ABSTRACT
Topical retinol application effectively reduces the effects of photoaging and improves skin condition, e.g. influences the process of keratinization of the epidermis, which improves stratum corneum structure and reduces transepidermal water loss. However, cosmetics use lower concentrations of retinol, which has been associated with emerging hypersensitivity reactions as well as redness and irritation of the skin. The question arises whether the vehicle used in the cosmetic may be important in stimulating the inflammatory reaction in the skin and if the concentration of retinol used could significantly affects the growth of epidermal cells. The aim of this study was to evaluate the effects of different concentrations of liquid crystal retinol (0.15%, 0.3% and 0.5%) on the clinical and histological characteristics of a reconstructed epidermis skin model. It also compares the effectiveness of 0.3% retinol formula in liquid crystal to that in lipid. The study used reconstructed human epidermis tissue containing normal human keratinocytes. Four original formulas containing retinol were tested: 0.15%, 0.3% and 0.5% with a liquid crystal base, and 0.3% with a lipid base. Interleukin 6 (IL-6), transglutaminase-1 (TGM1), and epidermal growth factor (EGF) mRNA expression was measured expression of the skin-equivalent tissue for 10 days of exposure. Histopathological analysis and mRNA quantification were performed. Gene expression was analyzed by total mRNA extraction. All liquid crystal formulas induced higher EGF mRNA expression than lipid base formula. IL-6 expression did not differ significantly from the DPBS reference values. Interestingly, TGM1 expression was found to increase together with increasing retinol concentration (0.15%, 0.3%, 0.5%). Histological examination revealed changes in epidermal structure, mainly hyperkeratinization of the stratum corneum. Our results support the hypothesis liquid crystal formula might be regarded as more beneficial since it inducess less pro-inflammatory action manifested by lowered expression IL-6. In addition, EGF expression was found to correlate significantly with the retinol concentration of the liquid crystal formula: 0.5% > 0.3% > 0.15% (P < 0.05). Lower concentrations may increase TGM1 expression, thus enhancing the formation of a protective layer of cornified envelope.
Subject(s)
Epidermal Growth Factor/biosynthesis , Epidermis/metabolism , Interleukin-6/biosynthesis , Liquid Crystals , RNA, Messenger/biosynthesis , Transglutaminases/biosynthesis , Vitamin A/administration & dosage , Epidermal Growth Factor/genetics , Epidermis/drug effects , Gene Expression , Humans , Interleukin-6/genetics , Liquid Crystals/chemistry , Organ Culture Techniques , RNA, Messenger/genetics , Transglutaminases/genetics , Vitamin A/chemistryABSTRACT
BACKGROUND: Microdermabrasion is a popular form of mechanical peel, used for many aesthetic purposes. Because it removes the superficial epidermal layer, it has an impact on hydrolipid skin coat. OBJECTIVE: The aim of the study was to examine the changes taking place in the hydrolipid coat of the skin after microdermabrasion measured by skin hydration and sebum level. METHODS: Sixteen healthy women were included in the study, and the aluminium oxide crystal microdermabrasion device was used over the entire face of each patient. Measurements of stratum corneum hydration and sebum level were taken at baseline, just after the treatment, and 30 and 60 minutes later. RESULTS: A statistically significant difference in stratum corneum hydration was found on the cheeks 30 minutes after treatment and in the T-zone immediately after the procedure. Sebum reduction was observed immediately after the procedure irrespective of skin type and face area. In addition, sebum value was found to return to baseline 1 hour after the procedure. CONCLUSIONS: The observed changes in epidermal barrier function may be responsible for the clinical improvement following microdermabrasion.
