Expression of Cytochromes P-450 2E1, 3A4 and 1A1/1A2 in Growing and Confluent Human HepG2 Hepatoma Cells-Effect of Ethanol.

In cultured human hepatoma HepG2 cells, cytochrome (CYP) 1A-associated 7-ethoxyresorufin-O-deethylase (EROD), CYP 3A-associated benzyloxyresorufin O-debenzylase (BROD) and CYP 2E1-associated p-nitrophenol-hydroxylase (PNPH) decreased during time in culture. The enzyme activities in cells at confluence were 35-60% of the activities in cells 24 hours after seeding. Similarly, CYP 3A and CYP 2E1 proteins were present at higher concentrations in growing (G) than in confluent (C) HepG2 cells.

Metabolic capacities in cultured human hepatocytes obtained by a new isolating procedure from non-wedge small liver biopsies.

A new isolating procedure of human hepatocytes has been developed using two-step collagenase digestion by a non-perfusion procedure (NP) of non-wedge liver biopsies. 1. A yield of 2-7 x 10(6) hepatocytes/g liver, 52-95% viability and 13-75% attachment were obtained from liver biopsies weighing 6-60 g, comparable to that obtained when using the classical perfusion procedure (P) to isolate human hepatocytes from wedge liver samples of 50-150 g.

Rifampicin and isoniazid increase acetaminophen and isoniazid cytotoxicity in human HepG2 hepatoma cells.

Acetaminophen (APAP) induced a concentration-dependent (0-30 mM) cytotoxic effect in human HepG2 hepatoma cells which was significantly increased when intracellular reduced glutathione (GSH) content was decreased. The cytotoxic effect of APAP (0-30 mM) was significantly lower in a day 3-treated compared to day 1-treated HepG2 cells. A 3-day preincubation of HepG2 cells with 5 microM 3-methylcholanthrene (3MC), 50 microM rifampicin (RFP) or 1 mM isoniazid (INH) significantly increased 15-30 mM APAP cytotoxicity, of about 15-20% for INH and RFP and 35-50% for 3MC.

Antifungal properties of essential oils and their main components upon Cryptococcus neoformans.

Cryptococcus neoformans opportunistic fungus met in the last phasis of AIDS is inhibited in vitro by several essential oils on natural volatile compounds. The minimal inhibitory concentration may reach 100 microliters/l and minimal fungicidal concentration 200 microliters/l with Palmarosa or Cinnamon oils. Among phenolic compounds, thymol and carvacrol are most fungitoxic.