N-
Acetyltransferases (NATs) plays an important role in the first step of arylamine compounds metabolism. Polymorphic
NAT is coded for rapid or slow acetylatoion phenotypes, which are recognized to affect
cancer risk related to environmental exposure.
Aloe-emodin has been shown to exit anticancer activity. The purpose of this study is to examine whether or not
aloe-emodin could affect
arylamine N-acetyltransferase (
NAT) activity and gene expression (
NAT mRNA) and DNA-2-aminofluorene (
DNA-AF) adduct formation in mouse
leukemia cells (L 1210). By using high performance liquid chromatography, N-acetylation and non-N-acetylation of AF were determined and quantitated. By using
reverse transcriptase-polymerase chain reaction (RT-PCR) and PCR,
NAT mRNA was determined and quantitated.
Aloe-emodin displayed a dose-dependent inhibition to cytosolic
NAT activity and intact mice
leukemia cells. Time-course experiments indicated that N-acetylation of AF measured from intact mice
leukemia cells were inhibited by
aloe-emodin for up to 24h. Using standard steady-state kinetic analysis, it was demonstrated that
aloe-emodin was a possible uncompetitive inhibitor to
NAT activity in cytosols. The
DNA-AF adduct formation in mouse
leukemia cells were inhibited by
aloe-emodin. The NAT1
mRNA in mouse
leukemia cells were also inhibited by
aloe-emodin. This report is the first demonstration which showed
aloe-emodin affect mice
leukemia cells
NAT activity, gene expression (NAT1
mRNA) and
DNA-AF on adduct formation.