Effects of 3-methylcholanthrene and aspirin co-administration on ALDH3A1 in HepG2 cells

The effects of two different protocols of 3-methylcholanthrene (3MC) and as pirin co-administration were studied in a well-established human hepatoma c ell line (HepG2). During this work, we have performed toxicity tests for ce ll viability/cell proliferation as well as studies on the expression of ALD H3Al after exposure of HepG2 cells to 3MC or/and aspirin. For the evaluatio n of toxic concentrations of 3MC and aspirin, the WST-1 test was used. WST- 1 is a reliable cytotoxicity test which is based on the cleavage of the tet razolium salt WST-1 to formazan by mitochondrial enzymes of living cells. A broad range of drug concentrations for either 3MC (0.25-50.0 muM) or aspir in (0.05-10.0 mM) were used for cell exposure, in several periods of time. The expression of ALDH3Al in HepG2 cells showed typical time- and dose-resp onse curves of induction after application of 3MC (1-5 days, 1.5-5.0 muM, r espectively). When cells were firstly exposed to 3MC (2.5 and 5.0 muM) and then to aspirin (0.25 mM), the induced ALDH3Al activity was further enhance d in a statistically significant way (P < 0.05). On the contrary, when aspi rin application was preceded 3MC exposuring a statistically significant dec rease in ALDH3Al inducibility was observed, as compared with the applicatio n of 3MC alone. <(c)> 2001 Elsevier Science Ireland Ltd. All rights reserve d.