Jacek Arct

Common cosmetic hydrophilic ingredients as penetration modifiers of flavonoids

Nowadays, flavonoids are present in many cosmetic formulations, mainly in the form of plant extracts. The main reason of still increasing popularity of these substances is their beneficial biochemical activity. The main factor affecting activity of flavonoids in the skin is their skin penetration ability. The studies have evidenced that flavonoids from grape leaf extract as well as flavonoids like quercetin, rutin and catechin can migrate through the model lipophilic membrane from aqueous solution. The influence of common hydrophilic cosmetic additives on the permeation profile of flavonoids has been checked. The partition coefficients of examined flavonoids in the octanol–water extraction system were determined. Correlations between permeation coefficients and log P of particular flavonoids were plotted. To determine the mechanism of influence of hydrophilic substances on the permeation profile of flavonoids, the solubility of these compounds was investigated. Studies suggest that the presence of hydrophilic additives causes the increase in the flavonoid solubility that decreases the activity of flavonoids in the vehicle. In such a situation, the driving force for the penetration is reduced and the decrease of permeation coefficient can be observed.

Influence of Polyphenols on the Physiological Processes in the Skin

In the last decade antioxidants from a group of polyphenols have been proposed as one of the most effective functional ingredients of anti‐ageing properties that counteract the effects of oxidative damage to the skin. It has been shown that the use of polyphenols affects skin protection and mitigates inflammatory conditions of the skin. Numerous studies have confirmed that polyphenols by neutralizing free radicals, antioxidant activity and by their ability to chelate ions of transition metals can effectively reduce the level of nonprotein inflammatory mediators. The biological activity of polyphenols in the skin is primarily determined by their physicochemical properties and the ability to overcome the epidermal barrier as they try to reach appropriate receptors. This study reviews literature on the effects of polyphenols relating to the physiological processes in the skin and role of the major plant polyphenols in cosmetology and dermatology. Copyright

Methods for evaluation of cosmetic antioxidant capacity

The skin as the largest part of human body is one of the main targets for ultraviolet radiation, environmental pollution, toxic chemicals and some metal ions, which share responsibility for the formation of free radicals. The resulting free radicals, both oxygen and nitrogen species are one of the main causes of aging due to impaired regulation of cell respiratory metabolism involving incomplete oxygen reduction in mitochondria and production a superoxide anion, hydroxyl radicals et al. In modern cosmetology to minimize the adverse effects of free radicals, antioxidants, which inhibit free radical reactions, mainly autoxidation processes are used. Currently, not only many cosmetic products containing antioxidants are available, but a large diversity of methods for determination of cosmetics antioxidant activity is also accessible. These methods can be divided into three main groups: in vitro, in vivo, and ex vivo as reported herein. Due to lack of standardization and validation it is necessary to use a variety of methods as well as conditions for those purposes, which are presented to the context.

The influence of surfactants and hydrolyzed proteins on keratinocytes viability and elasticity

The knowledge how surfactants and hydrolyzed proteins influence the elastic properties of living epidermal keratinocytes is sparse. We demonstrate that the stiffness of cells measured by atomic force microscope (AFM) can be correlated with viability test.

Evaluation of antioxidant and antimicrobial activities of Oenothera biennis, Borago officinalis, and Nigella sativa seedcake extracts

The antioxidant and antimicrobial activities of Oenothera biennis, Borago officinalis, and Nigella sativa seedcake extracts were determined. Seedcakes were subjected to extraction using 50% ethanol (v/v) during 48 h at a solvent temperature of 50°C. The total polyphenol and flavonoid contents were assayed using UV spectrophotometry and the antioxidant activities were determined using DPPH and ABTS testing methods. Extracts were also analyzed for polyphenol content using HPLC. In vitro antimicrobial activities were evaluated using the disc diffusion method and resazurin testing. The ranking of the polyphenol contents and the antioxidant activities of examined seedcake extracts was O. bienis>B.officinalis>N. sativa. The highest antimicrobial activity in both tests was for N. sativa seedcake extracts against Pseudomonas aeruginosa (MIC=300 mg/mL), Escherichia coli (MIC=300 mg/mL), and Staphylococcus aureus (MIC=700 mg/mL).

