CHANGES IN HAIR DURING PERMANENT WAVING 215 (13) M. M. Bradford, A rapid and sensitive method for the quantification of microgram quantities of protein utilizing the principle of protein-dye binding, Anal. Biochem., 72, 248-254 (1979). (14) Y. J. Lee, R.H. Rice, and Y. M. Lee, Proteome analysis of human hair shaft, Mol. Cell. Proteomics, 5, 789-800 (2006). (15) J.M. Gillespie, Biochemistry and Physiology of the Skin (Oxford University Press, London, 1983), pp. 473-510. (16) M. Gerhard, Electrophoretic variability in human head hair: Polyacrylamide gel electrophoresis of hair proteins in the presence of sodium dodecyl sulfate and urea, Electrophoresis, 8, 153-157 (1987). (17) M. Gerhard and M. Hermes, Electrophoretic variability in human hair: Comparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis of body and head hair proteins, Electrophoresis, 8, 490-492 (1987).

J. Cosmet. Sci., 59, 217-224 (May/June 2008) In vivo spectrophotometric evaluation of skin barrier recovery after topical application of soybean phytosterols CARMELO PUGLIA and FRANCESCO BONINA, Department of Pharmaceutical Sciences, School of Pharmacy, University of Catania, Viale A. Doria No. 6, 95125, Catania, Italy. Accepted for publication January 28, 2008. Synopsis The skin's uppermost thin layer, stratum corneum, plays a crucial role in protecting the body against unwanted influences from the environment. Disruption of the stratum corneum, by tape stripping or chemical injury, results in epidermal recovery of the skin barrier. Soy phytosterols are widely used in the cosmetic field as active ingredients in creams and lipsticks. Furthermore, they deserve an important place among nutracosmeceuticals in fact, after their absorption from the diet they are transferred from the plasma to the skin, playing an important role in the constitution of skin surface lipids. The aim of the present work was to study the effect of the topical application of soybean phytosterols on skin barrier recovery in human volunteers using the extent of methyl nicotinate (MN)-induced erythema in damaged skin as a parameter to evaluate the rate of stratum corneum recovery. MN was chosen as an erythematogenous substance for its capability to cause an erythema whose intensity and duration are proportional to the quantity of the substance that has entered the living epidermis over time. MN-induced erythema was monitored using reflectance spectrophotometry as a noninvasive instrumental technique. The results show clearly that soy phytosterols exert positive results on skin repair in fact, three days after tape stripping, the sites treated with a formulation containing phytosterols showed an appreciable recovery of barrier function compared to those treated with a vehicle control without soy phytosterols. INTRODUCTION The permeability barrier of the skin is localized in the stratum corneum (SC), a compact mass of metabolically inactive cells embedded in an extracellular matrix of non-polar continuous lamellar lipid layers (1). These structures are viewed as the major obstacle against the penetration of exogenous substances through the skin (2,3). This feature of the stratum corneum is dependent on its elasticity, determined by the content of fats and inorganic salts, as well as by the hydratation state (3 ). Besides, skin Address all correspondence to Carmelo Puglia. 217