title: Visualization of astaxanthin localization in HT29 human colon adenocarcinoma cells by combined confocal resonance Raman and fluorescence microspectroscopy.
abstract: Astaxanthin, a carotenoid found in plants and seafood, exhibits antiproliferative, antioxidant and anticarcinogenic properties. We show that astaxanthin delivered with tetrahydrofuran is effectively taken up by cultured colon adenocarcinoma cells and is localized mostly in the cytoplasm as detected by confocal resonance Raman and broad-band fluorescence microspectroscopy image analysis. Cells incubated with beta-carotene at the same concentration as astaxanthin (10 microM) showed about a 50-fold lower cellular amount of beta-carotene, as detected by HPLC. No detectable Raman signal of beta-carotene was found in cells, but a weak broad-band fluorescence signal of beta-carotene was observed. beta-Carotene, like astaxanthin, was localized mostly in the cytoplasm. The heterogeneity of astaxanthin and beta-carotene cellular distribution in cells of intestinal origin suggests that the possible defense against reactive molecules by carotenoids in these cells may also be heterogeneous.
authors.affiliation: Lichttechnisches Institut and Center for Functional Nanostructures, Universität Karlsruhe TH, Karlsruhe, Germany. karlis.briviba@bfel.de
authors.forename: Karlis
authors.initials: K
authors.lastname: Briviba
authors.forename: Rainer
authors.initials: R
authors.lastname: Bornemann
authors.forename: Ulrich
authors.initials: U
authors.lastname: Lemmer
mesh_terms: D002851:Chromatography, High Pressure Liquid; D019073:HT29 Cells; D006801:Humans; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D024341:Xanthophylls / Q000032:analysis; D019207:beta Carotene / Q000032:analysis / Q000494:pharmacology
chemical_list: D024341:Xanthophylls; D019207:beta Carotene; C005948:astaxanthine