title: In vivo distribution of carotenoids in different anatomical locations of human skin: comparative assessment with two different Raman spectroscopy methods.
abstract: BACKGROUND
  The cutaneous antioxidants form an efficient protection system against the destructive potential of free radicals, produced by environmental factors, such as UV-sun irradiation, hazardous substances and lifestyle habits. Most of the antioxidants cannot be produced by the human organism. Thus, they have to be incorporated by food and beverages.
  
  
  METHODS
  In the present manuscript, the distribution of carotenoids as a marker for antioxidative potential in human skin was investigated with two different in vivo Raman spectroscopy methods with an excitation wavelength of 785 nm (Skin Analyzer) and at 488 nm (resonance Raman spectroscopy). The carotenoid profile was assessed at three different anatomical locations (palm, forehead and volar forearm) in 12 healthy volunteers.
  
  
  RESULTS
  In untreated skin, the major fraction of the carotenoids is located in the upper part of the stratum corneum (SC). The amount of carotenoid is lower in the upper part of the SC on the forearm compared to forehead and palm shown with both methods. Both methods detect similar distinction patterns of carotenoid levels for the three anatomical locations.
  
  
  CONCLUSIONS
  The present study supports the hypothesis that antioxidative substances; here carotenoids, are secreted via eccrine sweat glands and/or sebaceous glands to the skin surface. Raman spectroscopic methods are an efficient tool to analyze the distribution of carotenoids in the human skin over time and with the Skin Analyzer over different layers of the epidermis. Resonance Raman spectroscopy is suited to analyze deeper parts of the skin.
authors: Center of Experimental Applied Cutaneous Physiology, Department of Dermatology and Allergology, Charité-Universitätsmedizin, Berlin, Germany.
authors: Maxim E
authors: ME
authors: Darvin
authors: Joachim W
authors: JW
authors: Fluhr
authors: Peter
authors: P
authors: Caspers
authors: André
authors: A
authors: van der Pool
authors: Heike
authors: H
authors: Richter
authors: Alexa
authors: A
authors: Patzelt
authors: Wolfram
authors: W
authors: Sterry
authors: Jürgen
authors: J
authors: Lademann
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000032:analysis / Q000378:metabolism; D002338:Carotenoids / Q000032:analysis* / Q000378:metabolism; D004817:Epidermis / Q000737:chemistry / Q000378:metabolism; D005542:Forearm; D005546:Forehead; D006801:Humans; D008663:Metacarpus / Q000737:chemistry / Q000378:metabolism; D008875:Middle Aged; D012627:Sebaceous Glands / Q000378:metabolism; D012867:Skin / Q000737:chemistry* / Q000378:metabolism; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013545:Sweat Glands / Q000378:metabolism; D055815:Young Adult
chemical_list: D000975:Antioxidants; D002338:Carotenoids