through the skin barrier. Grapes contain valuable phenolic components and grape byproducts are widely available low cost raw materials. This review presents an overview of the application of phenolic compounds from grape products and byproducts as sources of natural ingredients for cosmetics.
Abstract: Phytic acid is a natural compound widely used as depigmenting agent in cosmetic emulsions. Few studies are available in the literature covering the stability and the antioxidating property of this substance, used alone or into emulsions. Therefore, the purpose of this work was to investigate the thermal behavior and antioxidant properties of phytic acid alone and into cosmetic emulsions. The thermal behavior of this substance was evaluated by thermogravimetry (TG)/derivative thermogravimetry (DTG) and differential scanning calorimetry (DSC) and the free-radical-scavenging activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH). TG/DTG and DSC curves allowed evaluation of the thermal behavior of phytic acid. These results showed that the substance presented four stages of mass loss. Thermal decomposition of the material initiated at 150 °C. Thermal behavior of the cosmetic emulsions detected that the addition of phytic acid decreased the thermal stability of the system. DPPH free-radical-scavenging activity showed that phytic acid incorporated into emulsion had no antioxidant capacity compared to BHT. In summary, we concluded that the thermoanalytical techniques (TG and DSC) were efficient and reliable in the characterization of phytic acid alone and incorporated into cosmetic emulsions.
Abstract: The copper binding tripeptide GHK (glycyl-l-histidyl-l-lysine) is a naturally occurring plasma peptide that significantly declines during human aging. It has been established that GHK:Copper(2+) improves wound healing and tissue regeneration and stimulates collagen and decorin production. GHK-Cu also supports angiogenesis and nerve outgrowth, improves the condition of aging skin and hair, and possesses antioxidant and anti-inflammatory effects. In addition, it increases cellular stemness and secretion of trophic factors by mesenchymal stem cells. GHK’s antioxidant actions have been demonstrated in vitro and in animal studies. They include blocking the formation of reactive oxygen and carbonyl species, detoxifying toxic products of lipid peroxidation such as acrolein, protecting keratinocytes from lethal Ultraviolet B (UVB) radiation, and blocking hepatic damage by dichloromethane radicals. In recent studies, GHK has been found to switch gene expression from a diseased state to a healthier state for certain cancers and for chronic obstructive pulmonary disease (COPD). The Broad Institute’s Connectivity Map indicated that GHK induces a 50% or greater change of expression in 31.2% of human genes. This paper reviews biological data demonstrating positive effects of GHK in skin and proposes interaction with antioxidant-related genes as a possible explanation of its antioxidant activity.
Abstract: Our study presents a new method for tracking nanoparticle penetration through different layers of the skin using near-infrared dye-loaded nanoparticles (hydrodynamic diameter = 156 nm) and optical imaging. The dye-loaded nanoparticles were mixed in a topical skin cream, applied to human cadaver skin and incubated either for three or 24 h post-application, skin tissue was clipped between glass slides prior to imaging for signal intensity across the skin thickness using an optical imaging system. The data show that nanoparticles penetrate through all the layers of the skin but there is almost an exponential decay in the signal intensity from epidermis to dermis. Depending upon the incubation time, about 55%–59% of the total signal was seen in the epidermis and the remaining through dermis and hypodermis. The advantage of the method is that it allows quantitative analysis of the extent of penetration of nanoparticles through different layers of the skin without interference of any background signal from skin tissue, and without requiring extensive tissue processing. Our method could potentially be used to study the effect of nanoparticle properties and/or the use of different formulation additives on penetration of nanoparticles through different skin layers.