Effects of luteolin on arylamine N-acetyltransferase activity in human liver tumour cells.
The human liver tumour cell line (J5) was selected in order to evaluate whether or not luteolin affected arylamine N-acetyltransferase (NAT) activity. Using high performance liquid chromatography, the NAT activity for acetylation of arylamine substrates (2-aminofluorene and p-aminobenzoic acid) was determined. The cytosolic NAT activity in human liver tumour cells was 2.74+/-0.26 and 1.68+/-0.20 nmol/min/mg of protein for 2-aminofluorene and p-aminobenzoic acid, respectively. Luteolin displayed a dose-dependent inhibition to cytosolic NAT activity and intact human liver tumour cells. Time-course experiments showed that NAT activity measured from intact human liver tumour cells was inhibited by luteolin for up to 24 h. Using standard steady-state kinetic analysis, it was shown that luteolin was a possible noncompetitive inhibitor to NAT activity in cytosols. This report is the first to show how luteolin affects NAT activity in human liver tumour cells.
Chen
J C
JC
Institute of Chinese Medical Sciences, China Medical College, Taichung, Taiwan, Republic of China.
Chung
J G
JG
Lin
K M
KM
D010129:4-Aminobenzoic Acid / Q000494:pharmacology; D001191:Arylamine N-Acetyltransferase / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D003600:Cytosol / Q000201:enzymology; D004305:Dose-Response Relationship, Drug; D005100:Expectorants / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology*; D005449:Fluorenes / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D008113:Liver Neoplasms / Q000201:enzymology / Q000378:metabolism*; D047311:Luteolin; D009153:Mutagens; D013997:Time Factors; D014407:Tumor Cells, Cultured
D005100:Expectorants; D005419:Flavonoids; D005449:Fluorenes; D009153:Mutagens; C012177:2-aminofluorene; D001191:Arylamine N-Acetyltransferase; D047311:Luteolin; D010129:4-Aminobenzoic Acid