title: Curcumin decreases the DNA adduct formation, arylamines N-acetyltransferase activity and gene expression in human colon tumor cells (colo 205).
abstract: The effects of curcumin on the N-acetyltransferase (NAT) activity, AF-DNA adduct formation and NAT gene expression were examined using the human colon tumor cell line (colo 205). Various concentrations of curcumin were added to the cytosols or to the medium of human colon tumor cells. The NAT activity was determined by high performance liquid chromatography assaying for the amounts of acetylated 2-aminofluorene (AAF) and p-aminobenzoic acid (N-Ac-PABA) and nonacetylated 2-aminofluorene (AF) and p-aminobenzoic acid (PABA). The NAT activity in the human colon tumor cells and cytosols was suppressed by curcumin in a dose-dependent manner. The results demonstrated that gene expression (NAT1 mRNA) in human colon tumor cells was inhibited by curcumin. The apparent values of Km and Vmax of NAT of human colon tumor cells were also decreased by curcumin in cytosols. Curcumin may act as a noncompetitive inhibitor. After the incubation of human colon tumor cells with AF with or without curcumin cotreatment, the cells were recovered and DNA was prepared, hydrolyzed to nucleotides, the adducted nucleotides were extracted into butanol and AF-DNA adducts analyzed by HPLC. The results also demonstrated that when curcumin was added to the media a decrease in AF-DNA adduct formation was seen in the human colon tumor cells. The finding of AF-DNA adduct formation in cultured human colon tumor cells suggests the usefulness of cultured cells for assessing arylamine-induced DNA damage.
authors.affiliation: Institute of Integration Chinese and Western Medicine, Department of Chinese Medicine, Show Chwan Memorial Hospital, Changhua, Taiwan, ROC.
authors.forename: Jung-Chou
authors.initials: JC
authors.lastname: Chen
authors.forename: Jiunn-Ming
authors.initials: JM
authors.lastname: Hwang
authors.forename: Guang-Wei
authors.initials: GW
authors.lastname: Chen
authors.forename: Mei-Fen
authors.initials: MF
authors.lastname: Tsou
authors.forename: Te-Chun
authors.initials: TC
authors.lastname: Hsia
authors.forename: Jing-Gung
authors.initials: JG
authors.lastname: Chung
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D001191:Arylamine N-Acetyltransferase / Q000187:drug effects / Q000378:metabolism*; D001483:Base Sequence; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000201:enzymology* / Q000235:genetics*; D003474:Curcumin / Q000494:pharmacology*; D018736:DNA Adducts / Q000187:drug effects*; D017931:DNA Primers; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D000970:Antineoplastic Agents; D018736:DNA Adducts; D017931:DNA Primers; D001191:Arylamine N-Acetyltransferase; D003474:Curcumin