title: Relative inhibition of lipid peroxidation, cyclooxygenase enzymes, and human tumor cell proliferation by natural food colors.
abstract: The most abundant water soluble natural food colors are betacyanins and anthocyanins. Similarly, lycopene, bixin, beta-carotene, and chlorophyll are water insoluble colors. Pure betanin, bixin, lycopene, chlorophyll, beta-carotene, and cyanidin-3-O-glucoside were isolated from Beta vulgaris, Bixa orellana,Lycopersicum esculentum, Spinacia oleracea, Daucus carrota, and Prunus cerasus, respectively. These natural pigments, alone and in combination, were evaluated for their relative potencies against cyclooxygenase enzymes and tumor cell growth inhibition by using MCF-7 (breast), HCT-116 (colon), AGS (stomach), CNS (central nervous system), and NCI-H460 (lung) tumor cell lines. Among the colors tested, betanin, cyanidin-3-O-glucoside, lycopene, and beta-carotene inhibited lipid peroxidation. However, all pigments tested gave COX-1 and COX-2 inhibition and showed a dose-dependent growth inhibition against breast, colon, stomach, central nervous system, and lung tumor cells, respectively. The mixtures of these pigments were also evaluated for their synergistic effects and chemical interactions at various concentrations. The mixture of anthocyanin and betanin negated their efficacy in the cell growth inhibitory assay and did not enhance the COX enzyme inhibitory activity. This is the first report of a comparative evaluation and the impact on biological activities of these pigments alone and in combination.
authors.affiliation: Department of Horticulture, National Food Safety and Toxicology Center, Michigan State University, East Lansing, Michigan 48824, USA.
authors.forename: Muntha K
authors.initials: MK
authors.lastname: Reddy
authors.forename: Ruby L
authors.initials: RL
authors.lastname: Alexander-Lindo
authors.forename: Muraleedharan G
authors.initials: MG
authors.lastname: Nair
mesh_terms: D000872:Anthocyanins / Q000494:pharmacology; D050859:Betacyanins / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D005505:Food Coloring Agents / Q000494:pharmacology*; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects*; D009369:Neoplasms / Q000473:pathology*; D010860:Pigments, Biological / Q000302:isolation & purification / Q000494:pharmacology*; D010945:Plants, Edible / Q000737:chemistry
chemical_list: D000872:Anthocyanins; D050859:Betacyanins; D016861:Cyclooxygenase Inhibitors; D005505:Food Coloring Agents; D010860:Pigments, Biological