Induction by xenobiotics of phase I and phase II enzyme activities in the human keratinocyte cell line NCTC 2544.

This study analyses the expression and induction of several drug-metabolising enzyme activities involved in either phase I or phase II biotransformations in NCTC 2544 human keratinocytes. The phase I activities 7-ethoxycoumarin O-deethylase (ECOD), 7-ethoxyresorufin O-deethylase (EROD) and 7-pentoxyresorufin O-depenthylase (PROD) were easily detectable in basal conditions. During incubations lasting up to 144 h in the presence of the classical cytochrome P450 inducers beta-naphthoflavone (BNF), 3-methylcholanthrene (MC) and phenobarbital (PB), a considerable and significant increase in all the three activities was observed.

Synthesis of ionones and carvone analogues: olfactory properties and preliminary toxicity assays.

Vilsmeier reagents react with alpha/beta-ionones and carvone to produce aldehydes 7-11 in a one-step procedure. The indene derivative 11, which came from the double iminoalkylation of carvone and ring closure with the elimination of dimethylamine, was practically odourless, while all the others had peculiar odours which were very different from the starting material. The cytotoxicity data of 9 and 10, which are the most promising potential perfume ingredients, are also reported.

Iron-induced Lipid Peroxidation in Human Skin-derived Cell Lines: Protection by a Red Orange Extract.

Although photodamage and photoprotection have already been extensively studied in cultured cells, few data have been reported in the literature regarding the in vitro behaviour of skin cells toward a chemical stress, such as iron-induced lipid peroxidation. We investigated the susceptibilities of two human skin-derived cell lines (NCTC 2544 keratinocytes and HFFF2 fibroblasts) to lipid peroxidation induced by FeSO4/histidine, FeSO4/ascorbate and Fe2(SO4)3/ADP. NCTC 2544 cells were more susceptible than HFFF2 cells to lipid peroxidation (assessed by measuring the content of malondialdehyde [MDA]) with iron/ascorbate and iron/ADP as pro-oxidants whereas, with iron/histidine, the same level of MDA production was achieved (about 10nmol/mg protein) in the two cell populations.