Moisturizing and antiinflammatory properties of cosmetic formulations containing Centella asiatica extract

Centella asiatica extract is a rich source of natural bioactive substances, triterpenoid saponins, flavonoids, phenolic acids, triterpenic steroids, amino acids and sugars. Thus, many scavenging free radicals, exhibit antiinflammatory activity and affect on the stratum corneum hydration and epidermal barrier function. The aim of the present study was to evaluate the in vivo moisturizing and antiinflammatory properties of cosmetic formulations (oil-in-water emulsion cream and hydrogel) containing different concentrations of Centella asiatica extract. The study was conducted over four weeks on a group of 25 volunteers after twice a day application of cosmetic formulations with Centella asiatica extract (2.5 and 5%, w/w) on their forearms. The measurement of basic skin parameters (stratum corneum hydration and epidermal barrier function) was performed once a week. The in vivo antiinflammatory activity based on the methyl nicotinate model of microinflammation in human skin was evaluated after four weeks application of tested formulations. In vivo tests formulations containing 5% of Centella asiatica extract showed the best efficacy in improving skin moisture by increase of skin surface hydration state and decrease in transepidermal water loss as well as exhibited antiinflammatory properties based on the methyl nicotinate model of microinflammation in human skin. Comparative tests conducted by corneometer, tewameter and chromameter showed that cosmetic formulations containing Centella asiatica extract have the moisturizing and antiinflammatory properties.

Evaluation of skin colouring properties of curcuma longa extract.

The aim of this study was to evaluate the skin colouring properties of curcuma extract in cosmetic formulations. Objective measurements of the skin colour changes were done by Chromameter using the CIE L*a*b* colour space parameters. These measurements were correlated with the results of the sensory analysis. The observations showed permanent, visible and statistically significant changing of b* component after one application of emulsions containing 12% and 25% of turmeric extract. The change of skin color remained also after removing the emulsion. Sensory analysis indicated that the tested emulsions with curcuma extract have a significant impact on skin smoothness, spreadability, cosmetic absorption and pillow effect.

In vivo and ex vivo evaluation of cosmetic properties of seedcakes

Abstract The seedcakes are a potential source of natural bioactive substances: antioxidants, protein, and carbohydrates. Thus, they may scavenge free radicals and have an effect on the stratum corneum hydration and epidermal barrier function. The aim of the study was to evaluate the in vivo and ex vivo properties of emulsions with the seedcake extracts using the pH meter, corneometer, tewameter, methyl nicotinate model of micro-inflammation in human skin, and tape stripping of the stratum corneum. The in vivo and ex vivo studies showed that the emulsions with Oenothera biennis, Borago officinalis, and Nigella sativa seedcake extracts have anti-inflammatory and antioxidant activity. The 6-week topical application of the emulsions with the B. officinalis and N. sativa seedcakes significantly reduced skin irritation and influenced the improvement of the skin hydration and epidermal barrier function compared with placebo. The seedcakes due to their antioxidant and anti-inflammatory activities have potential application in anti-aging, moisturizing, mitigating, and protective cosmetics.

Evaluation of antioxidant and antimicrobial properties of enzymatically hydrolysed Cucurbita pepo and Linum usitatissimum seedcakes

The antioxidant and antimicrobial activities of ethanolic extracts of Cucurbita pepo and Linum usitatissimum seedcakes before and after enzymatic hydrolysis by glycosidases: alpha-amylase from Aspergillus oryzae, beta-glucosidase and beta-glucanase from Aspergillus niger and enzymes combination in a ratio of 1:1:1 were investigated. Total phenolic, flavonoid, reducing sugar content and antioxidant activity according to DPPH and ABTS tests were measured in non-hydrolysed extracts and compared with the results obtained for the extracts after the application of immobilised enzymes. In vitro antimicrobial activity was evaluated using the disc diffusion method. The extracts from hydrolysed seedcakes had a higher phenolic, flavonoid and reducing sugar content as well as higher antioxidant and antimicrobial activities in comparison with those of non-hydrolysed one. The highest antimicrobial activity showed L. usitatissimum seedcake extracts after hydrolysis by an enzyme combination. The enzymatic hydrolysis of seedcakes improved the extraction of phenolic compounds and therefore improved their antiradical and antimicrobial properties.

Preliminary study of guard hair morphology in four dog breeds

BACKGROUND Morphological differences between mammalian hair types are useful for species distinction. Differences in animal hair structure are observed between species, whereas there may be breed differences within a species. HYPOTHESIS Guard hair structure may vary between different dog breeds. ANIMALS Hair samples were collected from 73 dogs of four breed types (wire-haired Dachshund, Labrador retriever, German shepherd dog and Yorkshire terrier). METHODS Hair was measured and analysed by scanning electron microscopy. The following were evaluated: hair thickness; medulla to hair cross-sectional area ratio; scale density, pattern and margins; and medulla shape, composition and structure. RESULTS There were significant differences in all measured parameters between breeds. CONCLUSIONS AND CLINICAL IMPORTANCE These study findings may be useful for the study of classifying dog breeds and for forensic identification of a dog breed through hair sampling.